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What octane gas?

Yesterday's Tractor Forums
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farmall pete

Member
I know Tractor Vet's opinion to burn high octane gas in the C-263's & 291's. It makes sense, but man the way these tractors go through gas that's quite a hit to the wallet. Here in New York 91 octane is about 50 cents higher than 87.

Two questions: what octane gas are other folks using in these engines and have you seen any negative effects from it? And will the octane boost additives accomplish the same result as using high octane gas?

I just tore down a c-263 and that had bad scoring on the pistons, but that engine had 8,700 hours on it without an overhaul so I can't really say what effect the fuel had on it.
 
With respect to IH gasoline powered tractors and the strong recommendation coming from Tractor Vet, I would agree with him. I remember when we had an 806 IH tractor with a gasoline powered engine on the farm. That tractor finally went down the road in 1976. If you look at the Nebraska Tractor Tests on these vintage tractors, I seem to recall the gasoline used during those tests was on the order of 93 octane. Our 806 would not run properly on lower octane fuel. My dad talked about having high octane gasoline blended in to increase the octane back in the 1970's, perhaps even the late 1960's, too. The latter years, when I remember that tractor best, he purchased a Conklin product that would accomplish essentially the same result. Up until the 806 was traded off, it was doing the heavy tillage work including plowing. In those days, we had a 4020 JD gasoline powered tractor and the 806 gasoline powered tractor. They both would burn a lot of gasoline when pulled hard. We did not have the issues with the 4020 not running properly as the octane rating of gasoline was lowered, like we did with the 806. I wonder if that might have been due to the 4020 having a larger displacement engine (341 cubic inches) as compared to the 806 (301 cubic inches), and the 4020 having a lower compression ratio by comparison. Carburetion on those JD gasoline powered tractors is known to be more temperamental/problematic, and they can be rather thirsty even under light loads by comparison to their IH counterparts. I ran an early 706 IH for a neighbor for quite some time, and it seemed to be fairly economical on gasoline consumption.
 
The 93 octane you referenced is the Research number. Using today's (R+M)/2 rating the fuel used for the Nebraska test was 88.4 octane per the R and M numbers in the test report.
 
Yes, going by the (R+M)/2 and *ASSUMING* that the difference between Research and Motor octane ratings is a certain amount, 8 as I recall, you *CAN* convince yourself that 89 octane gas is the same as 93 octane gas.

All I have to say about it is, you can put a LOT of gallons of 93 octane premium gas through that tractor before you'll even come close to paying to overhaul that engine because you burned up a piston by using cheaper gas.
 
You don't have to assume anything regarding the fuel used in the Nebraska tests. R and M numbers are both listed. In the years from the late '50s into the early '70s, the pump grade never exceeded 89.

You can make arguments about long term use of a given fuel or whether octane requirements increase for an old engine. But regular gas of the time (~89 pump grade) was considered adequate. That suggests using intermediate grade as a minimum.

As far as adding octane boosters:
1) Effectiveness depends on the composition of the original gas. So you don't know how much it will raise octane.
2) If you mix it according to the label, it will cost more to boost regular gas than the added cost of buying higher grade fuel in the first place.
 
I have used 87 octane in all my Farmalls from a Super A to 706 and have yet to have one issue arise from it. I can't see myself paying the
higher price for 91 when my equipment runs just fine on regular. I have no doubt that the Tractor Vet is correct in his opinion on suitable octane,
but I use what I can afford.
 
Where did you set the ignition timing? It's all in the timing and what type of valves and seats that are installed. The offical IH manual recommmends 93 octane because the original valves and seats back in the day weren't hardened. The high octane fuel provided better lubrication for top end components that will have been replaced by modern hardened valves and seats if any valve work has been done over the years. The manual also says that if 93 octane isn't available to retard the timing 1 degree for each octane lower than 93, so if you're running 87 octane then 93-87=6, so take the factory 22 degrees and subtract 6 degrees to get 16, so set your timing to 16 degrees fully advanced. These engines are only 8.5:1 compression ratio and they will NOT predetinate/ping on 87 octane gas. And no, when the machine shop resurfaces the head to make it flat again it does NOT raise the compression ratio a significant amount. You would have to mill off a lot more than that to raise it significantly. Save your money and buy the 87 octane.
 
(quoted from post at 14:55:37 05/02/17) . . . if 93 octane isn't available to retard the timing 1 degree for each octane lower than 93, so if you're running 87 octane then 93-87=6, so take the factory 22 degrees and subtract 6 degrees to get 16, so set your timing to 16 degrees fully advanced.
Click to expand...
eep in mind that you are still using two measures of octane. Today's 87 isn't 6 less than 93 RON.
 
AH i disagree with you on the valve seats and valves as they were hardened seats back then . Any valve problem with the later gas engines was due to carbon deposits and ash build up on the exhaust valves from the oil . Run low ash oil and you will not have a problem with the valves .
 
When I was a kid we had 2 gas burners, 1939 Farmall A, and a allis wd-45. My Dad always added lead additive to the gas, then my brother blew the head gasket on the allis and I rebuilt it new valves and all, we never used lead additive again. I always thought the lead additive was for the valves or seats. Never do I remember getting higher octane fuel. Except for our Bronco with a 351 dad said it knocked on lower octane so he always bought 89 or 91.
So now I still have those tractors Plus a 51 Farmall M and a ford 8N. I always give them a little Marvel Mystery in the fuel tank, but should I run Higher octane, or find lead add?
 
Steve WHILE we could get true 93 we ran the bag off the two 706 gassers , one 706 is owned by my buddy and the other is owned by his brother also a vary good friend . Both tractors were sold to them by me Vernon's tractor is a 67 and came with a 291 Eugene's is a 64 and was a 263 from the factory . Both tractors ran fine other then we did have a valve issue till we wised up and switched oil and that solved valve problems . when we did the rebuild on Eugene's 706 due to the fact that his engine had five holes that were C and D class bore and one A -B class bore and a couple C D bores were way out on the loose side why not just bore the block and go with the 291 over bore for a C263 and make all the holes the same and also before we did the bore we line bored the block and centerlined the cylinders off the crank . all was well with that tractor from first start up on to 8 hours on the dyno for break in all winter long moving round bales hauling manure , pulling wagons while doing the corn choppen and even the first day of plowing come spring . Till he put gas from his tank and not from the little gas station down the road . The fuel supplier was suppose to bring 93 charged for 93 and brought 87 . When eugene hit the field from filling the tank it made it down the hill to the far end and about 100 feet back going up the little rise when she seezed all 6 brand new pistons and locked up due to piston swell . when i tore it back down i knew right off what happened as all the damage was done above the top ring . To prove my point we had the gas from his tank taken to a lab and had it tested , we did not tell the people at the lab what brand of gas it was or the octane that we had ordered when they were done they told US who's gas it was what was in the gas and the octane it was and it was 87 laced with MTB and on a working engine that sends the combustion temps off the scale , good for car emissions because a car engine is not a working engine and they are computer controlled and fuel injection . we were able to clean up the sleeves and put six new pistons in and changed fuel suppliers . All was good till a new driver brought 87 out by mistake and the tractor did not make it 500 feet from the fuel tank and she ate a piston . The fuel supplier knew me well and knows i know how to build engines as i had built his pulling engine . Yes it was a winner Matt saw the piston after he picked it up off the floor after it bounced off the wall after i threw it at him . Yes they paid for the repairs came out and removed the gas cleaned the tank and put the 93 in . And again that tractor ran well as it was the GO TO tractor . It mowed over 400 acres of hay each years and sometimes five hundred if we got a fifth cutting , planted all the crops , sprayed all the crops ground feed in the winter every week did a lot of manure hauling raking wagon pulling . Yes it did burn gas somewhere around 350 to 400 gallons a year . At the time yes we were paying 20-25 cent s gallon over 87 BUT do the math and we can burn a lot of gas before it goes over the cost of and overhaul . We can burn a lot of gas before it goes over the cost of another diesel tractor . I am coming up on 71 years old and have worked on engines for a lot of years . The one thing a lot of you young guys don't understand is that back when these tractors were built was during the golden age of performance and the gas at the pumps was a lot higher in octane and yes it was the research method Reg. was 95 or better high test was normally 105-107 yep that is what it was . Ford in the 67 model year had 2 390 2BL engines one would run on Reg gas and the other required hightest . there were low grades out there and two come to mind here Gulf had Gulftane it was a 93 octane fuel and Sunoco had the 190 and it was about the same and those two grades would make and old 6 cylinder Chevey pick up ping let lone any V8 's of the day . Gas did not start going down hill till the early 80's as we could still get the good stuff at the Maw and Paw stations . I was driving a 78 F250 4X4 pick up with a 1971 460 V8 in it with a 11 to 1 compression ratio and was still getting 100 plus gas for it NO it would not run on reg. and i was not having any problems running it with out lead . Now two years ago they stopped making 93 octane gas and the best coming down the pipe now is 90 and you guessed it we now have two 706 gassers with melted pistons . There is a C301 at the machine shop as i type this that oh guess what she melted four pistons just pulling aset of four bottoms on one of the flat field around here plowing down corn stalks for oats. Yep he was running 87 . I am not doing the work on this one BUToh guess what they called me to go look and see what happened . so what is my idea on this . well at this time i am looking for pieces and parts to install a couple DT360's and turn the C291's into boat anchors.
 
RE . . . "I know Tractor Vet's opinion to burn high octane gas in the C-263's & 291's. It makes sense"

Why doe it make sense? All high-test gas does is burns slower then low-test. Higher compression ratios
lacking computer controls often need slow-burning gas or they detonate (knock). But on a super low
compression tractor engine?? Makes NO sense to me unless you have an engine with a piston-knock issue with
the timing set properly.

Nebraska Tests used gas with likely more octane then needed (unless testing a high-compression Oliver).
They used gas that today is octane 88.7.

I assume your IH engine has a 7.6 to 1 compression ratio and likely works fine with the cheapest gas you
can find. That unless the timing is too advanced.
 
On your two or three tractors you can get by with the 87 and if ya want 89 , now as to the SNAKE oil stuff save your money . If you run a good eninge oil and a good grade of fuel and keep everything in tune your good to go , Now if they are getting tired then there is no magic juice in a bottle or can that will fix the problem It seams the problems do not show up on the older slower turning engines .
 
Would it be better to have one of the piston makers build you a set from blank forgings? Will not be cheap but maybe cheaper than down time.
 
Ah the gas of the day back then was 95 octane on reg. at the pumps as said below there were some lower that were 93 . and yep your about right on compression ratio BUT that was when NEW Before they have had a valve job and some shaved off the head because they oh guess what THEY WARP so now you pushing over 8 and maybe headed for a 9-1 . Trust me on this and the other factor on this is oh guess what the org pistons from the factory were Forged and the new repalcement are CAST and they do not like the heat of this new gas . Now as far as timing there are two different setting on a 706 all depending on if it is a C263 or a C291 as the 291 is a higher compression engine So on the 291 you set full advance at 18 degrees BTDC and the C 263 ya set at 23 Degrees BTDC. AT full rated RPM. Yes i have checked the dist. for correct centrifugal advance on a dist machine and set them as per spec. . Myself i have come to the endof my rope on these even though i liked then and know every inch of them . so the only way i can see keeping them around and using them is to do a transplant and make them diesels because you can not get the fuel to use them as they were ment to be used . No we do not work ground with them anymore but even just running the haybine works them just as hard . on our hills . today you can not even put together and old V8 out of a car built back in the time frame as these engines were built and make then JUST factory stock and run them on the gas we have today . You will not even take a 67-70 Ford Galaxy with a 390 2 BBl that was a premium fuel engine and run it or even the reg gas on this gas today as one was a 9to 1 engine and the other was a 9.5to 1 engine and shame on you if you got 10.5 one or like the 429 an 460 at 11 to 1 . Or my old 390 with the 13.5 to 1 today you can not even run a 9to 1 with a carb and dist. on the gas of today . And a car or pick up engine is NOT a working engine as it is NOT under load like a tractor . Yea you can go drive them on tractor rides and probably do ok . But your not even going to come over here and hitch to even a 1219 john Deere haybine and go mow first cutting hay on 87 gas . that same haybine behind my 806 on the hills on a still day will make the rounds with the smoke hanging in the air and if ya cant see the tractor over the hill the black smoke rising up in the air will pinpoint ya.
 
Hardened valves and seats didn't show up until the mid '70's in automotive and ag industries. That's when unleaded fuel showed up. There are factory bulletins still floating around about Farmall experimenting with different valve train parts in late '60's. My dad was an engineer at the local Rock Island Farmall plant from the mid '60's until they closed their doors in '84, so he was there when my 706 was built. He even remembers the guys name who wrote their manuals and knew him personally. He has the 560 and W4 out at his place that were used for a brake for load testing at the plant for many years. The W4 is fitted with a water pump in place of the engine and the 560 was used against compression. After so many hours they would tear them down and inspect for wear. They didn't use high octane fuel.
 
NO . your still fighting the gas problem as the gas today is a flash burn and a hot burn . what is needed is a REAL FARM gas of a true 93-95 octane . NO AL KE HOL just gasoline . even better would be gas to run the old classic cars as they came from the factory with the 10- 12 to 1 compression ratio. and that would be 105-107 . Just showen my age here . As that was my time . Last true performance cars were the 71's and 72 they got castrated and it was down hill from there. I H stopped building gas tractors by 75 . Myself i loved my gas tractors , easy to maintain they were cheap to buy and for my massive hobby farming they were a perfect fit . Always started down to minus 35 ( after that i was NOT going out and playing on a open station tractor) . I can tell ya this that 87 octane in a working 460 gasser that has lived o the same farm since new in 59 will not pull a loaded I H 550 spreader full in the field up the hills with out seezing up . Ya put the fuel that a 460-560 requires in it and it runs like new and just two points on the octane is all it takes as they required 89 .
 
All that matters is if the engine suffers from pre-ignition, does not. Resurfacing the head after a valve job is not going to change the mechanical compression ratio to make any real difference. Excess carbon build up, yes. That is why it was common for engines in the 50s-60s in cars to get carbon-removal jobs at 60K miles or they'd start pinging on regular gas.

Buying high-test is just throwing money down the drain unless someone has a problem tractor that pings and knock on regular gas. I have yet to see that happen on any farm tractor other then an Oliver 1800 that had much higher CR then most other tractors.

Note that the Oliver 1800 gas holds the record for being the most efficient gas tractor ever tested at Nebraska. Had a 8.5 to 1 CR and that is very unusual for a farm tractor. It was worked to the max with no issues at Nebraska with 84/92 gas which by today's octane rating - is 88 octane.
 
When ya grind the seats you can tell real quick if it is a harden seat or not and yes the ones in the new engines in the 460's on thru the 856 gas are hard . same as the exhust valves . . Now here is a little food for thought Ammaco use to sell unleaded gas back in them days and i ran there hightest in my 68 Road Runner and my 71 340 and trust me on this i was not easy on either one of them . Most sane people would not ride with me . Now back to the seats on the heads if you used a reg. stone on them seats you made a lot of stone dust real fast and had to drees the stone on each seat . Now if ya look at the OLD aftermarket parts books it listed them as a harden seat . Then along came the no lead gas and heres a good sale gimick when a valve job came in and most people fell fot it and got handled on the HARDEN seats deal and ye some engines only had the valve seat cut into the cast head was it necessary for the most part NO . on the valves there has been a lot of different exhaust valves used in engines , from stainless to sodium filled and everything inbetween . The only problem with valves in a I H engine is the build up of ash from the wrong oil used . You run the low ash and you have no vale problems , choose to run something other then low ash and you will get good at R &R of the head. Getting my friends and customers to switch oil was a gun shot wound to the foot for me as it stopped the income of doing valve jobs .
 
I read some saying that gas was 95 octane at the pumps when these tractors were made, and others say it was 89. Which was it? My understanding is the measurement system changed, and "old" 93 is equivalent to "new" 89???

I don't understand why forged vs. cast pistons would make a difference. Aluminum expands at the same rate either way. Is it a different alloy for forged vs. cast, and that's what changes the expansion characteristics?

I understand that the higher the octane, the more compression can be applied before ignition. What else varies according to octane? Lower octane burns hotter? Does the burn time lengthen or shorten according to octane?

I did more research into the various octane boosters. I came away with the belief they make a lot of claims but there's not much science to back the claims up. Might better just spend the money on the higher octane gas if needed.

Soon I'm going to have a 656 with about $3k in parts and machine shop work, plus my own labor. I'll probably run it 200-300 hours per year doing mostly hay and a little tillage. I'd like to treat my new engine right, so I can pass it to my children.
 

My 656 was made in 1973, has never been rebuilt, and has hardened exhaust valve seat inserts. Just had 2 of them replaced because they had come loose.
 
well i can tell ya this , that there is NO carbon build up min the heads NONE and just how many times have the heads been milled ground and shaved . Do you know i sure don't . Also i have never found the usuable thickness anyplacce on that head . I have seen where ya may have to take .007 off to clean one up and i have seen where .035 is needed . I also have seen heads come back after a couple years of running where they ate and exhaust valve once again because of not using low ash oil and oh hey didn't i just take a cut on that head last time and it needs .010 to get it flat . So how many times has this been done so now what is the compression ratio ?? Also we are talking farmalls here not and OIL ALL OVER . LOTS of difference between the two . Different head design different piston design ain't the same animal . Now i don't know where your at and don't really care but here our gas has always been the research rating and gas is NOT the same as it was back in the days . BUT hey i only work on these i call it like i see it and i have gotten to the point i really don't care what ya run or how you run it . If it takes a dump on ya it is no skin off my nose or knuckles and what ever it cost ya to fix is not coming out of my piggy bank. And i am sure that you have way more years of engine work and have never made any mistakes or spare parts in doing so.
 
One thing not mentioned is time. The time issue is the difference between the 2000 Rpm of a tractor compared to the 3 to 5000 rpm
of a car engine. The slow engine, and its timing, can require higher octane fuel because the combustion cycle is far longer, in
milliseconds, than the car engine. Higher octane fuel, burning slower, is less likely to preignite from combustion heating and
detonation from the pressure buildup in the unburned fuel remaining while the flame front travels while the piston is near, at , or
just past TDC. Jim
 
I'll say it one more time. If an engine needs a slower-burning gasoline - it will knock and ping. Are there a few old tractors that have been modified and are worked hard and are no longer reliable on regular gas? I'm sure there are and I am equally shore they are in the minority. These old tractors were designed to run on the cheapest fuel available to a farmer except for a few exceptions like the unusually high compression Oliver 1800.
 
I have had many makes and models of old tractors loaded to the max on a dyno with cheap fuel and never had one yet that showed any pre-ignition problems except one. The one we had the problem with was a John Deere 2020 that we found out had a Deere high-altitude piston kit installed. Note we were only at a 1400 foot elevation and thus the problem. With that tractor -it knocked even with high-test gas and the ignition retarded by 6 degrees. Finally tore it down and put standard pistons back in.

Can you name any farm tractor with a gas engine other then the Oliver 1800 series that requires better then regular gas? Maybe there are some with CRs over 8 to 1 but I cannot think of any. I suspect 8.5 to 1 or higher is where the need for a slower burn is needed.

I don't understand the comparison the car to tractor engine. A car, on average, runs less then 2400 RPM, and a tractor often runs and works hard AT 2200-2400 RPM. I don't see where this has anything to do with any of this.
 
It was 95 reg gas here in Ohio back in the day 105 was the norm on hightest and the better places it was 107 , Sunoco had the 260 and it was 109 on the RESEARCH method A case in point here for you young bucks that know it all . OLD gas burnner trucks , now i am talking straight truck and semi's ran HIGH TEST , ALL OF THEM Yep they were LOW COMPRESSION BIG INLINE OR V* GAS engines . Back in the early sixty's till i went into the service in 66 i drove occasionally a 1957 B60 Mack when i first started driving it it was a 6 cylinder Thremodyne gas with a five and a four transmission twin screw pulling a new Rodgers T 1 Low boy rated fifty ton and you fed it HIGH TEST , the white Mustangs with there BIG inline 6 gas used HIGH test yep the 105 or better stuff . Cars from the sixty's depending on engines required nothing less then 93 and up to oh wait the 105 or better . Remember this was the start of the go fast days and everybody was in the game . As a kid in high school i liked fast cars i had fast cars when they laid the pavement on the local drag strip i was 9 years old and oh wait i was there with my cousin and ran the gallion 8 ton rolling the black top . My cousin and a family friend were the ones who made this happen . As i got older and went with my cousin many times i wanted to do this . well i helped him build his hand made vet in nthe back yard garage at my aunt and uncles house . His hand made Vet caught the eye of Fisher body and the end results was the stingray as ya know it . That car was built for A/MP with my job and my income i was able to play and play i did so i learned a lot about engine building and fuels . working for a construction company i did what ever from running equipment , diving the one lowboy to wrenching on everything to welding and machining . After the service i was not able to go back to the construction co.due to a union split and did not get my book transfered as when this all took place i was in the middle of the Tet offensive. So when i came home i had no job to go back to , so i was ASKED to come to work for a Chrysler Plymouth dealership and became the guy that worked on the Performance cars . Got to go to all the schooling offered , learned more stayed there for awhile and was offered a job with a large Ford dealer to head up there drag racing program and work only on the performance cars , till they found out i knew trucks and diesel engines so i worked on them and here once again little know Fact that yep they required hightest in the HD and super Duty trucks , NOw on a reg old F 500- 700 with a say 330 -360 engine then you could run 95 octane BUT you throw in the H D or S D then it was the 100 Proof stuff. SOOOOO the gas back then in the days of my youth was on the low side 93 and on the high side 105 or better on the Research method . as even back then people did not want to run the gas that was needed and we addressed this atleast once a week also the issue of Sohio boron with Valve cleaner as it was death to the Ford H D and Sd engines . I had one guy that ran a Fleet of Ford dump trucks all gas powered and all had either a H D or a S D engine and they were all eating valves till we got him to stop using the Boron and started using hightest from the little Gas town truckstops that dotted this area . The Boron did not affect the car engines just the truck engines. Now did it do this to the othe big gas engines , Don't know i only saw the Fords. Now according to the owners manual on a 706 it say's the recommend octane is NO LESS then 93 Research , nothing about any other grades . SOOOOOOOOooooooooo the 93 is the LOWEST grade in a 504, 656, 706,756,806,856. Just sayen and know they did good if fed with the proper FOOD.
 
Let me tell you this IF you ever hear a C263 or a C291 PING it is to late . When that top of that piston starts to swell they will swell well over .025 so fast that you will not be able to get you foot on the clutch when she stats to die as the pistons guild to the walls Normal skirt to wall clearance is .0035 to .0045 the diameter of the piston around the rings ranges between .019 and .021 smaller then the skirt area So when you hone to fit as these new pistons out of the box are NOT one size fits all so you hand fit each to the bore your going to put it in and when they swell it is above the top ring . Now is it because of head design or is it due to the little dome i can not answer that as i am not that savy on this . . You can get away with the 87 in old M-450's unless ya do as we did and go with the above 8500 ft. pistons in one s/MTA that will give a 806 diesel a run for it's money . No i am not telling you what all we did with it. Do i care about the 1800 Olivers NO do i work on olivers NOT vary often . I work on Farmalls , we farm with Farmall . when i work on a Farmall what ever i am doing i know what tools to take to the job with out going back to my truck or tool box I have all the special factory tools for Farmalls . BUT i am soooooo tired of this subject from people that do not work on them or have no idea on how to work on them or even what is wrong with them as you can see by this page asking for help then beat you up when you offer FREE advice . There are THREE of us on here that WORKED on FARMALLS for a LIVING that made them go when the owners broke them . Now Pete and Owen have a few more years on me as to working on them . I can also tell you this that you will foul more plugs on 87 then the other. The gas at the pump today is made for the cars of today NOT the cars and trucks and tractors of yesterday this new gas does not even work in lawnmowewrs or chainsaws.
.
 
Have you tried blending in some 100LL?
I don't know for sure if the 93 octane these days has ethanol or not. For several years the small engine groups were pushing 93 pump gas as the way to get no ethanol. I contacted Shell directly and they told me that ALL grades have the 10% ethanol. I wish they would sell more beer and quit putting it in fuel.
 
My relatively new Ford 500 cruises at 70 turning just over 2 grand.
I think you have to look more at modern combustion chamber design and mixture homogenation vs. the old stuff.
 
The modern car has a computer timed spark with a learning curve. They have knock sessors and use them at all speeds and throttle positions to keep the engine on the edge of knocking. (best economy and power) Old Farm tractors do not. The time factor is based on the idea that rate of flame propagation on a working tractor at wide open throttle, with rpm driven timing, can detonate more easily than the controlled car engine. I believe the RON based numbers of the late 50s through the 60s are bogus. There are charts of fuel octane from around the world that provide a window into the extremes of fuel being pumped. I believe as you, that few require (3 R+M/2) fuel unless modified pretty far from stock. Jim
 
We can get 90 with no Al ke hol and it is sold as Recreation gas . BUT the best coming down the pipe is 90 with out . I can see where what they call 93 will become a thing of the past here before to long as it has now reached a price of fifty cents a gallon over the 87 and the rec 90 is a buck and a half over the 87 . No we have not tried that av gas but we looked into it but at that time it was 5.60 a gallon . so the petroleum companies could care less about what we want as we do not make up the masses and how much gas would they sell to us guy that have old tractors lets see here of the guys around me that still run old tractors over the course of a year they might sell 2500-3000 gallon , now how many gallon of 87 do they sell around here ,????? lets see every night i see a tanker load of gas coming into town to one of the may stations and sometimes i see the same tanker make two trips as they come past my place so that could be around 17000 gallons a night . Now that is just the ones coming out of Canton Ohio as there could be some that come out of the Congo in W Va also .
 
and one other point of retarding total timing . here with the timing set at the spec's you timing at idle is at TDC and If you back off the 6 you say then your at 6 degree after TDC and starting will be hard and you will have pop back thru the carb and on a C291 ya knock off 6 degrees off the 18 from the top it will be even harder to start . and your power levels will drop like a rock. Then just and FYI they get hotter with retarded timing . learned that in schooling at Ford performance . when one of you brain childs come up with a way to make this all work out let me know as i have run out of ideas and plum gave up on them . even the diesel fuel is not what it use to be and with the new diesel there is less Hp. in a gallon and lower fuel mileage per gallon . The new fuel is not friendly with old injection systems . and on this one just talk to pump men . I know mine is happy as a lark .
 
I hear ya.
Av gas prices are definately regional. A small airport about half hour from hear sells it for $3 and change a gallon but some of the larger ones are $5+. That small airport was quite a bit cheaper even when all fuels went high about 8 or 10 years ago.

Have you ever messed with propane? It has high octane although you lose some BTU.
 
If you were using 87 octane and got 8700 hours out of a gas engine without a rebuild I'd say you need to keep doing what works.
 
You guys keep comparing a tractor engine to a car engine.

A tractor engine is expected to work at 100% rated output for hours on end. A car on the other hand only uses a PORTION of its rated output to accelerate to speed, and basically coasts from there. The only time a car would be using 100% of its power output is in a hard acceleration such as a drag race, if even then. Any other time it is only using a tiny fraction of its power output.

If you were to put a car engine to work at 100% of its power output, it would be shot by the end of the first 8 hour shift, if it lasted that long.

This is also why a tractor's HP output is so much lower for a given displacement. A car might have 350HP out of 300 cubes, but a tractor only has 75HP, and still melts down if things aren't just right.
 
Car and truck engines have been used in tractor and other farm equipment and held up. Chevy 292 and the Chrysler slant six are but just two
of a number of automotive engines used in tractors and farm equipment.
 
What was your Dad's name? I worked at Farmall from 1976 till 1981. Most of that time was salaried, mostly in Material Scheduling, my desk was on first floor just feet away from the doorway to the stairs down to the tunnel across the road to the plant.

I was on a first name basis with the top 3 Quality people, and Assistant plant manager. He appreciated the hard work we did in scheduling keeping parts coming in. With out a doubt, best place I ever worked, and if I named several other places I worked, 85% of people would instantly recognize the names.
 
My 2 cents: I had a 351 4 barrel Windsor
engine in a 1985 F150. Mostly stock except
for a high-torque cam. Cast iron heads and
manifold. Anyway, I had a lot of problems
with pinging no matter what I did, and I did
a lot. The solution ended up being what my
machine shop owner recommended, which was a
solid-copper "head saver" which goes on the
block before you install the head gasket.
Fixed it right up, no more pinging, truck
still had great power, on 87 octane gas.
 
My newish 99 suburban cruises around 1700, that's at 65 or 70. Pretty impressive what the newer heads and roller cams can do for a stock plain old vehicle these days.

Only thing I don't like on the car is that it has the throttle-by-wire where your right foot is not mechanically hooked to anything. There's a tiny delay whenever you step on the gas. It's not really a practical issue but I notice it.
 
The key is your use of the words "on average. " When it comes to permanent engine damage, what happens in an engine is not related to what goes on most of its duty cycle, aka "on average." Damage such as melted pistons can take place in a matter of seconds in an engine that otherwise would last, trouble free, for years, given it received the right grade of high octane gasoline. There are certain factors that reduce tendency to pinging and/or damage from pinging. Among them are aluminum components such as intake manifolds, heads and block. All of these you will find in modern automotive type engines, but none of these will show up in a gasoline powered tractor engine. Forged pistons are much more expensive than cast, much more precisely machined, and much stronger, yielding some limited room for detonation before the engine lets go. Again, average wear and tear doesn't apply here, it's about the engine's ability to withstand a bad tank without destroying itself. These old seasoned mechanics know their stuff, and they freely share very valuable insights. Show them some respect.
 
I see some keyboard warrior thinking going on. Get in the seat of one for years on end, fix them as they break then come back n tell us what we already know and tell us more about gas, and how to blow up an IH 6 cyl Gasser.
 
Tractor vet nailed it in two words. A hot burn. Those engines cyl heads, are very badly restricted thru exhaust ports. This causes cyl temps to spike under full load. What happens when your cyl temps are 300 degrees to hot? She pings cause the heat is preignighting the gas.
My 01 ranger, with a Vulcan set up for flex fuel, will not run on 87 until I realized, its running too hot. Pulled out the 195 dropped in a 160, and its a different truck.
Heat. Think about it.
 
(quoted from post at 01:31:44 05/03/17) I have had many makes and models of old tractors loaded to the max on a dyno with cheap fuel and never had one yet that showed any pre-ignition problems except one. The one we had the problem with was a John Deere 2020 that we found out had a Deere high-altitude piston kit installed. Note we were only at a 1400 foot elevation and thus the problem. With that tractor -it knocked even with high-test gas and the ignition retarded by 6 degrees. Finally tore it down and put standard pistons back in.

Can you name any farm tractor with a gas engine other then the Oliver 1800 series that requires better then regular gas? Maybe there are some with CRs over 8 to 1 but I cannot think of any. I suspect 8.5 to 1 or higher is where the need for a slower burn is needed.

I don't understand the comparison the car to tractor engine. A car, on average, runs less then 2400 RPM, and a tractor often runs and works hard AT 2200-2400 RPM. I don't see where this has anything to do with any of this.
Click to expand...
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Yes, I sure can from the voice of bitter experience tell you that IH C221, C263, C291, and C301 all require high test 91 octane R+M/2 to run smoothly. The latest is my Farmall 656 and it ran rough and was fouling plugs. I thought I was in for a rebuild. A friend suggested I try Hi test 91 octane gas first . I did and the results were almost unbelievable. The tractor now runs smoothly with no noises and doesn't foul plugs any more. In other words it runs the way a Farmall should and I can hook it onto a decent load and without any protests do the job it was intended to do. The problem with the gas is not only the lower 87 octane but the ethanol has extra water in it. Just the other day my 2011 Ford F250 got a fill up just after the gas dealer received a shipment from the refinery. Filled it and then proceded about 1000 feet down the road and all of a sudden the truck stalled out. I pulled over on the curb and eventually got it started again. As soon as I got it home I dumped in two gas line antifreeze canisters and the truck has worked perfectly ever since. Then one of my neighbors told me a similar story about the same filling station and he had trouble with his 10 year old car that was previously trouble free.
 
I said "flex fuel " Vulcan. In 01, those were the highest hp/torque output for that engine up to 2003.
High cyl psi, combined with a 195 thermostat, with our 87 octane, pings.
Now, that works fine with 89, or flex fuel being flex fuel can be upwards of 100 plus octane.
 
Like I said - you don't have a gas problem. It had all of 155 HP at 4900 RPM, and a 9.4:1 ratio - the typical 3.0 Vulcan in the 1980s had a 9.3:1 compression ratio. Starting in 2004 all Vulcan engines had a 9.5:1 compression ratio. Strangely enough the HP and Torque differences from 2000 to the end of production were very similar.

Flex Fuel means it can run on regular (87) or high ethanol content (100). The much bigger issue the fuel mixture adjustment that the fuel injection system had to go through to enrich the fuel air mixture when running E85.


Given the age you probably need a new knock sensor. I had the exact same issue with my 1997 4.6, it would knock if running on straight 87, any combination of 89 and 87 and it didn't knock. It was still doing it after I replaced the intake manifold gasket - it stopped when I replaced the 18 year old knock sensor.
 
(quoted from post at 21:06:33 05/05/17)
(quoted from post at 01:31:44 05/03/17) I have had many makes and models of old tractors loaded to the max on a dyno with cheap fuel and never had one yet that showed any pre-ignition problems except one. The one we had the problem with was a John Deere 2020 that we found out had a Deere high-altitude piston kit installed. Note we were only at a 1400 foot elevation and thus the problem. With that tractor -it knocked even with high-test gas and the ignition retarded by 6 degrees. Finally tore it down and put standard pistons back in.

Can you name any farm tractor with a gas engine other then the Oliver 1800 series that requires better then regular gas? Maybe there are some with CRs over 8 to 1 but I cannot think of any. I suspect 8.5 to 1 or higher is where the need for a slower burn is needed.

I don't understand the comparison the car to tractor engine. A car, on average, runs less then 2400 RPM, and a tractor often runs and works hard AT 2200-2400 RPM. I don't see where this has anything to do with any of this.
Click to expand...
--------------------------------------------------------
Yes, I sure can from the voice of bitter experience tell you that IH C221, C263, C291, and C301 all require high test 91 octane R+M/2 to run smoothly. The latest is my Farmall 656 and it ran rough and was fouling plugs. I thought I was in for a rebuild. A friend suggested I try Hi test 91 octane gas first . I did and the results were almost unbelievable. The tractor now runs smoothly with no noises and doesn't foul plugs any more. In other words it runs the way a Farmall should and I can hook it onto a decent load and without any protests do the job it was intended to do. The problem with the gas is not only the lower 87 octane but the ethanol has extra water in it. Just the other day my 2011 Ford F250 got a fill up just after the gas dealer received a shipment from the refinery. Filled it and then proceded about 1000 feet down the road and all of a sudden the truck stalled out. I pulled over on the curb and eventually got it started again. As soon as I got it home I dumped in two gas line antifreeze canisters and the truck has worked perfectly ever since. Then one of my neighbors told me a similar story about the same filling station and he had trouble with his 10 year old car that was previously trouble free.
Click to expand...

George 3, I notice you didn't mention the C-281 engine. Why is that? I ask because I bought a 450 with the 281 and this post got me to thinking about which gas to use.

Thanks
 
My understanding is the 2001-2003 Flex Fuel 3.0 in the Ranger had knock sensor, the "regular" engine did not after 1997(?).
 
George 3, I notice you didn't mention the C-281 engine. Why is that? I ask because I bought a 450 with the 281 and this post got me to thinking about which gas to use.
Click to expand...

Because the C281 is the older 4-cylinder low compression engine that runs just fine on 87 octane pump gas.

This discussion is only about the high-compression 6-cylinder engines. The only 4-cylinder engine that fits this discussion is the C200, used only in the 544 gas tractor.
 
Good morning! The sohc 3.0 had the knock sensor. Vulcans stopped getting them, (just a quick guess) was 97.
It is two ecm systems combined, mass air, and speed density. My 01, has map sensor.

I have built 5.0 harness that I added
mass air sensor, that still used a map sensor.
A lot of the trucks had this combined system stock.
Back to flex fuel,, I have had my ranger for a long time. Its my favorite truck.
It pinged as soon as I first filled it with 87 the first time. I too thought I had major engine issues.
I ran a cyl psi test, at 185 psi cranking. So for a while, I just ran 89. Fixed the ping, but the cost to operate got salty.
One day, my engine temp was fluctuating. I popped the thermostat out, which was a factory 195.
Now, to go back a tad, the coolant, had to get over 210 degrees in the block before it got the thermostat to open. And that kept fluctuating the temp.
The heads were always hot in my opinion. And if I closed the heater valve, it got worse.
I wanted to get it to run on 87. And I did, it runs fine, no ping. I had to put a 160 thermostat in.
I figured, I had heat issues in the heads, once it got to 200 degrees Water temp, the 87 would preignite due to excessive heat that it couldn't get rid of.
Since, it runs about 170, the heads are much much cooler to touch. It now runs on 87 with no issues. Which is astounding, being 180 psi is the border line limit for 87.
Going back to the IH 6, it's kinda the same issue that the Vulcan had. I've discovered that the exhaust ports are very restricted in the angle valve heads. I've gasket matched several heads and manifolds, and put them to work.
They all ran 15-30 degrees cooler under load, I did use 87 in my dyno testing. But used 93 in long term use, especially in the 291 and 301.
I wish to have a laser temp gun someday.
 
The c200, is exact same as a 301 but
with two cyls less. Same bore,
stroke, same piston and rod.
C281, even with high domed pistons
and gas heads, you never seen cyl psi
much over 160. Bolt on a lp head,on a
264-281, bump cyl psi up to 200 and
it will ping, diesel, on 87. But,
bump psi up to 280, and it will run
on flex fuel and 89 mix.
That's a whole topic in itself.
 
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