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O/T a litte bit

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O

old

Well-known Member
Location
Camdenton Missouri
But I do use it to haul tractors. Ok heres the deal. I need to tune up my 1980 Chev pick up. It has a 350 engine. Now then do I go with the factory called for spark plugs or do I go with a little hotter plug?/ I'm asking because I want to get the best MPG out of it as I can. My thinking is if I go with a hotter plug it will burn the gas better and by doing so get better gas mileage. So am I thinking right or am I wrong??
Thanks
Hobby farm
 
All gas vapors should explode under factory specified conditions and spark plugs. However, if your carb is starting to dribble gas in the cylinders or just not vaporizing gas well, then the hottest spark plug in the world won't give you better gas mileage.
 
Oh really? Daily driver? I suppose if you keep clean fuel going through it, the carb will stay in good shape. All it took for my dad's '85 chev with the holley 4 barrel was a piece of dirt in it to make it go NUTS.

I would think that maybe a one step hotter plug MAY improve fuel economy- it may also improve 'sniff' testing emissions.

Since gasoline has 10% ethanol in it now, it may not be a bad idea to step up to a hotter plug...
 
Daily driver heck no who can afford to drive every day. But as far as the fuel system it has a brand new gas tank on it as in less the 10 fills ups since put on. I drive it about once maybe twice a week and its been 2 may 3 years since I did a tune up on it. When I fire it up the first time for the day it does put out a little smoke but that clears up fast I figure valve seals leak a tad bit. One nice thing about being retired is I don't have to drive any thing day in day out I can stay home and only drive when I really need to do so
Hobby farm
 
This old truck is over cooled. It never shows more then maybe a 1/4 of the way up on the gauge unless you let it idle for a long time and then it still does not get all that warm
 
A hotter or colder plug will make no noticable difference in fuel economy. If you are fouling plugs it may increase the life of the plugs.
Good compression, correct timing and advance, a correctly adjusted and jetted carb, proper tire inflation will all help more.
 
If it was mine I would go to my local part house and get a set of Platinum plugs and then forget about it.

Best thing I ever did on my 86 Samaria.

Walt
 
Go with the parts store recommended heat range plugs. Ever since we went to unleaded fuel and electronic & computerized ignitions hotter plugs will just cause knocking and overheating if not needed to burn oil in a oil burner.
 
I was always a beliver in buying cheaper plugs. Then when I got plugs for my newer Dodge Ram they only had Bosch premium plugs for it. Greatly to my surprise milage went up a MPG. I've since put them in all my vechiles with a milage improve ment in all of them. Used the standard heat range too.
 
OH FOR GOSH SAKES... A "hotter" plug doesn't cause overheating of the engine!

It causes "pre-ignition" or "detonation" that breaks pistons (and even the tips of the spark plugs), but it sure as heck doesn't make the engine run hotter!

This is because using 'plugs that are too hot for a given application means that the plugs will remain incandescent long enough after the power stroke to "light off" the new charge under compression, BEFORE spark occurs. BANG! (KNOCK)
 
Auto Parts,

You posted: "Ever since we went to unleaded fuel and electronic & computerized ignitions hotter plugs will just cause knocking and overheating if not needed to burn oil in a oil burner."

That's a SILLY comment, as that has ALWAYS been the case. Unleaded fuel and electronics have NOTHING to do with it!
 
Can't see where the plug would make preignition knock any worse or better since the preignition is set off by compression and heat buildup in the cylinder aided by a fuel with a low flashpoint and the cylinder fires before the plug spark fires.Lots of time carbon build up is the main cause of preignition along with timing being too far advanced.
 
Now I see the problem. You don't drive enough. The fuel in your tank is evaporating and you're going nowhere. Run that fuel through the engine and go somewhere and you'll get better mileage and not even have to tune it. Just a thought:>)
 
Now I see the problem. You don't drive enough. The fuel in your tank is evaporating and you're going nowhere. Run that fuel through the engine and go somewhere and you'll get better mileage and not even have to tune it. Just a thought:>)
 
Now I see the problem. You don't drive enough. The fuel in your tank is evaporating and you're going nowhere. Run that fuel through the engine and go somewhere and you'll get better mileage and not even have to tune it. Just a thought:>)
 
Rich, Id stick to the recommended heat range NOT a hot plug. That engine isnt like our old relatively lowwwwwwwww compresion low RPM tractor engines where we just parade them often and light duty use. I dont see how a plug that retains more heat (hotter plug) will cause it to run any better. The "hot or coldness" of a plug is only a mechanical thermal parameter relative to its heat retention and has nuttin to do with the spark energy or incerease or decrease thereof i.e a hotter plug is physically temperature hotter.

Id install a thermostat if needed to get n keep the temp up to 180 or so.

John T
 
Rich, Id stick to the recommended heat range NOT a hot plug. That engine isnt like our old relatively lowwwwwwwww compresion low RPM tractor engines where we just parade them often and light duty use. I dont see how a plug that retains more heat (hotter plug) will cause it to run any better. The "hot or coldness" of a plug is only a mechanical thermal parameter relative to its heat retention and has nuttin to do with the spark energy or incerease or decrease thereof i.e a hotter plug is physically temperature hotter.

Id install a thermostat if needed to get n keep the temp up to 180 or so.

John T
 
Well ain't this something. Try to be a smart @$$ and make a joke and end up with a triple post and show what A dumb @$$ I really am :>(

Have A good one guys
Pete
 
Once the fuel charge ignites it has to burn.A worn spark plug can fail to spark under pressure and the unburned fuel charge will go out the exhaust.This is the only way you can lose milage.Burn better, more complete burn are BS terms invented to sell tractor owners transitorized big buck ignitions.Gas and oil fouled plugs will fail to fire often.The spark voltage will run up the nose of the carboned insulator in a thin stream.That wont ignite the fuel charge.Testing suspect plugs on the bench with a Model T coil will prove this.I test ignition parts on the bench with a T coil.I used a T coil to test the spool type rotors on early Ford V8s for breakdown 50 years ago. Rotors can arc to distributor shafts.The 9N 2N 8N and later Ford tractors need a hotter plug with the gasoline we have now.Ill repeat, a spark plug has to fail to fire to affect gas milage.All the buzz words used to sell more plugs are BS.
 
Rich,
The hear range of a plug is the a heat dissipation range, it really has nothing to do with the "heat" of the fire in the plug. If you will take 3 differant plugs, that are the same, but with a differant heat range you will see the steel part of the plug is longer in a hotter plug.
Jim
 
My engine in my first truck was a '73 chevy 350. I had to use hot plugs because it burned a lot of oil. For best fuel milage I found the ususal suspects to be pretty effective. Good PCV valve, clean air filter, good plugs and wires, good cap and rotor. When using conventional oil, the milage would decrease toward the end of the oil change.

I also increased the spark advance. Stock is around 4 degrees BTDC. I advanced it to around 8 degrees. I had to run 89 octane and it did ping under heavy load, but for normal driving it had better performance and lower cost per mile than 87 octane at the factory timing. Good luck.
 
Does anybody use the multi-electrode plugs ? Years ago dad and uncles swore these were the only thing worth using in the JD and Farmalls of the time.
 
I have a trusty old 80 chevy too and if your getting 10 MPG running uphill, downhill 35mph or 75mph or just sitting there idiling your doing good. Changing gears or adding overdrive will help more than plugs but in mine I run delco R45TS. I think the R44TS was stock but like others have said its based upon how its tuned and what the plugs look like after it runs. My 92 chevy runs R43's and it gets better mileage (14mpg or so and 230,000 on the original motor) but of course is TBI and has overdrive.
 
John T ---

A 1980 Chevy truck, is getting a little extra oil past the rings.......one extra heat range usually helps burn that off....I would not increas the timing more than 2*...........Don
 
Old ---

Back in about 1941 ....I was about 5 years old....Dad sold our new Buick and bought war bonds.......

We always had horses around, Dad loved them.....We used a black pacer (horse) and a black buggy with red wheels and white rubber tires.....

We only lived about 3 miles from town (Harrison Ohio).....Problem...the cars were in the way.....Tony went faster than they did........good milage....good memerys...Don
 
When my truck is tuned up good it gets around 17 MPG but it also had an automatic in it at one time and now it has a 4 speed so its geared a little on the high side. I can do 60 MPH in 3rd gear and its still not close to red line
 
If the air/fuel mixture in the combustion chambers is firing when the the plugs spark. Then all a hotter plug is going to do is increase the tendency for knock, dieseling & detonation.
A clean airfilter, ensuring the choke is 100% off, the heat riser valve is 100% open, the timing initial, centrifical, vacuum are set and working. And air up the tires to what the door sticker says.
If the engine isn't too loose going to a 5W-20 synthetic oil will reduce drag. Synthetic in the diff too.
Removing the engine driven fan and adding an electric unit that operates only when required would be the next step. Water pump bearings will last longer that way too.
Cheapest mileage improvement would be to trade to a 1990's pickup with fuel injection and overdrive transmission. Can't hardly giveaway used pickups with fuel prices. The old truck will be worth good bucks as clean scrap steel.
 
Been around GM small blocks for a while starting with the 265, timeing and carb.[if it has one] setings should be checked. But the two things that make notable is a clean air filter and tire air press. I DO NOT go by the door sticker! Read the sidewall of the tire and inflate to the max.
 
I've got that same year, K10, retired to snow plow duty, but I drove it full time for over 5 years, it too was an automatic with spicer manual type hubs, which was a lot better than the full time ones, that auto trans. went and a friend at work had a complete 4 spd set up, everything out of a mid 70's chevy farm P/U truck with about 30,000 miles on it before it rusted out. The trans lube was still clear in it, changed that out though, to 85/140 cling, and put the 4 spd in there, differentials were 270's so the speedo was off, definitely highway gears made one trip home with it and it was retired.

Matter of preference on the plugs, I can remember doing that (hotter plug) with the first engine in this truck, which had some blow by, but went back to the normal range when I put a new one in. Thermostat does need to be right, engine needs a certain temp to run the best, I've tried it without the thermostat and all that, seems to like 170-180 to run best.

Another small block chevy I had beefed up along with the auto trans, was put into a '78 vette, the one thing that impressed me about that was the inexpensive, but higher voltage Accel HEI ignition module/kit that went onto the stock distributor, it was like $100 then,'91 or so, + 8mm wires and I forget which plugs, now been warned to stay away from champion, that motor would start instantaneously in the freezing cold, and having the carb dialed in, timing and all that jazz, was probably the first time I actually got everything situated just right, something was just unique about how it started, I figured the extra ignition voltage was it. This 350 motor was in the 325-375 HP range, never knew exactly it was nothing radical just a few steps up from stock, more compression, little extra lift on the cam, had roller rockers. It actually was a screw up, someone had put dome top pistons, (compression was ridiculous) radical high lift cam, never even pinned the rockers, they would have broke loose, had them shave the domes off the pistons and tone everything back down to something reasonable that you could drive, long story, some genius thought the more radical the better, thing would have come apart when I got it.
 
An you are still alive can't believe it.

There is reason for the door numbers its controllability on the road.
Going to the Max on the tires can get one killed real fast.
Walt
 
I always thought splitfire or other multi electrode plugs were just another gimick to take your money and work no better than a conventional plug, well my opinion changet a couple years ago.
I have a cheap Ryobi string trimmer and leaf blower from TSC that tended to foul plugs. The carbs have no high speed mixture adjustment and tend to run rich at our altitude. I really did not want to lean out the oil mix any, yet was getting very few hours out of a plug, especially at light load.
I tried different brands of conventional plugs with no improvement of the fouling problem.
I was back at TSC for about the 4th set of plugs when I noticed the E3 sparkplug display in the lawn/garden section. The bubble pack said more power and use less fuel, I thought "yeah right", then I noticed it said " guarnteed not to foul or your money back" I thought "oh really ?" I asked the counter man, "will you honor this no foul or money back warrenty ?" He said they would.
OK, I bought a magic E3 plug for the worst plug fouler, the string trimmer. I ran it for the next couple weeks and was not able to foul that plug even when I purposly idled it too much.

I then put them in the Ryobi leaf blower and the 2 cycle Lawnboy push mower. The mower did start easier and leaf blower did not foul the plug.

OK, this is good, next lawn garden machine project is the 20 year old Roper rider mower with 17 hp Briggs twin.
This Briggs engine has been a hard starter as long as I have owned it (6 years).
It would not start with the throttle at any position but slow idle, and would miss under a hard pull.
I thought weak ignition, so I replaced the coil /module assy. Waste of money , It improved nothing. several sets of conventional plugs of different brands were no help.
OK lets try some magic E3 plugs with the goofy bottom electrode.
Tried them, and now it fires right up cold at even wide open throttle and does not miss even under a full load.

I got my education that not all this stuff is snake oil.
E3 sparkplugs
 
The way I've always understood it a hotter plug does nothing for the combustion proces itself. The "hotness" of the plug is based on the diameter of the electrode and how long or short the ceramic covering it is. This all simply determines how fast or slow the plug disapates heat therefore how good it is at burning off deposits left on it from the combustion process. Now running a "hotter" coil will, I've been told, create a larger, therefore "hotter" spark or in many cases allow for a larger plug gap. The larger or longer spark will in turn ignite the most fuel vapor in the shortest amount of time giving a longer and more complete burn which would equate to more power out of a given amount of fuel therefore better fuel economy.
 
Fan shroud makes it cooler, not hotter! Look at old plug. If black, go hotter. If brown, tan or blistered and electrode eroded, replace with same heat. Tweak carb using vacuum gauge for highest vacuum reading. Power time, in my book. Get enough advance to get a slight ping, back off a hair. Fan clutch good if not already used.
 
You posted:

"Apparently you are about as poor a comedian as you are mechanic"

Apparently, you are dumber than a box of rocks!

About the first thing you will be taught in ANY "Mechanics 101" course is that a 'plug that is too hot will cause detonation. And you ARGUE with that basic fact??????????

Is stupidity a TRADITION for you???
 
Apparently you quit class after the first day when you thought you knew it all.As a practical
application a lot more things cause preignition than too hot of a plug.Is running your mouth at 78 RPM while the brain is running at 33 1/3 a tradition for youself?
 
Wow how do you manage that out of one of those old beasts. I had mine geared high once but didn't like it so I swapped back. Not good enough for towing.
 
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