Oliver OC-3 information

[JordanB427]

Hello I believe I have a 1955 oliver OC3 crawler. I am looking for information as to what I should have for Compression in PSI. We have had trouble getting the crawler running, initially thought It was timing, have timed it to the best of our knowledge, machine will backfire every so often. it does not seem to be drawing or pulling fuel, carb is in good shape has been removed and cleaned. New plugs and Good spark. sediment bowl is clean and tank is also clean and clear. any information or help would be greatly appreciated. thank you

 

[J. Schwiebert]

How much compression do you have, throttle wide open all the plugs out? You have aphone number or e-mail? J.

 

[JordanB427]

[email protected]

 

[JordanB427]

Not sure how accurate our compression gauge is. It
showed 25 pounds in each cylinder. Where should
the timing gear on front of motor be if all other
marks are correct. I.e. Fly wheel mark and magneto
mark are both visible in sight holes.

 

[JordanB427]

Not sure how accurate our compression gauge is. It
showed 25 pounds in each cylinder. Where should
the timing gear on front of motor be if all other
marks are correct. I.e. Fly wheel mark and magneto
mark are both visible in sight holes.

 

[old]

How long has it sat with out running?? If it say for more then a 1 or so fill the cylinders with ATF and let ti sit a week or so. Then pull the plugs back out and spin it over to free and clear out any ATF and then check compression. Most old flat heads engine need around 90PSI plus to run well if at all

 

[J. Schwiebert]

I sent an e-mail to that address and it came back to me.

 

[RBoots]

Those Hercules don't
appreciate weak valve
springs either. A lot of
times at an idle they
will drop a couple
cylinders until you rev
it up when the valve
springs are weak. Just a
thought.

Ross

 

[JordanB427]

[email protected]

 

[JordanB427]

I am unsure how long it sat. We have had it for two years. Couldn't get it going at first so we let it be and now started wrenching again.

 

[JordanB427]

I would guess 4 or 5 years.

 

[JordanB427]

I added email to this reply

 

[old]

Plug the plugs out one by one and fill with ATF and if it has a horizontal exhaust pour ATF down it till it will not hold any more. Put each plug back in so as to keep dirt etc out let ti sit a week or so then spin it over with the plugs out to clear the cylinder and then try to start it

 

[oliver90owner]

Question. Has the engine timing been interfered with, since the engine was last running correctly? 25psi is rediculously low for all cylinders.

That gauge may need checking by comparing with a tyre guage or similar!

 

[JordanB427]

The machine was bought at an auction sale where it was found in a building under a pile of stuff. The radiator, hood,and gas tank were off of it. There is fresh paint on the water pump and front cover of the motor. We removed mag and inspected and cleaned it up. We have spark on all four cylinders but compression is obviously low. It leads me to believe the gentleman who owned it whom is deceased might have removed front cover on the motor and did some sort of adjustment on the timing gear. When the Timing mark is visible in bell housing and also visible in the mag the marks on the timing gear are at a slight angle such as this /. My guess is that the timing still is not right and that valves are open or closed when they should not be or should be.

 

[oliver90owner]

The ignition timing is unrelated to the engine timing - the relationship of valves opening and closing wrt the pistion position. If that is incorrect, the engine will not perform. If your pressure guage is reading near correct, I suspect the timing is out by a tooth or two or a few.

RAB

 

[JordanB427]

what is the best way to time the motor. Is there a procedure to time the valves and what not aside from the ignition.

 

[jethrow4]

I have a 1955 OC3 w/Hercules IXB3 motor. Compression should be at least 100 - 110 PSI. There is a timing mark on the flywheel visible
through a hole in the bell housing on the magneto side. Typically the flywheel is stamped with "SP" (spark) and should be visible through
the hole when number 1 cylinder is at TDC. If the cam gearing has been changed, Zimmermans has a document describing how to re-time the
gears.

 

[oliver90owner]

There are probably several ways to achieve a result, but the easiest is to follow the engine manufacturer's instructions, for which they will supply gear markings, to be matched up at rebuild, with the number one piston is at TDC (crankshaft timing - assuming, her, that the flywheel has been fitted correctly, if the bolt pattern is not asymetric).

RAB

 

[jethrow4]

If you are confident your ignition timing is correct and you are getting a spark in each cylinder at the right time then the next thing to do
is check valve seating. This can be done with a leak down test or remove the valve cover and plugs, rotate the engine by hand and check that
the valves seat correctly. There should be .006 - .008 gap between the push rod and valve stem. I've had to grind the bottom of a valve to
get the proper clearance. I try to post Zimmermans Engine Timing document here.

 

[JordanB427]

Thank you for the info. I talked to me Zimmerman and the timing is correct. So I have other issues in the motor

 

[JordanB427]

Thank you for the info. I talked to me Zimmerman and the timing is correct. So I have other issues in the motor

 

[JordanB427]

Soaked cylinders. Compression came up to 115-120 in all but one. Added more atf to that cylinder and started soaking again.

 

[old]

The one that did not come up is likely to have a valve that is not closing all the way. Some times you can take the plug out and use a punch etc to pop the valve back down and then cycle it a few times that way to free it up

 

[JordanB427]

I am going to let it soak a few days. When we did the initial soak I don't think that cylinder filled all the way out. So when I put more in I rotated motor until I could fill cylinder right to the top.

 

[old]

That will work if it is an exhaust valve that is sticking open but if an intake the ATF will end up flowing into the carb

 

[JordanB427]

No compression in that one cylinder yet. Both valves are moving. Either rings are stuck or possibly hole in piston. Guess I won't know unless I pull head.

 

[old]

Being a flat head should be easy to pull the head off. Could well have a valve not closing all the way but not likely to be a hole in the piston other wise that cylinder would not hold any ATF. If I where you I would fill that cylinder with ATF and then see if you can hydro lock that cylinder. If you can not lock it up watch where the ATF comes out and you will then know if it is a valve or rings

 

[JordanB427]

I will have to get a head gasket when I pull the head unless they are reusable.

 

[old]

That is why I said you should try the hydro lock test first. That will tell you if you have a valve problem or stuck rings etc. And yes your not likely to be able to reuse the head gasket but I have been able to once i n awhile but not a good idea unless you just plan have to

 

[JordanB427]

So put a spark plug in that cylinder and turn it over with atf in that cylinder

 

[old]

Yes fill the cylinder with ATF put the plug in and by hand turn it over till you hydro lock it do your best to make sure you put a lot of pressure on it so as to force the ATF out of where ever it maybe be able to leak out of be it a valve or what ever. It will not be likely to leak past the rings much but it the rings are sticking that will help free them up

 

[alejandroflores]

Old - tractor guru

My Name is Alex and I am trying to help my father-in-law get his Crawler going,

I read through your posts on yesterday's tractors.

May I ask you a question about the ATF procedure and timing
OC3 WITH XB4000 distributor.