Type M Engine Question

MECHANICAL
1

I have noticed oil around several of the center head bolts for the last couple of seasons. I do torque the bolts to 65 ft.lbs. each year and the engine runs fine. Is this normal?

engine
engine1512×2016 1.17 MB

2

I would. especially if you have just had a rebuild or head gasket change. there is a pattern for such a thing. check mitch lapoints site. it takes no time.

3

I’m sorry for the delay in answering, I would not consider this normal but it’s not catastrophic. If the engine was recently rebuilt, the pistons may not have fully sealed, and if it’s an older ENGINE, you might have a little oil coming up to the top of the cylinder being pushed up a head stud. If the engine is running, OK, I wouldn’t spend too much time worrying about it. If you wanted to try and stop it from happening, I would find a metric washer that fits tightly over the half inch stud and then put the original thick washer over top of that. I would use a little sealer and then put the nut on and tighten it. That should at least eliminate the oil from coming out of the cylinder stud I’ve seen this many times and as I said earlier, that’s not necessarily catastrophic.

4

Thanks Dave. The engine was rebuilt about ten years ago and runs fine. I will look at this again in the spring as it is 15 and snowing now.

5

That’s not oil, it’s combustion gas leaking and going up the studs. Which means the head gasket is failing, sometimes a retorque will stop it for another season. That spot is where it starts and/or out the STBD side of the head. So no not anything detrimental, other then plan on doing a head gasket soon. But a few musts need to be followed. Use plenty copper coat on new gasket, have the head checked and flattened at a machine shop (leave if they even suggest using their belt sander), chase all nuts studs then clean washers or replace, oil all the studs and make sure your torque wrench is accurate. First run do all your retorques while hot, takes usually 2-4 on the first run in the water run hard you want the engine fully warm, then do one more after your done, which likely won’t have any movement.