The Stovebolt Site Forums The Shop Area Engine Shop Do I have a head gasket problem?

Hello,

I recently got my 216 running for the first time. It runs really well, but there are some concerns. I believe it is a '52 (or '62?) dealer replacement block.

I did a dry and wet (poured a bit of oil down the plug hole) compression test before firing it up. Results are below, (dry / wet):
1) 76 / 98
2) 76 / 90
3) 72 / 89
4) 70 / 86
5) 90 / 100
6) 89 / 110

I have read that the cylinders should not vary any more than 7-10%. Do these numbers indicate a potential head gasket leak? Likely between #4 and #5? I will do a valve adjustment soon to attempt to improve these numbers a bit.

Another concern is I opened the water jacket drain plug and the sludge that came out was oily. From what I have read it is normal for this to be rusty material, but oily can't be a good sign is it?

I changed the oil a long time ago when I first got the truck and it did not seem to be contaminated with coolant, but I am no expert. But if I do have a bad gasket, am I doomed to pulling the head and replacing the gasket or are there other options or potential causes of oil contamination? I am not 100% committed to keeping this engine, so I don't want to dump a ton of cash into it. Thanks.

James

Cylinders 1-4 have stuck or worn piston rings. Getting a 20 PSI rise by adding oil tells me the oil is helping the rings get a better seal momentarily. A head gasket problem would cause low compression on two adjacent cylinders due to leakage from one to the other, or there might be bubbles in the radiator and/or overheating from a compression/combustion leak into the cooling system. Before you take anything apart, try this- - - - -Change the oil, using any old brand of inexpensive straight 30 weight. Add 2 or 3 quarts of Diesel fuel or kerosene to the crankcase so the crankshaft is partially submerged. Start the engine, and run it a t a moderately fast idle, maybe 1,000-1500 RPM for 15 minutes or so. DO NOT DRIVE THE TRUCK! The crankshaft and rods will splash the oil/Diesel mix around like an agitator in a washing machine, and you'll get a better cleanup of the internal parts than you'd ever be able to do with a brush and solvent. Shut down and drain the oil while the engine is hot. If sludge and varnish has the rings stuck, It's possible this procedure will clean up the deposits and let the rings get a better seat. If not, you haven't spent much time or money trying to do a simple fix. Several people here have tried this procedure with pretty good results.
Jerry

Hi Jerry,

That sounds like a simple approach. I have a bunch of Walmart 5W-30.., that should be fine no? It already has a pan full of the same 5W-30 from about 2 years ago and I haven't ran it more than 2 minutes in those 2 years. Can I use the oil in it or would you recommend changing it again?

Any insight into the oily sludge in the water jacket? Thanks,

James

"Read my lips- - - - -straight 30 weight!" 5W-30 is water-thin and has no business within 100 yards of any stovebolt engine! What I'm recommending is plain old SAE 30 single viscosity oil. For the purposes of a flush like I'm recommending, buy the cheapest non-detergent oil on the shelf at the parts store- - - -it's only going to be in there 15 minutes. 5W-30 oil STAYS the thickness of 5 weight the whole time, and provides virtually NO cushioning effect between the parts in an old, loose-tolerance engine. You might as well take a sledgehammer to those fragile Babbit bearings!

Deal with the compression problems first- - - -a little goop in the cooling system is a minor concern right now.
Jerry

Hi Jerry,

I had read that the winter weights perform the same as the straight once up to operating temperature, with the only difference being it would help it flow better upon first start up. Since this engine is not going to be running for long periods for the foreseeable future I thought the winter weight made sense. I also live in a cold climate so wouldn't the thinner start up help oil reach all over more quickly for those short 1-2 minute run sessions?

I am not questioning your advice, just want to learn more myself. Sometimes what I think is the logical conclusion is not always the practical one!

Thanks.

James

James, you need to follow Jerry’s advice to the letter. Then, if it works as advertised and you decide to use the engine, switch to whatever you want, Jerry will never know.🛠

The great oil debate has been beat to death on Stovebolt for many years. Do a search for some interesting reading.

Haha, fair enough. SAE 30 it is. I will report back on the result once I fix the water pump and do the clean out procedure Jerry described.

Good thing I haven't run the engine much at all with the 5W in there. Thanks Martin.

James

I was going to say something, but Justhorsenround did summarize eloquently.
(PS ... Martin, don't worry about that 5W-30 oil you had in there. Minutia issue.)

Don't take my word for it- - - - -do a test. Take a metal 1-cup measure and drill a 1/8" hole in the bottom. Then use a stopwatch and time how long it takes cold, then hot (200 degree) 5W-30 oil to drain out. You'll probably be surprised to find that the oil doesn't "thicken up" as it gets hot.

I run 15W-40 in everything I own - - - -lawn mowers, motorcycles, Diesel farm tractors, cars, and trucks. The reason I recommend 30 weight for the flush is that it's going to be diluted with a couple of gallons of Diesel fuel. If you have a few quarts of Valvoline 50 weight racing oil handy, you could use that for the flush job (not for everyday operation).
Jerry

This is really good info. I recently changed from a 10-30 oil to a straight 30weight on my 235 because of a startup rod knock until oil pressure was established. the removal of the multi vis oil proved a huge benefit on this old engine.
Steve

Thanks Steve, that further reinforces the fact my oil has gotta go.

I have been able to source some SAE 30 locally for cheap, but it indicates it is for diesel engines. I am assuming that is the typical modern day use for straight 30, and it would be suitable for my bolt? But you know what they say about assuming...

James

No problem using the Diesel-rated oil- - - -if it's rated for engines with 22:1 compression, handling bearing loading on a 6:1 engine is as piece of cake!
Up there in the great frozen north, you might consider one of the heavier viscosity multi-weights for better flow during cold starts, the above 15W-40 or maybe a 20W-50. My objection to the lightweight stuff is that it's intended for modern engines with microscopic oil clearances, not the gaps you could throw a cat through on old stovebolts. Something has to be there to cushion the parts as they try to hammer each other, and slightly thicker oil is the logical choice.

Here's another experiment to try in the interest of proving my point- - - - -lay a piece of cotton denim on a concrete floor, then fall forward and do a face-plant onto it. Now do the same thing, but substitute a sofa cushion for the denim. Same material- - - -cotton- - - -different thickness! Now do it again- - - -and again- - - - -and again- - - - -66 times a second. That's what rod bearings are doing at 2,000 RPM. Tell me which one you prefer, for running a few thousand miles between shim adjustment of those Babbit rods.
Jerry

Can't fault you for being creative with your analogies, Jerry!

I was thinking the diesel flush process might disturb any crud that might be in the pan. The pan bolts are still painted suggesting the pan has never been dropped at least since it was re-bored. If I were to drop the oil, pull the pan and clean out the crud already in there, do you think I could reuse the old pan gasket if it is in okay shape? Just for now until I decide what I want to do with this 216. I am a little concerned about reintroducing the pan crud into the cylinders if I thin the 30 weight with diesel.

James

The splash-flush method with the solvent will clean the crankcase far better than you'll ever be able to do with a brush. Do you clean your clothes with a brush before putting them in the washing machine? No, the pan gasket won't be re-usable unless it's only been on there a matter of hours or days- - - - -certainly not decades! The crud in the pan will get dislodged, emulsified, and drained with the hot oil after the flushing is done. The engine will end up cleaner that way than it's been in years. It also might spring a few oil leaks, because some of them only hold oil because the oil can't make its way to worn or damaged gaskets through the sludge! Be prepared to replace things like the valve cover gasket, side cover, and possibly the rear oil seal.
Jerry

I too am of Jerry's understanding. But as opposed to 15-40. I generally use 20-50. But only on "high milers". Reason being;
the higher viscosity helps "fill" the larger "gaps", and helps prime the oil pump faster in the morning, when the rig is first
started. Potential downside; it's harder on seals, and gaskets (higher pressure).
That said. It's always been my understanding, and belief that for a new(er) motor. Single weight oil is a better choice.
Multi-weight oil is achieved by adding polymers (plastic molecules (balls)) to the oil. So it's actually more stable, and
durable than multi-weight oils.

Lastly, and along the lines of "washing" the crankcase; I usually dump a half a quart of tranny fluid in the crankcase
about 50 miles before an oil change. Because tranny fluid is such a high detergent oil. It helps thin, and loosen
any gunk that might be forming anywhere. Not good for an old "loose" engine. That "gunk" helps, more than hurts.

--Chris

Which ones of the seals and gaskets get full oil pressure applied to them? The only one I can think of would be the oil pump cover gasket. How does having more oil pressure affect the sealing capability of an oil pan gasket, valve cover gasket, or the front or rear oil seals?
Jerry

Spot on, Jerry!
I'd have to say that has *nothing* to do with the pressure generated by the oil pump. But from
the pressure generated by the crank agitation... and before you say it; yes. that *is* what the
crank ventilation "system -- whichever you have" is for. But on every (older) rig I ever used the
20-50 on, ultimately, and suddenly began to "weep" a little oil. But the pressure gauge indicated
much better pressure, and earlier on. and no puffs of blue smoke at startup, or driving down
the road.

--Chris