Blown head gasket or head?

[Nemo von Klepper]

Blown head gasket or head?

There must be something wrong, there‘s water in the number 2 & 3 cylinders. It’s a pity too because I got the engine running evenly and well. Now I think the plugs are water fouled.

Anyway I’m determined to do as much of the work as I can, but this is my first rodeo so to speak. I have had a head off before only to inspect the cylinder heads on a dead engine. Anyway I can’t remember that it was that difficult and the manual makes it look straight forward. I imagine there’s an even chance the head is cracked. Is there anything I should know before getting into this?

[LarrBeard]

Blown head gasket or head? There must be something wrong, there‘s water in the number 2 & 3 cylinders.

F-134 or L-134 engine?

If you have the L-134, you don't have that big of a job in front of you. Tape the plug wires out of the way, pull the plugs and start undoing head bolts around the perimeter toward the center of the head. Persuade the head to come off and give things a good looking over. I hope you have a blown head gasket, but in the long life of the '48 - it did have a cracked head when Dad drove it as a flathead.

I would defer to gmwillys' opinion here, but if you do have a blown head gasket, it might be worth getting the head checked for flatness or warping before you put it back on. Warping could have been why the gasket failed.

And, as always - a picture or two helps the rest of us know just what to look for when we have the problem.

[Nemo von Klepper]

Yes, it’s an F, and it could be warped. Simplest case I was going to hold a straight edge in it and check with a feeler gauge.

I might not get around to this right away; next month maybe. Is there anything I can do to minimize rust or pitting? I’ve blown most of the water out and drained the cooling system.

[gmwillys]

It would be well worth having the head magnafluxed. You can check the head yourself to get an idea if it is warped with a straight edge. Check the deck of the block as well to ensure it is flat.
The F head is a bit more prone to cracking than the L head. In my opinion, if the water shows up after after running a while, then it would be a cracked head. If the water shows up after sitting overnight, then it would be a head gasket. A cast iron crack will open when heat is applied, while a gasket will deal more after being heated, then cooled back to ambient.
To prevent any rust issues while waiting to get time to year into the head, use WD-40 to fog the cylinder. Then replace the plug.

[Nemo von Klepper]

WD40, that sounds right.

Right now I’m weighing my options. This was a pretty big setback and I’m trying not to let it get me down.
It seems to me the rebuilt head in the KW catalog is a “plug and play”.
There are also NOS heads available that I could rebuild myself.
Obviously if the head checks out, I’ll just put new gaskets on.

Making lemonade out of lemons I’m thinking of making this one as bulletproof as possible. I’ve read someplace that valves or valve seats suffer from the higher combustion temperatures of modern gasoline. I imagine there are remedies one can build into a head, harder valves or seats.

[gmwillys]

The issue with modern gasoline is that the lead acted as a cushion between the valve and seat. The original head can have hardened seats cut in by a machine shop, then stainless valves. Then you don't have to worry, except for running ethenol. Don't. Ethenol will just cause you headaches. There is additives that are supposed to neutralize the effects of the corn alcohol.
One thing I find it important to add on the subject of valves. Remember that on an F head, the intake valves are in the head, but the exhaust are still housed in the block.

[LarrBeard]

WD40, that sounds right.

I imagine there are remedies one can build into a head, harder valves or seats.

Pulling the head on the F-134 is a bit more of a job than an L-134. Don't forget that short head bolt that hides under the throat of the carburetor.
The guy who rebuilt the F-134 for the '48 forgot to put that one back in - and it caused an unbelievable month long headache before we found it!

Exhaust valves are the ones that take the real beating. Keep in mind that when the air-fuel mixture burns in the compressed combustion chamber, the intake valves are closed and the rim of the valve is seated up against the head - giving a good heat sink for the lip of the valve.

But, after the air-fuel mixture has burned, the exhaust valve opens and the very hot exhaust gases flow out past the open valve. The top of the valve is washed in the hot exhaust gases and that makes the exhaust valve much hotter than the intake. Once hot gases erode a bit of the lip of the valve, hot combustion gases erode the cast iron of the seat area in the block unless hardened valve seats have been installed. Normally, hardened seats are installed during overhauls to keep erosion down.

Tetraethyl lead, in addition to enhancing octane rating of gasoline, actually put a thin coat of a lead oxide on the surface of the valves which protected them from exhaust erosion. No lead, no coating, we get erosion. The good news is that our engines are low compression engines and they don't burn up "instantly" like the high compression V-8's did.

Here's hoping for a bad head gasket!

[Nemo von Klepper]

I'll probably pull the head this weekend just to see what I'm up against. If the head is blown, I'll buy a new one this coming month. Any recommendations for sealing the top of the engine to keep out the debris while I'm rebuilding the head? I was thinking of cleaning it up with gasoline and then just duct taping the entire milled surface. A simpler solution would probably be just putting a garbage bag over it with a bungee cord around the block. What would you do?

[LarrBeard]

A simpler solution would probably be just putting a garbage bag over it with a bungee cord around the block. What would you do?

Garbage bag and bungee work for me. A light coat of oil protects everything nicely.

[Nemo von Klepper]

So I got the darn thing off. Some of those head bolts were quite a bear and I was sure I was going to skin my knuckles in the very least.
The last one I was sure I was going to have to go out and buy a breaker bar.. Visual inspection gives me no clues other than to confirm coolant in cylinders 2 & 3.
3994
I cleaned it up as much possible for this stage, getting the gaskets scraped off. I checked with a straight edge and 0.25 mm feeler gauge.
3995
The gauge was consistently the highest point in any place I checked. I do not feel at this point the head is warped. I’m more inclined to think the gasket was faulty.

[gmwillys]

I agree with your assessment. A piece of advice, spend a little extra and purchase a Felpro head gasket. There was a question that popped up last week about the head gaskets that come from Crown. I happened to have a Crown engine gasket kit sitting on the shelf. The head gasket seemed pretty thin to me. I've read that others have had issues with them sealing. Walck's Willys has a copper head gasket for $40.

[LarrBeard]

In a later post gmwillys suggested:'

"...Walck's Willys has a copper head gasket for $40...."

When I rebuilt the '48 we had the head off several times chasing aw-pooh's and just plain dumb mistakes that people made. Good shop practice says not to try to reuse a head gasket. If it has been squeezed down - get a new one. Yeah - it costs $$$, but taking it back apart isn't cheap either.

I'm not sure, no one can really swear to what happened, but the last head gasket might have gotten reused. After we got the truck running well, it developed a tendency to get a water ooze down the driver's side of the block between the head and the block. It did that as it cooled down - or if it did it while it was running that water evaporated so quickly I never caught it.

There was a very slight indication that there might be a small internal leak, there was a miss on start-up for a minute or so, but not bad. A mechanic friend suggested a radiator additive that sealed head gasket leaks, so I dumped a can of that sludge in the engine. Of course the stuff said " ... wont harm engines or cooling systems ..." (kind of like "I'm from the guvmint and I'm here to 'hep yew...).

After a bit the leak down the side of the block sealed off. The miss went away. I left the stuff in the cooling system. But, one day in January 2108 I took the truck out for a winter run, the thermostat stuck and I blew about a gallon of filthy brown river water sludgy coolant all over the truck. The stuff hit the fan, literally, and blew back all the way to the door panels! I'm still cleaning up that mess from places I missed last spring.

You ask; "OK Senior Chief. What's the point of all of this story?"

A. At $40.00 plus shipping, the copper gasket really isn't all that expensive. Although some folks differ, a gasket sealer is not a bad idea on old blocks. (GmWillys, your thoughts???)

B. Fixing it right is cheaper in the long run, and:

C. If you decide to cheat with a sealer, get it out as soon as possible. It will seal the thermostat stuck!

[gmwillys]

In my opinion, if the fix comes in a bottle, it's a bandaid. I have seen where block sealers have worked, but I've seen newspaper being used to fill quarter panel rust holes, before the Bondo was smeared in. I have used Silver soder flakes to "fix" a leaking power steering gear box, one night at the races. The input shaft was pouring oil, and we were up against the clock. It worked rather well, after the pump quit growling while eating the flakes. Didn't leak another drop while we ran it.

In my opinion, I would buy the copper gasket. It will seal better than any paper material will. On a true copper gasket, they can be reused, if care is taken in removing the head. I wouldn't recommend it personally reusing one, but it can be done.

[LarrBeard]

On the '72 Pinto I stuffed newspaper in the body cavities to hold the window screen while I smeared bondo over it. It kept out the water until I gave it to the kid across the street. Desperate times dictate desperate measures.

[gmwillys]

Maaco and Earl Scheib were notorious for adding news print to their body work.

[Nemo von Klepper]

Thanks for the advice. I think the head might be ok, but there might have been a crack in the block, running from a coolant jacket between the No. 2 & 3 exhaust valves. 40224023.

I'm not sure if this is a deal breaker for this engine.
If this engine is toast, I'm not sure what my next best option is. I'm tempted to build my own engine, but I don't know where to find an F-134 block. I'm tempted to build an L-134 since I can find a new block. I'm not sure how many of the parts would transfer.

[gmwillys]

That is a tough decision. Odds are, the crack is just the tip of the ice berg, as for how deep it goes. Welding what you can see, will do little to what you can't see. In my humble opinion, I would get a cheap head gasket, put it all back together, then purchase a good quality block sealer. This will prolong the engine's life until either the new replacement F head engines become available, (sometime in the near future). This will keep you enjoying your ride for the time being. A tip though, do not use your good radiator while performing the sealing process. Rig up a bucket or a barrel to circulate water through the block. Use the container as a heat transfer, so the engine doesn't get too hot. You don't want to clog your radiator with the material from the sealer. Do some due diligence on what product to use. I just picked the first one to come up. Research is the key.

https://gobdp.com/blog/repairing-cracked-engine-block/

[Sebastian21]

You best bet is to find out if the block is cracked. My engine was a 1962 F134. Pull the engine out. This not too hard. A engine lift from harbor freight works just fine. You remove the engine from the top out and in my case through the cab. I have a FC model. Then get it boiled out and x rayed. That will tell you where the crack is. Mine was cracked but I could not find a new block. Then you can determine to switch engines but that leads to many new problems. How to adapt to the running gear. If you have a lot of hot rod shops you may get some help but you will still need a good mechanics to solve a lot of problems. I sent my block off to be welded. The company welded it, tested it and returned it in a week. It has been running several years with no problems. Modern welding is much better then 40 years ago. The company I used said my block was the smallest they ever did. They usually do large industrial engines. Finding a used engine my not solve the problem because you do not know what shape it in in. There is no point in installing a engine only to find it to is defective. You are dealing with 60 year old motors that received much abuse. So my advice is to repair what you have or install a new rebuild motor. Either way it is going to cost several thousand dollars. I did this to a FC so your engine removal will be some what easier.

[LarrBeard]

Look down inside the threaded bolt holes and the coolant passage and see if the crack extends down into them. You might use a dental pick or some similar sharp pointy tool to see if you can pick up the crack.

Oh, by the way, there was a post yesterday of a newcomer who had an empty F-134 block laying loose in the back of his CJ-2A

[LarrBeard]

http://willysjeepforum.kaiserwillys.com/showthread.php?2067-New-to-forum-Help-please

[Nemo von Klepper]

Thanks, I'll check it out.

I was thinking about pushing block sealer into this crack with a grease gun through the head bolt tap, then I would chase a tap through the head tap before reassembly. My thought is that it would give it a head start and then when I had the head reinstalled I could run block sealer again through the cooling system. I'm wondering if it might not be better to remove the thermostat or plan to replace it immediately.

Thoughts?

[Nemo von Klepper]

Ok,

So I'm going to try to see if I can use block sealer to keep it going for a while, until I figure out what to do next.

I did a little research into part numbers this morning as a feasibility study of building and installing an L-134 as a backup plan. Probably way simpler than installing a short block V6, or the only other engine I have lying around, a Saab T16 (Turbo 16v) lol --not as far fetched as it sounds. I've seen Mercedes diesel engines installed in Willys SWs and somewhere in Serbia there's a BMW M3 racing with a Saab T16 It's just way more work and money than I want to spend.

From what I can make out, my oil pan, crankshaft, water pump, distributer, rods, pistons, timing gears and backplate are all the same parts as a CJ3A. It looks like the fly wheel and cam shaft are slightly different. I can probably use my flywheel, but I'll have to take a closer look at the cam shaft. I guess if I invest into CJ3A parts, it won't be too bad; I like the lower hood of the 3A and maybe I might even eventually find a 3A body in better condition than my 3B.

[LarrBeard]

When I was in college I spent most of a summer working on what was probably an ex-Civil Defense CJ-2, or maybe even an MB/GPW. It broke my heart when I found the crack in the block in the passage where the distributor shaft goes down to the oil pump drive gear.

But - I learned a lot about Jeep things playing with that project.

I'd go for the block sealer. Put in a 185-degree thermostat to get as hot as you can. Run it, then drain about half the water out before it cools to keep any leaks from getting into the combustion chamber. Let it cool, refill it. Repeat several times. That should get the sealer into the crack. The issue is that it is in a high pressure area, and around that exhaust valve gets hot, lots of expansion pressure pressure there.

One school of thought says to keep sealer in there to keep stopping up the crack. The other says get it out because it tends to seal things (like thermostats) that don't want to be sealed.

[Nemo von Klepper]

Thanks.
I was thinking of changing the thermostat after the job just to remove that potential problem from the equation. What would you think of running it without a thermostat for the job, keeping an eye on the temp gauge?

This jeep has already proven to be an education. I was a need based Saab mechanic before this. I preferred to farm out the work whenever I could. These jeeps are so simple in comparison that I find myself getting into stuff that I wouldn't have on my Saabs. Now I find myself doing even more challenging stuff on the Saabs.

Speaking of engine swaps, I once lifted an entire engine out of my '64 Saab 96 with my bare hands.

[gmwillys]

I wouldn't run without a thermostat, or at least the restriction of the body of the thermostat. On my old derby cars, I would take the thermostat out, cut the center out, then reinstall the outter portion. This slows down the water for more even heat transfer.

I once knew a guy who had a foreign auto repair shop. He dealt with mostly high end rides ranging from Mercs to Jags. He bought a lot of vehicles that the owners couldn't afford to fix. He always had a couple of Saabs in the inventory, because Saab was the sound the owners made when they received his bill. As a side note, he liked dealing with strippers and dope dealers, because both pay their bills in cash.

[Nemo von Klepper]

Yeah, I thought about that after I posted. If the object is to run hot, I need to restrict water flow.

Re: Saab, yeah, I have good luck with them, but then I've been driving them since my first car at 16. Because of the longevity of my Saabs (knock on wood) some of my friends get the impression they're more resilient than other cars. Maybe, but I don't lone them and when a friend asks my opinion about a Saab when they see one for sale I tell them "if you want one you need to be very mechanically inclined, or wealthy; preferably both". That said, the guy that put a Saab T16 in his BMW M3 track car did so because the Saab T16 is a more resilient engine with a higher power to weight ratio, etc. It was an interesting project, but I think 240 BHP would be badly served by the Dina 18 transmission in the case of my jeep. My object here is to keep it as original as possible too.