Cracked head

[bhut]

Without going into the whole story, I recently inherited a '29 closed cab A pickup. It broke down on the 35 mile trip back to my house, and I hoped that it was a radiator problem, although I feared it might be something worse.
When I went to drain the oil, out came a quart of water, and I knew I was looking at a head gasket issue. Wet spark plugs confirmed that. Closer inspection of the head/block joint showed that it had been leaking and someone had "fixed" it with stop leak. To make matters worse, the engine builder had stacked TWO FelPro copper head gaskets - I could only suspect why and couldn't believe it had ran as well as it had previously. After what is easily the most difficult head removal I have ever done, I did not see an obvious gasket blowout that caused the leak, but I did confirm my hunch about the two head gaskets. The head was warped. It is also visibly cracked through the jackets between cylinders 2 and 3. Looking at the coolant passages in the block is giving me pause as well, although the cylinder bores look ok for wear.
The truck has a later motor, so I'm not worried about keeping it all original. I am in the market for a new head and wondering what aftermarket heads are out there that look stock beyond the Snyder or Brumfield. Would also appreciate any feedback on either of those heads, since they seem to be fairly popular. Looking for a good stud puller as well, if someone has a favorite. Thanks in advance!

[larrys40]

congratulations on inheriting the truck... It probably needs some work to get it whipped into shape... this is just part of it.

First... I would not "assume" that the "engine builder" or "rebuilder" did the double head gaskets. There are plenty of folks doing their own repair work that do these kind of things as well over the years... especially when they are trying to fix things either because they don't have the know how, equipment.. or are trying to do it on the "cheap".

I would agree that two head gaskets are a problem.... so with that premise and the head cracking. If the head has a crack between the oval center hole and the round water jacket hole... I wouldn't worry about it too much. It is common. If the crack is going from the water jacket to the stud hole... it can be fixed... with a valve guide bushing as a fix to the stud hole. Search this site for head repair and crack repair.

I would determine that issue.. maybe post a photo or two here for advice. Put a straight edge on the surface of the head and determine how much it is out of flat overall. Depending on the crack issue.. either after repair if needed or if it is a slight crack as I described between the two water jacket holes I would have the head surfaced at a competent machine shop. Also, I would discourage just changing studs unless they are rusted and/or determined they are really an issue. Just for the sake of changing them is not a good reason to change them. You may end up with more than you bargained for.

As for heads.. I would recommend you use/find a good original head.. unless you want to spend the money for a Snyder 5.9 head. The original head is your most economical.. and even if you get a new H/c head.. it should be surfaced to ensure that it is flat as well.

I surface my own heads and blocks... so I'm use to doing them and have the equipment at my disposal.. but I understand if you don't it is a pain to find a shop to do them. Check with one of the local Model A folks in your area if you don't know of any...
With water in the oil.. I would recommend removing the pan for clean out. It would probably be time well spent anyway as you would be able to check out things on the lower end a little, make sure the pan, dipper tray, oil pump is in good order.

If you remove the pan remove the dipper tray. Drain all oil out, remove pan, drain any remaining oil out. take pan over head with two hands and slam open end downward into grass. The force will take out the dipper tray. Last thing you want to do is pry it out. When pan is clean replace tray, regasket, rails and rear main pan cork, and you're on your way.
I recommend copper coat on both sides of head gasket before placement on block.

Larry Shepard

[CarlG]

Time for a Snyder's 5.5 head!

[tbirdtbird]

any head that is warped is not gonna seal not matter how many gaskets they use. If i work on a customer's motor and there has been any overheating issue I will always have the head milled. $45.00 is cheap insurance.

Almost every head I have seen has the crack you mention between cyls 2-3. IMO it is a thermal stress issue. Post a pic so we can be sure. There was a discussion of this very recently, search it, you just use Permatex #2 around the studs so coolant doesn't weep up under the nuts on the studs. My own 180A has that exact same crack.

If you opt for a brand new head, do not throw that one out, it is serviceable.

[Gunmetal blue2]

I would check the clearance of the block and piston height. they may have put the two gaskets for proper clearance on the head and pistons. Just a thought, my two cents [so the piston don't hit the head.]

[Purdy Swoft]

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Just to add to what Gunmetal blue says, the pistons normally rise about .032 above block deck height. If the block has been decked a few times , it could be the problem .

[Charlie Stephens]

Originally Posted by Purdy Swoft

Just to add to what Gunmetal blue says, the pistons normally rise about .032 above block deck height. If the block has been decked a few times , it could be the problem .

…and if the head had been milled a few times it would further add to the problem.

Charlie Stephens

[bhut]

All,

I verified the head was warped with a straightedge last night before posting this. I hope to hold onto this truck forever, so buying a new casting without 80 years of corrosive wear or previous milling is a long-term investment. It may be worthwhile to seek out a better spare than what I have, since this has 4 cracks between jackets and two head bolts.

I am posting some photos of the head, but after cleaning up the block this morning I honestly think the head is the least of my worries. I've got significant pitting on the deck; combustion area surface and erosion in the valve seats. It also looks like the block is thin in some of the water jacket areas, so I suspect it has been milled a time or two. Those pics will come in another post.


passage erosion by Ironcars, on Flickr

Upper water passage crack by Ironcars, on Flickr

Middle passage crack by Ironcars, on Flickr

[jm29henry]

if you are looking for a reasonable original head you could call berts model a center the have so many original part and his prices are more than fair the also do model a repair so they know what they are talking about plus they will send you a great free parts catalog with a lot of great info. There toll free phone #is 1800- 321- 1931 hope this helps

[Purdy Swoft]

The head in the pictures doesn't look like it has ever been shaved much if any. Its got a lot of cracks and better used heads can usually be found for fifty to seventy five dollars. If it was me, I would go with a Snyders 5.5 or a 6.0 head. You can measure how much the pistons rise above deck height with a feeler gauge. If the pistons rise more than .032 , that will tell about how much the deck has been shaved, if any. The next concern would be whether there are any cracks at the valve seats. While the head is off is a good time to do some valve work if needed. Its always best to replace the head studs and nuts. Removing the old studs is risky. Its not unusual for a couple of studs to wring off, it happened to me on the last two. In the old days I always used the old studs but the risk of wringing one off when tightening is still possible. The deck on the last engine that I replaced the head on was worn because the previous steel clad gasket had been installed, upside down. I used one of Snyders premium silicone coated gaskets with an original head. The Snyders gasket has worked real good, even though the deck of the block was worn and had some pits.

[RonC]

Check the deck height to see if its been shaved. I think the spec is 11.500-11.505 from the bottom of the pan flange to top of deck