Plenty of donors at the Pick & Pull type yards. Don't forget all of the Dodge mini-vans that have the 3.0l.

You might be able to find some that could be used as is. Spend the money on replaceing the guides, lifters.
<img src="/forums/images/graemlins/cheers.gif" alt="" />

Nothing warms the heart like a ground swell movement of kindess and support gents! Your thoughtfullness is overwhelming. I am searching for solutions and will keep everyone updated on whats happening. For now I will not be passing the offering plate though <img src="/forums/images/graemlins/smile.gif" alt="" />

PM

I guess I would trust the machinist and his experience with these engines, but .002" doesn't seem to be a game ender to me.

The FSM spec for standard bore oil clearance is .002-.0035", so while the .002" looks like it would cause a spot with no lubrication, but since the engine has already been running in that condition, the truth is in what the bores look like. Do you see discoloration from heat? If not, they'll probably run ok unless there is a similar warp in the head and you mill that away. The way I said that is probably confusing.

BUT - to be safe and in agreement with the machinist is wise - particularly if his overall warranty is riding on the choice. I'd look for a set of heads from a DIY junkyard. Buy a warranty on the heads so you can take them back for another set if the machinist doesn't like 'em. As mentioned, the Caravan/Town & Country/Voyager heads will work - as will Diamante SOHC heads. You'll need to swap in your cams.

Frank

The heads have a .003" warp to them; the cam journals are off by .002".

Are the bends going in different directions? If not hot press the heads to get the bearing journals back in line.

Its also just about impossible to say what the heads were like before the overheat, the heads donÆt always warp just one way. When really hot and clamped down by the block all kinds of things can happen. Part of this is depends on how the cam surface is tied to the deck and the other part is what residual stresses were in the casting.

While Frank has a point that .002" is not a huge amount to be out I would not set an engine up that way and there is no way to know how the bearing was running before the overheat. Part of this is that the heads were clamped down to the block so the running alignment would have been different.

If possible I would get a second opinion from another shop.

The last shop I used told me my 2.6 head was junk. I took it back and did the straightening work myself. When I brought it back to get a skim coat taken off the deck and the seats cut it was funny to have the machinist asking me all kinds of questions about how I did it.

This is a common method for shops that specialize in aluminum heads.

Kevin

That's what I was getting at on a half-asleep morning. If the heads and cam bores are warped in the same direction, sufficient clamping pressure may straighten the heads enough to come back into reasonable alignment.

One thing to look for is possible deck thread crud that may have given incorrect torque readings. Another is the possibility that the rebuilder used the old torque spec of 72 lb-ft instead of 80 lb-ft. I know that doesn't change the fact that they're now warped no matter what the reason, but if someone is trying to get a running fix at a minimal cost, it might be worth the effort to install an old head gasket (after cleaning the deck threads and measuring clamping range), torque to spec and recheck the cam bores. If they come back a little closer, it should be ok.

Another way to get a little more clamping pressure is to use head studs at 100 lb-ft, but it does add to the cost.

I reinstalled the original head on my MM with about .005" of bow and it seems to have sealed fine with 80 lb-ft on a Felpro gasket. I don't know how it would have fared over time, because I replaced it with the Galant head, which I had machined.

It's always better to get the head right before it's installed, but sometimes "right" just costs too much - but then sometimes taking short cuts is more expensive in the end. Decisions, decisions.

Frank

I have sucessfully straightened aluminum heads myself. I talked my old machinist into trying it on a 2.6 head. I got him to clamp it to a steel plate, drilled for the inner head bolt holes, and shimmed the outer ends (the center of the head was bowed up) at about 140% of the warpage in the middle. IIRC, it was out about .010 at the center, and we used .014" of shims at each end, and torqued the center bolts to 80ftlbs at the center holes, and 50ftlbs at the next outer pairs. We put the whole assembly in his decoking oven and heated it to about 550*F for 12 hours. It came out with only a .001 warp, which we cut off. Cam bore came out under .001 of offness, which we align honed out. This head is still on my turbo 2.6 and I got at least 50k out of it before the stock piston broke under 21psi of boost (I got a little carried away with a boost increase using the grainger valve and had eliminated the 2bar fuel cut).

I may have typed the ammount it was out incorectly. He said that the cam bores are "twenty thousandths" out. You can see where the cam was stressing against the head as its marred a bit. I think I found rebuilt heads for $220 per shipped on fleabay:

Head link

At twenty thousandths (.020"), forget it - they're toast. Just get some good used heads and put the correct cams in them.

Frank

web page

Believe it or not .020" is a typical amount to straighten a head.

I'm confused though, the deck was off by .003" but the cam bores were off by .020". Seems to me that if that was caused by the previous owner the cam bores would be wiped out.

Kevin

Oh, I believe it - I just haven't tried it and probably won't.... for all of the reasons listed in the article.... some I hadn't even considered.

We can still find 3.0L heads in good condition for less than all that would cost - as you pointed out earlier. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank