I can't seem to find much of anything on the new board here so lets run through this again. EA-82 cylinder heads are know for having cracks between the intake and exhaust valves. What is acceptable?

 

Cracks only on the outer surface above the valve seats?

Cracks below the valve seats, and if so how far? (How far before the valve guide?)

 

I've got three sets of heads in my garage that all have what look like some kind of crack below the valve seats. One set came off of a good and running motor.

 

Keith

The crack between the valves are okay. here's a copy of the FSB that covers it.

 

http://home.comcast.net/~c.moe/heads.pdf

 

The other issue is the crack where the exhaust runners meet, on 1st and 2nd generation EA82T heads.

Originally posted by GLCraigGT

The crack between the valves are okay. here's a copy of the FSB that covers it.

 

http://home.comcast.net/~c.moe/heads.pdf

 

The other issue is the crack where the exhaust runners meet, on 1st and 2nd generation EA82T heads.

 

Thanks for the link. Now the question is what is common and acceptable for cracks below the seat if anything?

 

Thanks,

Keith

What about cracks on MPFI heads, big enough

to let the valve seat come out of the head? haven't tore these done yet, so no clue as to depth of crack. But it's wide at the CC area.

i had cracks in my 87 ea82 t heads and was wondering if they were 3rd gen or 2nd. What year does 3rd gen start and do they swap into 2nd gen.

Ive seen gen 3 heads cracked like that. Infact, the new motor i have for the RX, 145K miles on it, its cracked like that. Gen2 heads. I have gen 2 heads on the GL-10...they are not cracked.

On the heads, front side of the exhaust port is cast into the metal is the lettering "EA82" find it - it WILL be there:

 

Gen one = EA82 only

gen two = EA82 "UNDERLINED"

gen 3 = EA82 IN A BOX

 

and thats the way to check.

 

if you look at the pdf those are the only "cracks" allowed... and from what I understand their fine... how ever the cracks elsewhere aren't allowed.. from what I've head/seen.

 

I'm no expert by ANY stretch of the imagination but, i have learned a thing or two from folks like Morgan, Skipper, Dr. RX and PAganQWA sooo yeah... among the many.....

Well, what makes this all very intersting is that I've got three sets of heads (second gen) that all have small crack looking things on them below the valve seats. One set just came off of a motor that I was driving and had no problems. Motor wasn't using oil or antifreeze and it wasn't down on power. This makes me think something funny is going on here. I'll put up some pics tonight that show the "cracks"

 

Keith

I've never seen a gen1 or 2 EA81 head that wasn't cracked. They will work fine as long as you don't massively over heat them. I have a motor here that the valve seats fell out of. But the car had been stuck in the mud (up to the grill!) while wheeling and I figure they thrashed it trying to get unstuck and over heated it.

 

The great thing is if you go to a upullit you can get heads already pulled because people pull them, find a crack and toss them back!

I have a set of Gen 3 heads that I'm in negotiations to sell to someone here.. they both have only one set of valves with a small crack between the valves. My buyer is understandably concerned about this as I'm selling the heads as-is... how would any of you feel about using heads with cracks as i've described? and this type of cracking can be repaired, right?

I would use them.. hell if I had the scratch, I would have bought them from you for my new engine... yesm they can be repaired, but they will just crack again.. as long as they are just the hairline cracks between the valves, they are OK

how big of a hair line?

 

The gen 2 heads I jsut pulled of a known good turbo engine with 145k miles has those cracks.

My EA82 was overheated by loosing all coolant. After that episode, I checked compression and the driver's side went from 150psi to 75. The passenger's side was a bit better at 115psi.

 

Should these heads be replaced? Or head gaskets? Or should I just ignore it?

 

I don't see any coolant consumption or loss of power. All seems as normal. But that 75psi kind of worries me. I think I pulled it when it was cold, could it be compression is different when hot? Please, someone tell me definitively. I want to take this one to at least 200,000 on the engine and I have 100K to go.

Viceversa: did you try squirting oil in the cylinder and doing another compression test? That will indicate whether it is rings or either valves or head gasket.

 

If it's only got 75 psi on one side and 115 on the other, I would be AMAZED if you have not had a decrease in power. My #1 cylinder has 75 in it, with the other three at 150, and I'm going to rebuild the engine because the loss of power and fuel economy has been dramatic.

I have a selection of cracked carb/spfi heads that are cracked in various ways... if I have these (mig/tig) welded will they last???

I finally got my heads mostly cleaned up yesterday. Each head has one combustion chamber with the "okay" crack in it. There are several questions that come to mind here. What would cause this and why only in one cylinder per side? Can this possibly cause problems down the road, especially since this engine is going to be modified and see some hard use? What can I do to prevent any further cracking?

 

Thanks

take a small punch and tap the crack untill it is closed. it is still there but less likely to cause problems.

Wow I am really glad I saw this thread. Just pulled the heads on my Ea82t tonight and saw the cracks. I was already looking on ebay for some remanufactured heads. I am wondering though the cracks can be seen inside the intake and exhaust manifolds just hairlines though. Is this still ok? I will get some pictures tomorow to try and show what is going on.

A pressure test from a machine shop will determine if they are leaking or not. If they don't leak, then valve seats coming loose should be the only possible failure point. I guess these can be staked in if it makes you feel better.

the RX we put the top end of onto a carb block, the motor ran fine but developed a rod knock.

 

we pulled the heads, they both had the crack. the cracks were of the normal nature, and with that, the cracks go all the way down to the valve GUIDES, still, normal for these cracks.

the crack may be splayed a little, enought to catch a finger nail on. but those are not too bad. whats bad is the valve seat falling out, so the punch to flatten the cracks sounds like good preventastive measure on an otherwise good head

 

personally, the only questionable head that i used and had a failure on was one with a crack in the EXHAUST PORT, between the webbing, where there are water passages.

 

as far as between the valves, its all metal, and no passages. the heads on the rx were both a gen 1 and a gen 2, but were both fine, and run good now with new head gaskets

 

to answer the compression question, i would say its the head gasket itself.

 

here are some pics of the RX, with the head and engine build. we ported these heads also, and are running them on a 8.5 compression carb block, with "shaved" pistons, before and after.

http://www.warpthree.com/milesfox/87rx/rxbuild/rxbuild001.html

Allright I think the heads will be fine. Sorry for calling it the exhause and intake manifolds my mistake.

Originally posted by Falenseraf

Wow I am really glad I saw this thread. Just pulled the heads on my Ea82t tonight and saw the cracks. I was already looking on ebay for some remanufactured heads. I am wondering though the cracks can be seen inside the intake and exhaust manifolds just hairlines though. Is this still ok? I will get some pictures tomorow to try and show what is going on.

 

what you are seeing is the casting inside the exhaust and intake ports, looks kinda like fine cracks, but its in the casting.

 

the "normal cracks" are between the valves, and if you take a valve out, it may go to the valve guides, no problem

 

the cracks to WORRY about are the ones in the exhaust port WEBBING

When you start mixing oil and coolant and coolant starts squrting from random places on the head the cracks are too big

 

Thats how I found out atleast! lol

If it's only got 75 psi on one side and 115 on the other, I would be AMAZED if you have not had a decrease in power. My #1 cylinder has 75 in it, with the other three at 150, and I'm going to rebuild the engine because the loss of power and fuel economy has been dramatic.

 

 

 

I pulled compression cold, this may be a factor. When it gets hot, it may change.

I see no visible differences in anything.

 

One other explanation is that my compression tool broke. In fact, shortly after that, it stopped showing any readings whatsoever, just a consant 0. It looks normal on the outside, so I don't know what the matter is.