340 X heads cracks between spark plug hole and intake seat

[PRH]

found 2 cracks on one head and 3 on the other

Two seats for 5 cracks?

 

[fishmens67]

Run-em

I always respect your opinion, but would you run them without at least pressure testing them?

 

[Newbomb Turk]

Two seats for 5 cracks?

lol I never said I was good at math! Give cracks is 5 seats so yeah, just do them all.

 

[junkyardhero]

If the guides are good why change them? That makes way more work.

At minimum he needs two seats IIRC. Since I don’t like cheese dicking out because when you do it comes back and bites me in the ***, I’d do all the seats under the intakes.

The OP doesn’t need to do it but I would which is why I said it that way.

His shop is already sketchy on it.

i was playing devil's advocate. because if the heads look like that, what are the chances the guides are minty fresh?

me, i subscribe to: in for a penny, in for a pound. they're off, and the guides are the least bit sussy? thems is gettin' got too because i ain't looking to come back around fiddle **** with that when it starts gettin' slappy and pulling oil-- because the customer isn't gonna remember cheaping out on it a year on down the road.

i've got betting down at the dog track and dancing ladies to attend to, that leaves little on the plate to be r&r'ing some mess that coulda been taken care of the first time around.

 

[junkyardhero]

"Old ***" I guess is somehow older and crappier than just "old". lol

there's a definitive ranking around here somewhere, it's on a laminated sheet. maybe it fell behind the tool box? but yeah, that's the gist of it.

 

[HSDemon]

I just talked to the machinist and he is going to pressure test them, if they pass he will install all new seats in all the intakes. The heads have brand new bronze guides so that should all be good, for those that are asking. The only reason I am going through the expense is that these are some really nice old school ported and polished heads, the work that was done on them looks great, a lot of time and energy was spent by someone who knew what they were doing on these heads.

 

[PRH]

You do realize some more porting will be required to blend the new seats into the bowls……right?
Well, that’s if you don’t wanna lose flow.

 

[HSDemon]

You do realize some more porting will be required to blend the new seats into the bowls……right?
Well, that’s if you don’t wanna lose flow.

Yes, I told the machinist that he would need to do this, I am not anxious to see the bill...

 

[Dartswinger70]

Yup I'd run 'em if they aren't leaking antifreeze into the chamber...i got rid of a 340 block years ago because of a visual crack like that I was a dumb kid and wondered if i could have kept it...some other yahoo was saying "its junk" and I believed it...

 

[missing linc]

Buy some of them newfangled aluminium cylinder heads.

 

[HSDemon]

Buy some of them newfangled aluminium cylinder heads.

You know what, knowing what I now know that would have been the best road to take, but I wanted a stock looking engine compartment, where the only deviation from stock would be a set of headers. I wanted to just port the stock cast iron intake and use the stock Thermoquad with the choke and everything else working. Stock valve covers, air filter etc... Just a good flowing set of cast iron heads, a nice hydraulic roller somewhere in the 230 degree at .050, a good set of roller rockers, and the only thing that you could see from the outside that was not stock was a set of TTi or Doug's headers. Hopefully a combo that with 3.55 gears and the 4 speed could run in the high 12's... If I were to do this again I would not even think of doing cast iron heads and go straight to a set of trick flows, but the aluminum heads just damage the illusion of the stock looking engine compartment, and look too modern for the look I was going for.

 

[autoxcuda]

You know what, knowing what I now know that would have been the best road to take, but I wanted a stock looking engine compartment, where the only deviation from stock would be a set of headers. I wanted to just port the stock cast iron intake and use the stock Thermoquad with the choke and everything else working. Stock valve covers, air filter etc... Just a good flowing set of cast iron heads, a nice hydraulic roller somewhere in the 230 degree at .050, a good set of roller rockers, and the only thing that you could see from the outside that was not stock was a set of TTi or Doug's headers. Hopefully a combo that with 3.55 gears and the 4 speed could run in the high 12's... If I were to do this again I would not even think of doing cast iron heads and go straight to a set of trick flows, but the aluminum heads just damage the illusion of the stock looking engine compartment, and look too modern for the look I was going for.

It's a bummer companies keep coming out with small block mopar heads but no one has one with stock looking ends like the 440 source heads.

And some of those new heads perform very close to their competitors. So why not a unique feature.?

 

[HSDemon]

It's a bummer companies keep coming out with small block mopar heads but no one has one with stock looking ends like the 440 source heads.

And some of those new heads perform very close to their competitors. So why not a unique feature.?

Would be nice.

 

[PRH]

If I were to do this again I would not even think of doing cast iron heads and go straight to a set of trick flows

That is the easy button.

 

[sdavis21918]

I have a pair of 340X heads that I planned on using on my 72 Duster 340. They are fully ported and polished, they have the valve spring seats worked over for vitton seals and dual valve springs, they have bronze guides, and they basically have a ton of work on them. I took them to a local machine shop to get them checked and resurfaced and they found 2 cracks on one head and 3 on the other. The cracks are in exactly the same place, between the spark plug hole and the intake valve seat. I am not sure what to do and neither does my machinist. I attached some photos in the hope that someone can tell me what to do. The machinist suggested opening up the spark plug holes and putting inserts in them and new steel valve seats, but he is not sure of where the water ports are on these heads or how much of an issue this is on these heads. He said that certain cracks on certain heads are quite common and do not affect anything, and other cracks on the same head might mean a direct trip to the trash can. I am sure that there have to be some old school cast iron cylinder head gurus here that will now what to do and if these heads can be saved or if they are destined for the scrap yard. I live in East Texas, and someone may know of a place in the area that maybe specializes in this type of work, or on Mopars.

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Disassemble first, pressure test, find out if coolant is leaking from it. Do standard tapered pin crack repair on crack through seat and spark plug hole. Pressure test repair. Install intake seats, repair spark plug holes with solid insert. NOT Heli-Coil in this situation. Do valve job, install heads and go.

 

[mopar head]

but the aluminum heads just damage the illusion of the stock looking engine compartment

Paint them, at a glance they look stock.

 

[mgoblue9798]

As others have said, pressure test and run em. Looks like the cracks go straight from the plug boss to the valve seat.

 

[Jim Lusk]

I have had cracked X-heads like that. One set I traded to a machinist buddy of mine and he fixed them. The other set I sold on here (yes, the buyer knew they were cracked). I currently have two sets with no cracks. Oh, and about old machinists, my buddy that fixed my old set was in his 20s at the time, maybe. He's 46 now...

 

[HSDemon]

Disassemble first, pressure test, find out if coolant is leaking from it. Do standard tapered pin crack repair on crack through seat and spark plug hole. Pressure test repair. Install intake seats, repair spark plug holes with solid insert. NOT Heli-Coil in this situation. Do valve job, install heads and go.

Do you think that they need a solid insert in the spark plug holes? Machinist recommended that but I was not sure if that was necessary.

 

[sdavis21918]

Do you think that they need a solid insert in the spark plug holes? Machinist recommended that but I was not sure if that was necessary.

I am an ASE master engine machinist, Gas and Diesel Engines. Started in 1989 (yes I have a grey beard and hair). The solid insert will seal better, and not allow crack to spread.

 

[HSDemon]

I am an ASE master engine machinist, Gas and Diesel Engines. Started in 1989 (yes I have a grey beard and hair). The solid insert will seal better, and not allow crack to spread.

Thanks, then I will go ahead and tell the machinist to do this.

 

[Hellrats]

I have a set of W2 heads that have that same crank in every spark plug hole. Been like that for many years and have never had any problem with them.