Cracked head

Anyone have experience with a cracked head?
I had one manifold bolt that was busted off on the rear drivers side.
Since I have it out, I drilled and extracted the bolt. I then noticed there was a crack at the back of the bolt hole and it travels out to the back of the head then up. Maybe 2 inches total.
Not sure if happened while I was extracting the bolt or if it was there the whole time.
Being that it's on the outside of the head, if I drill the end of the crack to relieve the pressure, preheat and weld the crack, think it will hold?

pull the valve cover see if the crack is right thru,..

It's not. Valve cover is off. It goes from the rear of back manifold bolt hole to the back of the head, turns up, then turns back towards the front

71novaguy wrote:

Not sure if happened while I was extracting the bolt or if it was there the whole time.
Being that it's on the outside of the head, if I drill the end of the crack to relieve the pressure, preheat and weld the crack, think it will hold?

I've heard of it being done. However, IIRC, the entire head must be stripped, slowly heated over several hours, welded, then slowly cooled in an oven. Once completed, it may be necessary to resurface the head due to warpage, however the heating/cooling process should remove any internal stresses in the cast iron.

It might be cheaper and easier to buy a new head.

Well if that's the case, I might as well by the trick flow top end kit

Take it to a competent engine rebuilder for a professional opinion and cost estimates. Then look at the price of new heads

Where are you? There is probably someone local that will sell you a head or pair cheap.

if the crack is not right thru,..
whats the worry,.?

if the vital fluids aren't leaking out,..

drive it,..

I haven't seen it (a picture is worth a thousand words) but if the head is not currently off the motor, and the crack will not compromise the head bolt's grip, and it is not leaking fluids/compression, I'm inclined to agree with Nick. Drive it, see what happens and fix/replace if necessary. Of course, if you plan to take it on a cross-country trip in the near future, your perspective may differ!

What engine is it? you don't have your car listed in your signature.

He said it was a 96 LT1 in his lifter thread.

I think its a gm b body wagon with a small block chevy,...

I did not read his lifter thread.

A pair of aluminum Corvette heads would work good.

It is not cracked through, but I worry that once I install the exhaust manifold bolt, it will add more pressure and continue the crack. That or the threads will also crack through and that bolt will lose its grip. I wish I had looked more before i extracted the bolt to see if it's pre-existing.

I don't think that area is under any extreme stress, but last thing I want to do is run it, after a could of heat cycles, it really expands. I talked to a welder at work. He said welding it is easy, but it controlling how fast it cools that determines if it's going to crack more.

So, i can get a reman head for 300. I'd probably do both just to even things out. Or, I did find a set of edelbrock aluminum heads for 1000...

Personally, I'd go for the different head and not take the chance. I'd rather do the work once.

That's where I'm at. Couldn't sell the wife on the trick flow set up but she's good with the edelbrock heads

trick flow and edelbrock aren't all that good.  You can get a set of LE1 aluminium heads from [You must be registered and logged in to see this link.] that will perform well at a reasonable price.

Don't spend 300$ on a stock head.

If your going to buy performance heads...Give Lloyd Elliot a call. Great products, amazing customer service and he's willing to take the time to discuss your build and answer questions/make recommendation.

Asking if anyone has experience with cracked heads,. has gotten u a lot of options ,. some experienced. some not,.

Do what makes you comfortable,.
you're going to anyway,.

The heat cycle you mentioned is not much in relation to what the head is capable of sustaining,.

I would get a mirror and look very closely to see if its a recent crack or has been there for a long time,.

I,m not sure where you are located, but i have numerous sets of low mile cast heads,..

I looked at le1, but by the time I finished with shipping, it didn't seem worth it.
Re-reading the eldlebrock heads, it was 1000 each, yikes.
I am south of Atlanta,ga. I found of set of stock heads close by for 200, but they were rebuilt and had some crackes welded at the bolt holes and replaced a cracked exhaust seat.
So, I finally think I settled on a set of new factory heads. I found a pair, fully assembled, for 300.

Done did it. Picked up new heads for 300. Only question is I currently have castings 12554290. I picked up 10125320 castings. Can't find any specs on these. They appear the same. He believes these castings have thicker casting at the head bolt holes?