So... Uh... Is this fixable?





Obviously there's some pretty good gouges in the combustion chamber, and it appears the seat its either pulling away or whoever did the seat (who would even do seats with a chamber this bad?) couldn't get it right.

Thanks,
Mike

 

Not being a machinist, I'd lean towards no. You'd have to port those heads beyond the damaged area in order to assure a proper seat. There doesn't appear to be enough material to do that. But an engine shop would be best to determine that. They would know the limits.

 

I've seen repairs of things like this on aluminum heads, but I suppose it's probably a bit more difficult with cast iron.

 

Look at the head , close to the "11:00" position near exhaust valve's seat .

If that's what It looks like (a crack) the head is now a paperweight .....

 

By eye it looks like a scratch, but it could be deeper than that I suppose. Only one real way to find out - but there's no point and bringing this to a machinist unless there's a chance of repairing all of the pitting and gouges. I can only guess that something must've gotten into the cylinder.

 

is there anything special about this head that you would even think about repairing it? you most likely wouldn't even get it out of your hands before they said nope

 

I have seen MUCH MUCH worse fixed. The dings in the chamber can be smothed down. The seat can be cut out and replaced. hell, you could have a shop machine in 2.02/1.60 if you wanted. The biggest problem with any cast iron head is they crack. Ive heard both, that if there is cracks in the seat, but the head holds pressure, run it. On the other hand, some will say the opposite. Id start with how much you want that head/s. How much $ you have to put into them or new. So IMO, Yes, Its fixable. Is it cost effective to do so?? Depends on what kind of head that is... If its just a run of the mill chev head.... Totally up to you. (looks like vortec/heart shape chamber) My advice is call around and find a machine shop. A good machine shop is hard to find. IMO, one of the most important checks in a head is seat run-out. 0.001 or less. A good machine shop will agree.... Others don't even know what that means. If you want help finding a good shop, pm me. I belong to a group of high quality machinists nation wide. Good luck.

-Dan

 

So, the machinist was completely unimpressed with my concern, haha. He thought I was bringing in something much worse. To be fair, the pictures make it look a lot worse than it really is.

He's going to clean it up and install a new seat after magging it, and then mill it. If he's satisfied, I'm going to run them. I'm having him order the valvetrain components also, and he'll do a valve job on it once he has the valves in hand.

I'm pretty confident in the machinist. He's been at this particular shop since 2010, shortly before I left.

 

Make sure he mills the intake side too.. I cant remember exactly what the max is but I know if you machine so much off the combustion side, you have to machine the intake side as well for proper fitment when assembling the engine. Sounds Like you have a good machinist. OOOHHH $hit... its brainerd guy!! lol.

 

Oops. I missed your comment somehow, Z.

Would I still have that problem considering that these are aftermarket heads?

Additionally he wasn't sure if he'd have to mill them or not, considering the blemishes are all within the combustion ring of the gasket. He's going to check them for flatness after he fixes the valve seat issue.

Not sure when he'll get to them as I told him absolutely no rush on them since I don't have the motor out yet anyways.

Edit: Also, I should mention he's going to flow test them while he's at it, so I'll have numbers for everyone that has questions about the flow on these heads. He's curious and is going to do it for free, so, why the heck not!

 

You should not have to mill the intake side of heads..

At about .040" off the decks you will need to elongate the intake manifold bolt holes, .060" to .080" you must really check the intake match and MAY have to mill intake side of heads. At .100" you will for sure have to mill intake sides.

The damage shown in pics should clean up with less than a .010" cut. In fact I'm guessing .004 to .006"

 

Thanks for the info, Night!

 

Your welcome

 

Sounds like you found a good shop, but I learned the hard way to never tell them you're not in a hurry. I did that and I found myself waiting on him for several months and after I started asking for updates each week and getting none, he finally rushed the job and I ended up with the wrong crank, he went out of business and then I found the block wasn't fully clearanced for the stroker crank, found some extra oil control rings, but because I didn't know they were extras I had to pull a few pistons to make sure. Next time I'm asked if I am in a hurry I'll say "I don't need it tomorrow, but next week would be great."

 

Eesh. That's crappy!

Hopefully my experience will be better, haha. I've worked with him briefly, albeit years ago. He's a good guy so I didn't want him to feel compelled to rush my job just because it was mine, if that makes sense.

 

Nobody mentioned the crack between the ports?

 

We'll know for sure once it's fluxed, but I believe its actually just an illusion due to a small cliff protruding.

 

So, remember how Lurbie said to never tell a machinist "no hurry"?

Yeah...

So, it's been like a year, and I'm finally assembling them. Here's the rub.

Thankfully, we were able to get it cleaned up. I had him install larger seats and stepped up to 2.02 intake and 1.6 exhaust valves. After he installed the new seats, I took them home and spent about 8 hours or so porting them and cleaning up the exhaust runners. Finally got them flowed, and here's the results. The after porting results were performed on a SuperFlow bench using a 4.060 bore (.020 larger than my actual bore).

See attached.

As you can see, I gained everywhere except for .1 lift on the Exhaust, where I lost approximately 4CFM. Everything else shows pretty darn good improvement. Of course, this is assuming that the advertised numbers for these heads aren't inflated to begin with.