s2kyee

Hello!

I posted a while ago about my suspicions of a burnt valve. Finally got around to taking the head off and low and behold.. C3 cracked/burnt valve

Prior owner didn't do required maintenance and here's the result.
The main question.. cylinder head rebuild or just replace cracked valve?

Any shop recommendations? I'm in Northern UT but can ship anywhere. I prefer quality and will probably stick towards OEM. I may turbo eventually just for some early power, but not sold on the idea.
Just as an FYI to anyone providing advice-
Compression test was good on C1,2,4 (very low on C3).
Leak down was within 1-5 PSI / 100 PSI on C2, C4, within 8 PSI on C1. Less than 50% on C3
CEL came on as soon as I bought it, C3 misfire. Cleared code and did preliminary replacement work (plugs, etc). No light since but obvious there was an issue with compression. Finally got time to pull the head and found a C3 cracked valve




Thanks guys =)

Slowcrash_101

Start smart, pull the valve and try a new OEM one. Check for guide play, and pour a little water in the exhaust port, to check that the valve seats properly.

If the guide is worn and the seat is trashed, you would honestly be better off looking for a replacement head in better condition.

It's easier to rebuild the head than the block, but that still doesn't make it easy. The head comes from the factory with a 4 angle valve job. If you press in new seats and don't cut them properly you will likely lose power. The valve guides are a little tricky to get the install height perfect.

s2kyee

Can I replace just the valve? Any tips on pulling it? Manual starts going into freezing and heating and I go

randomwalk101

may be just do a Kswap...these engines are crazy expensive now. You'll get more torque out of the bigger engine and cheaper for parts for the future too.

s2kyee

Seems like everything is crazy expensive now

Hondassport

It is a simple valve job, take it to any reputable machine shop they will know what to do, tell them you do not want more than .005 inch taken off the head to tru it....Pete

Slowcrash_101

The valve is easy. Pop the retainer for the spring and the valve comes out.

Replacing the guide or seat isn't always necessary, usually a worst case scenario. That's why you check with a new valve first.

s2kyee

Thanks =) looks fairly easy. Found a highly reviewed machine shop in the area. Thinking of bringing it to them just to clean it up and test themselves. There's a good amount of carbon buildup. Should I ask them to clean it or will that remove material?

User above posted to take off no more than 0.005" on the mating surface. I was just going to ask them to clean it at best (no lathe/material reduction)

Did a bench test, basically said the same that the leakdown showed. C1 had an ex valve with a very slight dribble (water). C3 spewed water akin to a Chris Farley skit.

Car Analogy

They are going to want to resurface the head. They are going to assure you they do this on all heads, and its never a problem. This engine is especially sensitive to its timing chain geometry, and shaving the head at all is risky. There is a max spec on how much can be shaved, but less is definitely better.

There are some posts from billman on his recommendation for how much can be safely removed. Find those, and tell the shop ahead of time.

If you don't discuss this with them ahead of time, they may just shave it as a matter of routine, even if you didn't ask for it. Then you paid them to ruin your head for you.

s2kyee

Will do =) Looks like 0.004", but I'm going to ask if they can do less (none) and just clean it up with chemicals. Condition looks great, just the valve got burnt up (hopefully). Going to drop it off at the machine shop here and cross my fingers they're mindful of the spec.

Since it will be in short order, any good way to get a torque read on the head bolts?
I see where Billman says the following, but how to tell if it's actually at 22ft-lbs (only have a click-type torque wrench). Do I need a gauge or something?