Won't start! PLEASE HELP!

[Dewayne Waldron]

I've recently built a 93 GS Turbo w/ newly rebuilt head w/ all BC internals, stock cams, bigger turbo, FMIC and piping, Evo 560 injectors, Apex SAFC2, and all the other usual goodies. It's timed perfectly, getting fuel and spark, and the cas is plugged up correctly. It cranks well but dosen't seem to want to start. Anyone have any suggestions? Please! I'm going nuts and dI need my car back ASAP!

 

[96eclipzGsT]

OK, here's what I've discovered. None of the valves are seating properly. That's where my compression is escaping. It was machined and built. I don't understand why this is.

If they are not seating properly they are most likely bent.

 

[Dewayne Waldron]

there's no way. I think it's the machinists error. The valves and all are brand new.

 

[steve]

The valves and all are brand new.

They were new. The second you cranked over the engine they ceased to be new.
If the timing was off that's all it would take.

Have you pulled off the rocker cover and looked at what's going on? You need to get your hands dirty at this point and at least pull the rockers and HLA's out to see if the valves seat.
If they don't then the head has to come off. If they do then look at the HLA's and make sure they are empty and not stuck.

Did you check the seating of the valves in the head before putting it on?

 

[kthackst]

If you bent the old valves the chances are you cracked the valve guides. This happens commonly when you bend valves. With messed up valve guides your new valves might not seat properly.

 

[steve]

This all assumes that whomever rebuild the head changed out any damaged guides and all damaged valves.

You need to pull the rocker cover and start inspecting the valve train.

All guides, valves, springs, retainers, and keepers have been replaced with brain crower. stock lash adjusters. I've never thought of messing with them.

If you bent the old valves the chances are you cracked the valve guides. This happens commonly when you bend valves. With messed up valve guides your new valves might not seat properly.

While BC doesn't make valve guides, the OP claimed they were replaced.

 

[96eclipzGsT]

If you ever want to fix your going to have to take the head off. You could have already pulled it instead of doubting everyone's suggestions on here.

 

[kthackst]

While BC doesn't make valve guides, the OP claimed they were replaced.

Sorry I over looked the guides. Well then the next step would be, if we assume he did get the guides replaced, what about the seats?

Did you get new seats, grind the old ones, at least use valve lapping compound?

 

[Dewayne Waldron]

Yes it was all supposebly done, Everything looked good before the installation of the head. My appoligies about the guides, They were replaced but I was only told what brand they were. I bought this head with everything done to it. It was beautifull when I put it on. I have the proof of what kind of valves, springs and retainers that were used. The timing was perfect and was checked out by several other people. None of the valves are sealing. I have gotten to everything but pulling the head back off, I'm fixed for time with getting it done for working late, and dealing with my kids.

 

[kthackst]

if you say the valves aren't sealing and the timing is correct. My money is on the seats. After you remove the head do this. Place the valves in and shine a light in the port. If you see any light your valve isn't seated correctly.

 

[Dewayne Waldron]

buddy of mine told me once I pull it, ,flip it over and dump water over each valve and check for leaks. Any other suggestions.

 

[Hughes]

Light Trick, works without fail. +1

 

[Dewayne Waldron]

Alright, Valves are not bent, but are not seating correctly. I'm gonna try and lap the valves to and see how well that does, if not, back to the machine shop. I appreciate all the help that all of you have givin'. I'll try to keep you informed as to how well it turns out. should be on the road soon. Thanks again.

 

[steve]

If they put the head together don't work on it, take it to them. Once you start lapping the valves, unless they tell you to, you erase any claim you might have on them.

 

[Dewayne Waldron]

True, thanks for that.

 

[Dewayne Waldron]

Resolved

 

[steve]

Resolved

Fill everybody in. Someone might really need the information in the future.

 

[Dewayne Waldron]

It's rather stupid but the head I bought was equiped width longer valves to accomidate a certain kind of 272 cams. It's about the same as longer lifters or shimming the lifters. The guy I bought the head from failed to ever mention this. So I had to go through the trouble of installing it and finding out the hard way. Now I have to pull the head again and replace all the valves which I already have another set of stock length BC forged valves. I was scewed on the cams, which I did pay for ($300) and never seen. Thanks everyone for your help of narrowing everything down.