hello,

trying to get an idea of what a bad valve guide may look like in its begginning stages... running built gsr head.. replaced the valves and valve seals, NOT the valve guides yet....
stock LS bottom end
shot peened rods

everything was redone on the head, except the valve guides....

30K on build.

leak down was about 8% at 80psi not too bad

issue is smoking on deceleration

12lbs boost at 290, tune is good, a little on the rich side but its there....

 

^^

 

You cant SEE worn guides. You will have to measure the valve to guide clearance. If the intake valves stems are oily then its likely the valve stems.

Is there any oil in the charge pipe or intake manifold?

 

what about the iddle...no smoking??

 

no smoking at idle... i saw it puff once or twice on a startup, very little....could have been water vapor....

no oil in charge pipe....

 

I would guess oil in the charge side, happened to me before. All the cylinders seem to be burning the same. A bad valve or something usually happens on one cylinder at a time or there is at least a difference between the 4. Check the turbo compressor side.

 

no oil on either side of turbo, took head into machine shop today, advised i do need a complete valve job.. he also explained to me the differences in oils here in cali, i guess there has been changes recently to the chemical makeup on certain oils and he has been seeing motors get eating up ... something about SN and SH type oils containing somethiing called resorcinolbis-diphenylphosphate (RDP) is being taken out for environmental purposes... i dunno he went into detail..

anyways, he recommended bronze valve guides... i will be running 91 what do you think on ferrea bronze valve guides compared to OEM for turbo application? some people say they are great and act as a natural lubricant with the bronze against the alloy type valve... some say they last only 30K miles... any experienced opinions?

 

Bronze guides last a very long time, but must be installed properly.

 

I will be having the machine shop install the guides. I am not a fan of heating the head with a torch and banging them out with a hammer.... lol

thank you

 

Larry @ Endyne makes his own guides. Custom to the guide port of the head. Best way to do it! In the case you have to re-do the guides(unlikely), you will be able to do that easily. Most bronze guides are o.s., and require reaming(or boring) to fit.