bronze guides or liners?

[NC87GN]

Have a set of mild ported 8445 heads that have about .004"-.005" guide play. The outside of the guide have not been cut just smoothed out to remove sharp corners. Do I go with bronze liners or bronze guides? Are there any type af name brand that I should stick with for durability/longevity? TIA..

Mike Banas
87 GN

 

[SloGN]

OEM

hey NC87GN


If you will stick with the oem heads and guides you will not have to wrry about it


KISS

 

[NC87GN]

I want to stay in the low 7 second club . Running 30# of boost with stock heads to achieve the same ET's is not my cup of tea.

In all seriousness, I wanted to hear from those running liners, as that is the most cost effective and quickest way for me to go today. More time, $$$ and work is involved in putting the bronze guides in like the champion irons. However I like to hear from the experts... Thanks in advance....

Mike Banas
87GN

 

[GNVAIR]

I run bronze liners ONLY on the guides that are out of spec on both my own car as well as my fathers. I have a few other cars running around with this set up as well with many many miles with no issues. Some people say that replacing the whole guide is the way to go, but $$ and expense involved is not worth it IMHO as the liners work extremely well. I agree with the KISS method.

 

[getchasum]

Mike, don't know if you have priced the work yet, but Ed Wedge of Performance Engines installed my guides. Installed bronze guides & hone to fit $145, plus the price of the guides.

 

[NC87GN]

Appreciate the quote getchasum. I talked with the machine shop that did my engine honing and boring and they said that they would use bronze guides 7 days a week and twice on sunday. The last time they used liners was 15 years ago and its old school. Not saying liners don't work but they would prefer the bronze guides. They quoted me about 250 bucks to clean up the existing angle cuts on my valves, insert bronze guides and clean up the rough edges. I thought that was reasonable..?

Mike Banas
87GN

 

[cruzn57]

valve guides?

and just what is wrong with cast iron guides?
its what came with stock heads, I admit alum heads must use something, but your machinest can install iron guides too !
check the price ,and check around,
which is better ???? ask 20 people, and 20 different answers.\

I prefer cast iron, regardless of price.
good luck

 

[VadersV6]

Your guide clearance is fine. You are barely out of spec at all. Bronze guides or liners had a huge tendency to wipe out quickly on just about every motor we put them on....even with clearances perfect when assembled. Our engine warranty provider stopped providing coverage for all engines equipped with bronze anything. We went back to iron and never had another problem.
Bronze is alot more thermally conductive than iron, but like anything with copper in it, its extremely abrasive. The only time you can even think about a bronze guide, is if you can absolutely guarantee that the surface finish of the valve stem and the guide both are perfect, and no foreign material will ever get inside your motor. I dont know anyone who can guarantee that.
Like said above...its what was put in by the factory for a reason.
BTW, dont ever ever ever knurl a guide. Would you knurl a cylinder and throw the piston back in? Its a hack approach to a problem, and the tightened clearance doesnt last.

 

[getchasum]

Originally posted by NC87GN
Appreciate the quote getchasum. I talked with the machine shop that did my engine honing and boring and they said that they would use bronze guides 7 days a week and twice on sunday. The last time they used liners was 15 years ago and its old school. Not saying liners don't work but they would prefer the bronze guides. They quoted me about 250 bucks to clean up the existing angle cuts on my valves, insert bronze guides and clean up the rough edges. I thought that was reasonable..?

Mike Banas
87GN

reasonable?...Yes, the price of the guides is around $35-$40.

cruzn57, I wonder at the heat range a turbo builds, if you get metal transfer to the valve's stem from a bronze guides like you do from cast???
I seen where the guy Jay C. uses to do head work, likes to use stainless on the exhaust guides????

 

[cruzn57]

good question!

what is the thermal expansion rate of bronze, cast iron, or bronze liner?? that may have something to do with it, not sure,
I ran a machine shop a few yrs back, bronze guides required more clearance, or they'd stick, on a non turbo motor!
Mercedes Benz specs say .003- .005 on their bronze guides.
makes you wonder,
I'm sure the factory uses iron due to cost, there may be other reasons, heat transfer, expansion , oil retention, etc,

Me? I'll stick to Iron guides,

Thanks for the input!