Okay, so my buddy and I were talking today, after we pulled our neighbor's head and discovered 2 bent valves and a chipped valve guide. What would be the best route to go? OEM or mangenese bronze valve guides (supertech).

Car is a DD, stock 94 GSR, oem valves.
As far as the guides go, assuming the rest of the guides are w/in clearance, should my neighbor just replace the 4 guides on the cylinder with the 2 bent valves with oem guides, or replace them all with bronze guides?

I've read the previous threads claiming bronze wear out your valves quicker, but can the pro builders chime in please? Thanks.

 

yes a bronze guide will wear faster then a stock iron guide.but you get benefits the iron guide can't give you.like better heat transference from the valve,tighter guide clearences that allow better valve stability and longer vj life.also you usually don't have to worry about the guide breaking off and falling into the cyl.
I can run a bronze intake guide and ferrea valve at .0008 valve stem clearence where a stock iron guide is around .0015-.002.

 

What is your take on cutting back valve guides to improve flow? I would rather thin them out but now cut them back. I think that would further reduce valve stability, but after seeing some other aftermarket guide measurements, they are shorter than stock guides.

 

unless it's a race only head and will be freshened mid season I have no problem with it.otherwise I stay away from it.

 

When you port DD heads, do you remove some material from the guides to thin the O.D. a bit?
Also, which do you prefer, Supertech or Ferrea guides?

 

i prefer to replace all guides w/bronze for the reasons stated earlier.

 

Thank Ed, Mark (ruffrhyder) and I have been debating on what to do on this head.