Bullet valve guides

Rovernuts · Post by **Rovernuts** » Mon Apr 21, 2008 12:31 pm

I was about to purchase some of the bullet valve guides which i read were better but my machine shop says that they don't even bother with changing the valve guides............possibility of galling the valve guide bore........they would re and re the existing valve guide before doing the 3 angle valve job...........is this going to flow as good as new valve guides........they say yes but i'm not sure

Thanks

Darkspeed · Post by **Darkspeed** » Mon Apr 21, 2008 12:54 pm

re-lining the guides is a popular alternative - but for the performance benefit smaller bullet/tapered guides are the way to go - The preferred method of removal of the RV8 guides is to machine them out rather than pushing them. Other way is in the oven and heat the heads then press the guides out.

Andrew

Post by **katanaman** » Mon Apr 21, 2008 12:54 pm

Bullet guides will flow better whatever is done and is usually one of the first things you would do to a set of heads. No point doing big valve multi angle anything when there is a dirty great big guide in the way. There shouldn't be any problem fitting new guides, many people do it at home never mind a machine shop.

ChrisJC · Post by **ChrisJC** » Mon Apr 21, 2008 1:53 pm

The machine shop I use drill (or machine in some way) out the old guides.

Chris.

kiwicar · Post by **kiwicar** » Mon Apr 21, 2008 5:35 pm

as said above, heat the heads in the oven and push them out with a stepped drift that goes down the center of the guide and has a shoulder that is the same size or a very small amount less in diamiter than the outside diamiter of the guide, don't be tempted to bash them out with a hammer. you will need access to a press but it is the best way IMHO. Boring out the guide is OK if you can set it all up very acuratly with the piller drill but you risk damaging the bore that the guide fits into which will right off the head if you can't get oversize guides.
Mike