I'm having my heads rebuilt for my L98 motor. The machinist wants to do a 5 angle valve job on them. The original is a single 45(?) degree angle. My question is, Is a 5 angle valve job durable? I wanted a 3 angle (Yes I know I'm old school) and my machinist wants to go 5. I'm sure the 5 angle will raise flow some but what about durability, how long will it last? This is not a max effort small block build, just freshening up an old L98 for fun driving. Thanks!

 

It will last just fine, the valve sealing surface doesn't change, just the angles leading into and out of it.

With modern cutters, there's nothing magical about multi-angle valve jobs anymore.

 

So you recomend the 5 angle? I know from looking at the 45 degree factory angle that anything will be an improvement. Thanks.

 

3, 5, 7, whatever's easiest for him with his equipment, as long as he isn't going to charge your a premium for it.

Maybe consider some waisted back-cut valves while you're at it.

 

Thanks Brother, Cant afford the new valves this time. But thanks for the advice.