I decided to go with Poston's larger, (1.77), stainless steel intake valves. They are the cheapest available. The heads will be ported and polished at a reputable and long established machine shop.
I went with the stock exhaust valves and a 3-angle cut on the exhaust seats. (The stock exhaust ports flow so well that spending more money on H/P exhaust valves is just waste).
Originally posted by Freddie's Buick
I went with the stock exhaust valves and a 3-angle cut on the exhaust seats. (The stock exhaust ports flow so well that spending more money on H/P exhaust valves is just waste).
There a several ways to improve flow in the heads. Porting, or the widening and re-surfacing of the inside include removal of casting flash left over from production. All cast sharp edges are smoothened out. Afterwards, the surface is polished. It is an expensive and time consuming process.
Another way is to have the valves grinded in such a way as to not interfere with flow. This is very cost effective and greatly improves flow.
The other way is to have a 3-angle cut on the valve seat. This is just as efficient and cost effective as the special grinded valves. Flow is increased and any good machinist should know how to do this.
