One of the engines i am rebuilding is a stock 70 455, the only mods i am doing is a booster plate ,adjustable regulator, stage 1 cam, and i have bowl blended, polished the chambers and port matched the heads, i will be running stock exhaust manifolds with a 2 1/2 exhaust system,, sence this engine wont see over 5300 RPM'S, would it make eney sence to have a 3 angle valve job done? sence the heads are still in good shape i was going to lapp the valves and install new seals. Or should i just drop the $$$$ and have them commpletly rebuild?
I would use a 3 angle vj while your at it if your going to have any bowl work done you need to blend the valve job into the bowl.The valve job is one of the most important things to making a good working cylinder head.It will be worth it.
See if you can find a machine shop to do a blended multi-angle job. The angles are there but are smooth and continuous rather than 3 distinct angles.
thats what i have done to higher H/P build ups, i was woundering if it will matter in this moter, being only a max of 400 H/P?
I think you are heading in the right direction Kelly. Seems the exhaust manifolds would kill any potential benefit the machining might gain. IMHO, these incremental performance mods rarely have any effect on street motors. In that the largest compromise in air travel in a buick motor is the exhaust ports, (the severe downward port design to accomadate fenderwells, firewall and accessories) I would lap them in and go with it. The work you did on the intakes will keep your fuel suspended in air and optimize your combustion. Not to shiny on the intake side, surface turbulance on intake runners, also benefits atomization.
you went through the trouble to blend the bowls and port match the heads why not finish the heads right instead of backing out on a good valve job the valve job will have more effect on how the engine than port matching the heads unless the ports are majorly mismatched
I never got a set of heads out of a machine shop for less than $150.00. They have to bake and blast, vat and blast valves, resurface heads, and they never to fail to find a valve or 2 that is .0002 worn. 3 angle valve grinds will not yeild greater gains than the other items you did. I did hundreds of them when I worked in a machine shop. Yes, the defined seat angle assures a postive seal, but the idea that two 1/8" cuts on either side of the 45 degree primary cut on a valve seat is going to net giant improvements in flow, seems a bit of a reach. Now, if you are swirl polishing intake runners and combustion chambers and looking for those last 3 or 4 CFM before you head to Indy, then look at your valve grind.
