My opinion would be that a good quality stainless valve would be all you need.
i am going to be running some GM aluminium heads (#12363391) on a 502 BBC. the heads have stainless 2.25/1.88 valves. would it be wise to get some inconnel exh. valves since this is going into a jet boat? or will the stainless ones be fine?
thanks... victor
My opinion would be that a good quality stainless valve would be all you need.
It depends on how you drive it and how long. All the big HP high dollar engines use inconnel or better, Manley has a newer material I was told at SEMA.
its basically a river pleasure boat. 18' rogers,berkeley JG A/B with a droop, ride plate, and place diverter, 502BBC crate motor with those GM aluminium heads, a comp cams xr288hr cam, roller rockers, edelbrock air gap rpm performer intake, and a demon 850 vac sec. carb. and O/T headers. ill be running a banderlog valve to help keep the water off the exh. valves and into the chamber, so that should help some with any rusting. im so glad the girlfriend likes to ski, otherwise id be sure to try and make it a hot rod for sure. but basically will just be cruising and skiing, and an occasional hot lap just to make me happy.
It sounds like SS valves would be OK but you might ask around in the jets section to see what other jet owners use.
It's been my experience that extra money put towards the valve train will reap better rewards than many other routine modifications. Sure Inconnel valves are great for an exhaust valve but it can often be pricey and non-benifical for this application. Unless you're going to run a Turbo, NOS, or blown set-up donÂ’t bother with anything else other than SS valves.
Stay away from the cheap crap though...
There are alot of vendors out there selling cheap imported SS valves for pennies on the dollar. Sure they look great when they arrive to your door and they have all "bling bling" chrome tips, swirl that...blah blah blah....on the bench, but under "Real World" conditions they fail quickly. Not something I want to incorporate into my BBC.
A BBC Rect.port motor with .580" or more lift should invest into something a little more quality like Ferrea valves. They have been manufacturing killer intake and exhaust valves for almost 40 years now. They're Competition Plus line may best suit your application and wallet as well.
The Ferrea valves range from $20-25 per valve, but believe me it's money well spen. The robust design and superb quality that actually weights less than many competitorsÂ’ valves will increase your reliability exponentially. Lighter valve train means more RPM as well!
I'm sure there are more folks on the boards here who build motors for a living that could chime in their experiences as well. Ferrea is not the only bus in town making good stuff, but alot of folks swear by them.
~Ty
The Ferrea Comp series is an excellent choice. REV has a nice competition series also. A good stainless is all that is needed. In some endurance testing that I was priviledged to the data, the exhaust temps in NA boat motors just don't get that hot.
Chris
Since Edlebrock now makes GM heads why not just buy the Edlebrock Marine heads and get the Inconnel valves included as well as hard annodizing?
Yea Ray and they are cheap too.
Most opt for the Inconnel when blown and/or a tight LSA cam. Less overlap to cool the valve in that instance.
Ray,
Good choice in oil pans on that engine.
Chris
Stef's Performance