Valve seats
02-12-2004, 01:48 PM
#1
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Valve seats
Are the valve seats pressed in? How do they get in there? They are steel or something so they must be "installed" at some point in the manufacturing process.
The reason i ask is there is one he!! of a lip on almost all of mine where they make the transition to the aluminum of the intake port...area in questions is a red dotted line.
Nice finish on those intake ports huh!
Any issues with taking this lip down? besides not letting the dremel slip
The reason i ask is there is one he!! of a lip on almost all of mine where they make the transition to the aluminum of the intake port...area in questions is a red dotted line.
Nice finish on those intake ports huh!
Any issues with taking this lip down? besides not letting the dremel slip
02-12-2004, 02:35 PM
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Armed and dangerous ............ Give a 5 year old a hammer and you learn how many things need hammering ........ The heads are cast , as such things move around a bit but the machining with a mill is done in the correct spot so things like the port to the valve seat NEVER quite line up . The cleaning up of such variations PROBABLY will not hurt might help BUT just do not "hammer too much " . My old race engine 2.6 liter short stroke 911 with straight stacks mechanical injection you could look down the intake and see fire in the intake ports at 3,000 rpm and yes I " ported " them .......they sure were pretty !!! it made no power below 4,500 Rpm I had to down shift at 6,000 and spin it to 8,500 to make any power BUT sure were pretty !!! I actually had a head from a well know 911 port artist and copied what he had done . Sure were pretty ......... I really " hammered " them !! Once you start it is a bit like unprotected sex ........ you just want to go a little further and then you will stop .
02-13-2004, 08:30 AM
#7
Three Wheelin'
Tony, all the various porting articles I've read pretty much mirrors what Jim said, but not quite as entertaining! In a nutshell, leave the heads alone except for cleaning up casting flash and blending together any mis-matches as you've found.
Don't waste your time polishing the ports either as a rough surface is better than the eye-candy smooth one for boundary layer purposes which helps keep the fuel from falling out of suspension and 'wetting-out' on the port wall surface.
All of these little details you keep attending to will add up nicely in the end.
Don't waste your time polishing the ports either as a rough surface is better than the eye-candy smooth one for boundary layer purposes which helps keep the fuel from falling out of suspension and 'wetting-out' on the port wall surface.
All of these little details you keep attending to will add up nicely in the end.
