No definitive answers from the other forum regarding quench....was really hoping get input from a guy who stated that forced induction and nitrous engines "should have all quench areas removed" I wouldn't try doing this to another set of heads (chamber softening) until it's proven to make a difference at all.
Thought I'd give a little update on the heads. The port work was such that I got dangerously thin on some of the port walls and the valve seats. They were to the point I really did not expect to get much Street use out of them. I have gotten almost two years of Street use and it just rolled over 7,500 miles with no issues
It went high 10's fairly easy. The current fuel system is the limiting factor now.
The exhaust seat are extremely narrow (maybe .045 -.050) and the exhaust ports are cut to within .065 of hitting water in some areas. It's actually very surprising to me that there hasn't been any issues. The car is driven 6 or 7 days a week in stop and go traffic so the heads have seen plenty of heat cycles.
I just noticed you run the DLS 210/210.Two questions is it the 114 LS and are you 1.55 TD or 1.65? With your good flowing heads where do you shift ? ( that was 3?)
My heads were just cleaned not ported stock heads eight years ago and I new any thing over.500 lift the bottleneck would show it ugly head .
I bought 1.55 rockers and DLS cam at that time. This and a small 5857 turbo only mods.And shifted 5200 rpm .
Two years ago I broke the engine ,bought a Zimmerman from Nick and a set of Champion heads. Running the same DLS 210/210 114LS .490 lift . I sometimes think with ported heads and the lower lift rockers I’m giving up some horsepower. I do shift 1-2 @ 5800 2-3 5600.
What is your thought on this combo? My new ET is 11.55 @118.
I believe the cam card said 112+2 and I'm running the 1.55 ratio. Car is auto shifting 1-2 @5700, 2-3 @ 5490 and trapped 126 @5550
Contrary to what some guys have said I'm finding that cam to be very versatile. It has a nice smooth idle, good vacuum and in my case (manual shifting) will get up on the 6300 rev limiter in a heart beat.
I have no doubt that raising my shift point a couple of hundred will yield a better ET
Mike i think i am going the same route you did and porting my stock heads when i rebuild my motor so i am sure we will behaving alot of conversations on this topic... Great Job bud it is coming along awesome.
Good to hear from you Henry! I know your schedule is tough but you should try to make the meeting.
For someone wanting to port their own heads I would suggest reading up on valve to throat ratio. Other than cutting through a water jacket I'd say this is where most mistakes are made.
For a street driven car 90% intake and 85% exhaust is the maximum, reducing each by 5% would be much safer because this material is needed for a good valve job. Everything has to be symmetrical ( though some throats are intentionally cut asymmetrically to complement port design). Once you understand the math for determining ratio it will become apparent that the smaller exhaust valves are less forgiving if you make a mistake.
I don't like completely eliminating guide bosses or huge intake ports.