Interest in Performance Parts for slants?
I am here in indy and have a few, but Bill is right without the proper head work and all the other goodies your pissin in the wind. I have some guinnea pig motors iam working on. Do you have anything started.
Thanks for the support, Sleeper, but my point was, because of the narrrow bore spacing parameters, even WITH the proper head work and the biggest valves you can stuff in there, making a deep breather out of a normally-aspirated slant six just isn't gonna happen.
Consider this:
The slant 6 has the same identical cylinder volume as a 302 V8 (1967 Chevy Z-28.)
Slant over-size valves 1.75" intake/1.5" exhaust
Chevy 302 V8 STOCK valves 2.02" intake/1.6" exhaust
Total valve area:
Slant: 2.40 intake + 1.77 exhaust = 4.17 sq. in. of total valve area per cylinder
Chevy: 3.20 intake + 2.01 exhaust = 5.21 sq. in. of total valve are per cylinder
That is a difference of TWENTY FIVE PERCENT!
That is a comparison of a STOCK 302 Chevy (37.75 cu. in/cyl.) to a "BIG VALVE" slant six (also 37.5 cu, in./cylinder.)
That is what valve size most people end up with in their ported slant six heads, as the largest practical head diameters for the two valves. There are offset guides available to install still larger sizes of valves, but with the 1.75" X 1.5" valves taking up 95% of the bore, installing larger diameter valves begs the question of shrouding on the combustion chamber walls and/or cylinder walls.
Anyway, that is the problem; resitricted valve size that is dictated by the (relatively) small cylinder diameter.
The biggest ports in the world won't help that problem. It all boils down to the weak link in the chain, which in this case, is the size valves that will fit.
That's why aluminum cylinder heads, electronic fuel injection, roller cams and exotic intake manifolding are just band-aids on a problem that can't be fixed with bolt-ons; the only thing that will cure this lack of breathing ability is more cow bell... er, in this case, forced induction of one kind or another.
My personal choice is turbocharging because lying on its side as it does, the slant 6 leaves a LOT of room in even the generation I A-Bodies for a turbo and plumbing, but any kind of supercharger or turbo will work well, I think, and N20 also can be used to get around the /6's breathing problems.
But EFI on ANY kind of a N-A manifold isn't going to do it...
Just my 2-cents...
