Camshaft / Rockers Combination - 3.1 Stroker (Page 3/3)
82-T/A [At Work] OCT 13, 11:26 PM

quote
Originally posted by La fiera:

Actually the polishing part of the process is what i don't like. Believe it or not polishing a pipe in the inside where air travels will create resistance due to turbulence
of the friction between the mirror-like surface and the air traveling on it. I know it sounds counterintuitive but that's why I'm upgrading my intake and head port to gain more CFM by removing friction.




That never occurred to me! So what you're saying is really you just want to get rid of the restrictions (bumps, ridges, etc...), but you don't want a polished surface?
RayOtton OCT 14, 07:45 AM
A long, long time ago I read the same thing in Hot Rod magazine.

I seem to recall something about too smooth surfaces reducing turbulence too much.
La fiera OCT 14, 01:29 PM

quote
Originally posted by 82-T/A [At Work]:
That never occurred to me! So what you're saying is really you just want to get rid of the restrictions (bumps, ridges, etc...), but you don't want a polished surface?



Its on the same principle of the dimples on a golf ball. Its more important in my intake manifold
design because of the location of the injectors in relation with the track. If I would polish the track, the fuel that sticks to the walls of the manifold would not have anything to slow it down (rough surface). The fuel would just trickle down fast into the combustion chamber in liquid form. What the roughness does is slow down the fuel and gives it time to evaporate so when the valve opens it can be sucked into the combustion chamber and burn quickly. Fuel has to evaporate before it burns.
Raydar OCT 14, 05:48 PM

quote
Originally posted by 82-T/A [At Work]:
I think what I'll do is replace everything else (valves are new). So should I just go ahead and order all new parts from Crane Cams? Do you happen to know what I should be looking for when I order from JEGS or SUMMIT? Thanks!!!



I wouldn't use the Crane lifters. Have heard bad things about them.
Most people seem to recommend GM lifters, although they are rather spendy. (And that was a long time ago. It's been probably 15 years since I built my engine. I hesitate to recommend anything, since things are constantly changing. Listen to "modern" advice.)
I would, OTOH, buy the springs that Crane recommends for your cam, if they are still available. You'll have to make measurements, or give all the info to the people who do your head work. (Compressed and "relaxed" spring height, etc.)
My rockers were the Comp roller tip rockers. Didn't see any point in going full roller. Lots of money for not a lot of gain. (Did I already say that?)

[This message has been edited by Raydar (edited 10-14-2019).]

olejoedad OCT 14, 06:07 PM
One bit of advice is to buy all of the valvetrain components from one repudable manufacturer.
The advances in computer assisted design enable the manufacturers to analyze valvetrain dynamics and the associated destructive harmonics, and use that info to minimize problems.
Mixing and matching sources could lead to unhappy results, even if the components are purchased from repudable manufacturers.
lou_dias OCT 15, 09:21 AM
roller tips don't do much but roller fulcrum does which is why the GEN2 rockers are roller fulcrum from the factory...
...but when I rebuild a motor I like new parts and that's why I went full roller...and that's why I made my valve cover spacers...