[Ron Sutton]

Originally Posted by ccracin

Ok, Ron, I have taken it all in. This is great information. I am going to recommend the custom cam. I hope they can get it in time. This is what I came up with for the part and grind number of the cam you suggested. I got this from the master lobe catalog.

Part# 12-000-5
Grind # CS 6263/6414-S108

With regard to the exhaust, I am not sure they will be able to go this route at first. I will find out what they have now. I know it is not a crossover system. I think if I can get them to do most of this on the engine, the budget may take a beating. What do you think we can get away with at a bare minimum?
I probably should know what they have first. So find out & list it on here. If they can't afford step-headers, they need to go with the 1-3/4" straight headers. If they run 1-5/8" primaries the cam & headers will be working against each other. Just know they are giving up some low end power with 1-3/4" straight versus 1-5/8"-to-1-3/4" step headers.

An less expensive alternative to true merge collectors are "Insertable Collector Reducers". (Photo at bottom of page)

They basically slide into the 3" collector material & run a few welds to hold it in place centered at 9.9" from the end of the primary tubes. I've used them with some positive results when the exhaust was too tight to fit a merge collector in there.

An H-pipe is dirt cheap. It is the same 3" tubing as the exhaust. When I re-read my initial exhaust post #4 ... I saw I worded it incorrectly & went back to change it. (The corrections/additions are in red) You want to weld the H-pipe in so the leading edge of the H-pipe is at 19.8".

The rest of the exhaust needs to be 3" too. If it's smaller, that will not work with this cam cambo.



How about the carb? Anything I should tell them to pay attention to? I would can provide here will be greatly appreciated.
I can't tell you what the specs need to be, but the carb is critical in two areas. Obviously, ANYTHING that can be done legally to increase airflow is a priority. Get with a proven carb guy known for building good gauge legal GAS 2-barrels.

The second part if getting the fuel curve correct. This is all internal with orfices & bleeeds. How we do this is running the exact engine on the dyno for 12-20 hours with the carb guy tweaking the curve & making runs until the fuel curve, idle quality, throttle response & power are optimum. The challenge is they can't afford to do this. So they just need to get with that proven gas 2-barrel carb guy & trust his work.


Do you have a recommended vendor for a blue printed oil pump?
The Melling Select pumps are pretty good out of the box, but being frank, we still disassemble them, check for imperfections & deburr them. Precision Oil Pumps blueprints Melling select oil pumps & offers them ready to go for what I think is a pretty good price. Their website is here.

They are not allowed the E-Curve Dizzy. Any options there?
I did not see a distributor rule. If you can run any MSD billet racing distributor, that would be my pick. They have hardened shafts & 2 shaft bearings. There are other brands too.

But if they require OEM distributors ... I assume they allow you to run HEI distributors. Performance Distributors offers their "DUI" distributor ... which is basically a HEI clone ... with the best HEI distributor parts (coil, pickup, caps, rotors, etc.)

I have mixed feelings here. Where rules allow any distributor ... and where there are no rules ... I wouldn't run the DUI distributor because there are much superior options for literally a few dollars more.

I have ran the DUI distributor a LOT and get good performance out them ... especially 7000 rpm & below. My qualm with them is the fast wear rate of the non hardened shafts. I had to rebuild the DUI distributors every season & put in new shafts. Otherwise the shaft "wobbles" and timing is erratic.

So DUI is the best option if you can not run a racing distributor. Be prepared to rebuild with new shafts every off season.

As far as the timing curve ... run biggest weights & softest springs so the timing curve is extremely quick. Set the total timing at 37° to start & tune from there.


Thanks.

You're welcome.