Ideal head for rules.

[englertracing]

do you have to run a 7000rpm pill?

[Keith Morganstein]

I honestly think they went far too big on both cam and head. Supposedly the head has had porting and port matching done. From what I've read this big runner casting is way way too big for our limited compression/cid. I figure a max of 195cc runner size from what Ive seen before here on the site, but i certainly want to hit the nail on the head if I'm going to spend for a different set of heads. The cam will shine if matched correctly with the heads. If i could find someone with an untouched set of the 185cc vortec bowties from a few years back those would be my first pick but not sure about the newer revised ones that are out now.....newer ones are even more expensive, not even sure if they are improved.

As far as valve size, I gather 2.02/1.6 is plenty but this is .030 over currently so larger valves likely are shrouded. If they have the original 2.00/1.55 valves probably a far better compromise with respect to the small overbore.

I would have picked the small bowtie vortec, BUT there are builders that use the large port bowtie vortec in various 2bbl and 4bbl classes and their engines run very good. A cam is whole lot less expense and work.

[Carnut1]

It would be interesting what could be done on the large port bowties you have and some creative epoxy work.

[88bluestar]

Around 3500 rpm
Tight turns
7000 rpm max

What is the RPM that you run to start coming off the tightest corner???
Between 3000 to 4000??? Lower or higher??
That is where you need to work from. if the engine while on track never see's less then 3000 or 3500 say that is a good bit of info needed when choosing LC for a cam as the tighter the LC the shorter the power band will be. But if you are in the lower lane it sounds like the chassis can use some work as well. Unless you can go down on gear and get up top and stay in the gas longer if the chassis will let you.

But as for head choice personally I would go to a Dart head if for no other reason is the off shore cast heads may not be consistent in port location and thickness when considering a full port job.

What does the bottom end for crank and rod weights?? Can you turn it any higher then 7000?? We used to run our north west tour engines to 8200 if needed and they were 9.5-1. and a 390 carb. Not a fair comparison but what are the guys that run at the front turning for rpm?? I know guys will never admit to just what they are really doing but you get the idea.