Strip Poker 388

My thinking of it is.... If I am at 9lbs now and I get the heads to flow allot better which will reduce the boost #.In Which would be less heat making it more efficient .Maybe making the same power that was at 9 but now is at 7 1/2 -8lbs.

In Theory?
Rob

Donzi502

If the exaust works better the cam overlap will make the intake work better as well, You may have to retard the cam a little to make the most of it. Our engine guy is very good. He heavily worked the exaust and it made a hell of a diference, i couldnt beleive the intake port making that much diference. Dont forget that the natural port design is for exaust that curves down, all ous all curve up. The bottom of our exaust port has been filled and the top worked hard. Must work. We get 900hp with a megablower and merlin heads. There is nothing flash really. Just put together well. Jas

bcarpman

It would seem like it, but no, actually it doesn't. SC's are incredibly inefficient, and even more so as the boost goes up. If the heads flow as good as they can, you'll gain HP with no bad side effects.

Just crank up the boost, and now you've increased the charge temperature, requiring less advance or compression or higher octane. Also, more power gets sucked from the crank to turn the blower (with all the crank and belt durability that goes with it.

The difference is readily apparent when you play with SC vs. Turbo. You need 50% more boost to make the same power as the turbo. The same is true for an engine that's built right with a SC. You can make a lot more power with a lot less boost and a lot less headaches (or a lot more power with the same boost)

JimV

Strip, I never did a back to back with unported vs ported but I ported a set of GM 990 headsfor a guy with a 36 apache. They made 815 hp and the boat gos low mid 90's with 6-7 lbs boost(vortech). We did a cam change too.

rssteiny

I am going to do a refresh / build up in march on my 500s
what can i gain in my stock 500 hp carb heads, and what kind of dollar to have them done. and what other changes like cam intake and so on ,pm me if you like.

JimV

Im working on some hp 500 heads and will dyno in the next week or two. I can post dyno numbers when their finished. The exhaust ports picked up an impressive 20% airflow or 60 cfm with a valve change and some minor port work.

rssteiny

Keep me posted as i may want to send you my heads to be done.

thanks rick