the t
the thing about these NHRA specs is; they are a recipe.
They are saying if you build to such and such a recipe, regarding compression and the factory parts;then they are gonna factor you to the listed horsepowers, and there is nothing the racer can do about it; if you don't like it, build some other brand.
Now; if you look at the recipes, there is a buttload of interesting gems to be found, especially as regards compression.
Take a look at the 360s for instance, first the 74/76 ones;
To make 9/1 at stock bore,requires a swept of 737.2/8.0=92.15cc, total chamber volume.
and the decks are 13.8cc plus gasket at ~7.2 plus head at 64.7=85.7cc; leaving 6.45 in the dish.
Next, the later 360; requires 97.00cc; which being
68.4+13.8+6.75+6.45=95.4...... where's the missing 1.6cc?
Ok I get that 1.6cc does not seem like a really big deal;the point is this;
where did the; 300 less 250=50 horsepower go? As far as I know the cams where the same, and NHRA says they are both 4bbls..... so where is the 50hp?
Is NHRA saying .4 of a point of compression is good for 50hp? interesting gem that.
But it gets better
look at the 340s. From 71 to 73 they all had TQs and the same cam and heads.... so are they saying that 1.7 points of compression makes 55 horsepower? Sweet gem
What about the 318s?
My research shows the 69 318 2bbls to be rated at 230hp.. with 2bbls and either 9.2 or 9.5 Scr depending on the source.
NHRA says they can build a 78/80 4bbl teener at 9.0 and get the same 230hp. AFAIK the cams were the same. What are they saying? That a half a point of compression is equal to big-port heads and secondaries?.. What a gem this one is
Anyways, jus ruminating
