Thread: what size cam

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got the block torn down and it'll be back from the machine shop in a few days 406 clened up it was already bored and the forged pistons in it were good i had the crank turned the 441 heads i had bought were milled and ported already they have 1.94 intake and 1.60 exhuast never heard anyboy talk about the the pistons have 12cc dish my question is what cam would be best for me with the info I have just given I wanted either comp xtreme 268 or xtreme 274 cam what stall and size carb should i use

I would use the 2800 hughes converter and a 650 carb eithercam is good. I ran a 268 in my Nova- sounded much bigger!

I'd probably do a 750 carb, a little too much carb is better than having too little. A 750 would work just fine on a 406. I'd use the smaller 268 cam and use a 1.6 rocker, it will increase lift a little and overlap which will be needed with those smaller heads.

With 4.155" bore, 3.750" stroke, 76 cc heads, 12 cc's in the piston and 9 cc's in the gasket bore (4.200" x 0.039" Fel-Pro 1014) and the piston zero decked, static compression ratio will be 9.58:1 with a squish of 0.039".
Using a cam with an intake closing point of 35* ABDC will yield a dynamic compression ratio of 8.4 on the KB calculator, which is probably about the limit for pump gas. Here's an example of a dual pattern cam with that spec. It's ground on 112* centers, but you could have it ground on alternate centers to give you some rump rump if you wish, just as long as you keep the intake closing point at about the same place. I'm not saying use this cam, I'm just giving you an example of cam timing that should work.
http://www.cranecams.com/?show=brows...tType=camshaft

Shoot, you're right techinspector. I was thinking of the 441 head being a 64cc camelhump. Got mixed up with the 461 head.

And I kinda doubt that block is zero decked so it is probably going to have less than 9.5-1 static compression. So both those cams are going to be a bit big for that compression ratio.

Originally Posted by techinspector1

With 4.155" bore, 3.750" stroke, 76 cc heads, 12 cc's in the piston and 9 cc's in the gasket bore (4.200" x 0.039" Fel-Pro 1014) and the piston zero decked, static compression ratio will be 9.58:1 with a squish of 0.039".
Using a cam with an intake closing point of 35* ABDC will yield a dynamic compression ratio of 8.4 on the KB calculator, which is probably about the limit for pump gas. Here's an example of a dual pattern cam with that spec. It's ground on 112* centers, but you could have it ground on alternate centers to give you some rump rump if you wish, just as long as you keep the intake closing point at about the same place. I'm not saying use this cam, I'm just giving you an example of cam timing that should work.
http://www.cranecams.com/?show=brows...tType=camshaft

One thing to remember in a 400 sbc the cam will act like it is smaller by 300-400 rpm's depending on how you have it installed.