335 HP 396 290 Head Casting Build & Dyno Test

[Paul Precht]

I'm guessing you didn't flow with the manifold on.

[HP HUNTER]

Originally Posted by Paul Precht

I'm guessing you didn't flow with the manifold on.

You would be correct, I simply wanted a base line on the heads as they were run. The 396 was a 440 HP engine as run, I know the factory intake easily supports more than that from other builds I've done in the past. I would be interested in knowing what a worked over intake was worth? I'am pretty sure the heads can be very much improved on, we're going to see soon.

https://classracer.com/classforum/sh...ad.php?t=78477

[HP HUNTER]

Here's a better picture of the head before work was started. Notice both valves are sunk quite a bit. I checked all the valve heights, and checked PV clearance, CC the chamber 100.5. So according to my calculations its short on compression.

[HP HUNTER]

Seats installed.

[HP HUNTER]

Setting height, there's 60 now with a 2.065 valve BBC.............

[HP HUNTER]

Intake flow long port now:

.200 153 + 21
.300 214 + 29
.400 250 + 15
.460 262 + 5

[Mark Yacavone]

I hope you guys are appreciating this.
You could spend 4-6K for a set of Stocker heads and not get this much information.

[goinbroke2]

Originally Posted by HP HUNTER

Setting height, there's 60 now with a 2.065 valve BBC.............

For us crayon eaters in the class, can you explain the pictures in better detail please?
I understand you want all the valve heads the same height in the chamber so with sunk seats, you're replacing the seats and getting all the heads to sit at the same height...got it. But in the picture where you say you have .060, you're measuring from the deck height and what? I can't see but I'm assuming you're going to the top of the seat you installed?

Once all valves are sitting in the same place in the chamber, the cc's should be closer to start with...am I on the same page or in left field?

[Mark Yacavone]

Originally Posted by goinbroke2

For us crayon eaters in the class, can you explain the pictures in better detail please?
I understand you want all the valve heads the same height in the chamber so with sunk seats, you're replacing the seats and getting all the heads to sit at the same height...got it. But in the picture where you say you have .060, you're measuring from the deck height and what? I can't see but I'm assuming you're going to the top of the seat you installed?

Once all valves are sitting in the same place in the chamber, the cc's should be closer to start with...am I on the same page or in left field?

60 is the degree cut in the seat, that didn't exist before. This is a good part of the low and mid flow pick up.

[HP HUNTER]

OK- the valve job is 30/45/60/75/90 on a BBC production head the valve bowl is too big to get much if any 60 degree angle with a 2.065 valve. In the picture you will see the lap line, below the lap line is the 60 degree angle which is around .180 wide, that 60 degree angle is partially responsible for the low lift flow gains. If you look at the picture before modifications you will see there is very little 60 degree angle below the 45 degree seat. Hope that explains it.