Holley Speed Demon Carb

MSD Distributor

The original plan was to use an Edelbrock RPM Airgap manifold, but the runners were just so small.

I elected to go with a Victor instead.

By using an adjustable pushrod checker and dragging the rocker left/right across marker pen line I found I needed a 6.40"  length pushrod to place the rocker .050 the intake side of the centerline.

While adjustable guide plates are a great idea, they take way longer to install.

AFR 195cc Heads

Flow @ .600 lift In 308 CFM Ex 231CFM

Based on CID CR Duration and airflow

this 376 will effortless break through the 500Hp mark

The cam degreed in at 105 In centerline

In duration @ .050 measured 238

Ex duration 242

Here are the custom made 4032 forged pistons.

3.47 :- 2 + 5.4 - 8.2 = 1.065 needed for the compression height

You see the dish volume being 10.7cc

The combustion chamber is 58cc, I add 1cc for the area above the rings.

The bore is 4.155 stroke 3.47 gasket diameter 4.200 and thickness .040 the piston was up 0.001 the net result was a static compression ratio of 10.81:1 and when taking in the closing point of the intake valve an effective CR of 9.15:1

Jumping ahead in photos shows the crank pressure was 180psi


This build was a small block Ford. I used a Dart SHP block 4.155" bore 8.200" deck height.

The stroke was 3.470" for a final CID of 376

As you can see clearances were a shade under 0.002.

The rods being 0.0019" and the mains closer to 0.0017"

The mains were STD whereas the rods were -0.001 undersize

I prefer exactly 0.002" even 0.0025", but I don't like to see them looser than 0.003.

With a straight main bore you can get away with 0.0015", but the use of 0.001 undersize bearing would loosen such a size to 0.0025"

The only way to establish exact clearances is by using -0.010 bearings and grinding the crank undersize to suit.

I only do that when abosultly neseccary, typicaly I can adjust clearances with the bearings, sometimes with half STD and half -0.001"