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Pontiac - Boost Turbo, supercharged, Nitrous, EFI & other Power Adders discussed here. |
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Old school C/H methods for boost applications?
Gentlemen,
I will kid you not, this is not my area of expertise but I ran into a situation today while assembling my new 428 Pontiac bracket motor. The engine is a factory 4-bolt 428 block and I am using a old 421 s/d forged crank with Eagle 6.625 floating rods. Both the pistons and rods use a .990 pin. So putting in the first couple of pistons into the motor, I noticed by eye the deck height from the piston to the block was a bit large. I confirmed by measuring it and had a WHOPPING .047. Certainly not good for a n/a motor. My good friend Jack Ferris was trying to help me figure out where the F-up was. I eventually dug out the receipt for these pistons that I bought from the late Greg Merrick (Pontiac Gregg) over a decade ago and they say 428 blower pistons. For whatever reason, I thought they had a thicker crown to go with the very heavy duty pistons. With my digital caliper and by eye centering it, these pistons have a 1.55 C/H. A Icon piston for this application (428 4in stroke 6.625 rod) has a 1.95 C/H which covers the large gap I found. My question is: Are/were blower builds built with a lower C/H instead of a dish piston?
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
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