Verify my pushrod calculation please
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Verify my pushrod calculation please I measured the new cam lobes with my caliper. Heres what I got for what I need for pushrods. Figured another set of eyes on this would be good for verification. Thanks guys.
Stock cam base circle- 1.553
New cam base circle- 1.450
Stock pushrod length- 7.400
Length needed = ((stock base-new base)/2) + stock pushrod length =
((1.553-1.450)/2) + 7.4 = 7.452 for new rod length.
Stock cam base circle- 1.553
New cam base circle- 1.450
Stock pushrod length- 7.400
Length needed = ((stock base-new base)/2) + stock pushrod length =
((1.553-1.450)/2) + 7.4 = 7.452 for new rod length.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
I would run 7.425
Your calculation is correct but stock p-rod length is not 7.400
since average stock preload is in the .100 neighbourhood and 7.450 would put you over that, the next best choice is 7.425's
Your calculation is correct but stock p-rod length is not 7.400
since average stock preload is in the .100 neighbourhood and 7.450 would put you over that, the next best choice is 7.425's
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Originally Posted by PREDATOR-Z
I would run 7.425
Your calculation is correct but stock p-rod length is not 7.400
since average stock preload is in the .100 neighbourhood and 7.450 would put you over that, the next best choice is 7.425's
Your calculation is correct but stock p-rod length is not 7.400
since average stock preload is in the .100 neighbourhood and 7.450 would put you over that, the next best choice is 7.425's
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Ok thanks man, yeah ill go down to the 7.425's so i dont put too much preload on the lifters. I just didnt want too short rods so because i want to eliminate as much valvetrain noise as possible.
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Actually now that i thought of it, I am going with a .034 gasket and hope to be able to mill the 5.3L heads .030, so this will bring my rod length back up some, close to stock size.
So 7.39 stock + .0515(base difference) - .018(difference between stock and new head gasket) - .030 (head mill) = 7.3935
The 706 5.3L cast heads unmilled do keep the same height as LS1 heads right?
So 7.39 stock + .0515(base difference) - .018(difference between stock and new head gasket) - .030 (head mill) = 7.3935
The 706 5.3L cast heads unmilled do keep the same height as LS1 heads right?
Last edited by brad8266; Jan 19, 2007 at 08:23 AM.
Trending Topics
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Originally Posted by PREDATOR-Z
What is your piston deck height? .034 gasket seems tight unless pistons are 0 deck or below.
And with all the variances you're playing with better get a push rod length measurer.
And with all the variances you're playing with better get a push rod length measurer.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by brad8266
Yeah i was gonna get the checker anyway most likely. I believe they are out the hole .006, it would be a tight quench area. The motor is being clayed before any milling to determine how much i can mill. I have -2cc diamond pistons with eagle 6.125 rods, stock crank.
Look at .040 gaskets (Cometic) or Mr. gaskets are .042 (but 4.100 bore)
Thread Starter
TECH Senior Member
iTrader: (23)
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Originally Posted by PREDATOR-Z
If true then your quench is at .028, way too tight for a street application.
Look at .040 gaskets (Cometic) or Mr. gaskets are .042 (but 4.100 bore)
Look at .040 gaskets (Cometic) or Mr. gaskets are .042 (but 4.100 bore)
