stroker crank on a 68 BIGBLOCK
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 25
Likes: 0
From: ST HAON LE CHATEL
stroker crank on a 68 BIGBLOCK
HELLO
I PROJECT TO HOT ROD MY 68 L36 427ci WITH A STROCKER CRANK FROM SCAT .
longer strock 4.5 " (stock 3.75) and 0.535 rods
does any body has already do such modification?
how does the engine rev with such modication ?
much more torque compare to the stock 460 F/ lbs?
how many HP gain ?
thanks for any advice ,information of your car with this engine of modification
I PROJECT TO HOT ROD MY 68 L36 427ci WITH A STROCKER CRANK FROM SCAT .
longer strock 4.5 " (stock 3.75) and 0.535 rods
does any body has already do such modification?
how does the engine rev with such modication ?
much more torque compare to the stock 460 F/ lbs?
how many HP gain ?
thanks for any advice ,information of your car with this engine of modification
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: stroker crank on a 68 BIGBLOCK (Benjamin)
Generally the longest stroke that you can install in a stock 427 style block is 4.25 inches and they are used to make 496-508 ci big blocks. I've read that if the only component that you change is more cubic inches of diplacement by stroking and everything else being the same. You have no rise in power. Just the same amount at a lower rpm. If you don't increase it's breathing ability you'll stay the same.
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: stroker crank on a 68 BIGBLOCK (Benjamin)
Benjamin,
Welcome to the Forum! First of all, I doubt that you will get any more horse power from such a stroke increase, but you will get a boat load of torque. In my opinion, it will be more of a truck motor with that much longer stroke.
I would encourage you to get Desk Top Dyno 2000 software. You can plug in all these different parts and specs and get a rough idea of what the changes will do. It is a lot of fun to play with.
Chuck
Welcome to the Forum! First of all, I doubt that you will get any more horse power from such a stroke increase, but you will get a boat load of torque. In my opinion, it will be more of a truck motor with that much longer stroke.
I would encourage you to get Desk Top Dyno 2000 software. You can plug in all these different parts and specs and get a rough idea of what the changes will do. It is a lot of fun to play with.
Chuck
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: stroker crank on a 68 BIGBLOCK (gkull)
I have read that too but find that hard to believe. If true than wouldn't a 0" crank have as much power as a 3.75" crank? Ridiculous but isn't that what that is saying? Has to be some limit to that theory or my 0" crank joke would apply. If not, I am building a super destroked 1/4" throw crank big block and be the fastest vette ever. :rolleyes:
[Modified by Fevre, 2:59 PM 11/5/2002]
[Modified by Fevre, 2:59 PM 11/5/2002]
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: stroker crank on a 68 BIGBLOCK (Fevre)
I have read that too but find that hard to believe. If true than wouldn't a 0" crank have as much power as a 3.75" crank? Ridiculous but isn't that what that is saying? Has to be some limit to that theory or my 0" crank joke would apply. If not, I am building a super destroked 1/4" throw crank big block and be the fastest vette ever. :rolleyes:
[Modified by Fevre, 2:59 PM 11/5/2002]
[Modified by Fevre, 2:59 PM 11/5/2002]
Zero is Zero, wouldn't make any difference what the bore was. This would be the same as an engine with a broken crank. Yet within reasonable limits, the stroke determines what the rpm will be that makes the most hp. A 2" crank would probably develop about the same power as a 3.76" crank, but would you want a torqeless monster that needs to be spun to 15,000 rpm?
Chuck
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: stroker crank on a 68 BIGBLOCK (Fevre)
I understand 0 is 0 but your point about revving to 15,000 is more of what I am after. Has to be some limit to that theory.
Chuck
Racer
Joined: Oct 2002
Posts: 328
Likes: 0
From: Marlborough MA
Re: stroker crank on a 68 BIGBLOCK (Benjamin)
Isn't the 6.535" con-rod a little long for a 4.5" stroke? That would need a piston w/ a compression height of 1.01". I've been looking at pistons for my BBC, and the smallest I've found is 1.1". Maybe there are some custom pistons you could get though...
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Safety Car
Joined: Dec 1999
Posts: 4,148
Likes: 5
From: Roxbury NJ
Re: stroker crank on a 68 BIGBLOCK (Benjamin)
Benjamin, sorry, but you will never fit a decent piston, rod, and 4.5" crank into a stock deck height 9.8" block. You will need a tall deck 10.2" block.
With the '68 427 block, you will even have a hard time fitting a 4.25" stroke because the '68 427s didn't have the same crank throw and rod clearances cut into the block that a 454 and later 427 has.
Whenever I rebuild my '68 L36, I will probably go with the 4.25" stroker, but I don't expect it to be easy :D
With the '68 427 block, you will even have a hard time fitting a 4.25" stroke because the '68 427s didn't have the same crank throw and rod clearances cut into the block that a 454 and later 427 has.
Whenever I rebuild my '68 L36, I will probably go with the 4.25" stroker, but I don't expect it to be easy :D
Safety Car
Joined: Dec 1999
Posts: 4,148
Likes: 5
From: Roxbury NJ
Re: stroker crank on a 68 BIGBLOCK (Benjamin)
This piston has a 1.27" compression height, and it's sized for a stock deck height (9.8") 4.25" stroke, and a 6.385" rod.
%20of%20DSCN3374-01.jpg)
Your proposed piston would have to be .275" shorter, and the pin would be way under the rings. It might be possible, but I don't think it's a good idea if you have other options.
[Modified by Flareside, 8:35 PM 11/5/2002]
Your proposed piston would have to be .275" shorter, and the pin would be way under the rings. It might be possible, but I don't think it's a good idea if you have other options.
[Modified by Flareside, 8:35 PM 11/5/2002]