Point/Counterpoint: DOHC v OHV - Page 7 - ZR-1 Net Registry Forums

edram454 · 08-15-2015

Quote:

Originally Posted by pantera1683

Big Block?

Im surprised nobody caught it sooner. BB?

ed ramos #3028

Kevin · 08-15-2015

Quote:

Originally Posted by edram454

Im surprised nobody caught it sooner. BB?

ed ramos #3028

thought that was standard short hand.

XfireZ51 · 08-15-2015

Quote:

Originally Posted by Kevin

thought that was standard short hand.

Although it's a 427, that doesn't make it a big block. It's still an LSx block just a bigger bore. I may be oversimplifying it.

Kevin · 08-15-2015

Quote:

Originally Posted by XfireZ51

Although it's a 427, that doesn't make it a big block. It's still an LSx block just a bigger bore. I may be oversimplifying it.

fair point, well made and nicely presented. I'd forgotten that the ls7 was a sbc

Fully Vetted · 08-16-2015

Quote:

Originally Posted by Kevin

fair point, well made and nicely presented. I'd forgotten that the ls7 was a sbc

My mistake. I thought it was a BB.

mike100 · 08-16-2015

The LSx all have the same block dimension, but I took at as any v8 over 400 cubic inches to be a "big block" as the historical packaging generally had its threshold at about that size.

Fully Vetted · 08-16-2015

I had a 70 1/2 TA that had a 400 small block (Ram Air III). If I'm not mistaken the "small block/big block" designation was only applied to Chevy engines, tho. But the Pontiac 400 was always referred to as a small block.

XfireZ51 · 08-16-2015

Quote:

Originally Posted by mike100

The LSx all have the same block dimension, but I took at as any v8 over 400 cubic inches to be a "big block" as the historical packaging generally had its threshold at about that size.

396 was a big block back in the day, so displacement was not the determination for the designation. BB cylinder heads would not work on a small block and vice versa.

Kevin · 08-16-2015

I thought it had to do with the bore spacing?

XfireZ51 · 08-16-2015

Quote:

Originally Posted by Kevin

I thought it had to do with the bore spacing?

Well you could say bore spacing has something to do with it. Here's a very illustrative video of the difference. The name "big block" becomes pretty obvious.

http://youtu.be/LPZuEWli4gQ

08-16-2015	#66
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: Point/Counterpoint: DOHC v OHV The LSx all have the same block dimension, but I took at as any v8 over 400 cubic inches to be a "big block" as the historical packaging generally had its threshold at about that size.

08-16-2015	#67
Fully Vetted Join Date: Sep 2012 Location: Rockwall, Tx Posts: 1,510	Re: Point/Counterpoint: DOHC v OHV I had a 70 1/2 TA that had a 400 small block (Ram Air III). If I'm not mistaken the "small block/big block" designation was only applied to Chevy engines, tho. But the Pontiac 400 was always referred to as a small block. __________________ _________________ 1994 AB/Grey #141 430 RWHP/392 RWTQ FBI Lyposuction / Secondaries relieved of duty / SW Long Tube Headers / Corsa Exhaust / FIC SS Injectors / MSD Coils / Lightweight Pulleys / Corey tuned B & M Shifter / Aluminum Flywheel / Samco Hoses / Shelby Series One's / C4 No Flex Frame Stiffener BBC - Bling By Carter: Custom ZR-1 Center Caps / Custom Plenum Plate / Air Box Knobs / TB Cover / Oil Filter Cover

08-16-2015	#69
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: Point/Counterpoint: DOHC v OHV I thought it had to do with the bore spacing? __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"