Fenris Ulf

I know not many of you guys have a reverse-cooled LS1, but the LT1 guys seem to get away with 12.3:1 with 93 octane on the streets. Could an LS1 do the same if a reverse-cooled EWP was used? Why or why not?

Gimp98TNT

iTrader: (21)

the LS1 is also reverse cooled from the factory.

jmX

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Gimp98TNT:
<strong>the LS1 is also reverse cooled from the factory.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Erm. The stock water pump on an LS1 doesnt reverse cool the block. Maybe at one point GM had intentions of shipping the LS1 reverse cooled from the factory, but those plans fell through and it didn't happen.

Fenris Ulf

No, the LS1 is not reverse-cooled from the factory.

Anyone else?

Gimp98TNT

iTrader: (21)

Wow i feel about dumb now! <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

thanks for correcting me. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

Camaroholic

iTrader: (1)

Hey Gimp,

This should make you feel better:

http://www.akmcables.com/Revflow.jpg

I scanned that out of my '98 Firebird brochure that I picked up at the dealer. GM's marketing can be wrong too sometimes. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

-Andrew

LS171Malibu

So can anyone help with the original question? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Racehead

With reverse flow cooling the LS1's capability to deal with high compression on street gas would be very similiar to an LT1's. I won't go out on a limb and give you an exact #, but the LT1's, with reverse flow cooling, come stock with 10.5 or 6 to 1, and the LS1's, with traditional "block 1st" cooling, come with 10.1 to 1. Remember that the compression ratio that an engine can handle on street gas has ALOT to do with the cam that's in it. Bigger cams, as a general rule, can take more compression since the overlap tends to bleed some cylinder pressure off. It would help for sure though.

Bill

Fenris Ulf

Thanks Bill. Would the bleeding off of cylinder pressure affect be negated as the engine displacement is increased? For example, a 346 with a 229/229 cam would bleed off more cylinder pressure than a 422 with the same cam right?

Racehead

Fenris,
Yes I would assume that this is true. The pressures that are being bled off would have much more volume on a 422, but no more time to bleed them off. This would seem to assure that the cylinder pressures would remain higher on a 422 than a 346 with the same cam. You would have to also consider that any 422 is going to have heavily reworked heads on it so it might in fact bleed pressure off much more quickly, so maybe in reality it wouldn't be that differant than the 346 ? Kind of a can of worms here huh ! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Fenris Ulf

Yeah no kidding. In my assumption only displacement is changed in going from 346 to 422. Guess there is only one way to find out for sure <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />