LS4 FWD interchangeability

[zgeezer]

I've seen really cheap prices for LS4 engines w/o drive line. These are GEN III engines modified to fit East/West in front wheel drive GM products. Impala SS amoung others.

 

I know GM made a number of changes, cutting down on the front crank snout for example. But, does anyone know if a standard GEN III automatic transmission will bolt easily to the rear of this engine. In short, can it be converted to North South orientation using stock parts?

 

Did GM make any modifications to engine mount bosses on the block?

 

g

[BRAAP]

A quick search over on LS1tech.com revealed the following;

 

1) Crank is 10mm shorter at the snout.

2) Crank is 3 mm shorter on the flywheel end.

3) Bell housing bolt pattern is the GM Corporate FWD bolt pattern, not the RWD SBC or LSx bolt pattern so you wont be able to bolt up a T-56, etc.

4) Starter is mounted on the transmission, no allowance for block mount starter as on the RWD LSx blocks.

5) Water pump is offset for for clearance reasons.

 

 

LS4 is 5.3L that uses the 243 casting LS6 heads but with the softer LS1 valve springs and uses GM's D.O.D.

 

 

Some links;

 

http://www.ls1tech.com/forums/ls4-front-drives-2005-2009/556077-information-ls4-dod-4t65e-hd.html

 

http://www.ls1tech.com/forums/ls4-front-drives-2005-2009/572681-what-differences-between-ls4.html

 

http://www.ls1tech.com/forums/generation-iv-internal-engine/1099645-ls4-block.html

 

 

 

 

 

 

[zgeezer]

A quick search over on LS1tech.com revealed the following;

 

1) Crank is 10mm shorter at the snout.

2) Crank is 3 mm shorter on the flywheel end.

3) Bell housing bolt pattern is the GM Corporate FWD bolt pattern, not the RWD SBC or LSx bolt pattern so you wont be able to bolt up a T-56, etc.

4) Starter is mounted on the transmission, no allowance for block mount starter as on the RWD LSx blocks.

5) Water pump is offset for for clearance reasons.

 

 

LS4 is 5.3L that uses the 243 casting LS6 heads but with the softer LS1 valve springs and uses GM's D.O.D.

 

 

Some links;

 

http://www.ls1tech.com/forums/ls4-front-drives-2005-2009/556077-information-ls4-dod-4t65e-hd.html

 

http://www.ls1tech.com/forums/ls4-front-drives-2005-2009/572681-what-differences-between-ls4.html

 

http://www.ls1tech.com/forums/generation-iv-internal-engine/1099645-ls4-block.html

 

 

 

 

 

 

 

Thanks for the quick response. I guess there is no Santa Claus after all.

 

Good news for the Fiero hybrid crowd, though.

 

g

[hoov100]

desert truck and auto in coachella has a few complete 5.3 lm7's that are going for $500 as complete long blocks with all the little odds and ends.

[kiwi303]

1) Crank is 10mm shorter at the snout.

 

No problem, the accessories installed are engineered to use that snout, just can't put on a different set of accessories requiring a bigger pulley etc. just the stock one.

 

2) Crank is 3 mm shorter on the flywheel end.

 

3mm Spacer plate between the crank and F-wheel

 

3) Bell housing bolt pattern is the GM Corporate FWD bolt pattern, not the RWD SBC or LSx bolt pattern so you wont be able to bolt up a T-56, etc.

 

Aftermarket bellhousing, or an adapter plate, same sort of difficulty as putting a Z32 turbo box on a L series stroker.

 

4) Starter is mounted on the transmission, no allowance for block mount starter as on the RWD LSx blocks.

 

That's the sticking point. But I suppose the custom bellhousing might be able to fit a short motor gear reduction starter n the length between the flywheel and the GBox front, on the opposite side from the clutch fork opening. You'd probably need to use a small diameter racing clutch assembly to allow clearance between the inward bulge for the starter, and the clutch housing.

 

 

 

Nothing insurmountable by any means, just fiddly (read costly) engineering.

 

 

So who's gonna do it?

[BRAAP]

...

Nothing insurmountable by any means, just fiddly (read costly) engineering.

 

 

So who's gonna do it?

 

 

For a RWD LSx project, for the difference in price, time, fabwork, parts sourcing, and mental anguish, it seems like a win, win, win, win, win, to just hold out for an LM7, L33 if a 5.3 is is what you want, or or an LS1, LS2, LS6 LQ4 LQ9, Lxx....

[kiwi303]

But then you're not "Unique"

 

I've seen so many "I wanna be DIFFERENT" posts on here it makes me think of the goth and Emo subculures where the price of being "different" to the norm is they are so much more homogenous amongst themselves than the mainstream is to the mainstream...

 

look at a group of goths sometime... A bunch of identical mannequins, only differeing by the arrangement of rips and tears in the black clothes, same black eyeliner, same pasty white makeup, same hairdo...

 

 

Why be different? I prefer Effective to simply trying to be different for differences own sake. On the other hand, Lots seem to disagree with me.

[blackice280zxt]

But then you're not "Unique"

 

I've seen so many "I wanna be DIFFERENT" posts on here it makes me think of the goth and Emo subculures where the price of being "different" to the norm is they are so much more homogenous amongst themselves than the mainstream is to the mainstream...

 

look at a group of goths sometime... A bunch of identical mannequins, only differeing by the arrangement of rips and tears in the black clothes, same black eyeliner, same pasty white makeup, same hairdo...

 

 

Why be different? I prefer Effective to simply trying to be different for differences own sake. On the other hand, Lots seem to disagree with me.

 

 

 

:lmao::lmao::lmao:

[Starper57]

How about installing the lm4 in a early S10 that had a 2.8 3.1 platform use the same bell housing bolt pattern I'm wondering about the starter though and that should work with the small flywheel that came in the lm4 on the Monte Carlo and Impala SS

Just thinking about the starter that came on the 2.8 3.1 S10 in the early trucks that use the same bell housing bolt pattern as the lm4 I'd have to check the starter if anybody has any information on this let me know