i bought an LS4

time to experiment.

i have procured an LS4 engine. 303hp, FWD, 5.3 v8 from a 2006 impala SS.

the engine shares the cylinder heads(less titanium valves) with the LS6 Z06 engine, which is the main reason for purchase. they will replace the cracked heads on my 5.3 swapped 95 impala SS.

the other reason for the swap is total experimentation. I've read that the only difference between the crank of a LS4 and a rear wheel drive 5.3 is the snout for the balancer is shorter. the power steering pump is in the way of making the engine RWD with the throttle body pointing forward, but this might be a non issue if using in a car with no power steering, or a truck intake manifold that puts the throttle body up higher might make it moot and have both. OR if the crank is indeed the same except the snout, i can swap in a RWD crank and have an all aluminum 5.3 to play with down the road, as making it RWD would be as simple as using a trans from any v6 F body.

or i could be way off as i know not where the starter bolts on an LS4, so i might sell the shortblock, or i could keep it for a v8 rail buggy with a FWD gm trans

either way, it made more sense to buy a complete runner to get the heads i need than a set of heads that may or may not be usable cores.

now to get a proper cam, valve springs, and other bits to up the ante when i put the better heads on my car.

Its OK. Anyone here would need to change the spark plugs and find that a completely legitimate reason to buy a new engine.

I think you should buy an MR2 to put the engine in.

N Sperlo wrote: Its OK. Anyone here would need to change the spark plugs and find that a completely legitimate reason to buy a new engine.

Yup

The flywheel end of the crank is shorter too, and I have been unable to find out if any mt flywheels will bolt up.

That said, I have a project I would love to try the FWD water pump and accessory drive in. If you decide not to use it let me know.

oldopelguy wrote: The flywheel end of the crank is shorter too, and I have been unable to find out if any mt flywheels will bolt up. That said, I have a project I would love to try the FWD water pump and accessory drive in. If you decide not to use it let me know.

http://ls1tech.com/forums/ls4-performance/1327008-starter-mount-ls4-fwd-f40-6-speed-manual-transmission.html

I think the Grand prix GXP had a manual transmission option. You could get a flywheel there. Does it have a standard chevy bolt pattern for the bell housing?

Fueled by Caffeine wrote: I think the Grand prix GXP had a manual transmission option.

Unfortunately, no.

And it has the 60-degree bell housing bolt pattern, which means a RWD flywheel would be too big.

you're first on the list for the FWD accessory drive.

the fiero swaps i found with a manual used a rwd flywheel, machined down to use the ring gear from a 142 tooth typical flywheel that something of a cavalier/cobalt/s10/etc would use on a little guy engine. there is no traditional starter boss on the block, and it looks from pics like the rwd traditional dowel holes are present, so that leads me to believe one may be able to drill/tap the block in the bigger bell pattern. who knows though, it's all up in the air until i get it on a stand next to the rwd block i've got on the other stand.

i'll be doing some comparisons between the rwd and fwd blocks side by side. good thing i've got a handful of engine stands.

if i were to do a whole swap with this engine i'd buy a wrecked donor and take it all, and transplant it into a 91-94 lumina Z34, i love those things.

doc_speeder wrote:

Fueled by Caffeine wrote: I think the Grand prix GXP had a manual transmission option.

Unfortunately, no.

Drat.

Fueled by Caffeine wrote:

oldopelguy wrote: The flywheel end of the crank is shorter too, and I have been unable to find out if any mt flywheels will bolt up. That said, I have a project I would love to try the FWD water pump and accessory drive in. If you decide not to use it let me know.

http://ls1tech.com/forums/ls4-performance/1327008-starter-mount-ls4-fwd-f40-6-speed-manual-transmission.html I think the Grand prix GXP had a manual transmission option. You could get a flywheel there. Does it have a standard chevy bolt pattern for the bell housing?

Nope.. and nope..

this would be a good match for it

http://akroncanton.craigslist.org/cto/4520807854.html

I think the F40 6 speed from the G6 will work with some effort.

I have a Dodge bellhousing that mates to the Aisin AR trans (AX15, Toyota R series, GM MA5 http://en.wikipedia.org/wiki/Aisin_AR_transmission) that has the GM 60 degree pattern on the engine side. I would be VERY interested to see if there is a starter solution to be had using that transmission. I am sure that we can work something out.

The first couple pages of this thread may be relevant to your interests.

LS4 & F40 trans Fiero swap

on a little v8 british car forum there is a whole deal about the ls4, the above mentioned dodge bellhousing, and attempting to mount a traditional starter. apparently the prototype ls4 had a front sump oil pan and the starter mounted directly to the bottom of the pan. supposedly some guy posted a picture of it and has the parts, and if he would have the pan cast it would open up a whole new source of cheap all aluminum v8's.

as it looks, having it in the garage right next to a RWD block, it really makes no sense. it would make more sense to buy a bare L33 block and crank and an ls4 and swap the rest of the guts/heads/etc if an aluminum 5.3 was the goal.

i will probably sell the shortblock and all the external bits one piece at a time to pay for my heads.

i will not be using the accessory drive or water pump, so it's available to oldopelguy for whatever we deem is fair, send me a pm on it. i've got everything but the alternator and air conditoning compressor.

But an LS4 is one better than an LS3! Don't give up.

stripped it to the short block in about 20 minutes.

zero ridge, beautiful bores, crosshatch looks like it could have been done 17 miles ago let alone 170k.

CLEAN heads

What ever came of this?

It's on an engine stand in my shop, the short block anyway. It may soon be trying to live in the engine bay of an Isuzu Amigo.

Ohhhhhh now that would be fun!!!

First or 2nd generation Amigo? I had a 2nd gen, and it was a really excellent little truck, had zero problems in 128,000 miles, took it on many well-known 4WD trails. Very ruggedly built.

I know you said you wanted the LS6 heads (243s), FYI you can get those on pretty much any of the newer smaller cube LSs and on older performance 6.0s (TBSS and GTOs).

The 799 and 243 is the same head, except in the LS6 they have the hollow and sodium filled valves.

I just say this because sometimes you can get a set of late model 5.3 heads for cheaper than real LS6 heads.

Also if the LS4 is just a standard style LS block it may be worth selling and going with a iron block, because last I looked the aluminum blocks were still big money.

The value of aluminum 5.3s skyrocketed when people realized that they could be bored out to LS1 spec to reblock broken 5.7s.

Me, I wonder how much weight you could remove from an iron block. Supposedly circle track guys can get 1/3rd of the weight out of a SBC block. The new engines are made out of decent iron and are WAAAY overbuilt, so I wonder. There are a lot of places that don't need bosses, or don't need THAT much metal to support a gasket surface, and you could probably shave half the main caps off and it'd still be sound.