6' posed an interesting question about the LS series engines....

SO just perzactly what do they bring to the table, for the effort/expense..???

down to the nitty gritty so to speak....

open topic far as I"m concerned....

for instance, I have an #113 stock 194 valved aluminum headed 4 bolt main truck roller '89 355 block with ZZ9 cam, all roller....ten years old cam design....anyway it does 375 hp at 425 ft lbs....supposedly...large TPI induction, base, runners, manifold, tbody....most of the crap making it a hotrod engine....runs FINE, NOW....

finally....

but....so over that combo, just what does the LS engine save me in WEIGHT, Fuel economy, Tunability (PIA for ME what with '80s computer crap and all)?? will it bolt up to a 'standard Chebby bellhousing pattern?? given that I have all the other standard hotrod tricks, lets leave out all the headers, accessories/etc....
just what does it bring to the table??

lets assume for conversation it does the 'same' power levels....

 

It is all aluminum with a plastic intake and weighs about 100lbs less than an iron block/al head/al intake engine. With 1 3/4" headers and the stock efi intake it makes around 450 hp and will pull to 6500 rpm. I have an engine dyno sheet somewhere of 467 hp using 1 7/8" headers. This is with a stock cam of 204 degrees intake duration. Should I stop now?

 

Biggest thing is incredible flowing heads. That's where the power is anyway. No way to get better flowing heads for the $$$. There are several over the counter versions from GM that spank the best aftermarket ones for the 23* motors.

They have pin guided pistons, 6 bolt mains, good sealing front and rear, all aluminum..or iron versions are available.

Not real impressed with the oiling system.....but they do have a gerotor pump design.

Other than being *butt ugly* unless you lose all those coil packs somewhere and do some trick valve covers...they are a pretty killer motor.

But primarily it's the heads!

JIM

 

Yes the heads are 15deg ( correct me if I am wrong ), but they won't beat any 15 deg aftermarket heads

 

Well, all that and it looks like Johnny Friggin Space Rocket under the hood

 

light, computer run fuel injection and timing, 120,000 volts to
plugs, 15 degree valve heads, with spread intake runners, spread
exhaust runners. cam bearings bigger, cam drilled in center for
reduced weight, oil pump driven off crankshaft not camshaft.
taller deck height 9.20 block, deep skirt design 6 bolts ( block and main caps completely suround crankshaft ) taller deck height allows 6.125 long
rod.

 

OK, so far, i'ts 100 more hp, nice, but I seldom ever wind out an engine 5 grand is it, and that's very seldom....I"m from the olde tyme Pontiac school of thought tons of torque at idle tap the throttle and the car goes ape tschit....so what are the specific/actual torque specs for these engines at what RPM? is there a comparo chart for the LS1 vs LS2/etc???

100 lbs less weight is nice, but I would have thought it should be 200 lbs minimun....plastic intake vs this cast aluminum TPI crap....heads should weigh the same, but that block should weigh a LOT LESS....better than 100 lbs I would say, NO?? why not??

rotating assy would be damn near the same..crank/pistons/rods/cam, chain/etc...

what about the bellhousing pattern?? how about the crank pattern??

I know engine mount kits are cheep/available...plumbing is just that, plumbing, no rocket science....not sure about the serp drive....
electricals don't bother me one way or another....

This 'concept' for my '72 here is just in the dream stage now, I need certain basic information as above....thanks guys...

 

look, if you want to make it difficult, go ahead and swap. if you want the same power for less, get a cheap 434 shortblock from ohio crank, buy the 220 eliminator heads and have fun. if you want the best heads, buy some 15/18 degree heads and invest in a stout shortblock. the reason for the weight being close is the block being slightly taller, and additional support being cast in. i think ls1 are 17degree, and ls7 are 15 or 12degree. they all are great and can make alot of power. what do you want to do work to swap or drop in and drive?

 

 

The bare block itself probably weighs half that of an iron version, that's allot.

Or you could say the iron version weighs twice that of the aluminum, sounds even more impressive.

 

The reason for "only" 100 lbs is because of the extra material(volume) in the block and heads. The block is a deep skirt design, it goes way down compared to old design, the six bolt mains spread all the way across for cross bolting, the webbing is larger, the bore thickness is greater(sleeves plus blocks AL), plus general increases here and there in the block and heads. It is alot stronger the gen I or II. The bellhousing pattern is similier enough to bolt up anything old, there is one new hole and one eliminated but the crank offset is different, simple fixes for this are available. Crank pattern is diff, just get a new flexplate/flywheel. No, its not as simple a swap, but the aftermarket has us covered and it is worth it if you're starting with nothing any way, or realy want the best.

 

I just brought my new engine home tonight and it is still in the back of the truck. I will not do the swap till later in the fall but I am looking forward to it. I actually think the look of the LS is nice between the fenders of a C3. I borrowed this pic from an LS swap site I found.

 

When you have the ability to do it you will. At redline my C5 would break the speed limit in first gear!!!

 

Yeh, I well might, IF I did the swap....this bellhousing stuff is a bit disconcerting though, that moves either the engine forward or the tranny backwards for an inch or so for the adaptor plate, something expensive, I"d bet, don't remember them being too cheeep in the past.....

Disconcerting thing in that LS swap engine in the C3 there....no a/c....this is Florida, and so some daze, a/c is a necessity....gotta B....

can it be done with stock a/c plumbing?? just a compressor change??
I have an '88 vette compressor on my '72 presently, any similarities with the LS a/c compressors??

 

The LS2 is the way to go right now. There is a kit out ther from GM with heads, intake, and 90mm throttle body for $1,100 that will put you right at 500 HP. With a cam you're over that.

AC? There are kits out there, but they're not cheap. Somone on this forum has a kit that uses the same compressor you're using. He got the brackets from a guy in Cali, and if that would probably be your cheapest route. I don't have the information anymore. All I remember is that the guy drives a red Vette, so an in-depth search of the archeives would probably be your best bet. I went with Street and Performance for mine because of the supercharger. That's about a $1,000 kit with the Sanden compressor. Doing that with Vintage Air so that I can keep my firewall clean.

I would just get a LS1 with a T56 or 4L60E. Not sure what tranny you're running now, but overdrive is nice.

There are other problems like guages. Your stock speedo won't work and your tach has to be modified. The rest are pretty easy fixes.

After you work on a LS you'll realize just how much better these engines are the the GEN I's. Like others have said the weight savings isn't ALL that much, so you can save about $1,000 by using an iron block LS variant if you wanted to.

Here's a pic of the Street and Performance kit. The sandbags (1,100 lb. worth all over the car) are because I'm trying to see where my ride height will be.

 

You don't need an adapter plate for the bellhousing and it does not move the tranny front or back. There is only one bolt hole you will not use because they moved it on the LS, it's not enough to worry about. The differance is in the crank position, but GMPP has a pilot bushing just for this, cheap and easy.