Need help deciding: LS1 or stroked LT1/LT4...

[Hemogoblin]

Man, have I been spending a lot of time lately searching the net on this subject. Maybe too much time (according to my fiance), but hey, when you catch the bug.... I'm getting a little ahead of myself with deciding on which way I want to take this T/A but I want to possibly start collecting parts sooner than later so... Ok, here's where I'm at:

I've got a 93 Trans Am, 6 speed M29, Moroso CAI, SLP 1 3/4" SS headers and Y-pipe, Random Tech single cat, Borla catback, stock 3.23's, and some little odds and ends (ie. MSD coil, etc. etc).
This car has about 100K miles on it (160K kilometers or so) and has absolutely no issues. It's always had Mobil 1 Syn and (knock on wood) has been a great ride so far. Only changed the water pump, and nothing else. Very lucky so far.

Anyway, because the engine has been so solid up to now, I really don't know if I want to pull it apart to stroke it. So here is my problem:

I also plan on building a Jeep Wrangler 4x4 (I've been heavy into 4x4's for the last several years and want to get back in ASAP) and would like to swap out the Jeep drivetrain to run SBC, etc. If that happens, I would LOVE to drop in the LT1 I have now in the TA because it is in such great shape, and has all the accessories. Now, if I do that, I would need to "replace" the engine My options?

Well, I could get a 383 stroked LT1 built already, minus intake and accessories. The intake is OK because I can get a LT4 or ported LT1 for "cheap." Accessories are no biggie because I would replace most of them anyway (ie. water pump, Opti) but it would require buying AC, power steering, etc because I would be transfering all that to the Jeep too with the old LT1. If I decide to do this, I would at least be able to drop it in the stroked LT1 with no wiring, etc. I would have to reprogram the chip, but beyond that, it would be done. Now, depending on the options, and wanting to keep it daily drivable, what HP should I be looking at? Should I swap out the rear to maybe 3.42? With the M29 6 speed, the 3.42 will be equal to 3.73 in a later model F-body.

OR, should I just get a complete (with accessories and all) LS1??? Man, that sounds so tempting, but would it really be a wise choice? I have to admit, my knowledge of LT1's is limited, but even worse with the LS1's, so I could use a hand. My biggest concern is that I'll only be getting modest performance increase with the LS1 because it will essentially be in stock form aside from headers (new ones for the LS1), Y-pipe, and the existing Borla. Because the LS1's are OBD 2 (or is it 3?), I remember always hearing and seeing that simple power programmers can get A LOT of power out of them! That, I like And because it's all aluminum, no Opti, etc. is even better. And for the cost of a stroked LT1 with all its goodies, compared to a complete LS1, I'm not looking at much of a difference..... hmmm......

The only difference is that the LS1 would need a new harness but if I got a complete one, wouldn't it really just plug right into the F-body, with a new computer? I would think so..... but again, I don't know. Anyone know?

SO, what would you do???? Please, I'm not interested in adding a blower, turbo, NO2, or the like. It's really a NA choice. Or if you can suggest something even better than the above?

I thought about even getting a LS2 but was concerned about wiring, parts, etc. because it is still a relatively "new" engine. Maybe even a stroked LS1? Anyone?

The other question was if someone could provide me with HP figures from various LS1 mods and parts. If I'm looking at 450-500 HP with a stroked LT1 what would I be looking at with a HPP, exhaust, etc. on an LS1? Even a stroked LS1? Anything you guys can say to swing me one way or the other would help. Please do

Thanks for listening.... wow, that was long....

Cheers,
Steve

[Injuneer]

The LS1 is not as "plug and play" as you appear to assume. You would have to change a lot of parts you probably aren't thinking of:

-Tranny: LT1 T56 will not work with an LS1, input shaft and clutch are different
-Clutch/hydraulics/bellhousing: Ditto
-Complete PCM: LS1 has too many differences, direct fire ignition, etc., PCM is much faster, more complex
-Fuel system: LS1 uses a 'dead end' system, LT1 is recirculated
-K-member and motor mounts: completely different
-Radiator: LS1 is "conventional flow", LT1 is "reverse flow"
-Hood: LS1 is slightly taller
-Front springs: LS1 is lighter, car would sit too high

Probably a few other items.

Just assume the LS1 would be 50HP higher than an equivalent LT1, with equal mods.

[Hemogoblin]

Thanks Fred, I was actually hoping you would reply. You know your stuff (as I've seen from your previous posts) and I respect your input. I really didn't know about some of those related parts.... has me thinking now....
The tranny wouldn't be a problem because the engines I've been looking at usually come with a tranny, and one in particular with the T56 so I'd be good there. The PCM I figured would need to be swapped, and I could get the one from that engine/tranny combo. K-member I didn't know about but shouldn't be too hard to get around, as with the springs, rad, etc. But you're right in that they add to the "hassle" factor, and maybe more importantly, the cost.

I'd really like to know what you think about this: would you personally bother for the comparative extra 50 HP, and reduced weight? Or should I just stick with the LT1?

Thanks :-)

Cheers,
Steve

[soCalTA]

If it were me.......

I would leave the TA alone .. It aint broke... dont brake it ..
Drop in a new motor/tranny combo into the jeep. Assuming you have endless streams of cash .. then you can go back and work on the TA. Ported LT1 or LT4 heads ... new cam, etc.

[Dave M]

If it were me, I'd probably rebuild the LT1 when it comes time, and build it up then to how you want it for the TA. Find a cheap SBC to throw in the jeep. If you're determined to put that LT1 in the jeep, then stick with an LT1/LT4 for the TA. Much less hassle, and if built right you'd be smoking most LS1's out on the street.

[casey02ws6]

I would keep the LT1 in the T/A - new combo for the Jeep - much less hassle. Although an LT1 powered Jeep would be cool - I am seeing a car trailer with your T/A on back pulled by an LT1 powered Jeep As for the T/A's LT1 - it has plenty of potential. The LT1 is cheaper to mod than the LS1 too so there is no reason swap it at this point! Just my .02.

[Joe 1320]

If it ain't broke, don't fix it.

Seriously, when the time comes I vote for an LT-1/LT-4 build.

[thenuge876]

Another vote for keeping the LT1 it just seems like it would be too much of a hassle to put the LS1 in there, it seems like it would probobly turn into a much larger project than you originally anticipated, while you could instead create a rather stout LT1 that would smoke a lot of other cars.

[Sean 94z28]

Hemi Wrangler

Get conversion here

Sean

[Hemogoblin]

LOL Hemi conversion.... been thinking about that actually Haven't seen any prices yet though. I'll check out those links in a sec... I'm currently in Australia so because of the flip-flop time difference, I tend to see all your responses late in your evenings, so sorry for the delayed response.

I guess the votes are in, and looks like the LT1 has won. I was leaning towards the LT1 because it really has been good to me, and once it gets stroked, etc., I think the differences between the 2 engines would be negligible. But I don't plan on just running this one until it needs to be rebuilt because it defeats the purpose of wanting more power, now. If anything, I'll keep this one as is, totally complete, and just buy a Painless Performance LT1 wiring harness and swap in the engine into the Jeep. Then just buy a complete, stroked LT1 with better heads and all, new intake, new everything, and just drop it in with new headers and Y-pipe. I HATE the SLP headers I have now. Totally poor design and I would NEVER recommend them to anyone. First off, the AIR fitting was in a very bad spot and required some bending of the tube to fit, the flanges to the Y-pipe are only 2 bolt, and surprise, surprise if a bolt breaks (like it did for me ) you have an eternal leak. Now I have to remove the header to extract the broken bolt, remove the darn "flange" and weld on a 3 bolt flange. I hate doing work that should have been done by the manufacturer in the first place.... Oh, and to top it off, the Y-pipe is the most poorly designed piece I've EVER seen. It hangs so low, that going over speed bumps in mall parking lots causes it to scrape (my car isn't lowered). And it didn't line up properly with the exhaust either. So, it's coming off with the engine, and going into the Jeep. I've been running it for well over 4 years now and it's the only thorn in my side with regards to this car. I'll likely just scrap this Y-pipe and build my own.

The only thing that concerns me is that the Opti is so low on the LT1 that it'll surely get soaked when crossing creeks, or hitting mud holes. Any idea on how to protect it? Seal it? Anything????

Cheers!
Steve

[94 formula]

I'm going to have to go against the popular opinion and say LS1 unless you are going to do atleast heads and cam with the LT1. Just adding a cam to a LT1 won't get you a whole lot without doing some work to the heads. LS1's have been around long enough to proove that they are more reliable especially in the ignition area. They also have a 6 bolt main compared to the LT1's 2 bolt. Also with an LS1 you could just add your bolt ons and a cam and be close to if not over 400hp. If you would go with a stock LS1 and just drop in a moderate cam you would be amazed at the performance it gains. The LS1 is more powerful than the LT1 stock for stock but the difference is not that big the big difference is with a cam and supporting boltons you can get so much more out of a LS1. I'm not bashing lt1's I own one but the LS1 is by far superior in about every area. I own a LT1 and my brother owns a cammed LS1. Stock for stock I was right with him till around 60 mph then he'd pull on me like crazy. After adding a medium cam (112LSA, around .58in lift intake and exhuast) with headers and CAI he pulls on me like crazy all over the powerband still idles very smooth after having it tuned, also we got an average of 27 mpg on a cross country trip. After seeing this I will be picking up the first nice LS1 fbody I come across when I'm out of college and ditching my LT1.

[Hemogoblin]

OK, so after much thought, and seeing that link to the HEMI Jeep, I think I'm going to keep the LT1 as is, and just swap out the cam, heads, intake, etc. and add rear gears. It should keep me happy for a while But then I did some searching here, and saw that it would probably be a good idea to change the cam bearings to prevent premature failure. Now, knowing what I know about a SBC, but more importantly what I DON'T know, is that possible to do with pulling out and disassembling the engine? I have no idea how to get the old bearings out nor how to get them in. I tried searching the net with no success but I did see a tool used to install and remove them. Not sure how I would use it though! LOL BTW, even if the from clip and rad had to come off to do this, I would. Better now than later. Thanks

Cheers,
Steve

[Sean 94z28]

I have the same question. Although I think they are refering to spinning a bearing that connects the rod to the crank and not a cam shaft bearing.

So my version of this question is: what do you do to prevent a spun bearing (is simply replacing them enough?)? And two, how easy is it to do without removing the whole engine?

Hemo, I know you can change the cam while the engine is in. You just have to raise the AC condensor carefully up and out of the way.

Thanks,
Sean

PS, big drool on the Hemi coversions eh, Hemogoblin? Saves gas over the 4.0 too.

[Hemogoblin]

Tell me about it! What I would do to have one..... the only thing I noticed from that AEV Conversions website is that it appears you have to buy a brand new complete Jeep directly from them? And I can only imagine what they would charge.... They don't have prices listed though, yet, so who knows. But I'd be curious to see what they charge because if you swap out the engine for a Hemi, the front and rear diffs for a HP D44 front and HP D60 rear, and the tranny for the 5 speed auto, do they discount the cost of those brand new parts for you? IE. why pay full price for new parts you don't need.... hmmm.... guess we'll have to wait and see

Back to the F-body: I do plan on changing the actual cam while the engine is still in the car, but what about the cam bearings? Can that be done? Or does it need to be done at all??? Although my engine has 100K miles, I feel the engine is in great shape but I'm sure there is some wear. There has to be. That's why I wanted to change the bearings. Anyone?

PS. Sean, are you into 4x4ing at all? Or just a big Hemi fan

Cheers mate,
Steve

[Sean 94z28]

Just got back on the 4 wheel scene with an 05 Rubicon. Need to put the Z back on the road and then the next round of mods go on the TJ. Would highly recommend the Rubi. And use your LT1 for your economy car.
Wish I was joking, 2 ton brick walls don't get good milage. That's the Jeeps only downside. 13-14 MPG city.

Have fun bro!
Sean