VikingTrad3r

1stVetteFinally

From what I've read, at least for the LT SBC, 400 RWHP is possible for around $1200 USD. If you have a '94-96 LT1, for another $2k, you can get the tunability of the LS platform. And if everything goes right, by the end of this year, the early LT1 ('92-'93) will have this option available. $3500 for a head/cam swap and ignition change over is better than what a LS swap would cost, provided you can do the work yourself and save on labor.

http://elliottsportworks.com/home/?page_id=51
http://www.torqhead.com/buy-24xlink-...=0&sort=normal

Tom400CFI

Many inboards have been using the "LS" (Gen III and IV) in boats for many years now. It IS odd that Merc isn't yet. RPM can be changed w/a cam.



I'm pretty sure that's not true. In fact, one of the advantages of the Gen III^ is that you don't even have to pull the intake for a cam swap.

dclafleur

I think it's a lot of different factors. The reason I weight an LSx over a traditional SBC is the number of things I'll probably replace even if I were to stick with a SBC.

I'd likely redo my ECM as an '85 is a bit of a pain to find a tuner.
I'd redo my harness because my harness is in rough shape as most early C4 harnesses are.
My current block is a 2 piece RMS and if I pull it I'd like to go with a later 1 piece which would require me to replace my flywheel anyways.
With both I'd end up redoing my exhaust including headers too.

At some point with all the changes that crop up the LS motor looks like a good opportunity. From a maintenance perspective, the LS motors are almost magical compared to a SBC. Pulling the intake manifold or valve covers are far lower drama than on an SBC. I can't say that it's "worth it" to anyone but there are a lot of potential upsides to an LS motor.

aklim

Way I am looking at it, the cars are NOT an investment. Most of us are not looking to get rich from it. In fact, if we are not driven to the poor house and selling organs to get money for mods, we are doing good. That said, like everything else, there is depreciation since you got your use out of it. Roughly, if it lasts 10 years and costs $10000, it cost you $1000 a year to have fun. I buy a $10000 car, put $10000 into it and it lasts 10 years, it cost me $2000 a year for that fun license.

Assuming you get a LS3 crate motor, we are talking $7000. Compared to a LT1 or L98 long block of that same power rating and we are probably about the same place price wise. About $500 for the adapters to install the motor and trans, if I am reading this right. Now the fun begins. Accessories and hoses and sensors might not be reusable from the L98 or LT1 or you have to fabricate stuff which cost money. Changing over might be another $2000. Dyno tuning is a wash so we might be looking at several thousand more for it to get working. If you get a built LT1 or L98, it will drop in and use the same sensors, wiring and hoses.

Most of the builders I talk to seem to think it might be cheaper and easier to just throw a supercharger on it than to go LS since the engine isn't going to just drop in assuming you want everything to run right with all the accessories. I'd really love to see what the LS can do but as was told to me "Man's wants are many but his resources are limited" and unlike the accusation of the government, I can't simply print more money and kick the can down the road for everything I want.

aklim

As I understand it, the 85 doesn't talk to as many scanners as the later ones?

I think you don't have ABS or climate control so it may take some wiring work to the dash which you can replace with a rectangular panel and some gauges? Have you asked the speed shops around you? When I tell them I want things working as they were, they basically said "Time and Materials" basis which is why I like it from a technological standpoint but my wallet doesn't when it is a black hole project.

WileCyot

If you can and will be fabricating the necessary parts, doing the wiring, etc go with an LS. If you're mechanically ignorant and shouldn't be considering this, stick with the LT. If you are the latter but have a fat bank account, do whatever your heart desires.

dclafleur

My '85 is a black hole project but it's sentimental so no biggie for me. The gauges are directly fed on the '85 and output some values to the ECM so it can be wired in without needed to do anything outside of what I'd have to do for aftermarket gauges anyways. There is a guy in town who would tune my '85 I'm lucky in that regards I just like to use it to do stupid hot rod things with (hence my T56 transmission).

aklim

Then the path is clear. LS project is a good idea. No worries about who tuner is since you are able to get a dyno tune almost anywhere, relatively speaking.

I'm taking the fifth on it

C6_Racer_X

Unless I'm doing crazy forced induction, I prefer the aluminum block car engines. They are more expensive, but how much would you spend elsewhere on the car to ditch 200 pounds of weight?

I generally shop around for an entire donor car, buy that and part it out. I keep the engine (and often the transmission, especially if it's a manual) and sell off the remaining parts. I've never made a profit that way, but I've come within $400 of breaking even while still keeping the engine and transmission. $400 for an LS2 engine, a 6 speed manual and all the accessories and wiring harnesses to make it all run is a better deal than I've ever gotten from a pull it yourself yard.

Tom400CFI

I love it when people post this kind of stuff. 200 lbs? 200 lbs?? I don't care how much you spend...you could buy a million dollar, titanium, aluminum, beryllium, unobtainium block...and you ain't gonna save 200 lbs. How do I know this? B/c a plain old cast iron SBC only weighs ~150 lbs...so unless the Gen III weighs less than nothing...you ain't savin' no 200 lbs.

C6_Racer_X

My mistake there. The aluminum block LS2 6.0L aluminum short block I had on my scale a couple months back was 112 pounds lighter than a 5.3L LS1 iron short block. I weighed both with crank, rods and pistons installed, no heads or manifolds. Part of the difference is due to different displacement, but primarily it's the back itself.
I should have said how much would you pay to shave 100 pounds +/- of weight. It's still a significant weight savings, and you'd pay much more for lighter parts in other areas, and 100 pounds is a lot of weight on a sports car.

dclafleur

The aluminum blocks weigh in around 100 lbs. The iron LS motors are heavier than a SBC (unless you're comparing to an iron headed SBC).

Racer posted up a correction while I was typing we're all on the same page now

Tom400CFI

Copy all of that, and I agree....100 lbs saved up front is great. That's a big deal. But 200 lbs from a block? Nah!...nope.

cardo0

Yes, the GMPP catalogue lists weight for a iron sbc block at 185lbs while the GMPP aluminum blocks run 89 to 101lbs. The GMPP catalogue doesn't list any weights for their LS aluminum blocks but I did find a 225lb weight published for the Bowtie LSX iron blocks. And I recall the LS oil pan is fairly heavy piece - at least compared to a stamped steel sbc oil pan.

It kinda grinds me too when people post bad information like that. I may sound like I'm picking the LS apart but what I'm trying to say you have to consider the entire package and the LS aluminum package would be very fortunate to save anyone 100lbs over a sbc. Bot I will say you can buy brand new aluminum LS blocks from the vendors under $1800 where as a aluminum sbc block is over $4000. That makes a LS swapped car a reasonable motor to repower if you are truly in love with that car.

And the LS block deck is taller using the same bore spacing as the sbc making it a wee bit taller. Some claim that's not as compact as a sbc but it's only a quarter inch. Head's maybe a bit taller to though which can add up to a clearance problem with the hood.

Myself I have little trust in shops that advertise LS swaps/conversions. It takes not only a good mechanic but someone that can fabricate parts when needed and electrical wise technicains to make it all work with the stock instruments and controls. Ohms law alone won't cut with modern computer controls. And LS swap kits are limited in scope as the different models are unlimited. I don't think you will find a complete kit for any car and you are left on your own for much of the swap.

Reap up and think it over before you take the leap.

rlane5

If you can do the swap yourself, the cost isn't too crazy. I brought a rebuilt Jasper 6.0 with 35xxx mi. on it, from a person that had it in his pickup, that he said, his friend wreck. I paid $1000 for it. ( I wonder are they still friends LOL) I did the wiring myself and brought a tuning program to turn off the VATS. I brought stock C5 and Camaro parts to install it into the car. Once I started doing mods the cam cost more than the SBC, the headers were about the same price, and the intake which I just updated to a FAST a month ago was about the same, I had some 5.3 heads ported for $1150. I had a Super Ram, Hooker Headers, and a set of ported Dart Iron Eagle on the SBC. I ended up putting a LT1 conversion intake on the engine. (355) The Small Block Chevrolet is a great engine, but the LS and the new LT Gens are even Greater

Randy

Mike Holmen

Because you can. You could put in a BBC as well, probably cheaper power wise. I prefer LS design VS. the sbc, sorry guys, that just me. The gasket design is better, water pump is better. The motor isn't prone to over heat. Roller cam stock, awesome flowing head design. The catheral, LS3 port (rectangle) and LS7 (larger rectangle) just flow tons of air. A stock 0317 head has enough air flow for 500HP, without porting. Just has an overly large chamber (good for the boost adders).

Sorry guys, there is nothing wrong the SBC. I've just had over 20 SBC vehicles over the years

84 4+3

Well the inboards are a different animal, you can play with the gear boxes a lot more. But swapping a cam for low end power beats the whole purpose of the ls too... sort of. On the I/Os Volvo and merc just recently dropped the 350 actually. (They have it as a 300hp iirc still but the mid range 4.3 to 5.7 is gone) Merc uses some 4.5l v6 they built in house and Volvo did what ever they do. (Probably messed it up like when they dropped the tamd) With the sterndrive you're limited with the double 90 degree gears on rpm. The jets also use the ls. Now if I remember correctly the 496 was gen 3 and an excellent motor. The 454 and 502 were both gen 1 (454s liked to blow up according to my father. The 502s used a lot of oil) And mercury racing stuff is just insane. I thought the lt5 was cool then I saw one of those.

I think the problem is that with all the new regulations a sterndrive is already more money up front so swapping to ls would add even more and then you have to deal with making it marine ready yada yada. I see ls in drag boats and very light race boats a lot. Not saying that's all they're in. I grew up learning on the old stuff on boats so in my opinion a boat should be a cable steering box and a carb.

And as for the cam swap, the lifters don't clear the heads, the new stuff has a hole you slide a retainer into iirc but a large chunk of them have to have the heads pulled to get the lifters out. They overhang too much. I could be wrong on that but that's what I was told...

Now back on topic because I've derailed this enough. The ls is the good stuff.

rlane5

Cardo0, You are 100 % correct I've been doing mods on my 86 since 2005, and in 2013 I went to a LS platform

81c3

[QUOTE=Tom400CFI;
I'm pretty sure that's not true. In fact, one of the advantages of the Gen III^ is that you don't even have to pull the intake for a cam swap.[/QUOTE]

You are correct. You dont need to pull the heads on an LS to do a cam. You can hold the lifters in place with wooden dowel rods actually.... Ive done it and it works like a charm!