LT1 or LS1 Motor Discussion of Pros/Cons

[Dean!]

This is to be a civil (ie. anti-Fair-antic) discussion about the LT1 and LS1 motors, pro's, con's and reasoning.

It will serve as a central place for people to review when considering the LS1 or LT1 motor.

I will start off that I am LT1-biased and I will post my thoughts on the LT1. We'll keep this as objective as I, err, Fair, err, anyone possibly can.

[Dean!]

First hand observation of the LT1 and LS1 motors

I purchased a complete LT1 motor (complete means all brackets, bolts, accessories [alternator, a/c compressor, power steering, pullies], sensors, wires, exhaust and intake manifold, throttle body, bellows, fuel rail, injectors, all internals - complete, for $1650.

I have owned 4 LT1 vehicles with over 120k to 157k miles and have had zero issues with oil consumption on ANY of them. 3 of them were ragged on pretty hard including a "dedicated" weekend racer.

GoldenBoyzOwnzNone dyno'd 396rwhp and I forget the torque. I'm not sure how modified the motor is, but I would not classify it as radical. I presume this number grows with aftermarket heads, possibly 430, I do not have experience in that arena.

It is QUITE true that stock head/radical cammed LS1 motors can make 380 - 390 rwhp and supposedly 430rwhp with mild heads.

I think the cost differential (buying a motor TODAY) is pro-LT1, as well as reliability (oil consumption, no bent pushrods, etc, oiling issues at high G's) is also pro-LT1. In 5 years, it would be pro-LS1, because everyone will have LS7's or something..

NOW 30-40lbs extra WEIGHT is a considerable issue...weight will ALWAYS be an issue.... you can move the battery to the rear, but so can an LS1....

If I could purchase a *complete* LS1 motor for $2k, then I MIGHT change my mind completely... I have seen similar *complete* LT1 motor deals in the $1600-$1800 range.

[Dean!]

LS1 GRENADING Experiences...

On the same weekend at Motorsports Ranch, 3 of my fellow LS1 F-body friends grenaded their LS1 motors. At one recent Mineral Wells event, another LS1 F-body grenaded his motor.

These are friend to friend (car owner) first hand reports (ie. NOT "I heard a friend of a friend")

The 3 F-bodies at Motorsports Ranch all had under 35k miles on their LS1 motors. 2 blew up that weekend, the third one would burn 1 quart of oil every 600-800 miles. He recently rebuilt his stock motor that had approx. 33k miles. One of the 2001 LS1 Trans Am owners did NOT claim his motor under his factory warranty since he knew why, he was accountable, and he wanted to rebuild it "better" than factory.

I cannot explain in "car technology-speak" what exactly is happening, but under high G's at high RPMS, the LS1 motor (at least in the F-body) is being starved. I believe Terry wrote about an oiling and frothing flaw in the oil drainback design - I cannot describe it more intelligently than that. [Fair: Chime in]

The 4th F-body friend had missing/knocking issues as if it were a bent pushrod - after overhaul of his motor, he realized he had grenaded his motor. He is currently saving up for a rebuild of his LS1 motor.

I personally bent 2 pushrods on two different instances - NONE of them were missing a shift, though I will admit to hitting the rev-limiter a number of times during various autocross events.

The second pushrod incident I was verifiably cruising around 75mph in 6th gear on I-20 at night - mind my own business when it went - the check engline light started blinking. After pulling the valve cover and rockers, I had a bent pushrod.

On LS1.com and LS2.com you will also find many stories of AUTOMATIC TRANSMISSION LS1 cars bending pushrods...how does an automatic miss a shift ? You will find many stories of people simply cruising their merry way when the check engine light starts to blink - upon further inspection - bent pushrod. Now those are second hand stories - so I cannot vouch for any of them, NOR do I know any LS1 Automatic Tranny owners... I have reason to believe they are true.

Lastly, I will add that the same owners mentioned above witnessed a bone stock C5 LS1 Corvette driven by Lou Gigliotti of World Challenge Champion fame get grenaded at Motorsports Ranch.

Motorsports Ranch driving school has grenaded stock LS1 motors in their Camaro SS' used for the driving schools.

Also, I can verifiably claim that a bone stock 2002 Z06 with *factory oil levels* (ie. NOT 1 quart over, just at the FULL mark) grenaded his LS1 motor and he got it covered under warranty with 9000 miles - while road racing his car. He was later told to always run a quart over - I'm not sure how much road racing he has done since that time.

Also, I rode in a 2001 Z06 with an IMSA driver and I watched as his check engine light started blinking when he hit 315DEGREES on his OIL TEMPERATURE GAUGE.... I was the passenger for one 20 minute session at Watkins Glen. Apparently he had a lot of money and somehow was good friends with the dealership, as he didn't seem to back off at all. He said it would get warrantied. Best ride of my life I will tell you that! I thought my arse was t1ght3r than a fr0g at the end of that session....

[Tommy R]

LT1 or LS1 Motor Discussion of Pros/Cons

Here's a question about LT1 vs. LS1.... How do their torque curves compare? I realize the LS1 has the horsepower. But, does it sacrifice low or even mid range torque in the process? I'd really like to see some overlapped LS1/LT1 dyno curves.

I'm still not ignoring the possibility of getting an LT1 (or LS1) F-Body to play with in F-Stock and eventually in ESP, so I'd be very interested in the torque numbers above everything else. The weight is obviously also a consideration. Other than improved brakes in the LS1, are there other chassis/suspension differences?

FYI, the LT1's are still showing top level competitiveness at Nationals in F-Stock.

T

[McCall]

LT1 or LS1 Motor Discussion of Pros/Cons

Here's a question about LT1 vs. LS1.... How do their torque curves compare? I realize the LS1 has the horsepower. But, does it sacrifice low or even mid range torque in the process? I'd really like to see some overlapped LS1/LT1 dyno curves.

I'm still not ignoring the possibility of getting an LT1 (or LS1) F-Body to play with in F-Stock and eventually in ESP, so I'd be very interested in the torque numbers above everything else. The weight is obviously also a consideration. Other than improved brakes in the LS1, are there other chassis/suspension differences?

FYI, the LT1's are still showing top level competitiveness at Nationals in F-Stock.

T

LT1's have lower end torque but I don't have any dyno graphs to overlap. Also, there are no differences between a LS1 f-body and LT1-body chassis/suspension-wise.

LT1 RULEZ!!

[Dean!]

LT1 or LS1 Motor Discussion of Pros/Cons

Seat of the Pants Meter will tell you that the LT1 has more low end grunt...

Dyno charts reveal that my stock 98 LS1 Formula had over 310 rwtq at 1800 rpms through 6200 rpms...peaking at 336 or so.

I need to look at my LT1 dyno chart, but stock for stock, I'm fairly certain the LT1 does not have as much RWTQ throughout the power band.

The LS1 is super super flat..it just starts high....

The LT1 climbs on strong....

Man, I think I wanna through it all out the window and get Todd's 69 Camaro!!!!!

[C3]

LT1 or LS1 Motor Discussion of Pros/Cons

Actually LS1s have different front spindles which _supposedly_ make them able to get a little more negative camber in stock form. Other than that, they're the same.

[Dean!]

LT1 or LS1 Motor Discussion of Pros/Cons

LT1's have lower end torque but I don't have any dyno graphs to overlap. Also, there are no differences between a LS1 f-body and LT1-body chassis/suspension-wise.

LT1 RULEZ!!

I still stand that LT1 RULLLZZZZ but I'll take some snapshots of my LS1 Formula and the LT1 Camaro dyno sheets latta tonight if I no forgetty....

[McCall]

LT1 or LS1 Motor Discussion of Pros/Cons

Actually LS1s have different front spindles which _supposedly_ make them able to get a little more negative camber in stock form. Other than that, they're the same.

Bleh, what did you read that on a ghey message board somewhere??

The different front spindle was just for a different brake caliper attachement. There is no difference in overall design. Swapped them back and forth no problem with little change in alignment. Heck, only the toe changed slightly since I got the alignment checked right afteward.

LS1 brakes on a LT1 car is a cheap and easy upgrade Tommy!

Oh yea, Dean, LT1's torque curves are very flat.

[Tommy R]

LT1 or LS1 Motor Discussion of Pros/Cons

LS1 brakes on a LT1 car is a cheap and easy upgrade Tommy!

Oh, I know. I'm just thinking of F-Stock and ESP, though.

T

[C3]

LT1 or LS1 Motor Discussion of Pros/Cons

Hey I said "supposedly" - but they are different, you admitted it yourself

[McCall]

LT1 or LS1 Motor Discussion of Pros/Cons

Hey I said "supposedly" - but they are different, you admitted it yourself

Yea but I never tried to spout some sh1t about them giving you better alignment specs

[Fair!]

LT1 or LS1 Motor Discussion of Pros/Cons

due to drastically short runner length on the intake, the LT1 tends to suffer in low and mid range torque, compared to the LS1 and even the L98/TPI. This intake "design" was an over-reaction to the piss-poor TPI intake design. It DID make a LOT more power than the TPI tractor motors, and for that, it was a success.

The other goofy features of the LT1, such as reverse flow cooling, opticrap distrubotor, and cam driven water pumps, have all been assigned to the scrap heap of history with GM's Gen III/IV engine designs. Luckily, no one else uses these design features/failures on their engines, either.

The LS1 basically makes more power than an LT1 at ALL rpms... low, mid, top end. Its a substantial difference, everywhere. And it fixes a lot of what was wrong with the LT1. Granted, they did use some weak ass valve springs for a motor that likes to zing to 6500 rpm in stock form. That has caused a lot of bent pushrods [a relatively cheap fix], but luckily, not too many bent valves. Amy's 80K mile motor never bent any pushrods... and she is mean to it. Not Duck Mean [tm] tho.

I have seen numerous stock LT1 Camaros dyno 250-260 rwhp, on many occasions. These were cars of people we knew, like Soup Daddy and Matteucci. Stock LS1 Camaros dyno 295-315 rwhp [depending on year, conditions, etc.] with 300 rwhp being common for '98-00 cars. That's 40+ hp different, and its everywhere. Its almost a second in the quarter mile faster. That's huge.
[list]Amy's stock 1996 LT1 ran a 13.8@101.5, driving the ever livin piss outta it[/list:u][list]I've seen stock LS1 Camaros run 12.8-12.9@109+ at HRP...[/list:u]

Then you get the weight difference... and the brakes... and it starts getting hard to justify getting an LT1 Camaro over one of the LS1 flavor. Cost is about the only difference, and that is deminishing greatly with time.

Modded, they do tend to even out [400 rwhp is an achievable goal for either], but only at some mod levels/costs, and even then, the LS1 can get bigger... and starts to pull away in the 7.0-7.4L LS1 stroker sizes. 782 crank hp NA LS1 - seen that first hand. WOW.

The LT1 really suffers at high hp levels from a lack of aftermarket or race blocks. The LS1 has so many block options: stock LS1, sleeved LS1, siamesed LS1, iron block LQ9 6.0L block, and at the top the big dog C5R block.

Fair

[Dean!]

All you ever wanted to know about LT1

Great website on LT1 history
http://www.automotiverebuilder.com/ar/ar99928.htm

[Tommy R]

LT1 or LS1 Motor Discussion of Pros/Cons

http://www.turbomustangs.com/forums/...threadid=32773