i am going to look at a complete 3400 LA1 engine today at a local j/y.  i was planning on trying to get the heads/intake but wondering if i should just get the whole thing?

would the CR be too high for 10-12psi boost?  as far as i know the LA1 is 9.6:1.  this would be with either the GT2871R or GT3071R-WG turbo and using a FMIC.  what would the CR be if i used the 3400 heads on my LG5 engine?

i'm just trying to weigh the pros/cons of turbocharging a 3400 or using 3x00 top-end on my LG5.  i kind of like the idea of the increased displacement ecspecially if i can get a complete 3400 on the cheap. 

5 or 6 pounds on 9.6:1 on 92+ octane pump gas at our altitudes would be a safe combination.

Now I guess I need to do some research...but I thought the 8.8:1 in the LG5 was set by the pistons. I thought all the heads in the 3x00 series was a set deck and bowl height and no change in compression between all of them.

I need to do some research...but I think I am right. :icon_neutral:

just got back.  it turns out that the 3400 was locked up.

anyway, i did find a complete 2001 LG8 3100 engine...also blown (had a cracked oil pan anyway).  same topend as the 3400 as far as i know except the plenum says 3100 instead of 3400 of course.  he told me i could have everything from the heads on up for $150 so i will be picking that up on Friday.  looks like it's gonna be 3x00/LG5 after all.  i'm a little worried about the valvetrain part of the swap but it shouldn't be anything i can't handle.  i have alot of research to do.  i hope Jud and/or Shawn can help me out when the time comes  :icon_mrgreen:

There are guys on clubgp with turbochargers and around 9.5:1 compression running quite a bit of boost(I know I've seen some running upwards of 12-13psi and turning high 11 to low 12 second ET's there).

change of plans already :icon_exclaim:

i just bought the complete 3400 LA1 engine.  the guy had told me earlier it was locked up but it wasn't - i turned the balancer over by hand.  that was enough for me to chose the 3400 over the 3100  :icon_mrgreen:  the oil IS milky though so it will need a rebuild if i actually plan on going the full on 3400 route instead of 3.1L GEN-II/GEN-III hybrid.  i am really liking the idea of increased displacement, improved oiling and full roller valvetrain.  not to mention i could keep my TSTE's LG5 intact.  oh didn't cost anymore either.  $150.  not bad.

i'm going over with my brother's truck to pick it up in about an hour.  i'll have to post some pics.

http://www.turbosedan.com/ste/3400/DSC02559.JPG
http://www.turbosedan.com/ste/3400/DSC02560.JPG
http://www.turbosedan.com/ste/3400/DSC02561.JPG
http://www.turbosedan.com/ste/3400/DSC02562.JPG
http://www.turbosedan.com/ste/3400/DSC02563.JPG
http://www.turbosedan.com/ste/3400/DSC02564.JPG

Good find that thing looks almost new.  :icon_cool: I just put a 3400 block under my 3400 top end. Bent a rod in the old 3.2 when I ran out of gas the last time at the strip on an 8.6 1/8 mile run. :icon_redface: Oh well it served me pretty well.  :icon_sad: I coasted to the end. I am up to 10# boost on 93 octane with no knock counts. I am guessing, but maybe with a little spark retard 12 or 13 is attainable on 93 octane.

Get that thing in there. There are a few thing you gota do but it's worth it. The AC mount is the worst part. :icon_evil:

Jud

You got that for $150???? :icon_eek: Do they have others there??? Son of a...!!!

Personally I would go 3400 on top of an LG5 bottom...but that is something stuck in my head for a while now. It scares me to put a N/A under boost conditions just becuase it wasn;t built for it to bgin with. But if you build it right it would be a monster!

Quote from: TGPilot on May 05, 2006, 09:14:50 PM
You got that for $150???? :icon_eek: Do they have others there??? Son of a...!!!

Personally I would go 3400 on top of an LG5 bottom...but that is something stuck in my head for a while now. It scares me to put a N/A under boost conditions just becuase it wasn;t built for it to bgin with. But if you build it right it would be a monster!

i am one of those people with the belief there is nothing special about the LG5 shortblock.  i just haven't seen any direct proof that anything about it is better than the LH0.  besides, the LH0 shortblock in my Cutlass right now is doing awesome with 11psi shoved through it despite having 250,000 miles.  that thing just won't die and i am hard on it!  i think if anything the GEN-III is even stronger than GEN-II.  it is higher compression but also sounds like it's less prone to detonation.  the only thing i'm worried about is pistons.  custom forged pistons would cost $$$ but i could get them with a lower CR.  i want pistons that will reliably support 350whp and i don't know if stock cast pistons will cut it.  i think one downside to the 3x00 is lack of aftermarket roller camshafts but i haven't looked around yet.

just two weeks ago i had not even considered doing this.  then i started looking at the aftermarket turbos.  at first i mainly just wanted to upgrade with a larger turbine in mind.  GT28RS looked good, GT2871R looked better but the compressors were soooo big on GT2876R, GT3071R-WG, and of course the GT3076R-WG.  3x00 topend started sounding like a good idea.  then my brother spotted this 3400 in the j/y and next thing i know it's sitting in my garage.  the 3400 block just has advantages over the 3.1 block that i don't want to pass up on and i feel it will be a better foundation.  unfortunately the GT3076R-WG and FMIC will have to wait until next year....but i'll be ready for it :icon_biggrin:

there is still that 2001 LG8 3100 sitting there.  i could probably go get it and store if for you until you have time to come and get it.  it's just as clean as the 3400 i have is but i did notice that the oil pan was cracked (looked like someone overtorqued a bolt).  i had my choice of the two for $150.  of course, i still have that LG5 shortblock sitting in my garage if you'd rather go the hybrid route.

Sweet. :icon_mrgreen: Just FWIW, 300whp would push you well into 12 second ET's(mid 12's are more than possible with that amount of power. To give an example, a 94-96 model GP with an L67 swap + some modifications made about 270whp on a dyno and was turning high 12's @ 104-105mph on drag radials). Drag radials or slicks are going to be a necessity at the track in order to achieve some ok times with that power level.  I think you'll be fine on the stock 3400 pistons as long as you have a good way of tuning the car.

Josh, I think I told you about this before, but "Germ" has(had?) a turbocharged 3400 in his Monte Carlo that trapped 106mph at the track(T3/T4 hybrid @ 10psi).
http://www.cardomain.com/ride/271653

He's updated his page now, he didn't have all those modifications at the time of that run w/ the 106mph trap. Found a old post of his....

"i was running a steady 10-11 psi all day, everyday on a completely stock engine (minor polishing to the tb and intakes)," He mentioned in that same post about doing some computer tuning via a DHP powertuner.

I would imagine that 106mph would equate to about 280whp in one of these cars.

My engine has ~9.5:1 compression and runs 10+ PSI.  Yeah its at 4700 feet though.... :icon_neutral:

I agree with Kenny on the Hybrid swap.....am for this more because there are aftermarket cams readily available.  The roller cam really isn't going to gain you anywhere, its main advantage is ramp rates can be crazy high.  I don't think the idle motor would really enjoy running a car with 5 in/Hg of vacuum :laugh:.  The TGP/TSTE cars would actually be able to do this since vacuum brakes aren't a concern :icon_cool:

i started tearing it down today.  i haven't pulled the heads or oil pan off yet but i think it's safe to say it was a LIM gasket failure.

http://www.turbosedan.com/ste/3400/DSC02576.JPG
http://www.turbosedan.com/ste/3400/DSC02573.JPG
http://www.turbosedan.com/ste/3400/DSC02575.JPG
http://www.turbosedan.com/ste/3400/DSC02578.JPG
http://www.turbosedan.com/ste/3400/DSC02586.JPG

LOTS of sludge.

Chocolate MilkShakes anyone...Josh is buying!! :laugh:

Looks like my old 3.1 when i broke a headbolt......

Yuck!!!

well hey, thats a good price no matter whats wrong with the internals, although not too many of those very common intake failures are not internal, usually outside or just a severe oil leak.  Although I changed the oil on my buddy's 99 GAGT the other day, he had some milky substance under the oil cap, tasted sweet too, but I dont know if its coolant or what.  There wasnt any in the oil, it looked good, might just need a PCV. 

Good buy nonetheless.  Good luck with the swap.