Black92FX36spd

I've been told a LT1 can't handle 450 hp. I was wanting to stroke mine to a 383, but have been told I would be happier with a LSx engine swap. The Ls swap seems like a lot of work and for a street car with a little 1/4 mi. duty I think the stroker would be better. I was told the LT1's can't handle much over 400 hp. Doesn't seem right to me, (lt1 is an iron block isn't it?) seems like the lt1's were making over 400 hp before the LS1 was even around. What are your thoughts?

cv67

Your friend is mistaken
Stroke that thing get a good head on it, 450+tons of torque comes real easy. Maybe they were referring to the pm rods. Wouldnt trust them with too much power.

Black92FX36spd

He was saying the block couldn't handle it! He is a person I would usually trust, he has built a Chevy 302 and a couple other engines and also works at a parts store. Someone I would figure would know what they are talking about. I didnt want to try to swap everything then get it to wire into my gauge cluster then match up my black label ZF6 trans. Seems like alot of work when I can work with what I already have.

383vett

That's why he is working in a parts store and not building engines. Stroke your motor and don't look back.

T. Wayne Nelson

I agree, before I built my 406, my built 350 was about 450 horsepower at the flywheel. Ran good, many 1/4 mile runs. Sold it to a guy who put it in a boat, and he is still running it.

PLRX

We have many owners with modified L98 and LT engines with over 450 HP.

Tell your friend to pack sand or to go fly a kite.

rklessdriver

Jesus. Who in the heck comes up with this stuff?

You can make 450HP out of an LT1 with ported stock heads and a good camshaft on the stock bottom end....

A 383 or 396 with good heads and cam will make 450RWHP. Thats to the wheels and it's almost 550HP at the crankshaft. It's fairly common for built LT1's to make this kind of power. Quite a few of them are on this board.

It takes some skill to build more than 450RW but plenty of people (myself included) have.

LT1 blocks with proper prep work are capable of supporting over 1000HP.
Will

dizwiz24

full of it. Yes the lsx has some advantages. Its different firing order causes 7% less stress on the crank.

That's why you will hear about lsx guys 800 hp on the stock cast crank. However, ltx does have an advantage. It has an extra bolt arnd each cylinder at the head. Steel block / 4 bolt mains.

If you are gonna supercharge it, lsx offers very little advantages over ltx (once you put good flowing afr comp port heads on). Also you may need a custom ' Hogan' sheet metal intake. I guess a disadvantage to LTx is the parts are expensive because there isnt much available.

Now, if you are building a lightweight n/a road racer, then the reduced weight of lsx alum block makes sense.

I run 470 rwhp/ 470 rwtq thru my supercharged 93. No issues. Stock bottom end.

I'm upping that by an est 80 rwhp and still plan to keep stock bottom end

Nathan Plemons

He's completely and utterly full of crap.

FrankieD

I guess my stroked LT1 is an anomaly

Nathan Plemons

Must be, don't know that I'd trust it. You need to remove it and send it to me so I can thoroughly test it and ensure that it does make this power safely. To properly test the engine for durability I will need to have it for approximately ten years.

Because I'm such a good guy, I'm willing to perform this exhaustive test on your engine for free, I only ask that you pay the shipping and handling........

96GS#007

This is why friends do not let other friends do drugs

383vett

93Rubie

People who are ignorant of the facts.

Nathan Plemons

I think it's a problem with the opti. I heard once about this guy who had a friend who's uncle's brother's step son's twin sister said, they just plain junk.

Zix

Here's how my 383 LT4 does to the wheel on a Mustang dyno...

And this motor probably has about 20K miles on it now and still running strong.



Fell free to pass it along to your friend.

ScaryFast

****, son, that's a helluva a curve!

To the OP, add me to the list of people with 383 LT1 motors. Mine kicked out 414 to the tire last time I had it dyno'd, stock 10.5:1 compression, stock heads (ported, of course), original block from 1993. I have been racing on that motor for 8 years with no issues (other than ignition stuff).

Docderek05

Me want 383 !!! me want Stroker!! man that read out is awesome..!!!

dizwiz24

Zix, please give us some details about that build !

Very impressive.

N/A?
cam?
compression?
intake?
heads?
1 3/4" long tube headers (your 'TPIS' ones? )
tune?
forged or cast bottom end.

Zix

Naturally aspirated, 11.2:1 383 LT4

Cam is a 242/252 duration .55x/.56x lift w 1.6 rockers 110 LSA

Heads and intake were HEAVILY ported ($3000+ in machine work and parts, I supplied the heads and intake) I lost the flow sheets, but plan to pull the heads next winter and I'll get them flowed again. If I remember they peaked in the 320 CFM range.

Yes, 1 3/4" TPIS long tubes, no cats, Corsa exhaust

Main tune was done by a local shop here, and touched up a bit by a friend of mine.

All forged bottom-end.

Red-line is limited to 7000 because of the stock computer, as you can see it was still making power at 6800 where the dyno operator stopped, can;t remember why. Probably would have topped out around 470 or so if it went all the way.

I have the LTCC ignition coil kit installed and an running BKR7E-11 (cold) plugs. This engine really makes a lot of heat.

There are a lot of pics and info in this thread, I made it right after that dyno run was completed alllllll the way back in 2005. There are some pics of the heads on page 2 or 3 I think.

http://forums.corvetteforum.com/c4-t...o-466rwhp.html