94transbird

1.) Can a 3.800" crankshaft fit into a LT1 without hitting the coolant passage?

2.) Would I need forged pistons if I am not going forced induction or N2O? Power goal is about 400-450 HP. Compression goal is about 12:1 maybe a little less.

Any help would be great!

Gojira94

iTrader: (4)

Not uncommon to go as long as a 3.875" stroke, though pretty much anything over the 3.48" stock stroke will necessitate clearancing in the bottom end of the block. Need forged pistons, no. Good idea, yes. You may find some good quality .030 overs for less than you think. Others will chime in with specific piston recommendations based on their experience...

quik95lt1

iTrader: (7)

i ran speed pros........ .030 over they worked great and i didnt have any issues with them and they're around 385 with rings and pistons IIRC......only complaint is they are a bit heavy


if you want to step up the srp pro series kits are AWESOME...im running a set of .040 overs in mine right now they're light and strong......bit more $$ though close to 600 w/o rings

RamAir95TA

iTrader: (2)

1.) See above. +1.

2.) Is that HP level at the flywheel or rear wheels? Regardless, forged pistons are almost a necessity, IMO. Do it right - the marginally higher cost of a forged piston is money well spent.

James Montigny

iTrader: (13)

1) You're probably going to end up welding the block to fix breaks into the coolant passage.
It's really not that big of a deal.

2) No, you don't NEED them ... but if you're going to go to all the trouble and expense to
build a stroker (and you'll need new pistons anyway), why not buy forged?
The price difference is negligible in the grand scheme of your project.

FWIW, you can get over 400RWHP on a stock bottom end with heads and mild cam.

94transbird

I said 400 to 450 hp because I am in the hunt for more power under the curve and not peak power. And yes it would be rear wheels

And with a 3.800" crank wouldn't I need a different piston than what a 3.750" crank?

That would greatly limit the selection of pistons I can chose from if that is true. If that .005" doesn't matter too much and I can use the pistons that would normally go with a 3.750" crank then I will go forged.

Isn't the block cast iron?

James Montigny

iTrader: (13)

3.8 - 3.75 is .050", not .005"

And yes, a stock LT1 block is cast iron.
Stock F/Y-body heads are aluminum

quik95lt1

iTrader: (7)

you shouldnt have to weld any coolant passages to clearance the block........i clearanced mine to fit the 3.75 crank wit no problem.......and ive done 3.875 cranks wit no issue.......

94transbird

Sorry misplaced the decimal.

And welding cast is hard because it spreads the heat very quickly. Correct? So hiring someone to do it would be quite a bit of money correct?

94transbird

Ok. Well thats a good thing then

quik95lt1

iTrader: (7)

nah it can be done you just have to preheat the metal before you weld it

James Montigny

iTrader: (13)

Be careful with that thing, at .005 you only move the piston .0025" closer to the head, which is fine with a stock deck.
At .050", you move the piston .025" closer to the head, which in most cases means that you are now .010" above deck.
Not only are you talking about increased compression, but with enough piston rock, you're making contact with the head.

Here's what we did for my 383. Note that I used ARP fasteners and 6" rods, which required additional clearancing work.
I think we welded a total of five times.

94transbird

Ok so correct pistons will be needed. Who would sell an affordable forged piston for this application? Summit only list Wiseco's and GMPP hypernuectics.

Big Al

iTrader: (1)

Will a regular rotating assembly with a one piece rear main seal work in an LT1?

Something like:

http://www.jegs.com/i/Eagle/356/B130...oductId=749647

Al

James Montigny

iTrader: (13)

Not for 1992-97 LT1/LT4

quik95lt1

iTrader: (7)

wow.....i ran 6" rods with arp bolts too......i didn't have that issue at all.....i have a solid .025" or better too on the clearance.........i run an oliver rod which im sure is a bit less bulky than most but still i've built 383 hbeam bottom ends with 6" rods and never had that problem.......thats odd

James Montigny

iTrader: (13)

Here are a few other choices. (Eagle and otherwise)
http://www.summitracing.com/search/S...?Ns=Rank%7cAsc

quik95lt1

iTrader: (7)

heres a pic of mine...........you can see the couple of places i clearanced at the bottom of the cylinder bores but not nearly as much as your's up near the pan rails....

quik95lt1

iTrader: (7)

you can run regular sbc stuff in the motor......just go internal balance and run neutral balance damper and flexplate/flywheel and ur good to go


i've got reg SBC crank rods and pistons in my motor i even ran a two piece rear main crank and just used a moroso adapter to make it work in the 1 piece block

James Montigny

iTrader: (13)

The page he linked to specifically said "Not for 1992-97 LT1/LT4"
But I agree that it could probably be made to work.

Which rods and bolts are those?
Mine were forged Eagle rods and L19 bolts, the bolts look similar to yours.