Camaro_Zach

iTrader: (19)

I would like to start a project and build a 396 aluminum block ls1. I know of the various ways to acheive this displacement, but i do not know which is the best route. Big bore and offset grind the crank, or small bore and a lunati crank. Whats the advantages/disadvantages of the two. Thanks.

Camaro_Zach

iTrader: (19)

ttt...

Pro Stock John

iTrader: (34)

The stock bore strokers tend to have a lot more torque but only have a modest increase in horsepower.

I'd like to see a bunch of big bore mph #'s from the track.

The Juggernaut

iTrader: (7)

Spray it and be done with it.

99 Black Bird T/A

iTrader: (4)

Post deleted by 99 Black Bird T/A

Camaro_Zach

iTrader: (19)

high stall in an a4 with huge gears never encounters the 'bottom' end you are refering to. im looking for actual facts between the two, not theories and opinoins. Im not trying to come off as an *** when i say that, im just stating that im looking to expand my knowledge on the subject with viable facts and numbers. Thanks psj for the response.

01-z, spray = bad. I <3 my engine. i dont want to do ANOTHER stock v8 swap. hahaha.

Colonel

From what I've seen of LS1s, the big bore/stock stroke engines make as much TQ and alot more HP than the stock bore/big strokes. Now, do both stroke and bore and it's that much better.

Camaro_Zach

iTrader: (19)

Colonel, thank you. Im pretty decided on doin big bore and offset grind on the crank now...thanks for your input i appreciate it.

KraZy

iTrader: (4)

What is a big-bore costing these days?

Is it simple....just order a re-sleeved block and pick off the parts from your old block then ship it back?

Fenris Ulf

Not true at all, I have yet to see a stroker come close the torque I am making everywhere, let alone hold a candle to the power figures. Stroker kits are a waste of money, get a reliable sleaved motor and offset grind the crank if you want some more cubes.

99 Black Bird T/A

iTrader: (4)

Pretty much sucks.

Will you spray your new engine?

If I recall my ancient history correctly, when the Big Bores first appeared with the dry sleeves, MTI &amp; ARE weren't all that keen on the idea of spraying the dry sleved motors. The wet sleved Big Bore is stronger and less likely to drop a sleeve and should hold up to spray better than the dry. Not sure want the current view on spray a wet sleeved Big Bore is.

I can sure understand not wanting to do a stock replacement motor. While it's not up to BB or Stroker standards an LS6 long block might be worth a look to avoid doing a stock replacement.

12455109 - 97-98 Y (LS1) 12455109
MSRP PACE Price Qty Order
$4,784.00 $4,457.38

88894057 - 01 Y (LS6) 88894057
MSRP PACE Price Qty Order
$4,784.00 $4,705.01

For like $250 over an LS1 replacement the LS6 might be worth a look. SPDC probably offers something similar but I couldn't find it on their site at the moment.

Bore and Stroke it and you'll end up with a

rich

With a stroker you will see more low rpm torque with the big bore you will see more top end hp. with a big bore and stroke you won't need to go up in the rpm's 6100 or so after that you will run out of head. so big bore stock stroke rev it high or stroke it and shift it lower.

Camaro_Zach

iTrader: (19)

99 black bird t/a, thanks for the info! Id honestly like to stay away from spray all together, too much of a risk for my college budget

rich, ive been hearing that, i gotta look into that more. I would enjoy a 427 ls1

Texas_WS6

iTrader: (9)

What are the torque and horspower numbers on the factory engines? If I am not mistaken the 4.8, 5.3, 5.7, and 6.0 all have the same stroke and the bore is the difference. I know the hp is going up with the bigger bores but I do not have any idea about the torque. Now if you look at the old SBC I think you will see the torque go up and not realy the hp (327 vrs 350). If you look at the old Pontiac engines the 326, 350, 389, and 400 all used the 3.75" stroke and the bore was the only difference. Torque numbers did go up with the bore sizes but not as much as the hp numbers did.

What I think is, a person needs to figure out what his driving conditions are going to be and the RPM range he wants to operate in. If you want to be extremaly streetable and be able to use larger cams on the street, I think you will find a big stroke engine is better suttied for that and the power should be able to be made at a lower RPM. If you want all out racing, tall gears, and are not going to run on the street, then big bore and small stroke is going to be what you are looking for (as per your question wish way to go). The reason the LS1 makes more torque and feels so great on the street is the longer factory stroke compared to the 350 SBC (3.622 compared to 3.48) and they both make close to the same hp. The extra stroke makes the bottom end so sweet. But there is a point were too much stroke makes too many other problems ie.. Hooking up from the line or out of a turn.

All GM has done with the bore and stroke of these engines is go with the old Pontiac theem. Thats why I love them so much. Ad the great heads and the great fuel system, gods gift to real sports cars!!!!!

Camaro_Zach

iTrader: (19)

im like 99.9% sure its the stroke that differs. PSJ is sellin a 4.8 crank and i know its a diffrent stroke than the stock 5.7 one. perhaps both diffre, but im actually 100% sure the crank is a diffrent stroke.

Texas_WS6

iTrader: (9)

Really? I will check into it today and post the results here. You are most likely right. What about the 5.3 and the 6.0? Are they the same stroke?

Pro Stock John

iTrader: (34)

The 4.8 motor that you can get in a Sierra has the different stroke, it's a 3.27 stroke.

Gremlin5.3

The 5.3, 5.7, and 6.0 all have the same stroke. The 4.8 has the same bore as the 5.3, but it has a shorter stroke.

someday

here's the numbers:
4.8/294 = 3.78 bore x 3.27 stroke
5.3/325 = 3.78 bore x 3.62 stroke
5.7/346 = 3.90 bore x 3.62 stroke
6.0/364 = 4.00 bore x 3.62 stroke
8.1/496 = 4.25 bore x 4.37 stroke

ezss

I went with all a 387-388ci all-bore. Whoever said it makes less low end torque than a stroker I think that is an old, incorrect notion now. I was hitting 400rwtq at 3200rpm, peaking at over 450. Best numbers were 459rwhp/453rwtq...This from a H/c cam car that made only 400rwhp, the heads were reworked, but look to still be holding me back, so they will probably be replaced next.