Zoso1951

Just curious to know how many more cubic inchs can an LS1 be bored out.
I've heard of 383. Also, how much moding would my 99 SixSpeed Vette's
DIC ( computer) need to accept it and not go hay wire???
(Future plans after my LS1 gets 100 or 200k and it's time to rebuild)
or would it just be cheaper to drop in a LS7 ?



Thanks in advance!

Beast96Z

iTrader: (21)

The sleeve its self can only safely handle a .010" hone. The cubic inches come from adding more stroke, which is a swap of crankshafts. Swap in a 4" stroke and you get a 383. Swap in a 4.125 stroke and get a 396. You can deffinatlly build a 383 or 396 for cheaper than the LS7 will cost. A few sponsors are selling 402 ci LS2 short blocks for $3995. LS2 blocks are easily swapable into earlier model cars and they have a bigger bore.(4"). LS-1/6 blocks are 3.900".

Order 66

Largest i heard was 455 and that was a very long stroke. largest bore i know is 4.20 from darton.

Beast96Z

iTrader: (21)

I think he is refering to the stock sleeves. If you re-sleeved to a Darton set-up, then you could go as large as 471 cubes if you had the dough. 4.200"x4.250". It wouldn't be a very economical motor IMO.

camaroguy26

iTrader: (21)

if it's a 97 or 98 aluminum block it's recommended only .004 inch but 99 and later is .010. If you have an iron block you can bore it to a 5.7 or 6.0. The aluminum blocks have them liners and aren't recommended to replace them but if you do do your research and find a shop that has experience doing it. It will be costly.

JakeFusion

iTrader: (7)

Iron blocks (LQ9/4) are 4" bore and can be bored .030" over safely and if sonic tested .060" over. A 4.030" iron block is 370cid with a 3.622" nodular stock crank, 408cid with a 4" forged stroker crank, or 421cid with a 4.125" crank.

Standard block honing is 3.905" for the LS1/6, taking displacement to 347cid. Once again, that is due to the aluminum block having ductile iron sleeves that cannot be bored out.

Darton sleeves can be a pain, with the need for an Evans cooling system and the problems some shops have with installing them (dropping sleeves, coolant leaks).

Best bet for a lightweight, relatively cheap big cubic inch engine is the aluminum LS2 honed to 4.005" (or since it's new, 4.00 works with the option to hone later) with a 4" crank for a 403 or 402cid package. Personally, I'd go for the 4" bore, because that will unshroud the valves. You can then run a 2.08" valve in the head which will flow more cfm, and more cfm = more power.

Stroke is nice for adding displacement to gobble up the duration of large cams on a stock LS1 block, but with relatively contrictive heads, power gains are not proportional to cost (but there are gains, look at Tony Mamo's post under Dynometer section). However, a large cam that makes a ton of power on a 346 (but has less than ideal street manners) can be run in a 383 and still make the same horsepower earlier in the RPM range with more torque and will be friendlier on the street.

A 402 would have all the same components of a 383 stroker, and the only additional cost would be the LS2 block. Since you would have a complete LS1 long block, it might actually be reasonable to sell it off to offset some of the costs and go with the LS2 stroker.

Bryan @ Speed Inc.

iTrader: (19)

darton has new sleeves that go to 4.20" bores??? holy ****! monster motor. i'd do that with a 4" stroke crank for a big inch motor that still rev's to the heavens. let's see, that would be.................. 443 cubic inches. not too bad.

Zoso1951

So, without making my 99 LS1, a stroker, is it possible with AFR heads, the
right cam, Long tube headers, BB-PRT, swap out my 2:73 rear end to a
3:90, possibly use the Vararam, smooth sleave, & MAF, and a good Preditor
tune, to make it to 500rwhp? or would I need also use a roots type blower?


thanks again!
btw, for 99 C5, the rated hp is 345, so that's prob. 315rwhp, right?

JakeFusion

iTrader: (7)

I think if you did everything right, you could get 480-490 with a pretty substantial cam with the AFR 205s milled down with the proper gaskets, and ALL the bolt ons.

Roots blower would end up being about the same price, and would give you better drivability with a little more power.

jrp

iTrader: (16)

no, not without a serious combo that would be regulated too track only. if you want power out throught the 4ll60e and IRS you'll need cubic inches or FI.