derricklong

iTrader: (2)

Looked around, most of the info is a bit dated, if i missed one im sry.

Looking at building a LS based dirt late model engine.

have a CI limit of 365ci.

Most of the time we build short stroke large bore motors, and turn them to the moon.

With a engine having to be all steel, and using a LQ4/9 block, am I correct of thinking 4.030 bore and a 3.55" stroke for a 362ci engine?

Any other avenue to get a larger bore engine? Would it be worth it with the steel 853 casting head?

garygnu

could you retain the stock crank and use forged rods and pistons ?

batboy

iTrader: (6)

I'm not aware of any steel block options. Maybe you mean cast iron?

Do the rules say you absolutely can't go over 365 cubes or can you round slightly? With a 4.005" bore and standard 3.622" stroke, that calculates to 365.034 which I would think should be okay. If you have a brand new block with a virgin 4.000" bore that will be 364.123 with a stock 3.622 stroke. Using a 4.030" bore and 3.55" stroke would be under 365 cubes, but you would need a custom ground crank and custom made pistons (meaning big bucks).

A.R. Shale Targa

iTrader: (2)

I've often wanted to try this as well for some of my dirt modified customers.
The steel heads are apparently heavy but yet legal and around here they
allow porting so a good dozen or so hours worth of grinding plus a fresh VJ
and some 2.05/1.6 valves I'd bet would have them flowing half way decent.
I totally agree with the big bore short stroke combo as most nights the track
goes to **** (traction wise) and can't take the torque so the shorter crank
buzz motors are able to lay it down gently as long as the gear supports keep
ing them wound up. IIWM I'd have my old guy crank grinder take the rod
journals of the 4.8 crank down to small journal 2.0" and kick the stroke out
to 3.37"...then with a 4.065"(LS3 sized) bore it makes 349.xx inches.
Wegner automotive sells the timing cover that has the mechanical fuel pump
and front drive distributor provisions required by most sanctioning bodies.
Around here it's all flat tappet type cams...not sure if Bullet or who would
make those for LS engines but if you can run a roller; then hell ya..try it and
let us know how it works for ya.

snowman47

Idk where you could find heads to take advantage of a large bore of say a 4.185 using the LSX block. Use the 3.268 4.8 crank that'll give you 359.6~ci. Not sure if your rules would allow you to use that block or if that crank would work though...

schreurs1

Do your rules allow LS engines in the first place? Ive always wanted to run an LS motor is my car but the rules never allow it. Would be interesting to see how an steel headed LS would work on the track. Are you on alcohol or gas?

derricklong111

The rules state valve angle must remain stock... Chevy 23*. I see it as stock LS is 15* so as long as that doesnt change i should be fine.



Does anyone have a set of Cast iron heads for sale/free close to NC?

derricklong

iTrader: (2)

anyone have a part number of a new lq9 block? i had 12572808 but its discontinued?

squirlNUTZ

Try this http://m.summitracing.com/search/product-line/summit-racing-iron-ls-engine-blocks

The iron head is proving to be a more difficult piece to find