I am looking into purchasing a 393 all bore short block. This is one that I have never heard of being used before. 4.155 bore and stock stroke. What might be the potential downsides to this motor or the upsides. this just sounds like a HUGE bore. I have never seriously looked into a stroker before just do to the costs involved, but for the parts that are in this one, its a steal at what this guy wants for it. I would be using my MTI stage 2 LS6 heads and an X1 cam on this short block. So i am guessing that 460rwp wouldnt be out of the question.

A side question is what kind of improvments would I see "under the curve" on a dyno vs. a cam/heads stock c.i. motor? I have heard that a 420rwhp stroker will always be faster than a 420rwhp cam/heads stock c.i. car.

 

I wouldn't do it. I know of several shops (some sponsors on this site) have had problems with 4.155 bores and reliability/sleeve dropping issues, even with darton wet sleeves. To me, it seems that getting the bore to a 4.125 has been pretty well perfected, I don't think it's worth the extra 5-6 cubic inches to go to a 4.155 bore yet. Just my .02 I

 

4.125" bore and a stock crank = 392CI
4.155" bore and a stock crank = 397CI


I will be doing a Darton Wet sleeve soon and with the recommended max being 4.160", I'm going to stay down at the 4.125" level. The extra 5 CIs are not worth the loss in structural integrity. If you stay with 4.125" bore, you get a FULL 1/4" of material all the way around the bore.


If you want more than 392CI, look into adding more stroke.

 

Yes sir, I have one. 4.100x3.72=393.

I call it a 396, (because it's close enough, & sounds cool). Crank is ofset ground stock.

Track times in the sig. Dyno shows 420/500 HP/TQ with a 232/236 112 ls. This motor was built for nitrous. Dyno # were achieved with 1 3/4" Grott headers, all bolt ons, TH400, heavy driveshaft, 12 bolt, & 10" ET Streets. So, not a dyno queen, but nontheless, track times in the 9's on spray, & a 11.1@121 NA. Look for a 10 on motor soon. Car weighed 3550.

I chose to keep the liners thick, for future build ups, and more sturdy for the heavy nitrous shots.

Motor was built by ARE.

 

The ARE engines are never dyno queens.ARE cars prove themselves at the track not on a dyno.

 

I think it is safe to do a bore that size if you are keeping it N/A. The only problem I see if anything ever does happen to a cyl. it would need to be replaced there is no room for cleanup. Btw these can be replaced individualy.

Nate

 

I dont ever plan on running nitrous through this motor but I will be spinning the hell out of it in upwards of 7000-7500. will it be able to handle that kind of abuse.

 

Call ARE to be sure, but I dont see a problem running it up that high, provided the valvetrain is appropriate.

 

Sorry, that's not correct .

4.125" x 3.622 (stock) stroke = 387.24 CID (388)
4.155" x 3.622 (stock) stroke = 392.89 CID (393)

4.125" x 3.72 (offset) stroke = 397.71 CID
4.155" x 3.72 (offset) stroke = 403.52 CID

Class dismissed.

 

yeah what he said, i am working on the 392---->4.1" bore x 3.71 stroke.

 

Ouch

 

So to have the 3.72 stroke, is that an offset ground stock crank? You can only go with carillo rods then and Acura rod bearings or something like that right?

 

yes, it is offset ground..no, you dont need those expensive rods.

 

http://www.idavette.net/hib/ls1c.html

"The liners are finished with a bore size of 99 millimeters (3.8976 -in.). That, with a stroke of 92 mm (3.6620-in), makes the LS1's displacement 5.665 liters or 345.69 cubic inches."





edit: it has to be 3.622" like you said, 3.662" would make a 349.6CI stock motor.........damn 0.040" ..........

thats not bad......gives me better bore to stroke and rod to stroke ratios


that web site and the "Chevy LS1/LS6 Performance" book are both off.........hey the Haynes and Thunder Racing have it right.....

 

SW was running a 4.155 all-bore dry sleeve from MTI in his white C5. I wonder what happened to that car?

 

Hard for a few of the recent ARE engines to prove much of anything other than major head aches for the some of the customers...ring issues, paying for your warranty work, motors paid for that don't get built/shipped but require a 20 percent restocking fee according to ARE and my personal favorite photo copies of post dated refund checks that aren't actually mailed to the customer.

That's what ARE has proved over the last few months since getting booted as sponsor for failing to pay their monthly dues...

 

Fastest LS1 type car inthe country is running an all-bore 387 (C5R block with stock stroke). Ronnie Duke's car went 8.52 at the Thunder race and weighs about 3700 pounds. Of course, there was a little extra air going onto the engine

 

If you keep everything else equal on a n/a motor, more cubes will make more power everywhere on the torque curve, except in very extreme cases where friction and piston speed become prohibitive.

More stroke will make much more torque up until the old horsepower peak where the curves will more or less come together as they drop off.

 

Back to the original question, I suppose...

a) I have a 387, not a 393 (4.125")
b) I do have the LS6 stage 3 MTI heads and the X1

BUT I dont have a reliable clutch at this point, so I havent dyno'd the car :-/

I do enjoy it alot, and there is some crazy power up high, although I havent spent much time up there (if barely any) because I want to break the car in well, and well, I'm suffering through the same weather you are and I dont drive the car on wet roads.

Its a great setup, although for my purposes (street giggles) a 427 will be a better fit. (I'm waiting for experiences with the Eagle crank before sending the car back to MTI for the 4" stroke sometime in the next year or so, roughly)

Its interesting to note that the two items I need right now are 315 Nitto DRs and a Spec stage 3.

chris