Chiphead

iTrader: (2)

Talked to shop yesterday. Block is in great shape, will clean up STD bore with a hone. He'll put together a package with pistons/rings/bearings because he's going to balance it anyway. I also asked him to check big end roundness with ARP rod bolts.

What I'm struggling with is setting the CR. I'd like to run 87 octane with 10:1 compression, a mild cam and stock converter. I've been reading the threads about guys running cheap gas with L33 motors, with mixed results. BB recommends against it on their website.

Should I try to make it live with 10:1 on 87, or set the compression higher and accept that I'll have to use 89-93 octane?

lsxperformance

iTrader: (2)

That's all up to your tuner but I'm over 11 with 89 octane. You just may give up some numbers is all.

1FastBrick

iTrader: (17)

If it were me and it were a mild DD I would stick with the 10:1-1. He should have no problem setting it up for that.

If your going for max effort then run the 93 and add some more compression.

Chiphead

iTrader: (2)

I'm OK with peak numbers being a bit down on 87 for DD, I'd run 93 when towing or running it hard. I just don't want it to beat itself to death. The challenge is I want good MPG for DD and more power to pull my 5500lb trailer. Will a mild stall hurt ability to tow or require a huge cooler? I'd run a bit larger cam/stall if it would let me run 10:1 without pinging on 87 or 89. rear is 3.42 with LSD.

I sent BB an email on their website about tuning but I got a notice that it bounced. What is the best way to get ahold of them? thanx

lsxperformance

iTrader: (2)

I tow with mine pretty often. I have the multi disk converter tho. Ya def should get a big aux Trans cooler to keep things cooler when you out of lock up around town. The tuner will play a huge part in doing what you wanna do. I have different shifting/ lockup strategies in mine for use in tow/haul opposed to normal driving to keep mine in lock up as much as possible with the heavy loads to keep the Trans cool. As well as the fuel being used with my setup it was quite stingy with timing on 87 like in the teens total timing so I run 89ethanol blend in mine. It's a 6.0 I have been seein 16-17 hwy and 12 towin my 18' car trailer to the track with a camaro on. Race the camaro / truck hitch back up load car and go home. 13k gross weight of combined. But you can still run smaller cams and make them sound good if that's what your after.

Chiphead

iTrader: (2)

Here's the update.

Mocked up the 4 corners, #1,7,2,8 pistons to verify deck height. The pistons are .008" below deck on all holes. So I'm a bit concerned about quench. I'm using 241 heads.

What head gasket should I run? I'd really like to run the Cometics, but my decks are uncut and I don't think the surface finish is quite good enough. Is there a MLS gasket with 3.9" bore and .040-.045" that can be run with a stock deck surface?? Tnx!

1FastBrick

iTrader: (17)

Your piston can't be below the deck. If its a 5.3 dish piston, Maybe the dish is below the deck. But I have never seen a factory piston on any of the LS based engines below the deck.

They usually stick up past the deck and personally I usually see any where from .005-.008 above the deck.

Chiphead

iTrader: (2)

Speedpro hyper flattop pistons, 6.098" floater rods, stock crank. The pistons are .008" below deck. No dish, no valve relief, no kidding. I checked with a deck bridge and a dial indicator zeroed on the deck.

It's my experience that many builder quality cast and hyper pistons usually end up below deck. On the Poncho mills I'm used to, they can end up .020 to .040 below deck. Quench really goes to crap and requires block decking. That's why I usually stay away from them. I was pretty happy these are only .008" in the hole.

So, how bad is .008 and do I need to address it?

1FastBrick

iTrader: (17)

Typically on the LS based engines they are above the deck. At Least all the OEM ones I have taken apart...

I have not measured any with aftermarket pistons.

Chiphead

iTrader: (2)

Yeah, no argument there. The engine was originally a 4.8, and when I tore it down the factory slugs were above the deck.

The deck surface has the normal light pitting where the fire ring sat on the deck around each cylinder. What's the chance that 2 light coats of copper spray will help the cometics seal to the deck? Several threads on LS1.com say it'll work. A 040 gasket would give me .048 quench. Much better than stock gasket that would give me .060".

I'd sure hate to carry it back to the shop for decking, but if it'll make/break the combo I'll do it.....