cypris09

iTrader: (1)

So I managed to pick up a ls1 shortblock and 706 heads. From what I read that would put me in at around 10:7 to 1. I plan on running a torqstorm supercharger at 10 psi. I was going to run e85 but the closes station to me is about 20 min one way so that's out of the question. With that in mind what's a safe compression @ 10 psi and pump gas? I didnt want to run meth if I could avoid it but I'd also like something that will last a while so I would appreciate some schooling from those of you who know some things.

ss.slp.ls1

iTrader: (36)

I would consider selling your 706 heads and picking up some 317 heads. The larger chambers should drop your CR by about a point, that will be beneficial if running pump gas.

cypris09

iTrader: (1)

That's what I was thinking as well. Best case maybe I can find someone who would like to trade.

Torqstorm

An Ls1 with 317 heads is around 9:6 to 1. That would work excellent for boost.

Torqstorm

cypris09

iTrader: (1)

Well for some reason I'm having a hell of a hard time trying to locate a set of 317 heads. I was offered 243 heads for basically free but that would put me to 10.5 to 1. Would that be ok or should I just wait to find a set of 317s at a good price? I'm basically to the point that I either find a set of 317s or the ls1 shortblock sells and I buy a different motor lol.

JoeNova

You can always just get stock LS1 heads. ~10:1 isn't bad compression for boost with a good tune.

cypris09

iTrader: (1)

As in 241 or 853 correct? I was always told low 9s was where I wanted to be. I just want something that'll handle 10 psi and wont grenade. I plan on getting my tuning done at Big 3 racing in N.E. ohio. So I'd like think that they can handle the "safe tune" part.

jimmyg

My buddy runs a cam only ls1 @ 10 lbs boost on 93/meth . If you have heads allready, just invest in a meth kit. You will be fine

The BallSS

iTrader: (9)

SBE LS1 w/ CNC ported 317 heads, turbo cam, Turbonetics T7875 on 12 lbs. made 689rwhp through a T56 and 12 bolt on pump gas only, no meth.

cypris09

iTrader: (1)

I'd like to stay away from meth if I can. If I have to I guess I'll bite the bullet but I dont want to depend on it. 317s would be ideal but I cant get my hands on a set for whatever reason. I can get 243s for sure and possibly 853. 853 should put me at 10 to 1 correct?

I'd love to run e85 but closest gas station that has it is 15 to 20 min one way. Biggest thing is I just want it to last vs the oh I made 600 whp for 2 pulls and then it let go.

As far as heads go the 243s I can get for basically free. I have to double check on the 853s but I can trade my 706 heads straight up for them.

TPIZ92

iTrader: (10)

I am at 5.5 lbs on stock compression on pump. I run about 17.5 degrees and it seems like itll take more but i havent bothered. The kits usually ran stock spark tables which, after an iat modifier, puts the spark a tad lower than where i am. I plan to install 706 heads on this engine with the same boost and run pump gas. In your case, 10lbs (no intercooler right?) Might be a bit too much. You could get the 243s and port them and possibily gain a few ccs from chamber work, mill them to ensure they are flat and put you near ls1 compression with a better flowing head. Win win. I think you could make this combo work but youre quickly dimiishing that safety zone etc etc

That being said, running a meth kit is probably a good idea as others have said. So is running a ported set of 317s. You got some options.

JoeNova

Just get a cheap meth kit and run regular -20* F windshield washer fluid in it. Its not worth the hassle/risk not to when installing a kit takes ~4 hours and Washer fluid is only a couple bucks a gallon (or cheaper).

Porting heads with boost also isn't necessary. Even the lowest flowing of the heads (706) have made ~1100 HP at the wheels unported. Flow dynamics are greatly changed with boost, and a well designed setup won't need porting for power.
If you don't want to run meth, swap heads. If you don't want to swap heads, run meth.

cypris09

iTrader: (1)

I really just didn't want to be dependent on meth I guess. If I have to run it I'll run it. 243 heads put me around 10.5 to 1 the stock heads put me at 10 to 1 and the 317s are around 9.6 to . I'm struggling to find a set of 317s. I will be intercooler for sure.

So far the plan is truck intake, 80lb injectors torqstorm supercharger @10 psi and a cam. Possibly a brute speed but undecided. Yes I will be intercooled. That being said should I just aim for the 853 heads to keep me around 10 to 1 and run meth. Which will probably just be washer fluid. Or go for the slightly better 243s? That's 10.5 to 1

Bob@BruteSpeed

iTrader: (16)

The BruteSpeed cam would work very well for your combination. Bob

cypris09

iTrader: (1)

Bob what would your recommendation be headwise with your cam and 10 psi. Be it procharger or the torqstorm?

Bob@BruteSpeed

iTrader: (16)

I recently had a customer switch from a Torqstorm to a ProCharger as he was fed up with the problems he was having with his blower. If he sees this, perhaps he'll chime in. Bob

cypris09

iTrader: (1)

Would love to hear why he didnt like it. Fortunately for me, the decision on what supercharger I go with is probably one of my last. Once I figure out what heads I'm going with I'll make a final choice on a cam as well

V8sounds

iTrader: (1)

Where are you located? I have an extra set of 317 heads if you are interested. Feel free to pm me if interested, or text me at 419five79zero420.

Detoxx03

iTrader: (14)

cypris09

iTrader: (1)

I suppose that'll be the plan. Wait a bit longer to see if I can get a set of 317s and if all else fails I'll grab a set of 241 or 853 heads.

Thanks everyone.