Anybody ever run 11:1 compression with low boost?? I have a naturally aspirated 347 in a Mexican block running 11.40's on pump gas, and have the itch to go FASTER!! I'm thinking of switching the car to C16 and adding an S-Trim with an aftercooler. I really prefer to hear feedback from people who have actually done it, instead of people who have "read" that it can or can't be done safely. I'm looking to hit the 500 RWHP mark with some low boost (6-8 PSI). I know I am at the power limits of the stock 2-bolt block, and plan to build a 4-bolt block next year. I need to know if this is conceivable, or should I just save the change for next year??

Thanks,
Wayne

 

You can run a lot more than 8 pounds of intercooled boost on 11:1 compression with C16.

Ever read that article in MM&FF? They had no problems feeding 25 pounds of boost into a 12:1 mod motor, I know it isn't the same as a big bore windsor but if they can do 25 psi into a 12:1 mod you can surely do 8 pounds into an 11:1 windsor.

 

if money is any issue, why not start building the new block now with that money spent on the SC? build the block and put a TURBO on it

 

Well, the 347 I'm currently running is fresh; and I don't have the $4500+ in my pocket at the moment to build a 4-bolt shortblock. I have never driven a power-adder set-up, so I thought this might be my opportunity to get my feet wet, instead of jumping in head-first. As for the turbo set-up, I really do not want to part with the $1K+ worth of exhaust I have on the car right now. Something belt-driven will better fit my current set-up. My options are to: A.) Run a supercharger on my current 11:1 motor with good gas, or B.) Wait until next year after I build the 4-bolt block during the off-season.

As for the MM&FF article, do you remember what issue?? I have a few of them on my shelf, so perhaps I might have it. 25 PSI into a 12:1 motor seems like an aweful lot to ask for.

Thanks for the responses so far!!

 

It can be done with good results...

My buds Stang as an example... 306ci, SQ-Trim, 10.5 compression, street mode 5psi, 93 octane, reduced timing (20 total) the car runs 10.8-9's like this... race mode, 10psi, 115 octance, 24 total timing low 10's high 9.90's depending on traction... this car is not intercooled... An intercooler would certainly help a setup like this...

Good Luck!

 

Are you running aluminum heads?

 

It can be done, stroker347 on here did it with 5-7lbs and 10.5:1 compression with no intercooler. It worked for a while, until it took out a few pistons. You will really have to pay close attention to your tune with that setup, as it will probably not be very forgiving.

 

was that with pump gas??? the more i thought about this, the more im interested in it. it might be an option until i have the money to get new pistons and rods for my set up...


what would alum heads have to do with anything?

sorry, im not trying to steal this thread, :tard:

 

I'll ask him and get back to you, or maybe he will read this thread and chime in. You could PM him, I'm sure he wouldnt mind talking to you about it. I want to say that is was a 50/50 93pump gas/110 race gas mix, but dont quote me on that one yet.

 

Currently running AFR205's. I'm sure the aluminum heads would be beneficial in pulling some of the heat out of the combustion chamber. My camshaft has a 110 LSA, so that would probably help to relieve some cylinder pressure; which should help a bit too.

As for pump gas..........I will not even consider it. One bad tank of gas, and I feel quite sure I will have a pile of scrap engine parts.

Icepick,
Thanks for the real-experience feedback. That is valuable information. Do you have any specifics on your buddy's set-up?? (i.e. heads, intake, camshaft, e.t.c.)

I'm running an FTI camshaft, Highly ported VIC Jr. carb intake matched to the AFR205's, 650HP carb, 1-3/4" Hooker LT's with 3" exhaust.

Anybody else have any real-experience examples to share?? Thanks again for all the GREAT feedback!!