Blower Friendly Motor??

[TTBullitt]

I am looking to get some more power out of my motor through F/I. I am looking at the Paxton Novi 1200 passenger mount kit. Will my motor be blower friendly under 6-7 pounds of boost?
Here is my setup:

1965 Mustang Fastback
-Balanced 302 bored .030" with 9.5:1 Keith Black pistons,
-Edelbrock Performer RPM package (heads -1.9 intake, 1.6 exhaust- matched to intake, matched to cam and lifters).
-Cam specs: Dur at .050: Intake 224 degrees, Exhaust 234 degrees, Lift at valve - Intake .496, Exhaust .520.
-Holley 750 DP - Custom Jetted during dyno tuning
-Crane 1.7 Roller Rockers
-MSD Ready-to-Run distributor
-Hooker longtubes, Dr. Gas X-pipe, 3-Chamber Flowmasters
-Tremec 3550 5 speed with 3.55 rear end ratio

Also, I have a Monte Carlo bar in place right now (the straight one), and what would need to happen with that? I appreciate any responses.
-Taylor

 

[SadbutTrue]

what happens with the mc bar depends on the blower, but you might be able to find one that lets you keep it there. 9.5:1 is a little on the high side for blowers, so you might have to keep the boost lower. (Instead of 8-10 psi, perhaps 6-8 psi... this is all relative to the blower). But I see no reason why you couldn't use a blower with low to moderate boost and see nice gains.

 

[SandSprite]

Aren't the Keith Black pistons hypereutectic? Better than cast, but not as good as forged for boosted applications. For low boost, you should be fine.

 

[allcarfan]

You have two things working against you...your compresssion and your pistons. I thought the RPM heads had a 202 intake valve??

 

[blown65]

7 psi should be fine with those pistons, but that compression ratio is going to give you probs. Even with premium I'd think you'd have to retard the timing quite a bit at full boost. My car is 7.5-1 and I run 11-12lbs right now on Prem fuel at 32deg full timing.

 

[TTBullitt]

Sandsprite - Yes, the KB pistons are hypereutetic. We have had the motor in the car for a while now, but we had never really thought about going F/I. That is why we didn't go forged to start with. The motor is very strong though and should be very RPM friendly too. I just want to see nice gains from safe boost.

allcarfan - Yeah, there are 1.90 and 2.02 intake valve heads.

blown65 - So do you feel that 8 psi would be the maximum safepoint? Also, will I be able to still run pump gas?

Thank you for your advice and comments.
-Taylor

 

[blown65]

Id say 6psi on pump premium gas, but still be very careful of your timing.

 

[TTBullitt]

Hey blown65 - Thanks for the help. What kinds of gains do you think I would see with the novi 1200 kit under safe boost conditions?
The car dynoed conservatively at 270 rwhp and 298 ft tq with the current setup.

 

[customperforman]

these guys pretty much have it covered. on our dyno, weve seen a 10:1 car with 7-8 lbs run hard with no detonation on 100 octane, so you MIGHT get away with it. but the tune has to be DEAD ON. especially for the hyper pistons to last. one thing these guys didn't bring up: people always worry about the pistons, but you'll melt plugs before the pistons. go at least one range colder and gap them smaller than NA cars. make sure your ignition is on its A-game!

dont worry too much about the heads. you can get a thicker head gasket to lower compression a little, polishing the chambers will lower it a little more. if you start lunching head gaskets, you might need to O-ring the heads, but for under 8 lbs, i doubt it.

the novi 1200 is a great kit. its what im going to run on a gt-40p headed windsor once its built. im going t run 8.5/9:1 compression and i want it on 97 octane. a hint: adjustable boost retard! and the tune up! i can't stress it enough. the novi calls for a HP (holly) or Mighty demon carb, so expect to get a new carb.

as for the rest of the buildup, it seems great. it sounds like a strong car. one of the mustang magazines took a painfully stock 65 fastback factory rated at 225 hp and added the novi 1200 at 5-7 lbs (i think) and got 300 rwhp. so not bad. you should gain a realistic 75 to a lucky 100 hp since your combo is already pretty efficient.

Rick

 

[TTBullitt]

Hey, thanks Rick. I truly appreciate the advice. Would the 75-100 horsepower be around 6-7 pounds of boost?
Also, I am running the Holley 750 DP right now. Would I need a different Holley than the one I have? I do not know the part number off hand, but it is just the standard Double Pumper.
Lastly, how are you going to run 97 octane? Airport?
Thanks! -Taylor

 

[blown65]

Thicker gaskets arent always a good idea though, you change how the combustion chamber burns and instead of possibly making things better with lower compression, you might create worse hot spots cause of movement in the chamber. Its a bandaid way to do things, and a bad one at that.

Blown engines do better with colder plugs anyways, or at least with roots style. I personally run the coldest plugs I could find with zero probs.

I'd guess 40% increase in power, but its really all in your tuning, it will make a huge difference. BTW, an aftercooler on a centrifigal blower will get you some more safety with the high compression, and give you a very nice hp increase.

I'm sure under the right tune you could run more boost, but your window of error starts to become very small. Race gas, then ya crank it up, but normal driving I'd just go for the 6-7psi and be happy. Should be a very very nice increase. My old setup went from a 14.8@98 to 12.56@110 with the same exact motor + 10psi boost. Different blower, but non the less, cent should make more hp than my roots.