Any centrifugally-blown A engines on this forum?

[Bill Dedman]

Hi,

I have a 2001 360 Magnum in a '72 Valiant 4-door sedan that I'm installing a Vortech V-1, S-Trim centrifugal blower on. This is new territory for me. Always wanted a blown car, but never had the chance, 'til now.

I'd love to hear about other setups and what problems and successes other board members have had with their own centrifugally-supercharged A-engines.

Please respond here, or write me an email at [email protected] I will write back, guaranteed.

Mine is a stock 360 Magnum short block (except for the Hughes cam), with pretty much stock heads, TTI headers and 2.5" exhaust, a Crosswind dual-plane intake, and a Carb Shop "blow-thru"-modified, Holley 750 double-pumper.

Cam specs: hydraulic roller; stock lifters; 214/218 degrees of duration @ .050"-lift; 114 degrees lobe separation.... .525"-lift at the valve with 1.6 rockers (stock Magnum ratio.) Crane aluminum roller-tipped, needle-bearing rockers activated by thick-walled, chromoly pushrods, with 120# on the seat and 300# open, springs.

Car weighs 3,340, and has a stock-ratio, early (2.45-low) 904, with a 2,500rpm (unblown) stall speed converter, a TransGo shift kit, and an 8.75" rear end with 3.55 gears and a new Auburn limited-slip.

True 9:1 compression ratio (I cc'd everything) with 185 pounds compression on 4 hits of the gauge.

It ran 13.35 @ 102 mph, unblown (with a 3310 Holley) thru early 340 exhaust manifolds, with an M-P 180-degree, water-heated intake, on 8"-wide T/A "D.O.T." B.F. Goodrich Drag Radials (1.91 60-foot) on a 95-degree day, thru the mufflers.

I am hoping for some low 12's with the blower, but have no idea what to expect, insofar as maximum boost is concerned.

I have a Snowperformance BoostCooler alky/water injector set to start spraying at 4 psi of boost, and an MSD BoostMaster retard set to reduce timing by 2 degrees for every pound of boost, with 93-octane gas.

I'll appreciate advice and information from ANYONE running a ProCharger, Paxton, or Vortech (or any other centrifugal blower), as to what mistakes I might be making, here.

Using a 160-degree thremostat. Half-inch dia. fuel line to a boost-riented regulator, with a 310-gal./hr. punp that pumps at 30 psi., with a by-pass syetm on the pump and another at the regulator.

Stock (composition) head gaskets, and stock, hypereutectic pistons will limit my boost to under 10 pounds, for sure.

I may be stupid, but I'm not crazy... LOL!

I don't have S/S springs, but I have spring clamps on the front section of the stock springs, an adjustable pinion snubber (half-inch air-gap) and an air bag on the right rear spring for pre-load. New KYB rear shocks. I also just installed some 90/10 front shocks. I don't really want to replace the torsion bars unless I have to, but this was a V8 car with A/C, and I've heard that they have the same torsion bars as a 340 car. So, maybe I should.... dunno. Front end rise is pretty good...

I look for my 60-foot times to pick up a bit with the blower. I'd like to keep this 3.55 gear if I can.... I have to drive it to the strip, (60 miles, one-way) so I can't really put a 4.56 in it like I'd like to...

Thanks much for any information and advice. Anyone want to hazard a guess as to how much boost this thing willl produce with max impeller velocity (50K rpm) at 6,000 engine rpm?

I'm guessing 8 pounds.... but that's JUST a guess.

Bill, in Conway, Arkansas

 

[ace26]

I have a p1SC procharger and air/air intercooler on the 360 in my dakota r/t but it's fuel injected not carbed.Stock motor running around 8 to 10 psi boost. it runs great when somethings not broke on it=].Make sure you keep the fuel mix rich, you lean it out, expect blown head gaskets at the least.And make sure your tranny and converter can handle it. The boost is rough on converter and tranies when it comes on all of a sudden mines usually at max by 2000 to 3000 rpm.But the power is great.Have fun with your project.

 

[1969Swinger]

I have a P1SC on my 410" stroker. Originally it was a 360 with about 9.2:1 hypereutectic pistons..non intercooled, no water injection, and running around 10lbs of boost I blew a head gasket within two months.

I rebuilt the engine with Quench Dome 8.3:1 CR forged stroker pistons
Mopar Forged Stroker Crank
Eagle H-Beam rods
Edelbrock Perf RPM Heads Stage II ported by hughes with a stud kit
Same hughes cam as before 489/524 left 218/[email protected] 111 lobe sep.
Commetic Head gaskets
Water Injection
I run a Holley Fuel Injection style fuel pump
Aeromotive bypass style boost sensing regulator to increase the fuel pressure with boost.
I have the same carb only it's a 650cfm though at 10lbs of boost it will flow over 1200cfm and I've never had a problem even with the stroker.
A/F ratio on the dyno is around 12 all the way across
8.75 rear end with 3.23 gears..I used to run 3.91's but I hit the rev limiter before I crosses the finish line at 123mph

I've ran this setup now for over 2.5yrs with no issues at all.

With the 4sp on street legal 8" slicks I have to go real easy through first at the track.
1.87 60ft 12.00 @ 120mph is the best time I've ran on a 95 degree day.

With 9:1 CR the Water/Meth injection Kit is def a good thing.
I don't retard my timing under boost...I usually run 28deg total advance.
Running 8 or more lbs of boost you should run a blow off valve.

Sounds like you have most of the things you are going to need.
If you have specific questions let me know.

 

[Bill Dedman]

Thanks, Ace36, for the response to my post about my "blown" 360. I'll surely take your advice about the required "rich" condition necessary to prevent detonation.

I've been driving around without the blower, using this Carb Shop 750, and even took it to the strip for a baseline. It ran quicker and faster than it ever had with the stock 3310, but I had also installed TTI headers and an Air-Gap-style (Crosswind) intake manfold since I ran it before, so it wasn't exactly apples/apples.

But an observer told me it was SO rich, it was puffing black smoke all the way down the strip. The plugs were BLACK.... I'm surprised it would even run... but, it liked it.


It will be plenty rich with the blower, I believe. Carb Shop dynos those Holleys on a "mule" engine at 15 pounds of boost before they send them out, so I'm hoping that I will be okay, with the Boost Cooler alky injector and the MSD Boostmaster Retard. I probably will limit my timing uner full boost to 22 degrees, at least, for starters. Is that ballpark, do you think?

I know that "conservative" is the keyword if I want to keep my head gaskets...

Thanks again for any info.

Bill, in Conway, Arkansas

 

[Bill Dedman]

Hey, '69 Swinger...

Thanks SO MUCH for that great, detailed explanation of your setup. It sounds awesome!!! 123 mph... wow! If I can run 112-114, I'll be a very happy camper.

I'd like to know what kind (brand) of reverse-dome pistons you found for that engine. Down the road, I'd like very much to build an engine similar to yours, but with stock stroke. I'm retired, and on a "fixed income" and it wasn't "fixed" very well.... so, I have to stick to basics... not that I wouldn't LOVE to have a stroker, mind you, but I'll be lucky to get the H-Beam rods, forged pistons, and Edelbrock heads. I MIGHT go for R/T Mopar cast iron heads. I've read that their intake actually out-flows the Edelbrock heads, with both unmodified. I won't be getting any port work done, except for maybe a minimal amout of pocket-porting.

I'm getting finished with the wiring on my car, and may be able to finally fire it up with the blower on it, sometime later this week.

Talk's cheap...we'll see. LOL!

Thanks again for all the good information. I'll let you know how it runs, if I can get it to the strip. I have a fuel cell in it, and I might run it on av gas at the strip. No detonation worries with that (and the other band-aids I will be using.)

Pray for my head gaskets...

Bill, in Conway, Arkansas

 

[1969Swinger]

I had Diamond (http://www.diamondracing.net/) Custom make the Pistons for me as a Low Compression Stroker piston is definitely not your normal off the shelf part. 8.3:1 is about as low as I could go because of the space constraints on wrist Pin height with the extra stroke.

If the car was setup for the strip instead of a stock suspension driver it has the potential to run low 11's or maybe even high 10's.