#60455 - 09/12/10 08:02 PM
Re: McCulloch/Paxton vs Turbo
[Re: Beater of the Pack]
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panic
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Registered: 01/11/05
Posts: 1340
Loc: Hempstead, Long Island, NY
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The ball drive is a bit fragile if you run it too fast, Erb has some excellent articles out there on improving the oil supply.
A turbo is "free" (no actual power take-off), except for the power lost by less-than-ideal chamber evacuation on overlap (normally aspirated engines do fairly well, race engines very well, blowers completely remove all exhaust, turbos always retain some). The normal pressure ratio for streetable turbos is intake boost × 2 for backpressure: 10 psi makes 20 psi in the exhaust manifold. It can be reduced, but getting it down anywhere near boost is a lot of work. Pumping the cylinder out against 20 psi of resistance is extra work.
A 300" engine at 8:1 CR actually has 343" of possible mixture because the chamber is also full at ignition. It's not added to the official displacement because it's generally not "clean" mixture, but contains lots of exhaust gas (and of course, it means that the engine size changes when you change the CR - which it does). With a blower, the chamber volume burns also.
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#60460 - 09/12/10 09:11 PM
Re: McCulloch/Paxton vs Turbo
[Re: qparker]
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Mean buzzen half dozen A.K.A. Hank
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Registered: 09/23/04
Posts: 4549
Loc: Ca
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Yeah, Paxtons ball drive are not that great,,,yes, they are very quiet,but once you overspin them,forget it.
The Early McCulloch will not make as much boost pressure as the later Paxton ball drive set-ups.
The So called race compressor wheel was never an option as far as I know for the McCulloch.
The early McCullochs only made 4-6 psi max on a SBF 289 that had a standard small camshaft.
My 250 6 had a large camshaft,IIRC,236 degrees duration @ .050 on a 114 lobe center .550 lift. Part of the reason I could not make that much boost pressure,if I had a stock camshaft,I would have probably made 12-15 PSI
I could only get 8-10 psi max out of my SN-89 Paxton w/a race compressor wheel installed,JR Granatelli(SP),he said I could make 15 psi no problem & bought it indirectly from him as I was @ the business where I bought it through & he had delivered it to me.
I overspun mine one time & it instantly started making noise.
They sold there ball drive blower line set-up to Paradice (SP) ,they (Ball driven blowers) are not great for high pressure output,they start to slip,that's why they are gear driven now. The Novi series.
My Camaro ran low to mid 12's w/only 8-9 psi,& it was dead quiet,I gave my friend a ride in it when I had the blower on it & he just said,man, this thing makes some great torque! He did not know I had the Paxton installed. 
MBHD
_________________________
12 port SDS EFI 
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#60475 - 09/13/10 04:26 PM
Re: McCulloch/Paxton vs Turbo
[Re: Beater of the Pack]
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Mean buzzen half dozen A.K.A. Hank
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Registered: 09/23/04
Posts: 4549
Loc: Ca
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#60476 - 09/13/10 04:28 PM
Re: McCulloch/Paxton vs Turbo
[Re: Mean buzzen half dozen A.K.A. Hank]
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Mean buzzen half dozen A.K.A. Hank
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Registered: 09/23/04
Posts: 4549
Loc: Ca
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#60571 - 09/18/10 09:27 PM
Re: McCulloch/Paxton vs Turbo
[Re: jalopy45 #4899]
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Mean buzzen half dozen A.K.A. Hank
Active BB Member
Registered: 09/23/04
Posts: 4549
Loc: Ca
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Using a complete carb encloser is not necessary if you mod your carb ,like sealing the throttle shafts & other items.
http://www.theturboforums.com/smf/index.php?topic=136075.0
A carb encloser is pricey.
Some people say if your running low boost,you do not need an intercooler. I say, anytime you can lower your intake temps,do it.
Don't really need an intercooler if you are running 100% methanol in your gas tank. If not, use a methanol/water injection kit.
I did not run an intercooler,but I also had a positive deck,(pistons came out past the top of the block).002-.004"
That helps reduce the chance of detonation.
A B.O.V. will stop the pressurized air from going backwards through the blower.
I used an old HKS BOV.You can see it in a previous post pic.
Wastegates are for a turbocharged set-up.
If you will drive in cold weather ,a heated intake is a good idea.
Run a wide lobe center cam,115 or wider for a smooth idle,& not too much duration causing the boost pressure to just blow past the exhaust valves & not pressure the engine.
The cam I had was approx .550 lift,236 in 246 ex degrees duration @ .050 on a 115 lobe center,you could definately hear it. Too big for a tow vehicle,but good for my daily driver. 254 ci L6 
MBHD
_________________________
12 port SDS EFI
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