enkeivette

Who makes decent roots type blowers? The only companies that I'm aware of are Weiand and B&M.

How much boost is appropriate for a 383 with about 8.25:1 compression on 91 octane?

What has to be done other than an electrical fan and a bigger cowl? Will a stock style water pump fit? Will the stock pulleys work?

Thanks guys.

kdcollins

I am not sure who all makes blowers for gasoline engines but there seems to be some variety out there. I bought a Weiand 6-71 for mine. I have a 355 with 8.35:1 CR and set up for 6 pounds max of boost.

93 octane is the only fuel I have run to date so I am not sure how well the lower grades will do.

I did install an electric fan and a small base distributor, the stock HEI is much too big. Also, boost referrenced power valve type carbs are needed or modify your own (I modified mine). I am also running a stock replacement aluminum water pump with no problems so far. Also, I bought a blower kit that came with many of the pieces needed including the lower pulley. All of my accessories bolted up with minumal shimming with the exception of the power steering, I think I need a double groove pulley for it.

Good Luck!

KC

fugawi

try blower drive service

norvalwilhelm

While I am running a big block the prinicple is the same. I run a weiand
8-71. I too replace the distibutor with a small based unilite.
I also had to run intake manifold based power valves, you definitely need power valves.
I ran the stock water pump but did NOT run the supplied lower pulley. I moved the accessories in front of the 3 inch wide blower pulley and mounted them on custom mounts much lower and short accessory belts.
I also run the blower 15% overdrive but limit rpm to about 5400. This gives 12 pounds of boost but more important really snappy bottom end performance. Off a light I often see 9 or 10 pounds without pushing the motor.
I run 8-1 compression and 93 or 94 octane fuel but also run a MSD timing boost computer that pulls timing out of the motor in relatiion to the boost. I run alot of timing, 43 degrees but pull it out with the computer.
I get 15 mpg, easy starts and great low end torque.
good luck

bashcraft

About 15 years ago, I ran a Mooneyham 8-71 with teflon seals on a 427. The motor was in a boat and had 5.8-1 compression and I ran 22 lbs of boost with 104 octane fuel and 16 lbs with 94 octane.

With 8.25 compression and 91 octane fuel, you'll need to limit the boost to 5-6 lbs max. Of course you could always drop your compression down, or run octane booster.

MonzaRedConvert

Try these guys too. I've never dealt with them, but I know they've been around for a long time.

Dyers Blowers

SmokedTires

BDS is a pretty reputable company too

enkeivette

Norval, Matt at Comp Cams told me the same thing. My 110 LSA is not the best for boost, I'd be better off with a 112. How much power do you suppose I'd lose with a 110 versus a 112? Would it be mostly a low end power loss?

63mako

You got to be higher compression than 8.25. more like 9.8:1 to 10:1 with your combo. If your compession is that low with your components there is a design problem in the engine. Wrong piston for your rods and stroke or something like that. You need to check the installed piston height at TDC. Stock is around minus 0.030, 0.025 more or less, then you use a .015 gasket. A 0 deck with .041 gasket get you right quench and best compression. Don't sacrifice proper quench for a .1 or .2 Compression increase or decrease. You want to be as close as possible to 0.040 between the piston @ TDC and flat surface of head.

Garys 68

From your comment on "bigger cowl", I'm guessing you're going to try to fit it under the hood. I'm guessing none of the big blowers listed below would work.
How about a 177, marketed by holley. I've used them on marine big blocks (5psi boost), so 5-7psi shouldn't be that difficult on a 383. And with only 91 octane, you probably wouldnt want to go over that.
It also would be possible to fit one under a modified hood.
I'm kinda considering doing the same thing myself.

Ratsirt

Here is my install of a 144, almost complete.

blnvette

In my opinion Weiand pro-street blowers are better than B&M. The weiands have bigger endcap bearings. The B&Ms have teflon seals which I think is bad.My weiand is 16 years old and is overdriven and it puts out 8.5 lbs of boost. You need a cam with a lobe seperation angle of 114. This keeps the compression from being blown out the exhaust valve. You need forged blower pistons that are de-domed or dished. The only thing that I have had to do with mine is replace the front seal it started to leak oil and change the oil every few years. My water pump and pulleys are stock. I had to make a spacer for the fan so it would clear the blower belt.

turbovette80

Also, boost referrenced power valve type carbs are needed or modify your own (I modified mine). .can a Quadrajet be modified in this way?

kdcollins

Good question. I cannot answer this with my limited knowledge. Someone with some "smarts" will have to chime in.

KC

Ratsirt

Here is a picture of my install of a 144 with hood on.

kdcollins