471 BLOWERS who's running one got one or have info on setting one up

So who running a 4 71 blower supercharger older style set-ups. Looking for your help and info on what to use ,do or not to do . I had planned on running a multi 97's set-up 4x2 or so.
Ok, giving the 32 sedan a little more hotrod . I wacked the top the last few weeks and now I think I have collected enought parts for a older style blower 4-71. I'm still looking for info on what cam to run and boost. I have a later style 2" gilmer ? belt set-up but thinking of machining a pullies setup (being a toolmakes does come in handy) Any plus or minus of a pullies set-up? Does anyone have a drive chart on the size of the pullies?
thanks John

 

Ask Paul, had one on the Olds he put in 60's Style.

 

Mine is fairly well documented on the Hamb if you look up my old threads.

 

I did a search but not too much came thru, Lots of Fluff

 

Check with Kevin Lee - he's working on a similar setup

 

Ganahl's book on Street Supercharging is good basic info source, and covers disassembly and clearancing. I've got some similar stuff from od hot rod books, gotta get scanning capability! I now have a 4-71, manifold, and an ancient drive set, slowly figgerenitout. There is a bunch of good stuff on here, time for it to be pulled together for tech archiving so people can find it...

 

Give us some more information on your engine. Stock internals, cast or forged pistons, 4 or 2 bolt mains, cast or forged crank, current compression ratio, heads - valve size/ported/etc, etc.. If you're going to build a purpose built blower motor than the amount of boost and abuse it can take will probably be higher (depending on gas).

They did have 2" gilmer belt drives in the 50's - so you don't necessarily have to go v-belt to be "traditional" - just depends on your definition. Gilmer belts are a lot less hassle than v-belts - that is for sure. If you're running a gilmer belt, then make sure you have a good pop-off valve system or burst plate - as it isn't easy to "slip the belts" like you can on a v-belt drive setup. Even with a v-belt setup, you should have at least a pop-off valve that is correctly setup. The pop-off valves or burst plates save the blower from destruction when a major backfire or other problem occurs.

When you're running v-belts, you do have to run them quite tight in order to keep them from slipping - which can put more strain on other components (depending on how you run the water pump, generator/alternator, etc). Gilmer belts don't have to be as tight - as they have cogs/teeth. On a typical SBC, you might be able to over drive it a bit and still not make too much boost -- but you probably don't want more than 6 - 8 lbs on the street . . . unless you can control detonation and have the engine 'internals' to support it. Make sure you have a good ignition - really helps blower motors. (Like a vertex mag, Pertronix or a converted distributor with a MSD box or other 'enhancer').

If you're looking for a 4-deuce manifold, you might contact Mike at H&H Flatheads . . . he's working on a billet (yes I know most of you hate that word) adapter that takes four 97's - mounted sideways. It is a nice piece - have one sitting next to me as I write this!

 

First, whats a Gilmer belt for us dumbasses and second, pics of the adapter would kick ass.

 

here's a couple of mine

http://www.jalopyjournal.com/forum/showthread.php?t=124409
http://www.jalopyjournal.com/forum/showthread.php?t=166071

 

Gilmer belt has teeth, while V belt is ....well.....a V belt. Carl Hagan

 

John Im running one on a 327 with 2" gilmer and single 750 at 6% underdriven makes 6 PSI
running a mild Comp Cams Blower/Nitrous cam You will need forged pistons(dont ask how I know) Im running stock rods but with ARP bolts and Mainstuds

 

I'd like to see a picture of the 4x2 H&H adapter too

I also suggest the Ganahl book, it has a pretty good build of a 4-71 as well as a lot of basic info on supercharging.

I have only been running mine for a few weeks, maybe only a little over a hundred miles so far, and it's my first blower so I can't help much.

I do know that if you put it in front of a worn out old banjo it'll tear it up pretty quick

 

I just finished doing a 4-71 on top of a SBC for a friend. We went with the old Weiand manifold,Weiand 2-4bbl top plate,and a 2" gilmer drive. It was 355ci SBC with 9:1 comp,"double bump" heads,4340 crank,Lunati hydraulic blower cam,2 Carter 625cfm carbs It made 5psi boost @ 6% UNDERDRIVEN and made 440hp with no problems. There is more in it but its VERY streetable setup this way. I will post some pics of it tonight

 

There are a few basic types of blower belts - the 1/2" pitch traditional cog belt (2" and 3") and the more modern 8mm, 13.9mm and 14mm. All the modern 'mm' belts use a different cog profile - rounded instead of square. The 'mm' belts can take a lot more load without "jumping' on the pulley or other such bad things.

Here is a picture:



I'll take a picture of the 4-deuce manifold and post it later on.

 

I am putting together an old Cragar 4-71 with V-belts on a 392 hemi. Not too deep into it yet, just the rough mock-up of it in chassis stage. Haven't figured out the rebuild on the motor yet but it is going to be a street motor built more for low end torque than high rpm hp. So, I'll keep the compression on the low end. Keeping it all late 50's - early 60's in appearance. Might run it on propane, but not sure quite yet. I don't have any good photos at the minute, but I'll post some down the road before too long.

 

If you need any help or information, one of my "just about completed" engine projects is a blown 392, 6-71, RAS rockers, program 4-bolt mains, etc.. (Engine is done, just have to get the rest of the car completed!) I've been down the route on this motor and a few others - would be happy to help out if you need any info.

 

I got a 1962 Detroit 4-71 on a zz4 sbc. Weiand intake, originally it had 3" gilmer pulleys, but it wouldnt clear the radiator and fan, so we cut the pulleys down to 2" (2" belts were cheaper and more abundant also) and its putting out about 7lbs of boost (keepin it under 13:1 so pump gas can be used when necessary). I attached a spec sheet for the cam were using. Try to keep your compression at 9:1 or lower, its better to run lower compression and more boost than less boost and more compression (or so i'm told).

Heres a couple pages courtesy of BDS that should help you figure out your fcr and whatnot, they have more info if you look around.

Compression charts
http://www.blowerdriveservice.com/techcharts.php

Cam charts
http://www.blowerdriveservice.com/bcamspecs.php

good luck

 

Thanks for the offer. I will likely be getting to the motor within a few months and might hit you up on that. Thanks again.

 

I have one but it's not runing yet. it's for a small block ford it was very hard to find.

 

wait a minute john you chopped it? we need pictures.

 

Here it is

 

I have had that X2 for a very long time , I didn't know about the AVRG groupe,cool!

Thanks

I have bought some books in the past and now just have to dig them up, might have to buy some doubles. A 471 is that for a flat motor Bruce

The motor is a truck motor with 4 bolt mains ,8.2 or so compression, 1.94 heads not sure on the crank or rods but will check out specs. It was a GM crate motor (280hp)or replacement motor with very very low miles. It wasn't enought HP for my buddies 4X4 truck to turn 38" So he got a 502 502 and I got his. I'm not looking to kill it with boost but a bit more HP would be great. I have some weak old school parts working on the ass end like a Banjo rear.. I have a mag that need to be gone thru and have to find a joint to rebuild it, I would like to do it myself but don't know were to find info or parts. Might have to go with a Mallory if not.
I had wanted to go with the V-belt system to save space . It's in a 32 with a uncut firewall and want to run a stock hood. So with a V-belt set-up it gives me a inch or two. The blower came off a running car and has 10% pullies with 2" giler belt set-up, old Weiand 471 Blower intake and Dyers rebuilt blower. It's got a single 4 barrel set-up now but going to machine a 4x2 setup . It's kinda mocked up in the pics and might have to do some mods.

Sweet,please tell us more any more pics?

Oh shit I have a banjo, got any pictures of your set up? How about motor info compression?rods cam and what your drive?

Thanks for the reply and info

 

I did this one for my friends car, 4-71 on a y block 292, did forged 8.5:1 pistons, steel stroked crank, h beam rods and had Chris Nielson grind me a blower spec'd cam on the second motor. The first motor blew in a million pieces from abuse and detonation, this new motor I put a msd box that curves the spark 3 degrees with every pound of boost that comes in. Runs excellent.

 

Yep after years and years fighting myself not to chop it, to chop it ,I did when you would let me wack at yours. It's a small chop as you see in the pics. I had planned on doing a tech on the chop but a fellow hamber posted one the other day. His shop was cleaner then my garage, he had better tools and I used Child labor to help me lift off the top and put it back on. Plus the other guy looked like they were union workers too. I have the pics on two camers as well, my daughter was snapping one and I snapped a few on the family one. It looks more like a hotrod now and 90% done as of today. I stll want yours

WOW, sweet she has to go like heck to boot!

Great looking Y-block and a motor under used, I hope to avoid the later on blowing it into a million pieces. This is why I ask question first thing! Do you reccomend a MSD box more then a MAG or a simple mallory? This is just for daily rod driving

 

John the first motor we ran had a vertex mag in it and it was hard to get the timing to work at all speeds, the msd box will not work with a magneto but I wish MSD would figure out how to make one work. The msd box you need has a control dial on it which you can adjust how many degrees you want the spark to change as boost comes in, as far as a distributor we put in a new roto faze and removed one of the sets of points and the condensor, the dist is basically a trigger for the msd box, pretty easy setup and so far it works great, the only problem we had was you need a really good connection with your spark plug wires on the cap or it tends to carbon burn fairly easy, here is the box we used......

http://www.msdignition.com/product.aspx?id=5859

 

I like the MSD box and not sure if the Dizzy will fit with the firewall in stock location and uncut. I have a old Mallory YC series that had planned on tossing in a mod. I could run the box inside and out of sight. The mag fits the bill but does have its issues as you said. What happened to the other motor? Just over time or just in a short beating.

Does anyone have a chart on a 471?

 

The MSD 6AL BTM is a good Idea mine is hidden up under the dash and alows for easy timing adjustments for different octane gas so you to run much more timing for when its not under boost conditions and they like that. at 5 or 6 PSI of boost it should run fine you will need a good flowing exhaust and a cam change would be a good idea too mine is pretty detuned but very streetable and gets about 17 MPG I drive it all over the midwest with no problems so far

On a side note I was gonna come up with Mel a couple weeks ago so I could meet you but our plans got changed and I couldnt make it I'll look for you at the HCP
Mike

 

john, now i see why your not sellin your chunks!!!!!

 

Here is some more. I agree the MSD 6BTM is the way to go. I have played with a BTM on the dyno and they work well

 

I like this one...