Thread: 4-53 supercahrger help!!!

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Originally Posted by Itoldyouso

Yeah, I ran that arguement by the guy at BDS, and he said that thinking is backwards. I didn't fully get all he was saying, but he was telling me the 2 cycle had less of an airflow requirement because of the every stroke thing. He said to equate a 212 CI 2 stroke to a 424 CI 4 stroke is backwards.

It's over my head, but he is the expert.


Don

might be true if you're working with 15 lbs. of boost, but with 7 lbs. i dont think it makes no dif. thats all i ever run anyway.

A few years back I remember reading an article about a rod shop modifying the 4-53 blower for use on Ford flathead V8s. You might try a search on one of the "traditional" rod forums along this path.

You could take a look at the small B&M blowers to see if there's a chance they were based on the GMC 53 series and if the snout could be adapted. I've never been up close to a B&M, so it's just a swag.

You also should check to see if high speed sealed bearings are available for that blower. The stock blower was not intended to produce boost, just scavenge the cylinder during the exhaust cycle and refil to normal atmospheric pressure.

Cheers, Mark

[QUOTE=Itoldyouso]Yeah,
It's over my head, but he is the expert.

Well, maybe you can't make a direct comparison, but if not I don't understand why. If a four stroke engine of given displacement draws charges every 720 degrees (1 stroke out of four) and the same displacement two stroke engine draws a charge every 360 degrees of rotation (1 stroke out of two), won't the two stroke be pumping twice the volume of air in a given time period?? Somebody needs to convince me otherwise. ;-)

Bob

[QUOTE=Itoldyouso]Yeah,
It's over my head, but he is the expert.

Well, maybe you can't make a direct comparison, but if not I don't understand why. If a four stroke engine of given displacement draws an intake charge every 720 degrees (1 stroke out of four) and the same displacement two stroke engine draws a charge every 360 degrees of rotation (1 stroke out of two), won't the two stroke be pumping twice the volume of air in a given time period?? An engine's nothing but an air pump. What am I missing??

Bob

>The stock blower was not intended to produce boost, just >scavenge the cylinder during the exhaust cycle and refil to >normal atmospheric pressure.

True, and a good point.

Bob

if i'm getting my 7 lbs. of boost that i need, i dont see that it makes no dif. what it came off of. if the blower is to small then it would make a dif.

Sounds I have a exspinsive door stop. I think I will still put it on my engine just for looks. My dad has 8v71 blower But that seems a little big. He plans on putting it on a ford 460. But he need parts to.

How could this be to small, b&m has a 171 ci supercharger and they put them v8 I think this one is 212 ci Sounds like this might work if I spin It real fast.

Sounds like you may have two doorstops at the moment. I don't think anyone makes manifolds and drives for the 6V71 and 8V71 blowers either, this is a different case style than the normal 6-71 inline blower and the aftermarket offshoots.

You're correct about spinning the 4-53 blower faster, from a theoretical standpoint. The 53 series already was "high" RPM, twisting to a rated 2800 RPM at full load. But the faster you spin it the less efficient it becomes. I'd guess you'd have to drive it 50% over just to get 5 lbs of boost. As the pumps efficiency drops this extra energy converts to heat, which raises the air temperature being supplied to the engine.

While you can continue on with the project I don't think you'll be happy with what you end up with, and it's going to cost a lot more than if you stay with a standard (off-the-shelf) 6-71 configuration.

Sorry to be a stick in the mud.

Regards, Mark

At some point it becomes prudent to "cut ones loses." It appears that this 4-53 isn't a unit that is readily adaptable or suitable to your engine, so why continue putting money into it? I don't think you are going to be able to find all the pieces to make it even functional, and from what BDS says, even if you could it would provide no power increase.

I know human nature is to try to make the best of a bad situation, but to throw good money after bad is not the way to go.

If Weiand and B & M only use the rotors out of this unit, and nothing else, that should tell you something. Before you start spending one dime more, call some of the expert companies, like I did for you today, and then decide. You can always put it back on Ebay and maybe get some or all of your money back.

Don

what about weainds 174 ci supercharger they sell these for there big block chevys If you can put a 174 ci on a big block chevy why cant you put a 212 ci on a small block mopar?

Not a good idea to spin a stock case 4 53 to high because the end plates a re weak, try to put the bigger bearings in and you have to machine the stock end plates making them weaker still. Thats why weiand and B&M redesigned the case and end plate of the blower. Also of note the 453 is a bi lobe straight cut rotor design sowhen the air exits under pressure from the blower it creates a shock wave, so these blowers run hotter and make a lot more noise than the traditional 71 series designs that have a tri loe epicyclodal design to make the blower more efficient. There is hope for that 8 71 get a 6 71 case and end plates send the case off to get adapted and machined at dyers. They will put on a 1" spacer plate on the case allowing you to run the 8 71 rotors in the 6 71 case. The 8 71 rotors are the same diameter as the late 6 71 rotors but exactly 1" longer. An 8 71 clone is a good efficient blower for a 460 ford or 454 and up BB chev.

How high could a person spin one of these blowers. I seen pictures of people using 8v71 and 6v71. The 8v71 was on a boat engine and 6v71 was on dodge 340 in a dart.

Quite high, with the 6 71' s on dragsters they had on average 30% overdrive on the blower so withthe engine doing say 5000 rpm at 30% the bower is doing 6500 rpm and they really sing. But realistically on the street you would be doing only 7 lb's of boost so you would need a 28 tooth bottom pulley and a 30 tooth top pulley on a 671 360 combination.

what I ment was how Hi could a person spin a 4-53 supercahrger. Thanks for the info about the 6v71 I was wondering what pullies to use, would that be about the same for a 8v71?