A guy in my area is selling a tbi b&m supercharger for short $$ and I was just wondering what the difference if any,between a tbi and a carb supercharger.

 

what type of supercharger? it likely will work but wont be a bolt on and go type deal

 

I'm not sure what style it is I'm waiting to hear back from the guy now. I know it's b&m. I can't find much info on the b&m models but it seems like most of them are roots superchargers. Would the supercharger be just as tall as a 144? I'm trying to find something that'll fit under my 2'' cowl hood.

 

IIRC, B&M blowers were suck-thru roots type (I guess all roots type were suck-thru). As far fitting under the hood?

 

Yeah, it's the same blower. It's probably the 144-style blower (designs and tooling now owned by Weiand/Holley, as with the similar 142 line of blowers). It was made for a carb application originally, way back in the day. It will take a carb again. If somebody once mounted it on a TBI engine, it was a one-off or some limited run kit they made for TBI applications. In any case, the mounting flange should still be a carb-style mounting flange. If the flange can mount a Holley or QJet style carb you're good to go (it will).

Get ALL the pulleys and everything with it. They are VICIOUSLY expensive to buy individually.

 

I should also mention there are 3 basic designs of 144/142 blowers. Short nose (only fits early short-style water pump accessory engines like back in the 60s), long nose (which fits most modern applications that use long style water pump accessories) and super long nose (which fits only serpentine and certain 80s vintage v-belt carb application accessory setups).

Don't just buy it and then find out it won't fit past your existing accessory system Be sure what you're looking at. Don't be afraid to have Weiand/Holley tech support on speed dial.

 

So it is a screw type supercharger. And today I found out he has the whole wiring harness with the tbi unit and a tuned computer. Might be switching it all over now... Anyways I was wondering if anyone knew if a tbi unit is shorter than a Holley carburator... Height is still my main concern. And i read somewhere that tbi units are close to two inches shorter. I'll be looking at the setup tomorrow but if anyone knows in advance it'd be nice.

 

It's a regular old roots-style blower (not screw-type) that uses straight-cut lobes (no twist).

TBI is shorter than a carb but with the injectors up top and all I don't know how much shorter the entire setup would be with an air cleaner. In any case it won't fit under a stock hood. Period. Figure 4" cowl hood to squeeze it under and still have room for a reasonable sized air cleaner.

 

Thanks Damon for your help, I'm not too familiar with blowers and this will be the first one I buy.. How can i check this blower to make sure the internals are still good? im guessing the shaft should have little to no play. but is there anything else i can check? I've been reading a lot of posts on here and it seems like 4 inch cowl is the shortest you can go with a carb. I have a 3 inch harwood on it now and 4 just looks too big to me. I'm hoping I can squeeze it all under.... We shall see.

 

Not much you can do besides make sure it rotates smoothly and that there is no evidence (gouges/scoring) that the ends of the lobes have made contact with the inside of the blower case. They should pass only a few thousands of an inch apart but never touch. Touching is instant blower destruction. If they have touched it's usually at the bottom edge of the blower case near were it exits into the lower intake manifold.

 

So I bought the supercharger and tbi unit with the complete wiring and ecu. Also included in the deal were the 700r4 trans with a b&m shift kit. And the motor the supercharger was attached to. It was built by one of the local speed shops years ago for the supercharger, (the old swirl port heads have seen better days) and like all of them they eat oil. But forged pistons, pink rods and cam for supercharger. Left with all of it for 700$. I decided to use my motor though and just sell the trans and motor. I also need to get a new camshaft for a blower motor correct? Any suggestions?

 

Why in God's Holy Name would ANYBODY supercharge a TBI? Hahahaha!

 

Um...because they have a TBI?

 

Because they are gutless wonders NA!
THink its a cool idea just make sure it is tuned right before you start wailing on it. I like those little blowers they work good for what they are.

Fun hitting passing gear on the fwy next to someone and watching them hit the brakes when the blower starts to scream. lol

Blower cam is a good idea easier to tune, not saying a carbed type cam wont work though.

 

No **** Sherlock.

 

You don't need a new cam to work with a blower unless you want to. On a mild setup the blower basically just makes the engine act like it's got more displacement- a higher torque curve everywhere in the RPM range, but the shape of that torque curve is still basically the same.

Like any TBI engine, the tune in the chip will be dependent on the cam as much as it is on having a blower sitting on top.

In other news.....

Hey- I've got a cool "10 year memeber" thingie under my name on the left! I just noticed that. Reality is, I've been on the board since even before 1999. I think about 1997-1998 or so. Somewhere along the line I think they reset all us old-heads to 9/9/99 start date. But there are plenty who have been on here before that. That would mean I am a FIFTEEN year memeber sometime around now, in reality! Oofah! Before kids! Before male pattern baldness!

 

Well I'll be bolting it onto my motor and I don't know if you would consider it mild. It's bored .40 over. Dished forged pistons. Procomp heads ported & polished. And a comp cam valve lift .462 .469. Duration @ .050 218-224. Would that cam work well with the supercharger? Also it's just a plate under the tbi unit. Looks like I could run it with my carburator before I get the ambition to wire the tbi in.

 

That cam would probably be ideal for use with a little mini-blower. If it's got a wide-ish LSA (like 112-114*) you would really be in fat-city. That's right in the range of what I've found to be "optimal" for use with the little 142/144 blowers. Any more and the blower can't keep up with the cam up top. Any less and you're leaving some power on the table.

I run a cam with 214/224* @ .050 on a 112* LSA in my mild 383 blower motor. Idles smooth and makes almost exactly the same power as a previous cam I tried with 10* more duration and more lift.

You're good to go. Right where you need to be. Have fun!