24 replies to this topic

[LXCHEV]

Shouting out to all the LH/LX crew....

Has anyone fitted one of the low blowers to a V8 (ideally a Small Block Chevy). Once it's fitted up with a carb/s and air cleaner, how far out of the bonnet do they sit? Is it possible to conceal it all underneath an A9X scoop, or a bigger reverse cowl?

Keen to see pics or hear stories of anyone with experience here. Also what kinda combo's and HP levels did you go for?

Lastly - which brands are the best in the current market?

Here's a Weiand Pro Street style to show what I'm talking about....

[orangeLJ]

Vortech/raptor/whatever cemtrifugal sc could be a better option to keep it under the hood?

Just need a carby hat and appropriate carby for blow through.

[mr5000]

i like your way of thinking brett havent seen any one od this but keen to keep an eye out for a moment i was getting worried you were building a stock 350 to go back in

[LXCHEV]

Yeah I don't like the side mount centrifugal types - if I was ever going to supercharge mine, I want the traditional top mount roots style.... 50% just for looks, and 50% for the performance. If I was chasing performance only, then yeah - the centrifugal type would be the better choice.

I'm just trying to work out if it's possible to get a blower with carby underneath a scoop.... somehow I don't like the chances.

Hey Ryan, for a while there I was gonna build a stocko 350 for mine... but as usual plans tend to change! The next motor will not be stock.

[LXCHEV]

That's awesome! Great photo - he's obviously running a drop base air cleaner. Thermostat housing looks tight too, but as long as it works, it works! Damn that looks nice

I'll have to do some measuring of standard intake and carb for reference. Will be very interesting to see how it compares. Thanks very much for that info Jeff.

PS. I just want to say it again - damn that looks awesome!

[LXCHEV]

Very nice indeed! Well done. That thing must hammer

[V-SLR5000-P]

My own experience with low profile blowers is that they are a complete waste of time. I had a B&M 144 on a 350 Chevy and found the whole experience totally underwhelming. Low blowers are limited to about 450hp due to heating of the incoming air by high rotor speeds. These blowers will add maybe 100hp to a stock engine, but are not the ticket to big horse power.
In my opinion you would be better off putting the $4,000 towards a decent pair of heads and a roller cam.

[LXCHEV]

Very interesting to hear, that's great feedback. I've heard similar things for the 142/144 series.

Apparently the 177's are a bit better, and can push a decent SBC up to 500-600HP.

[MRLXSS]

Got nothing to ad, except Brett... I like your style mate!

I can't wait to finally go head to head with you at the track! How many tough Torana's do we have at Eastside these days! HAHA!

[V-SLR5000-P]

Apparently the 177's are a bit better, and can push a decent SBC up to 500-600HP

600 hp is a big number out of a rootes blown SB Chevy on premium inleaded. I don't expect my AFR headed, roller cammed 383 with a 671 blower will make more than high 500's.

[WhaleOilBeefHooked]

Years ago I saw an xy with gm roots as in 671 on a 351 under the shaker scoop, but a lotta work went into having it that low and you wouldn't want the sump or exhaust rubbing on tarmac, It's also gotta be legal......

[V-SLR5000-P]

So how much power can be expected from SBC with a low B & M rootes type blower??
B & M themselves published a Supercharger Technical Manual, its a pretty good read. The results from their own testing on a 350 Chevy were.

Standard heads and stock cam 320hp
Standard heads Super Street Charger cam 390hp
Big valve ported heads Super Street Charger cam 440hp

No test undertaken by B & M with a low blower produced more than 480hp (174 blower 9lbs boost). A Mega blower (671 size) on the same engine made 550hp. 500+ hp is too big an ask from a low profile blower, B & M testing their own product showed it.

[LXCHEV]

Excellent info.

I think I have an answer to the clearance question - finally managed to find these old pics that I took at an old All Holden Day...

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[LXCHEV]

Here was another article I found from Weiand / Holley... this is where I read about the possibility of 600HP.. but I highly doubt it would be a reliable combo... as they said themselves the test was just for kicks...

[TerrA LX]

This orange LX hatch, owned by an old work mate, parked next to SS Hatchback's (member) red LX hatch in the early 90's was low blown 308 rumoured to have 520FWHP (Not verified but it went frOcking hard) was under the scoop.

[Struggler]

Hi Brett, I have had a real good look at this myself, even got a second hand B&M 162 and got a custom drive made up. At the end of the day it is only going to pump 142/144/162/177 CI every rotation. A 6/71 will pump 411 CI every rotation so for the mini blower to keep up with a 1:1 driven 6/71 it needs to be overdriven at least 2.3 times. This is fine at idle and at low engine speeds but turn it hard at all and the intake air heats up too much and it rattles its heads off. The mini blowers use a 2 straight lobe rotor which is inefficient at best where the 6/71 uses a twisted 3 lobe rotor (unless you bought a Weiand in which case it uses the same extrusion the 177 does, only longer) which does a better job of pushing air around.

Bottom line, yes they make boost and in the right application they can be a lot of fun but to make the best max power out of them they need to be intercooled which is only really achievable by using methanol as a fuel or Nitrous as a chemical intercooler/power adder. Cars in the States are running 10's and 9's with Weiand 177's but they all use either alcohol fuel or Nitrous. They also go through a few blowers as they are not really intended to turn as fast as these guys are spinning them. After sitting down and thinking about it I decided to sell mine off to a mate who uses it in his SBC Landcruiser. In the Cruiser it is perfect, great boost off idle to get the heavy thing moving and it never gets revved. This is where the mini blowers shine.

I love the look of old school 6/71 style blowers and it is a fact they draw the biggest crowds but they are really inefficient. It takes a heap of HP to turn a 6/71 to 6000 rpm where the newer centrifugal blowers need a lot less. Go to the drags and see the 6/71 powered cars run. Usually its disappointing. Unless they are alcohol fuelled they run in the 11 or 12 sec bracket. Watch a 6/71 car in a burnout comp and its a different story, the off idle boost gets it killing tyres instantly and the boosted exhaust sounds great.

I could go on but it really is horses for courses, do you want to look good, go hard on the track or just drive the wheels off it ?

Hope I haven't confused you !

[LXCHEV]

Nah you haven't confused me at all... it actually makes perfect sense! Like I mentioned earlier - if you were chasing all-out max performance, then you would never even consider a low blower. There are way too many better options out there.

A low blower would just be something cool to play with.... obviously suited to a more mild application - a bit of bling, mixed with a bit of added performance & noise too. It's a boys blower, not a mans blower, LOL. I was interested in pursuing it, so I could have a traditional looking blower, but not through the bonnet, for use as a cool street cruiser.

Anyway, thanks for the great summary, it's helped a lot to put it all in perspective. I looked at a few tech videos where they talked about the 2 straight lobe rotors versus the twisted 3 lobe rotors, it's interesting stuff. Sounds like to be serious, inter-cooling would be a must. Personally I'm not keen on methanol, definitely not for a cruiser.

At the end of the day, I've decided against this too - I'm just gonna bang together another N/A 383 for now..... later down the track we'll just have to go for a Pro-Charger!!!!

Cheers.

PS. Great photo and great story TerrA LX!!! That's awesome

[Struggler]

... whipples can be carby fed. They still look like a old school blower to an extent and being twin screw are more efficient than a centrifugal blower.....

The Whipple is a really good thing, also the Magnuson (http://www.chevyhipe...gers/index.html). Unfortunately you have to pay for the privilege and both of these are considerably more expensive than a Procharger.