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Post Info TOPIC: Passive supercharging
Don


PRINCE EDWARD COUNTY

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Passive supercharging
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Many years ago when I was only about 12 I read an article about an experiment GM was doing with passive supercharging using a form of air entrainment. I never forgot it and mentioned it on another website some 4 years ago. Three weeks ago a rodder from down east (formerly from the SOO) hunted me up and called me by phone. He was cleaning up some old car magazines and found the original article. He had his son copy the whole thing and send it to me. It was written by Rodger Huntington so that would put it in the reality category and his articles were always bang on. There were photos but no dimensions. Using the pixel count in paint I was able to establish a relative number for each part. Deciding that the mixing tube which is the smallest diameter should never be smaller then the carb venturi diameter I used that as a baseline and developed all the rest of the dimensions by using the pixel count numbers. Ie If mixer tube has a 35 pixel diameter and the diffuser is 140 pixels long then it is 4 times as long as the mixer diameter so if the mixer diameter is made 1 1/4 inch then the diffuser would be 5 inches long and so on. In the time between mornings planned work and lunch I poked away making the parts one by one. Finally welding them together and attaching a proper air cleaner assembly. Initial testing is encouraging even if it is only on the bench. Using only 120 PSI in the entrainment jet I was able to produce positive pressure in the diffuser and a definate neg pressure in the air cleaner housing. It needs a larger opening. In the article they were able to produce and sustain 4 lbs boost for 15 seconds. They used a hi supply tank pressure and charged it with a belt driven small compressor or an electric compressor. They then used a 150psi regulator to maintain no more then 150 psi to the small entrainment nozzle. They said the entrainment nozzle pulled 8 times its own volume into the system. Where this will all lead who knows but it is certainly interesting fooling around with it. I have a stock slant six with low Kms (30,000km) I have sized everything for this engine. I would like to put it in the VW gasser with the passive supercharger deal for some just for fun testing. GM was claiming 40% increase in power and was exploring this for use to boost power for passing without requiring engine mods . So 40% on a slant six would give and extra 58 HP or 203hp. Not much you say? Really. When was the last time you saw a 203 HP VW Beetle? Anyway I will take some photos later and stick them up here. Time will tell if it was worth the effort or not.

don



-- Edited by Don on Wednesday 7th of May 2014 10:23:41 PM

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BADEN, ONT

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Interesting Don. I've never heard of this contraption, I'm definitely interesting in seeing/hearing more about it.

Those slant 6 produce some respectable torque.

Here's my daily driver when I was in college.

'75 Dart Swinger.jpg

'75 Dart Swinger 2.jpg

And that is without braking. Tough, cheap, fun and reliable.

 

 



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CLINTON, ONT

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Interesting    could you explain that again    It blowing air in the what ?  



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DUNDAS, ONT

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The only draw back I can see and It shouldn't  be a huge deal if it is only used in short spurts. Is there is no way to adjust the fuel volume with the increased air . So if your carb is setup properly under normal conditions the boost would lean the mixture while it was on. or am I missing something.



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Don


PRINCE EDWARD COUNTY

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A carb automatically mixes fuel with the air in proportion to the amount or air flowing through it.(Bernouli principle) More airflow more fuel. Huntington said he drove the cars it was on and it was impressive. A 58 Poncho went for a 0 to 60mph time of 12.7 seconds to 8.4 seconds. A 194 Chevy II could run easily with the eights. Paxton blowers to name just one commonly used to blow thru the carb with a sealed hat. A pressure box is even better. As long as the carb vent(internal vent or bowl vent in airhorn ) sees the same pressure as the incoming air it doesn't know the difference. Carbs BTW were my life. I have overhauled and reworked thousands of them, really no exaggeration. For one customer alone, a nearby machine shop specializing in marine rebuilds, I did an average of three per week for over 5 years. Very comfortable overhaul reworking and modifying them. I am far more concerned about getting the pressure results from the device. To maintain 150psi at the nozzle for even 10 seconds I need substantially more in the supply tank feeding a regulator. Haven't sorted that out yet. Just have the infuser, mixer, diffuser deal working.

don



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COBOURG, ONT

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this sounds kind of like those useless electric superchargers that people were getting tricked into buying off ebay.  boat engine bay exhaust blowers is all they were. 



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DUNDAS, ONT

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Just throwing the question out there Don . I can guaranty without a doubt you have put more thought into this the I have. Just figured at some point the high speed circuit is going to max out .Generating air pressure at above 150 isnt really  a problem making it cost effective and convenient is really the draw back.smile 



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GALT, ONT

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Don wrote:

 I read an article about an experiment GM was doing with passive supercharging using a form of air entrainment. It was written by Rodger Huntington I poked away making the parts one by one.  Initial testing is encouraging even if it is only on the bench. Using only 120 PSI in the entrainment jet I was able to produce positive pressure in the diffuser and a definite neg pressure in the air cleaner housing.  In the article they were able to produce and sustain 4 lbs boost for 15 seconds. They used a hi supply tank pressure and charged it with a belt driven small compressor or an electric compressor. They then used a 150psi regulator to maintain no more then 150 psi to the small entrainment nozzle. They said the entrainment nozzle pulled 8 times its own volume into the system. Where this will all lead who knows but it is certainly interesting fooling around with it. I have a stock slant six with low Kms (30,000km) I have sized everything for this engine. I would like to put it in the VW gasser with the passive supercharger deal for some just for fun testing. GM was claiming 40% increase in power and was exploring this for use to boost power for passing without requiring engine mods . So 40% on a slant six would give and extra 58 HP or 203hp. Not much you say? Really. When was the last time you saw a 203 HP VW Beetle? Anyway I will take some photos later and stick them up here. Time will tell if it was worth the effort or not.

don
-- Edited by Don on Wednesday 7th of May 2014 10:23:41 PM


 at the same time, they were trying to reduce the combustion chamber size with water injection,, and H2O had oxygen.. but it had its problems ..
I think they went on to find a way to put air entrainment in the fuel,,, oxygen bearing fuel like ether.. and that is what we are burning today..  MTBE .. which allows the fuel mfgr to make low quality fuel,, but wake it up with the additives.. and it burns "cleaner" ,,  as there is more air in the fuel mixture going out the tail pipe, so less parts per million...

http://en.wikipedia.org/wiki/Methyl_tert-butyl_ether

some track racers still put ether in the fuel ... at tracks that don't have a method to test fuel..

also,, Nos can be used to get the oxygen in...  

so,, not knowing about the method you describe,,, is it for general use in my driver,,, or just to win races.?

I see 200 + HP vw beetles frequently btw.. they are at the drag races all the time...

June 1 2014 Vw fun

siegfried_bly.jpg



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Don


PRINCE EDWARD COUNTY

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Its original intention was to provide power for passing for daily drivers. It never found its way into production but was tested in real cars with good results. I think turbo charging took over ie Olds F85 and Corvair Spyder. It is a bit bulky. I have thought about it many times over the past 52 years but that was the only article I ever saw on it. I am just exploring it purely for the fun and interest's sake. It supply boost just like supercharger or turbo. They said up to 4 lbs. Time will tell. Nice Volkswagens BTW thanks.
don

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ONTARIO

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The volume of air needed for even 4 lbs of boost will be the major factor.

Cool fun with cars though.



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GALT, ONT

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Articles like that open my mind a bit more.. very interesting to read about another way ... and last night, I saw an article to run cars on ammonia... I have to read that article to get the jist of that!

Keep the info coming Don.

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Don


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The volume of air needed for even 4 lbs of boost will be the major factor.
That is an interesting subject. I have a cousin Cecil Farrington who is big in tractor pulling. Cecil built a tractor some model of International that used a 6V71 Jimmy diesel. The association wouldn't let him run it because that engine has two superchargers and their rules allow only one. The engine was turbocharged as well as having the standard roots blower to supply the intake air that all Jimmys do. So Cecil being the crafty little begger he is removed the turbo, built an air box with a air solenoid operated valve, hooked up a truck air brake tank system and a regulator assembly along with three truck air tanks and proceeded to show them how it was done. I have seen it run and it is impressive to say the least. He has run it now for several years. I asked him about it and he told me he still has air left at the end of a 300 foot pull. He suggested I install a system on my rail to feed the slant six using a Scott air tank bottle for supply. He said it holds 84cu feet of air so figure out what the slant would use in 1/4 mile. I did the caculations at full throttle 6000rpm for the whole quarter mile and guess what? 63 cu feet! Now the engine wont run at 6000 the whole quarter mile so that would still allow a fudge factor. Cecil btw gathered up everything to make it including a scott air bottle from his personal stash of spares and was all gung ho to help me install it providing I would provide a 1/4 thick steel shield for the bottle if mounted near the engine. I waved him off. Not because I have any doubt it will work after seeing his success but because at my age I am not ready to sit behind a 700 to 900hp slant six. (Kenne Bell once said in an interview they tested a slant six at about 30PSI boost and got that kind of power on it.) Cecil has his dialed in a 28lbs boost but it is adjustable if competition gets tight. ) I can barely handle the approx. 280hp I have now and would prefer to live a few more years. When you do the math for 1/4 mile it is surprising how little actual air is needed. We are used to calculating for CFM but if you count the actual number of revolutions The engine makes in a 1/4 mile remembering of course that a four stroke makes two revolutions for every one cylinder filling it is not that much actual air on a small engine like mine. A slant six or a Buick v6 for that matter (same size, both motors)have a swept volume of one American gallon.
BTW Mickey Thompson and Danny Ongias were playing with a similar deal on a SOHC power funny car about the time of Mickeys murder.
don



-- Edited by Don on Sunday 11th of May 2014 08:08:20 AM



-- Edited by Don on Sunday 11th of May 2014 08:17:29 AM



-- Edited by Don on Sunday 11th of May 2014 08:18:47 AM

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NORTH BAY, ONT

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Thanks for the great read Don, interesting stuff.

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Don


PRINCE EDWARD COUNTY

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It would appear a paintball air bottle would provide enuf air easily and has a built in regulator of approx. 280PSI. How to get that from 280 to approx 150 is now the question but I am sure that is easily done. Remember now this air from the bottle is only a small portion of what the engine uses. the rest comes in by the entrainment principle. My understanding it is 1/8th. So just under 8 cu ft per run which allows 6 runs per bottle. Will start on the pressure box today using and old air cleaner base for the carb section.
don

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SOUTHERN ONT

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This crap fascinates me. Brilliant. Long live back yard science!!

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Don


PRINCE EDWARD COUNTY

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Thanks,

Is that two door your mopar? I started out with a 4dr 58 Dodge Regent. Your two door reminds me of an old gasser known as the Quebec Express

most cool those cars

don



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