Gator supercharger and belt driven turbos

[dieselbikin]

I just bought a book off of Ebay called Supercharging Small Engines, item 200379516029 . The author has a Yahoo group http://autos.groups.yahoo.com/group/superchargingsmallengines/ . Website with pictures, http://www.gatorsuperchargers.net/photos/photos.htm .
This is the book Ebay explanation:

Most small engines used in recreational vehicles and small economy cars don't have engine compartment space or can tolerate the high engine compartment heat of a turbo so superchargers are the natural alternative. Unfortunately, no affordable small supercharger has been available, so back in 2001 our group launched a research and development project to produce an inexpensive blower for the tens of millions of "forgotten" small engines. The resulting Gator Supercharger is impressive -- better than anyone could have anticipated. Higher boosts, cool running, and so simple almost any backyard mechanic can build one for a few hundred dollars. Only common hand tools and a small drill press are required -- no welding or lathe work necessary. This book carries you through the R&D step by step, providing details you couldn't find anywhere else. A short history on Paxton/McCulloch superchargers which we have worked with since the 60's, then into belt drive turbos and finally the new Gator supercharger. It also details draw-thru and blow-thru carburetor systems for small engines (but no fuel injection). This is a do-it-yourself book jammed with hundreds of pages of technical information, photos and drawings you can't find anywhere else in the world.
PHOTO: The new Gator Supercharger uses a two sided impeller, drawing air into the compressor housing from both a conventional inlet in the front and a rear inlet as seen in this photo (the reason for the K&N air cleaner). Not only does this increase blower output but the air cools the bearings as it is drawn into the compressor.
BELT DRIVE TURBO OR GATOR SUPERCHARGER? This book covers a wide range of compressor and extensively tested bearing options to allow the do-it-yourselfer to build the blower best suited for a specific application.

Anyway, I’m half through the book and excited about the concept because I can build it affordably in the garage. I joined the Yahoo group, but still waiting on membership approval.
I would like to build a 5-6 psi blower for my engine. It also covers driving the intake end of a turbo with a belt. Anyone else familiar with this setup? Later

[coachgeo]

Sounds interesting. Keep us informed

[andrewaust]

Interesting info on the websites dieselbikin, nice post.

I could see a good supercharger setup being more beneficial "especially with singles" then a turbo.

Nice to see Gator Superchargers working to build good reliable units, also supplying information.



A

[dieselbikin]

It appears I gave the wrong yahoo group and address. Try this one; http://autos.groups.yahoo.com/group/Carburetedblowers/?yguid=291759595 I asked a question about my bike and got a reply. Without the book it may not make much sense. Later.

[Diesel Dave]

Andrew said:

I could see a good supercharger setup being more beneficial "especially with singles" then a turbo.

I think the problems will be more or less equal, you have a compressor pushing air all the time and an inlet valve that opens for 120 degrees every other crank rotation.

You need somewhere for the compressed gas to be stored, preferably in an intercooler so the charge heat can be removed. after talking with a Dutch drag racer he said that the chamber size should be 3x cylinder capacity. Compress this chamber to 6psi just before the valve opens and cylinder charge should be increased by 4.5psi.

I also believe that the turbo should not be close coupled on a single......


But I'll shut up now until I get some time to experiment.

Dave

[dieselbikin]

I'm looking forward to some turbo test results myself. I just want to know if a Yanclone's exhaust can spin a turbo fast enough to create and maintain 4-6 psi. I hope the answer is yes too. It would be nice to not have a supercharger's parasitic loss.
At those boost levels an intercooler is unessasary for a supercharged engine, since it does not have the exhaust heating it. Later.

[cumorglas]

At those boost levels an intercooler is unessasary for a supercharged engine, since it does not have the exhaust heating it. Later.

but it would still be nice. you are still heating the air just by compression (p1*v1)/t1=(p2*v2)/t2.
and if you sized the intercooler just right it would function as your tuned plenum.

[andrewaust]

Andrew said:

I could see a good supercharger setup being more beneficial "especially with singles" then a turbo.

I think the problems will be more or less equal, you have a compressor pushing air all the time and an inlet valve that opens for 120 degrees every other crank rotation.

You need somewhere for the compressed gas to be stored, preferably in an intercooler so the charge heat can be removed. after talking with a Dutch drag racer he said that the chamber size should be 3x cylinder capacity. Compress this chamber to 6psi just before the valve opens and cylinder charge should be increased by 4.5psi.

I also believe that the turbo should not be close coupled on a single......


But I'll shut up now until I get some time to experiment.

Dave

When talking supercharger, I was keeping this one in mind http://www.dieselbike.net/commercialext ... extras.htm which does precisely what you said, pulls air into the combustion chamber on the inlet stroke. The Rynhart R&D Supercharger was a very promising design for singles.

I tend to agree with a previous statement, low psi doesn't necessarily need intercooling, especially if one was to use a Rynhart design, the yanclones wouldn't handle high boost either as they are above the 20:1 compression threshold anyway. My engine is running close to 23:1 compression. I wouldn't be looking at high boost, rather to keep volumetric efficiency to the greatest degree up to max rpm.

I cannot see a Turbo running well with a single, why? I've tried in a rather crude way and not really impressed with the results, although I wasn't expecting much. I'd like to keep rpm down to the torque curve, running the turbo would boost at high rpm with a high fuel burn. Maybe better with CVT's, but not for running around town with a tranny.

A

[dieselbikin]

I finally did a test run yesterday on my supercharger. It will generate 2 psi at approximately 12K rpm impeller speed. After that increased impeller speed does not increase pressure. I'm excited it built any pressure at all on the initial attempt. Version two is going to have to be a heavier duty design to cope with the massive vibration making the impeller housing vibrate against the spinning impeller/shaft supports. For a blower made out of sheet metal,particle board, and a leaf blower impeller its not bad. Version two's impeller housing will extend over the engine's intake to make an integral impeller/intake housing. The duct work will be cut into the particle board like the first version. The major improvements will be a stronger/integrated housing, stronger mounts, and closer impeller to housing clearances. My goal is 5 psi.

Here are my pictures at photobucket.
http://s488.photobucket.com/albums/rr249/dieselbikin/Supercharger/

[toyotaracer9]

I briefly read this thread and didnt see any mention of using a smog pump off of a car , they should easily make 5psi boost on engines around 400cc and not be over spinning the pump .

BTW that is a very nice air pump you built there Dieselbikin , what type of wheel design is in there ?

[dieselbikin]

Toyotaracer9,
Check out some of my new supercharger pictures on photobucket. Includes smog pump blower.
http://s488.photobucket.com/albums/rr249/dieselbikin/other%20superchargers/
Here is a teaser photo! LOL

[toyotaracer9]

Nice pics , it looks to only be a single vane pump . I had always assumed they were multi-vane .

[coachgeo]

....


When talking supercharger, I was keeping this one in mind http://www.dieselbike.net/commercialextras.htm which does ....)

needs the link updated.

[andrewaust]

....


When talking supercharger, I was keeping this one in mind http://www.dieselbike.net/commercialextras.htm which does ....)

needs the link updated.

http://www.dieselbike.net/commercialext ... extras.htm

Coachgeo - I'd do a web search for "The Rynhart R&D Supercharger" it should yield more info


A

[dieselbikin]

Here's my latest supercharger for my diesel bike. It will be driven at an 8 to 1 ratio.

[pietenpol2002]

If my calculations are correct that would come out to something in excess of 28,000 RPM's. While perhaps capable of generating some boost, I do question whether the bearings and pulleys are up to the task. In the absence of a well balanced unit, things can get real interesting at 28,000 RPM's. I had a prop begin to disassemble itself in flight on an old WWII vintage craft. You start to wonder just how many cycles that engine mount can take before engine and airframe part company. And that was at 2100 RPM's. Just concerned about the risk of your blower drive shedding parts in such close proximity to your crotch. And yet I'd love to see what you can do with this application. I applaud your pioneering the way for the rest of us.

[Sphere]

In the absence of a well balanced unit, things can get real interesting at 28,000 RPM's. I had a prop begin to disassemble itself in flight on an old WWII vintage craft. You start to wonder just how many cycles that engine mount can take before engine and airframe part company. And that was at 2100 RPM's.

My neighbour came home the other day. He's a pilot. I asked him how his flight went. He looked really annoyed and told me he had to deviate from the original flight path to switch planes. Did he have an annoying customer? Was it the weather? No, nothing serious, he just had engine failure midflight. His wife, standing next to him turned pale, then red and started fuming. I guess he hadn't told her yet.

[dieselbikin]

Thanks for sharing your concerns. Here is my perspective on the above.

The bearings are rated in excess of the speeds they will be turning for the load they are carrying, the pulleys maybe not. I'm less concerned that the impeller will be able to break through its housing with enough energy left to do harm than its shrapnel going into the engine. However, I do share your concern about the balance of the rotating assembly.

Boost or pressure is merely a measurement of resistance to flow. The larger the engine displacement and RPM the greater volume of air it consumes and the greater the turbo impeller's RPM must be to create a volume of air in excess of the engines volumetric requirement so that a resistance to flow is created which results in pressure, commonly referred to as boost. This turbo was designed to give a 2.2L engine @ 6000 RPM +15 PSI of boost with a turbine speed of less than 120K. Since the volume of air created is squared as the impeller RPM is doubled, filling a 0.4L engine @ 3600 RPM @ +5 PSI of "boost" with a turbine speed of 28,800 RPM is not unreasonable. If so I will simply increase the turbine speed.

There’s no question that the bike will be more complex/less reliable with a supercharger. I've just been a supercharger junkie ever since I was a little kid watching Mad Max hauling butt in the V8 Interceptor. What else am I supposed to supercharge for $150?

[pietenpol2002]

What you propose certainly seems reasonable and I love your R&D work. These little singles seem to beg for a supercharger, especially given the simplicity. Any estimate as to the power you'll make at 5 lbs of boost? And what are you using for a plenum/accumulator?

[dieselbikin]

Here's the blower minus air filter and final plumbing. I've run it, but do not have any data yet.

[toyotaracer9]

I must say thats a very nice homemade blower . I do have one quick question/concern , did you replace the turbos journal bearing with some type of ball bearing ? the reason I ask is because the journal bearings are made to float on a film of oil .

[dieselbikin]

Thanks for the warning. I'm using high speed ball bearings mounted in shaft collars that have the same ID as the bearings' OD. The turbine shaft is a precicion 1/4" unit, same as original, I threaded on both ends. The turbine wheel is press fitted on the shaft. The shaft turbine wheel is shimmed to the turbine housing with washers. The nuts on each end of the shaft control back and forth movement. Overal the hardware from McMaster Carr has been pretty inexpensive. The $50 for a used turbo was the big one.

[dieselbikin]

Built intake system from the kitchen sink.