Topic: Desperately Seeking Enlightenment (on a MagnaCharger!)

[Ricky_Racer]

This is a very long shot, but I can't think of a better group of fanatics to ask... Does anyone have any documentation, articles, photos, instructions, literature, leads or parts related to the installation of a Magnuson MagnaCharger on a CB750?

Desperately seeking assistance. Will repay favor with huge amounts of burned incense, chants and prayers to the gods for your long life, brilliant offspring (who will become genius NBA all-star millionaires) and many sheep in your flock!  Let me know and I will carry a coconut in my teeth to your door. 

Or at least buy you lunch.     RR

[Sam Green Racing]

Find me a fit looking girl to have this brilliant offspring with, and I'll see what I can find out for you.

You can send the sheep to Terry in Australia

Sam.

[scondon]

   I have a squirrel that lives behind my garage. Damndest thing, it can disassemble anything and draw out perfect schematics and installation/tuning instructions before slapping it back together. I think its father was a chinese engineer and its mother was a wood nymph. Send that charger up north to 'Frisco and I'll get the squirrel right on it.    Sorry Ted, you deserve a straight answer and really wish I could help ya

   

[sparty]

First, you have to source one of those chargers.  Can be a challenge to find one at a good price.
Second, you would need a modified frame so that the charger would fit.  I don't believe that the charger would fit a stock frame.
Third, you would need to be sure that your engine is stout enough to handle the extra power.  Which would most likely require better rods, valve springs and retainers, and some port work on the head.

Sparty

[754]

I think they did fit in a Honda frame, if you relocate battery and put carb there.

Do you have a line on one?

 The Kawi models did fit in the factory frame..

[Ricky_Racer]

Thank you all very much. Yes, I have a line on one that was on a Kawasaki 900 drag bike.  But I think the entire project might be a little daunting for me, and I'm not willing to make a long-term committment to developing the installation.

Jerry Magnuson did make installation kits for the SOHC CB750, but their rarity makes Drouins look commonplace.  He doesn't even have one of his own. The photo in this thread is of a Swedish chopper with a MagnaCharger.

I'm really trying to determine the feasibility of resurrecting a rare, complicated application from "the day."  However, given everything else I have on my plate, unless I get very lucky this may be a bigger bite than I care to take.  RR

[jaguar]

im also very interested in learning more about forced induction sohc

[754]

I think the earliest Magnachargers had  the belts showing, but not sure. Then they went to a kit for the Kawi that replaced the clutch cover & extended up to the blower with a cover over everything. I am thinking they also did that for Honda 750. I know that  some later RC Eng catalogs had a good clear pic of the Kawi setup.

I cant remember how the Honda was driven, but if I get one I will go of the crank side.

I have a Ford 3.8L bolwer sitting here, thought I could get it to work.. but it is just physically too big.

The one I am trying to get a hold of right now is used on the newer MINI,s From the measurement I got so far, it sounds like it will fit behind the carb spigots and be similar to your pic, in fact maybe a slight bit shorter(good thing).  I have not found the ratio of the stock Mini drive yet, but it appears to bebetween 1.6 to 2-1 overdriven.. and it is for a 1.4 or 1.6liter engine.. So I am thinking at 1-1 it will be closed for a 970 or 1000cc Honda.. The drive snout will probably have to be shortened.

I have hundreds of bike magazines fronm the 70's, mainly custom mags... I could probably find some pics if I ever get the time to start looking... You can blow 3 hrs reading them mags,, ond only get thru a few of them..

[Ricky_Racer]

754, you're correct that the MagnaChargers for the CB750 and Z903's drove the blower off the clutch, unlike the Drouin which drives from the stator.  Supposedly the MagnaCharger kits had some kind of "fingered basket" that fit over the clutch. That is one of the parts I'd like to see because I can't seem to get a grip on how it would have worked, but evidently it did - and very well.

The MagnaChargers also supposedly put out 30-35 pounds of boost, and that's a lot for a CB750 bottom end. Not a huge problem for the Kaw with it's roller crank, but a chunk of pressure against plain bearings with no stud girdle.

Just and interesting topic for discussion and investigation. If it's not discussed in this forum, then where?  RR

[Sam Green Racing]

Ricky, check this one out.

http://www.edstroementerprises.com/jep/BlowerDesign.htm

Sam.

[754]

I never think much about the Drouin, I recall lots off complaining back then about lack of service and parts availability.

I did see one on a Triumph at Bonneville last year.

A fingered basket to drive the blower would not be hard to make, getting the clutch throwout to work through it will be a bit more work. To me, the drive is the least of the problem, multirib pulleys are easy to make on a lathe.

Nice link to the blower design site, thanks.

[Big Jay]

Is the one that you have a line on an 80 c.i. or 110 ?

Jay

[Ricky_Racer]

Sounds like you have some experience with huffers, Jay.  How can you tell the difference between the 80 and 110?  And how will it affect the application?  Thanks.  RR

[754]

I think the rotor and case design were the same dimesions on all Magnachargers built for MC use back in the day. The difference in sizes were done by changing the length of rotors and housing. I think they also built a 40 and 60 ci version.