Supercharged Reliant Robin

[yukonphil]

I don't know if this should be in the tech bit but I've been told on other forums that there is a thread on here about supercharging a Reliant engine and somebody's actually done it, can anyone confirm this or point me in the right direction please? Thanks, Phil.

[panthershaun]

I know several guy's have started this type of thing but not sure if any ever got one running mate..

[yukonphil]

I know several guy's have started this type of thing but not sure if any ever got one running mate..

I would like to join this exclusive club! 

[trikerpete]

Welcome, pull up a chair and tell us about yourself. Im sure The Boss will be along later

Re: supercharging...look out for Toad, a member here, Im sure he did that

[kapri]

I've got as far as buiding a test 'chassis' for a universal Vortec style centrifugal supercharger .Fitted it on my Pinto in my POS  and it made the right noises and a little boost. I know teh areas that need refining but haven't been able to get time to work on it again. Thinking about dragging it out of storage for my minimalist rod project that I'm starting soon.

[Manky Monkey]

Hi Phil -& welcome to the Land of Mank.
Toad started a supercharged Reliant trike project, which then got sold to Lunatic. We're now using that engine in our joint T bucket project. Mr Toad didn't get beyond mocking up the manifold to accept a 'charger from a modern Mini though. We've got that supercharger, but there was some damage to the rotor tips, (can't remember if the coating was coming off or the blades were chipped. To be honest, we're just fitting it so we can say we've got a supercharged Reliant, than for any real power gain. Standard Reliant will do 80mph ish. We'd be happy, (& slightly terrified), if it reached a ton.
What are you building?

[yukonphil]

What am I building?  Well, err, it's a Reliant powered motorbike, that's two wheels not a trike .  Not knocking the trikes mind, The Flapster is perfection in my opinion and the others are v.nice too.  I've had this in my head for a good decade now, i want to transfer the simplicity of the Reliant trikes to a two wheeler. I'm nearly done, I hope, the engine is inline with the frame, Reliant gearbox, XS1100 transfer box and a hardtail frame with sprung seat.  The problem is, I spent a day classic trailing in a pre-war Wolsley Hornet that was supercharged and I can't get out of my head how cool it would be to run a 'charger on what will already be a pretty good headturner.  Don't get me wrong, I know if I wanted to go fast I should build a GSXR/CBR/ZZR, it's just the sound of the supercharger that appeals and the engineering.  Any comments on this hair-brained scheme are welcome.
As another thought, can the engine capacity be increased by a reasonable ammount?  As you can tell, i'm interested in what the possibilities are with this very lightweight engine.

[Olds]

The 750 racing club used Reliant engines for years and managed to get quite good power from them. Might be worth checking out their website.
Supercharged engines have been fitted into a couple of Liege cars and I can remember a pic of one on the web.

[panthershaun]

sounds like a cool project but we do need loads and LOADS of pictures.. I started to mock up a reliant bike several years ago but was going to use a Sunbeam (S7/8) motorcycle box  to keep the wheelbase short. what charger you going to use? the mini one's are huge compared to an aisin 300 which is designed for a 600cc motor so would work reasonably well with an 850 Reliant..

[yukonphil]

I do have lots of pics but I'm a complete pleb with computers but if anyone could put them up for me I could email them. Shaun, yes, there was a thread on RetroRides on this subject with the supercharged Liege but it turns out this is a foreign, expensive charger so wouldn't be an option.  There is a Shorrocks on Ebay at the mo that would just about bolt on but the worry is that these are old units and you can't tell the condition from pictures.  So that would leave an Eaton from a Mini or Mercedes, I am led to believe the Mercedes one is smaller but I'm far from an expert as you should be able to tell by now. I'm just interested in what people have seen done or done themselves.  I got hold of a copy of the 750 Motor Club tuning manual and it's very in depth but I'm looking for low down power hence the supercharger idea.  And the fact it will look and sound cool.

[Mendalot]

Sounds like your gonna fit in here nicely   Looking forward to seeing a few pics of this.

[morrag]

Like one of these m'bee.........................

[panthershaun]

I paid £186 for my Aisin direct from Japan, here in 5 day's... what do eaton's go for now??

[Tony oily bike]

If you're going to run a blower, you'll need to run some numbers to determine what you want. ie Boost, engine speed, engine size etc.
Try this site for some info:

http://victorylibrary.com/supercharger/super-drive4.htm

Drive ratio
    Once the type and capacity of the supercharger have been selected, the relative speed at which the engine will drive the supercharger must be tested to detect gross mis-matches:
    If the supercharger capacity is too small, this requires excessive supercharger RPM either above the safe limit (which will vary with individual models and types), or not practical for the drive method chosen (sprocket or pulley too large or small). Insufficient capacity also means that the supercharger is a restriction in the intake flow path until critical RPM is reached, where its capacity matches the engine’s demand. Below this point power will be less than in normally aspirated mode, both due to restricted breathing and of course the drive load.
    If the supercharger capacity is too large, this permits internal leakage reducing boost at low RPM, inefficient operation, and high power loss, or not practical for the drive method chosen (sprocket or pulley too large or small).  
    There is a rough method of approximating how fast the supercharger must turn in relation to engine speed. It does not include such factors as supercharger wear, the engine’s volumetric efficiency, intake restrictions, &c. and therefore is only useful as an estimator. To calculate the drive ratio to produce the boost desired with the supercharger selected, where:
R: drive ratio (supercharger RPM ÷ engine RPM).
C: engine displacement, either in cubic centimeters, liters ÷ 1,000, or cubic inches × 16.387.
B: boost, in pounds per square inch (psi).
A: atmospheric pressure, in pounds per square inch (psi); 14.7 is approximately correct for sea
     level and 70° F. Click for a Table of amospheric pressure at higher elevations: ). Please
     note that RAD is preferred to actual pressure when calculating the effects of air conditions on tuning.
V: supercharger volume in either in cubic centimeters, liters ÷ 1,000, or cubic inches × 16.387
     per revolution; Roots volume is “displacement”, eccentric vane volume is “swept volume”.
O: Cam overlap; subtract 30 from the overlap in degrees, then multiply by 1% (.01). E.g. for 65°
     overlap, O = 65 - 30 = 35, × 1% = .35.  

 
R  =  C × (B + O + A)  divided by  (V × 2 × A)

Maths was never my strong point (so maybe worth re-calculating), but using the formula above, I reckon the following will give you a guide line for an 850cc engine spinning at 7000rpm with 7 psi boost

Aisin 300 (the 300 stands for the swept volume), you'll be looking at spinning that little blower at around 14,875 rpm!

If you went for an Aisin 500, the blower rpm would drop to around 8925 rpm

If you then calc the numbers for an Eaton 45 (45cu inch / nom 750cc) the blower rpm would drop to around 5950 rpm
http://www.eaton.com/Eaton/ProductsServices/Automotive/AutomotiveAftermarket/Superchargers/PCT_221788


http://pub25.bravenet.com/forum/static/show.php?usernum=2099944454&frmid=5&msgid=922656&cmd=show

http://www.austinsevenfriends.com/Bruce/Supercharger%20Information%20and%20Formulae.htm

http://www.mankymonkeymotors.co.uk/forum/index.php?topic=13389.0

Lotsa options ..................

[hunter]

The 750 racing club used Reliant engines for years and managed to get quite good power from them. Might be worth checking out their website.
Supercharged engines have been fitted into a couple of Liege cars and I can remember a pic of one on the web.

Olds your right they used shorrocks blowers in the 70s,
But not these day's.They don't even use reliant motors anymore,Fiat punto motors now.