Supercharger project

[Craigorypeck]

well it sits in there nicely on the laser cut mountings and flange I had cut.. bonnet shuts and the pulleys line up ok by eye.. water pump pulley needs a bit of fettling to get it to fit.



Intercooler sat in nicely too..



Bit of TIG welding will have an airbox done up soon..

[Ghia15]

That thing is going to fly. I love the setup.

[Craigorypeck]

should work....... maybe

[Beakster]

Very nice

What are you going to use for a throttle body? Can the carbs handle compressed air? Are you going to use one of those boost referenced fuel pressure regulators? Sticking with the bike carbs, or thinking about bike throttle bodies?

Keep us posted, looking forward to the progress

[Craigorypeck]

Hey beakster.. Gonna use a malpassi turbo regulator, same one as on the espirit and reno 5. most bike carbs will handle a bar of boost, well the keihin ones do apparently.
had a back plate laser cut for the carbs so an airbox will be made soon. Loads of info online on turboing bike carbs.
My main concern are the ingredients.. AFAIA a CR of 10.5:1 will handle a moderate amount of intercooled boost but my cams may have too much duration.. at 288 degrees and with the verniers adjusted to reduce this I might still be blowing mixture out the exhaust..? need to do a bit more research me thinks..

[Supercharged Nat]

Look good!

Heres a tip for you, you maybe better off with a serpantine belt (the multi ribbed flat belts) rather than the toothed setup youve got there. I know on the big V8s they use toothed belt but that have valves in the intake manifold to blow-off all the unused air, such as when lifting off the loud pedal.

When i used toothed belts on mine the belt would jump the pulley no matter what i tried, maybe i didnt get the pitch right/ tooth selection right i dont know. I gave up and went with the multyrib poly belts instead. Didnt have any trouble after that. I think they are also more forgiving if anything is slightly missaligned- might come in useful!

keep at it! theres nothing like a screeming charger to make you grin

[Craigorypeck]

Hi Nat... I logged on to PM you as nige had said that the toothed pulleys might cause a problem and seen your reply!
Well I intend to use the vacuum (from the inlet manifold) to operate a blow off valve so releasing the pressure on closed throttle.. did you run a BOV??
I had intended to go with poly V belts but was finding it hard to get what i needed.
Nige said that the momentum of the charger coming off throttle at high revs would be sore on the belt, maybe even stip the teeth from it.. and the fact that my SC pulley is 40mm diameter i might be in trouble..
My pulleys run an L type toothed belt what did yours run?

[Supercharged Nat]

Keep up the good work, youl get there in the end. Yes i do run dump valves, the non recirculating type, i didnt want to dump all the hot compressed air back into the charger, it already gets hot enough! In fact i had two valve side by side and they still arent enough to prevent the charger from stalling when the throttle closes after wot. i stripped toothed belts, i snapped toothed belts and when they got slack from stretching they slipped, making horendous noises on deaceleration!

the solution was mutil ribbed belts, just like the charger originally came with... that should have been a clue for me from the start lol.

i really cant remember the type of tooth pulleys i used, it was that long ago. the pulleys i use now are sourced from scrap yard engines that where the right diameter to give me the ratios i wanted. then i machined hubs to mount them how i needed.

I find that its very on/off, that is the dump valves are held open by vacuum fromt he manfiold but with the charger vacuum is low at the best of times, so you only have to touch the pedal and you rocket off down the road- not good when parking for example, or trying to pull away from lights with a police car next to you....

[Craigorypeck]

Cheers Nat.. good info! I have found a serpentine water pump pulley and 2 alternator pulleys too so might even pay to have a crank pulley made and have the megajolt trigger machined on.. i probably will run with the toothed ones for now and see how it goes. Loads of fabrication to to first.
was gonna try one of those forge type recir valves but just vent to air.

[Craigorypeck]

Couple more bits done..


















bit more welding and fettling yet

thanks to nige and nat for answering the PMs!!

[Beakster]

Amazing progress! Looks like you've done most of the hard work already

[Craigorypeck]

Cheers beaks! Biggest problems was getting a readily available belt (in UK) to fit. I ended up with a cossie off centred cam belt tensioner. its belted now with an off the shelf size belt. Just waiting on my mate to tig weld the air box inlet and the BOV housing, mallory fuel regulator is scheduled to arrive soon (cheap from US ebay, but I'm getting messed about a bit) so i'm pretty much ready to go then.







Airbox with no inlet welded on yet



Got a massive 50mm Bov so hopefully the charger doesn't get any back pressure and the belt isn't under toooo much strain..



More decent pics soon, work permitting of course..!!

[yank290]

class man keep up the great work

[Ghia15]

You need to change the rocker cover as it is a supercharged engine now.

Looks good.

We will need some power figures for it soon.

[Craigorypeck]

got some more bits done

Bov collar welded in




pilot tube done too



doctored the catch tack to fit behind inlet pipe




Pipework clamped up and air box sealed









fuel reg to pipe up next

[Craigorypeck]

Well it drives! but its dodgy!... the boost surges in and out whilst cruising and it just sorta takes off. Back to the drawing bored and I'm putting a recirculating bypass valve in where the big BOV is to pipe air back to the charger inlet and a throttle body just after airfilter on the inlet. apparently this will make it behave on cruise.

regulator piped in too.. works a treat!

[Craigorypeck]

I have a really crap vid of the engine running, you can see the BOV opening and shutting, this is where i'm having problems. light throttle and it cant make up its mind, boost gauge goes from -10 up to +4 makes driving fun..!

[Beakster]

Fantastic work! You got it running and driving so that's the main thing. I'm sure you'll have it running smoothly in no time.

[Craigorypeck]

Cheers beaks! if it were simple I'd get bored.

[Supercharged Nat]

congrats! its looking good and sounds good too! you might want to look at your vac signal to the BOV- its either too weak or pulsing. you could put a weaker spring in the BOV but you may risk it not holding shut under boost. or you might need to get a stronger non pulsing vac signal- or a combination of all.

I wouldnt use a re-circulating one itl just pump hot air back into the inlet of the charger, making it even hotter and reducing its life!

You mnay find that even just increasing the idle speed a little sorts out the problem- a lsightly faster turning engine may produce a better vac signal......

Out of interest what fuel reg are you using? What fuel pressure do your carbs require? and what fuel pump are you using?

keep up the good work!