side car Bob, yes that was the one and same. Do you have photo's of it, I never had time to be bothered with pictures.
Do you remember the noise it made? That was the first time We fired it up, there was a guy on the back of my Thames Trader finishing it off on the way over to bay park.
The Thames broke a piston on the way home ( Zepher six engine became a Zepher five but still got us home) the super charger drive belts spat off in the end. Home made pullys didn't fit as well as they should have? all in all an entertaining day.
Nothing wrong with the stock cam profiles for a blown motor. Easy enough to rephase the cams to suit what you want in overlap.
I've done a blown 180 crank parallel twin. Very satisfactory with a plenum chamber three times engine volume. In your case that's still a very small plenum, LOL. Do you know the swept volume of the blower ? The one I used had been developed specifically for high rpm with anti turbulence bars on entry and exit ports. Builder had tested it to 10,000 rpm and it had a flat delivery curve. We ran it to 12000 - 15lb boost just off idle and right to redline.
Belt driving cams ? In oil or sealing the belt off ?
for simplicity, one belt to rule them all.
easy enough to seal the cams off and also drain the valve cavities too.
The supercharger I'm using is quite large ( for a 100cc) so I'll have to under drive it somewhat. If I can't get the efficient I want I'll Teflon TIP seal the rotors. Also the fuel will be introduced into the induction side of supercharger, there will be a potion of Castor oil added to the Fuel, this will help with efficiency and the alcohol with intercooling.
Okay...but in my experience you want some give in the blower drive, Your cams will have to be a toothed belt.
In my experience with mid size blowers, the problem is load reversals when you back off. Unless your toothed belt is pretty wide, you're going to lose teeth.
The ideal IMO is what i think you used on the Honda - a polyvee belt. They will slip on the overrun.
I went through several drive setups on a speedway TQ before realising what the problem was. When i did the blown F3 bike I didn't even consider anything else - and it was one of the few things on the bike that never gave trouble.
No pics unfortunately. I didn't own a camera until nearly a decade later.
I do remember it being a bitch to start & lent a hand at some point, that's when I remember you pulling a bolt out & letting the spare fuel run out on the ground.
I was probably riding a red CB125 I called the menstrual cycle.
Do you think the blower was a wee bit big now with the benefit of a few decades?
yes-------
No such thing as a too big blower - only the wrong drive ratio, LOL.
I guess that's what I ment, home built vain type supercharger but I fucked up the calculation for volume (I was an apprentice and you know what they are like) so the pumped volume was about double what I thought, I know now. The trimmed down Wade supercharger was a later development.
I would ditch the idea of the MX gearbox and clutch just use a VT250 gearbox as every wreaker has one. also with the blower you shouldn't need to rev it that high. either should you Neil
a few post ago you mentioned Teflon in the blower seals,From what I have heard the Toyota ones actually melt from the heat if any decent boost is used.
Screw compressors as used in air conditioners are the claimed to be the most efficient at producing boost with minimal heating, they are so efficient that the NHRA banned them.
because the size of the supercharger it will run a lot slower than the engine, probably won't be anywhere near.10000 rpm. Alcohol is a good intercooler and there will be plenty of it, Teflon TIP seals won't be a problem (if needed at all).
super charger drive pully has a shock absorbing element internal.
He won't need cams if he uses the centre of the cylinder head. Problem with that is locating the cams axially. Standard cams are located by discs on the left ends. I flipped mine over so the discs are now on the right. Yamaha helpfully cast recesses for them in the right side. Also helpfully the lobes are symmetrical so don't mind being rotated in reverse.
Link told me to use a 6 tooth crank trigger and 1 on the cam. I'll send you my tune file once I sort it a bit more. You should only need to setup your triggers & change the firing order. I have 80g injectors which might be OK. The problem if you go bigger is it will be rich low down despite short injector PW. I've got spares trigger discs.
Last edited by speedpro; 14th April 2018 at 22:53. Reason: spares
These guys - https://www.efihardware.com/products/c353/Coils supplied LS2 coils with in-built igniters for what I thought was a reasonable price. They've been working so far and should be OK with the revs as the max required dwell time is only 1.8mS I think.
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