Yet another 1976 Supercharger project

[calif wingnut]

ZZZZZZZZZ

[Qui-gon]

ZZZZZZZZZ

Is that you sleeping on the job again Jeffo? Shouldn't you be putting the SEI back together?

Nice pipe, when I get done the inner cone will match the engine colour

[Qui-gon]

Been a while doing other things so time for a mini update:

Remounted the fuel pump on the back wall of the shelter as I wasn't happy with the original placement. Seems to work ok even though the lift specification for the pump is close to the max:



Capped the end of the RH camshaft with a hand crafted aluminium cover. Looks a lot cleaner now:



Took a while to get the idle right. Just a small amount of surging caused by puddling on the manifold, but it runs really well so far.

[socrace]

Hey Qui-gon,
Finally got to check out your build, very nice job!
Especially like the small block chevy paint theme! And the seat, where did you source it?
The surging idle you mention could be something typical with some blowers, aka "blower roll". Caused by interaction between vacuum and blower efficiency; the vacuum in the manifold basically sloshes around like water in a bathtub. There is sometimes a vacuum operated bypass valve inside the blower body that can help. It could be that things are made worse by the design of the manifold, with that depression in the middle.

[Qui-gon]

Thanks for the complement. Its more or less finished but hey there is always something left to do. I am going to replace the starter switch assembly with a relay. I already burnt the switch out by a combination of old age and a higher power halogen headlamp. I also need to address the neutral switch. It is an led which is part of the dash and requires less of a ground to illuminate than the standard filament bulb. At the moment the led is full bright when in neutral and half bright when in gear! These switches are notorious for being leaky so another small relay will do the trick.
On the way to Alaska in the summer I called in to see Bill Bushling, one of the guys responsible for the original GL super charger "kit" back in the 80s. He gave me a few good tips and ideas for improvement. His description of the surging was "puddling" due to the manifold shape and fuel accumulating on the floor of it. When I first started it it was really noticeable when warm, now it's not as bad.
The seat Is a Darkwing seat from a guy in Florida. It is not a bolt on accessory and needs some individual fitting requirements. There is plenty of extra material left along the bottom edge which needs trimming off but it's very sturdy when bolted up. I am still not sure about the look but a few here seem to like it.

[Charlie503]

Nice work and a lovely bike.
I wish I had the time and cash to do a full rebuild like this. Keep up the good work

[Qui-gon]

Thanks! It hasn't taken a lot of cash, biggest single chunk was the blower stuff, but has taken a lot of time.

Gave it a real test down the road yesterday. It's been run around before but not in anger. It's insane. Twist the throttle and it's off with a generous power hit as far as I dare take it on the rebuilt motor.

Boost appears to max out at 7psi on the gauge which is probably optimum with pump gas and the current setup. It feels so right that you have to wonder why it wasn't a standard fit at the factory. It just feels like it belongs on the bike and not just another performance bolt on. Of course, stopping and turning it is another matter. Even worse back in '76, so I am on a mission to address that now.

[sunnbobb]

Very nice work. Very.

[gregforesi]

That bikes's a friggin beauty.
Regarding the brakes - Have you considered upgrading the front master? There are a couple out there with smaller pistons for a better mechanical advantage.

BTW - At one point Randakk was talking about adding a rev limiter to his blower bike because it wound up so fast. I don't know if he ever found one for it.

[robin1731]

snip
BTW - At one point Randakk was talking about adding a rev limiter to his blower bike because it wound up so fast. I don't know if he ever found one for it.

Dyna makes one that works very well and is easy to wire in.

[Fred Camper]

I agree that you need a rev limiter, it is just a mater of time before you miss a shift and on that bike a missed shift cannot be stopped fast enough with human response from what I have heard. No difference than running nitrous I think.

[robin1731]

If I were to do a blower or nitrous (my preference of course is nitrous), I would add a few more pounds of pressure to the valve springs too. Just for a little insurance.

I know Qui-gon's bike is done already. I'm just thinking about future builds.

[Qui-gon]

All good points:

sunnbob is that Quake logo derivative you have now?

That bikes's a friggin beauty.
Regarding the brakes - Have you considered upgrading the front master? There are a couple out there with smaller pistons for a better mechanical advantage.

BTW - At one point Randakk was talking about adding a rev limiter to his blower bike because it wound up so fast. I don't know if he ever found one for it.

I have been looking at the front master cylinder as a way of increasing the effort ratio. Randakk's is a very good price too. I have been looking at used off later bikes

Rev limiter is a good idea though.

snip

Dyna makes one that works very well and is easy to wire in.

I will check that out thanks. I have the shift light on the dash set to 8k5 but that won't help if I miss a gear!

snip

I know Qui-gon's bike is done already. I'm just thinking about future builds.

I wish! It will never be finished! There are many upgrades in the pipeline. I want to try the 78 engine I have with the softer cam soon. I am also looking at direct injection as an option and controlling all of it electronically. All of it depends on our circumstances here and whether I export the bike back to Europe when we leave.

[robin1731]

This is when DOHC's would really be nice. You could play with valve overlap. You could also play with exhaust duration. With a normally aspirated engine these both help but with any power adder, blower, turbo, nitrous, those little changes can be huge.

[robin1731]

Go here to check the Dyna rev limiters. The DRL-300 is the one that would work best. The 400 would work too but it has the two step on it. Although fun it isn't needed on a street bike.

http://www.dynaonline.com/skins/product ... v_limiter/