Supercharged Stock 1600 DP

[T-34]

Have heard of petrol companies diluting petrol with ethanol. Can't help but think something like that has gone on here. Have had a bad tank of fuel before. I thought the bus was going to blow up

Think I will syphon it out into the Range Rover and get a new tank of fuel from somewhere else.

[T-34]

Well I took the carby off to check it out and found that there was a little belt dust blocking the jet cover, not enough to completely block it but possibly enough to block the air a little. I also took the mains down a size. The mains were a slight bit rich with the 170's in and too lean with 160's but unfortunately I did not have a 1.65 bit. I fixed this by drilling a sloppy hole with the 1.6mm bit that I did have. Other than that there was no other issues that I could spot. Took the bus out for a drive and found it to be much better. Still possibly a bit on the rich side but I will opt to leave it until I can try another tank of petrol in there.

Also received a present in the post... a new serpentine belt kit



Which I fitted up (of course). I fitted the original pulley to the charger which coincidentally is the same belt type and ordered a new belt from my local autobarn.



The pulley ratio might be a little less than the vee belt but at least I should not have any more slip. I ran the engine and the belt tracks pretty well and does not seems to slip or grow.

I also decided to give the bus it's long overdue service. 3000k's in on the new build and 2500k since I last changed the oil. Thought it was a good idea as I'm just about to go on a bit of a road trip and I've also cooked the oil a few times with playing about with the supercharger.

As the oil was being drained I thought it was an opportune time to hook up the external cooler. I fitted the cooler coil a few weeks back but had not gotten around to connecting it. So with no oil in the system I ran the hose and connected it up.

Refilling the oil needs a different approach when you have a supercharger installed - not that filling / topping up oil in a bus is easy. Finally found a use for the multitude of spare vee belts that I now have in stock.



With everything hooked up I disconnected the coil and cranked the engine over until the oil light went out. Then I checked for leaks. Unfortunately one of the unions on the oil cooler was leaking. I tried tightening it up but it still leaked. I'm hoping that with a different fitting it should be okay but I could not get one this evening. I will pay a visit to my local outlaw speed shop in the morning and grab a decent fitting.

So at this stage I am not sure what boost the new belt setup will give me. The ratio is slightly less than the vee pulley but will obviously not have any slip. I'm hoping that it's still in the 5 psi range. Previously with the 80mm vee belt I was seeing about 4psi. The current pulley is about the same size. Guess I will have to wait until tomorrow to find out.

[T-34]

Ahh yes, one thing I forgot to mention. When I was testing earlier after cleaning the carby and decreasing the mains I loaded it right up to check the mains and obviously generated a bit of heat. There's a bit of road that runs past the airport with an 80kph limit so I normally go and take a run along there to open it up a bit.

Well after coming back along the other way I turn up towards my area along a slower road. So I'm in stop / start traffic and started to notice that as I'm pulling away, if I change up too soon and load the engine up it's starting to pink. At this stage, after just having run the bus pretty hard my oil temps were at 200 - normally they are around 180. Don't have a CHT gauge but I'm guessing that head temps were pretty high.

So I pulled over and disconnected the vac line - then carried on - the issue instantly went away. Obviously I am seeing both vac and boost at partial throttle - enough that even at 5psi it is an issue at the higher head temps. At wider throttle the issue diminishes quite a bit but at lower revs with a heavy load I am pretty sure that I am seeing both vac and boost.

Now I know that I can reproduce the same conditions I will try with the boost line connected up to the vac can with a non-return valve in the line. Whilst I might not be able to accurately measure the advance I will be easily able to tell if I am pinking. This will give me a clear indication if the boost signal cancels out the vac signal.

Might leave this experiment until next week tho.

[miniman82]

Believe me when I say, YOU NEED MEGAJOLT. By the time you get it you'll wonder what took you so long, ask anyone else that's gone that way and they will tell you the same.

[T-34]

Believe me when I say, YOU NEED MEGAJOLT. By the time you get it you'll wonder what took you so long, ask anyone else that's gone that way and they will tell you the same.

The setup works absolutely fine with the stock limited distributor. Not having the vac is a relatively minor compromise, but not one that makes the system un-useable, The difference is minor - it drove a bit smoother and temps appeared to be down a little. As I have explained elsewhere in the thread megajolt / megasquirt is simply not feasible on this build.

[Buggin_74]

Gday Mick,
this was my approach to filling oil with the blower on

[my_medusa]

ignition: what i did: put a pressur tin from a saab 900 turbo on my dizzy. so you can drive( cruise) your normal ignizion curve and have the boost retard you need. worked extreme good. so i could handle 1,2 bar boost on a 36hp supercharged engine.

[CobraJet]

I just read this entire thread, nice work! How is it running now?

I kinda like the idea of the supercharger only running at 5lbs. If your CR was set low you could add a turbo on top of this setup and bring some REALLY big boost into the equation! This would give you the low RPM throttle response AND not limit the high RPM power.

[T-34]

The supercharger is running really good. Been meaning to post an update to this thread. Will try and find some time to post an update this week.

[davidt]

Hi T-34,

I would also like to know how your project is going. You have inspired me to fit an AMR500 to my Fuel Injected 1915cc Scat engined Superbug. I know the engine is supposed to be too big for the blower but as I am only after around 30hp extra (currently makes 78hp atw or approx 100hp atf), I think it is achievable with around 5psi of boost (according to the mathematics). Here is the blower fitted to the engine. Still to come is the bypass valve (or blow off valve) and I am also going to fit a 50mm throttle butterfly into the intake pipe (connected to a diaphram vacuum actuator) to limit the air going into the blower at idle and cruise so as to limit the superchargers noise. My engine is controlled by a Megasquirt MS2extra ECM and the whole setup has been made by myself , see my blog for the build-up. My 1972 VW Superbug Rebuild (http://george1972superbug.blogspot.com. ... start.html).
I have also used a single 11A v-belt but so far I don't know if I will suffer the same slipping issues that you have been having. With shorter runs between the pulleys, I might get away with it (I have limited room behind my cold air box). Here's hoping!!!
Are you interested in selling me your larger (70mm and 80mm) pulleys so I can play with the tuning?

I love what you have achieved with your AMR500 project.
Talk to you later.

David Thiele
[email protected]

[T-34]

Just spent the best part of an hour crafting a reply but it will not let me post it as it's telling me that the images I'm linking to are too large.

Damn stupid forum.

[Clonebug]

Pics need to be 800 by 600 pixels in order to post.

I use Photobucket and have it set to upload all pictures at 800 by 600 so anything on my account is post-able.

[fusername]

you complaining on my picture thread made me wonder "who is this jerk" and now you have tripled your jerk status as I am already thinking about how much I can afford a supercharged mod to my 2.0 I was gonna rebuild it this fall with a 78mm crank, but now it looks like displacement will be remainig the same and boost is gonna go up!

[T-34]

Haha sorry bout that fusername. More boost is always advisable.

Clonebug. The images are already posted elsewhere, I just linked to them but unfortunately they are too large and so it will not let me submit the post.

[MarioVelotta]

How about just the URL for us