I've been waiting to get this build on it's way for far too long but working on another triple build has taken up most of my time.
I well be using a supercharger from a Mercedes SLK, I plan to remove the top cover and make my own better looking version.
I have an SU carb for this build and I will plan to leave the stainless intake pipework raw and bolted together with the star mounts.
So I finally got the engine mounted in the jig. I'm using the stock frame just to get the engine aligned and pitched right. Next is to weld some supports to maintain the engines position and then I will remove the stock frame and bin it and build the new frame around the engine.
I'm going to stick to the stock 30 degree rake and 1426 mm wheelbase to maintain some good handling. This is a bar hopper and I expect to ride it hard.
Things are progressing slower than I would like but sometimes life just gets in the way. Now I have digital readouts setup on my mill and lathe I can start the fun work of building, brackets, mounts and the axle plates and get the frame build under way.
not criticizing - just wondering if the radiator could have been turned around for better areodynamics ? your skill level and dedication far exceed mine
Ah you mean turn it so the center is pointing forward? If I did that I think it would interfere with the front wheel and I don't know how it would affect the cooling because the air coming into the radiator would be "caught" it would just slide off the side. Might also look a little odd I think!
I had a problem that I inherited from the previous owner of this top yoke. I was originally going to cut both these tabs off but I will use them to fix the headlight mount to.
Just for information - with reference to my post #193 regarding the SU carb, I got an answer back from Burlen and they confirm that all three holes I marked need air flow.
This may be tricky as I'm not sure it I can bend a tube of that radius so tight. I may have to make up something but keeping it neat may be tricky. :/
This is an interesting concept to me and I hadn't even heard about it let a long considered taking this approach until reading these recent posts. My first thoughts were that boxing in the carb would look pretty lumpy and ugly but I looked up [JAWS: old paxton supercharger setups] and it looks ok. I am still unsure how the carb attaches to the box and how I get the entry and exit intake tubing to and from the box, I'll have to do some more research on this.
Im not criticizing, I'm curious why you ran the tube through the drive chain instead of over it? I'm worried the chain may slap it if you engine brake the bike
I have no problem with people asking questions and these being asked will help the end result be slicker. So the reason I took the tubing through the top and lower run of the chain was for aesthetics only. There was a gap there and I figured I could run the tube through to fill it. I may choose to run a chain tensioner on the lower run as I did on my '68 chopper. As things stand I am not happy with how I have run the intake tubing. The bend CLR is too great and it looks a little clumsy. I just got a billet of mild this evening to make up a smaller die for my bender so I can remake the run and make it crisp rather than vague.
Im not criticizing, I’m curious why you ran the tube through the drive chain instead of over it? I’m worried the chain may slap it if you engine brake the bike
OK, so I get it. The carb sits snugly in the box and the air feed runs straight through the carb. I would have to deal with fuel feed and the overflow, throttle cable and choke.
Nope. The engine side of the carb is plumbed threw the wall of the box to the intake manifold. The super charger side is plumbed into the box so as to put all of the carb under boost. Which let's it operate all of it's systems at the same relative pressure. That allows the carb to work normally, under what ever the pressure is at.
To get around the timing issue add water injection to appease the demons of detonation.
I know your not there yet but i am still interested to know how you intend to deal with getting the ignition timing correct for boost are you just going to retard it globally or have you some other method in mind? I wonder if you may just get away with a global retard as there will be a small amount of boost present form the outset, but this could negate some of the extra power gained from the SC.
If super charger is a positive displacement (roots type) you will also want a pop off in the intake after the carb. Will save you from picking parts out of things and yourself.
There were some articles and books on turbo charging bikes back in the late 70's early 80's mostly from some guy's turboing BMW's.
Yes. Not only a pop off or blow off valve for over pressure, but a vac operated relief valve when backing off the throttle, to let the positive charge release until you need it.
Normally a roots type is draw through, where the butterflies regulate how much air is coming in. Your setup is not tegulated into the charger.
Like Jaws said ''for the hiccups'' (back fire in the intake) .
You could make or purchase one that you could set the pressure limit with to prevent over boost. But a driven positive displacement supercharger is usually set up so the drive ratio and size is limiting boost to a set amount.
I said the pop off valve is installed in the intake after the carb. That is were they are traditionally placed.But it could also be any were in the system after the blower, in a blow threw system.
Thanks Joe, I have seen adjustable blow valves so that looks like the one to get. Not had so much luck with a vacuum relief valve but am still looking.
Vacuum relief I think would be wrong way to say it. It would be a BOV (blow off valve) it takes pilot pressure from the intake for control and relieves boost pressure when it exceeds the valve setting.
Quote;/
Part # TIAL-Q-BOV 2 Psi Spring
Color: Silver
The first revision of the nine year old original TiAL BOV. The Q bolts right up to any standard TiAL flange so you can upgrade without having to re-weld. Through countless hours of R&D we were able to make the same size valve flow a staggering 60% more than the original design - that means 60% more air is blown off per cycle! This is the highest flowing BOV on the market. The Q will be offered in all of the current colors.
Color: Polished Silver
Includes: TiAL BOV Assembly, TiAL V-Band Clamp, High Pressure O-Ring, TiAL Air Fitting and Weld-On Flange (Available in Aluminum)
For use on turbo-charged and super-charged applications (Paxton, Vortec, etc.). The body and all internal components are CNC-machined from 6061 aluminum alloy. It features a large 1.98 in (50.5mm) valve; we believe this is the largest valve available with the highest flow capacity.
The valve seal utilizes a Viton O-ring that is clamped in place to prevent the possibility of sticking to the seat and pulling out. The valve stem and guide are Teflon-lubricated, hard anodize-coated for wear resistance.
The Blow Off Valve also comes with our own machined aluminum banjo-type air fitting and bolt, with over sized 10mm hose barb for quick actuator response. The actuator has a high temp silicone Nomex-reinforced diaphragm for long life.
Spring Rate: 2 PSI Spring Pressure
Use: For supercharged applications /Quote
Ok cool, thanks Joe and JAWS for the info. I get why I would need a BOV after the blower and before the carb but in the case of a "hiccup" wouldn't a BOV between the carb and the head do the job?
When you do it for love and fun,of course. My problem is I always see it from the billed hours POV. Hazards of the business.
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