Supercharged Stock 1600 DP

[Humpty]

Looking good there Mick.... I'm liking the supercharging idea.... Last year a mate and myself put a SC12 on his Volksrod.... It goes very nicely indeed... Fitting a turbo to my Bus in the very near future, but this AMR conversion looks very cool.... And agreed with Mario.... Fitting EFI to this would be a snack.

PS:.... Imagine one on a T34?

[T-34]

I've got the Type 34 all mapped out - stock Type 3 EFI hardware with megasquirt and a t3/t4 hybrid turbo connected through the stock air intake. All I need to do is weld a decent throttle body on the plenum and I am good to go. Got all the bits, just need to get around to it. Can also use a SP2 air filter assembly to run a paper style filter as well. Completely stock looking when you open the deckled but packs a nice punch.

My only issue is I'd need to tear down the engine again as I'm running a scat C35 cam - no good for turbo. (that and I still haven't got the Ghia road legal - lol)

Never did understand why the Type 34 never got EFI.

Would love to build a Volks-Rod for the salt - chopped and sectioned - got to be the way to go!! Check out the rules - very much greared to early 30's fords - lots of regs about removing fenders and channeling / sectioning bodies / doing roof chops - sounds exactly like a Volks-Rod!! After I've finished with the oval I will look to do a rod for the salt - not sure I would actually cut the oval up - more likely get a 60's bug and cut that up instead but it's deffo on my future plans!!

[Clonebug]

If your Draw through blower setup is anything like a draw through turbo it could just take a fair bit of throttle pumping at startup to get the fuel through everything and to the engine.

You will have low air velocity while cranking and a longer intake for it to travel through.

Pump the crap out of the carb while cranking once to see if that helps. Then check the plugs to see if they are wet if it doesn't fire.

[T-34]

If your Draw through blower setup is anything like a draw through turbo it could just take a fair bit of throttle pumping at startup to get the fuel through everything and to the engine.

You will have low air velocity while cranking and a longer intake for it to travel through.

Pump the crap out of the carb while cranking once to see if that helps. Then check the plugs to see if they are wet if it doesn't fire.

I did pump the crap out of it but it made no difference - however I'm not sure how the accelerator pump is set. From memory it's not pumping a lot. Will check the plugs to see how they look - didn't think of that!

Will give it a go tomorrow when I refit the carby. Might go get a can of 'start you bastard' and see if that get's it to catch.

[MarioVelotta]

I learned a trick years ago to help prime a carb. While cranking if you hold your hand over the opening the engine vacuum does a real good job of pulling fuel through the carb and into the motor. I have to do this on my little danger bike after it has sat for a couple months and the bowl is dry. A few pulls on the cord with my hand covering the intake to prime and she fires right up.

[Ol'fogasaurus]

Hand choking is great until you get a backfire and you smack yourself in the face or put out an eye; Oh, and toasted pinkies or bar-b-que’d palm roast smell awful and hurt too.

Be careful on how many times you rotate the engine before you look to see if there is any wet in the carb or check to see if the squirters are working. It's very easy to flood an engine that way. I think it is a waste of time if you have fuel injection.

Lee

[T-34]

Well not 100% what the issues was but a combination of cleaning the carby, resetting the float valve and float geometry, and removing / replacing it was the key. I also read a very helpful article on setting up DHLA's. The guy who wrote the article recommended not connecting the choke as it is a bit agricultural in it's operation (good job really as I have no way of hooking it up). Instead he recommended simply pumping the gas pedal four times and then starting it with the throttle lightly depressed and then letting it warm up. If that doesn't work try 5 times. etc. Well this worked a treat. So now I have a running supercharged bus

Another thing he recommended was setting the float by taking the top off of the carb and measuring the fuel level in there - it was a pretty in depth article. I don't even have the room to be able to take the jets out without removing the carby so I skipped this step but did take note of the bit where he said before you do anything simply turn on the fuel pump and take a look down the barrels - if there's any drips the float valve is letting by. Good advice!! Fortunately for me my $80 ebay Dellorto scrubbed up pretty well and now seems to (mostly) work

Putting the excitement aside, the bus may be running, but not without a few issues...

The belt tension is my big issue, the way I have designed the setup makes it hard to tension the belt properly, and even if I do the belt up extra friggin tight it still ends up flapping around on the undriven (slack) side which results in slip. I managed to cure this by holding a socket extension bar to the belt to take up the slack so I went ahead and fitted a second idler pulley to the slack / undriven side of the belt. This was a massive improvement but as the revs rise the belt still gets a little slack resulting in slip.

So my next plan is to fit a sprung tensioner to see if this addresses the issue. If this does't fix the problem I may have to look at grooved belts - something that I was hoping to avoid due to the additional cost it will add to the kit. I'm working on the principle that there is only so much people will be prepared to spend on a stock 1600 before simply building a bigger engine.

The other big issue that I found is that the engine wants to stall under boost. If I slowly bring the revs up everything is good (there is also no boost generated), but if I blip the throttle fast the engine dies (boost generated). Of course I'm not sure if the engine is dying because of the boost, or if the boost is because of the engine dying.

I have been a little worried that the supercharger is running too fast and might generate too much boost. However, after connecting the boost gauge in the dash I could see that it appears to be pushing out about 7 psi - which is great. However, as the engine starts to stall at this point I don't know if it might have some more to go. I really need to get it running properly to take check of what it's making.

Eventually I decided to take it for a drive to see how it ran. On idle / low throttle is was nice and crisp and pulled quite well, however it was pinking really bad on a wider throttle. Seems to me like the mains are too small - which is something that I was concerned about. Far from being an expert in these things I will need to swap the jets out before I can say that this is actually the issue.

Here's some pics...







I also took some video.

This one is just after I got it started.



Pretty stoked that it's running.



In this video you can see the issue with the belt - lots of flap and slip. You can also see / hear the engine dying as it comes onto boost / WOT



I added a second idler pulley which helped massively but did not 100% cure the slip issue. You can also see / hear the engine stalling when on boost / WOT



This is the boost gauge in the bus. It's peaking at about 7psi which is great, but I'm not 100% convinced that this is that actual boost that will be generated. Again you can hear the engine stalling as the boost rises / throttle opens fast.

Again - Point to note is that I'm not sure if the engine is dying as a result of the boost, or if the boost is the result of the engine dying.

One thing I'd like to be pretty sure about is the main jets being to small, but I won't know until I swap them out (anyone know a source for Dellorto parts in Adelaide??). However, the pinking could also be due to the timing...

I initially drilled out my dizzy and added some grub screws, this limited the advance a little but not enough. I then added to the equation by bending the tabs in a little. I'm using an SVDA. Normally I would set this at about 30 degrees overall mechanical advance (vac disconnected.) This gives me an idle of about 7-10 degrees.

So now with the dizzy modified I've set the timing at 7-10ish at idle and appear to be getting an overall mechanical advance taking it to approx 20ish (nearly impossible to tell as I don't have a degree pulley) At any rate I'm well off of the 30 degree mark I added to the pulley when I built the engine.

I'm figuring that the overall advance is good but now am a little lost as to where to set the timing. Any advice here would be greatly appreciated.

Mick.

[Humpty]

.... more likely get a 60's bug and cut that up instead but it's deffo on my future plans!!

You know I have just the car in the shed right?.... But I reckon I might take the new and improved POS to the salt next year!

[andy198712]

cant help but its a good bit of R&D there! looks like a nice kit.

is it slipping on the charger pulley or the crank pulley? maybe move the tensions nearer to the pulley its slipping on to get it bent around it more...?

how much deflection do you have on the right side of the belt system? ie tenstion? is it near stock valvues or less?

[T-34]

.... more likely get a 60's bug and cut that up instead but it's deffo on my future plans!!

You know I have just the car in the shed right?.... But I reckon I might take the new and improved POS to the salt next year!

What you hiding in there? Got any pics?

[Humpty]

A volksrod.....

Also.... No idea who in Adelaide would have a line on the Dellorto jets, but I know Gem Parts in Brizzy (I think they are there) has a good selection.... Check their ebay store.

[T-34]

cant help but its a good bit of R&D there! looks like a nice kit.

is it slipping on the charger pulley or the crank pulley? maybe move the tensions nearer to the pulley its slipping on to get it bent around it more...?

how much deflection do you have on the right side of the belt system? ie tenstion? is it near stock valvues or less?

I think it's slipping on the charger pulley although it's obviously hard to tell. This is why I mounted the second idler up top - nearer to the charger pulley

Belt tension is as tight as I can get it (obv not good for bearings)

The main issue appears to be that the belt seems to 'grow' Of course I don't actually believe the belt is growing, more a case that when the belt is loaded up the tension stretches out the slack and gathers it all in the slack side of the belt after the main pulley. Unfortunately this is exactly where I mounted the supercharger.

I will try moving the second idler down after the main pulley to see if this makes a difference - if it improves I guess it's the main pulley that's slipping. Might also try a stethoscope to see if I can pinpoint the source of the noise.

[T-34]

A volksrod.....

Also.... No idea who in Adelaide would have a line on the Dellorto jets, but I know Gem Parts in Brizzy (I think they are there) has a good selection.... Check their ebay store.

Volksrods are the go - better aero - less drag!! (well that's my theory at any rate )

Will check out Gem. Cheers.

[Clonebug]

One problem with your belt is that the idler pulley is really in the wrong place to keep tension.
It should be pulling on the slack side instead of the drive side of the blower.

You should try to reroute the belt and move that idler so the slack side goes around the idler pulley, then add a spring tension to it to keep pressure on the belt.
That might help a bit.
The driven side always stays tight without help.

Next on your dying engine....On my turbo that was a sign the main was too lean.
My turbo 1600 did the same thing on the first drive.... it would run nice when just barely cracking the throttle but if I pushed it to build boost or put load on it it would fall on it's face. A bigger main fixed that on my Pict 34.
Remember that is a fairly large carb for a 1600 and when you open the throttle a larger amount it gets a lot of air and no fuel due to how a carb reacts. You could try to make a bigger accelerator pump squirt to see if that helps.
You could probably save yourself a lot of headache and money on jets if you would get yourself a wideband AFR. It takes the guess work out of your fuel ratios and will save lots of time.

Jets stacks on Dells are not cheap when you start messing with the air correctors and emulsion tubes.

Your timing needs to be known also.....you don't want to be guessing what it is.
Put a degree pulley on it and then check it at 3000 rpm to see what max advance is.
Standard max is 24 degrees for forced induction but each engine is different of course.

[T-34]

One problem with your belt is that the idler pulley is really in the wrong place to keep tension.
It should be pulling on the slack side instead of the drive side of the blower.

You should try to reroute the belt and move that idler so the slack side goes around the idler pulley, then add a spring tension to it to keep pressure on the belt.
That might help a bit.
The driven side always stays tight without help.

Yes, on my original design I did't have the idler pulley there - the belt ran around the outside of the charger and then the alternator pulleys. However, i figured that running the belt like this there would not be enough contact with the pulleys (the belt only engages 90 ish degrees or so of the pulley). So to ensure that i had enough grip / contact I added the idler pulley in the location where it currently sits.

I'm making a compromise by trying to run with one belt to keep the kit cheap and simple. If I ran two belts as per other supercharger kits then I could fit the idler in the slack side of the belt and it would no doubt be all good and have lots of contact but this comes at the cost of additional pulleys. I will persevere with trying to get it to work with the single belt and will try as you have suggested. Perhaps my initial considerations about grip / contact were unfounded. No harm in trying.

Next on your dying engine....On my turbo that was a sign the main was too lean.
My turbo 1600 did the same thing on the first drive.... it would run nice when just barely cracking the throttle but if I pushed it to build boost or put load on it it would fall on it's face. A bigger main fixed that on my Pict 34.
Remember that is a fairly large carb for a 1600 and when you open the throttle a larger amount it gets a lot of air and no fuel due to how a carb reacts. You could try to make a bigger accelerator pump squirt to see if that helps.
You could probably save yourself a lot of headache and money on jets if you would get yourself a wideband AFR. It takes the guess work out of your fuel ratios and will save lots of time.

Jets stacks on Dells are not cheap when you start messing with the air correctors and emulsion tubes.

Your timing needs to be known also.....you don't want to be guessing what it is.
Put a degree pulley on it and then check it at 3000 rpm to see what max advance is.
Standard max is 24 degrees for forced induction but each engine is different of course.

Thanks for the advice. Much appreciated.

I will mark up my pulley and set the timing to 24.

Good to hear that I am on the right track with the mains.

With respect to a wideband. My plan was to get the carby set up on the dyno so it's not something that I had budgeted for. I just needed to get it functioning well enough to be able to drive it there. My issue is trying to figure out a ballpark setup so that I can order a set of jets / etc to get it running well enough to be drivable. Obviously too rich is not an issue perhaps I should just go big

I've been doing lots of reading but pretty much all of the info relates to twin carb setups so all of the basic formulas used to calculate choke / jet sizes doesn't apply. From what I have managed to figure out the emulsion tubes should be good and the idles should also be good (which is reflected by the fact that it runs and idles). Mains and airs I cannot figure out.

I hear what you are saying with respect to the carb size. I have 30mm chokes fitted and am hoping that this is enough to make the setup work. From what I have read with N/A single setups it is recommended to have quite small chokes to keep the velocity up - I'm guessing that the same may apply here. (this is actually the opposite of what I originally thought). I might end up getting 28's or 27's Will have to wait to see how the dyno tuning works out

I'm happy to drill out my current mains to get things working but cannot find any correlation between the orifice size and jet number. anyone have any experience in this?