Thought this might be of interest to some (except all you dyed in the wool N/A fans 🙂
A fellow now working for me a couple days a week (Robert) also works for Bullet Cars and has introduced me to the concept of the Rotrex superchargers. I am thinking of building an engine (maybe a mild 1916) or waiting until my type IV is built (mild 2056) for my splitty and installing one of these units. [unless I can pursuade Brad that he "needs" one for his 2110 in his ghia!]
Anyway I won't put up too much cut and pasted info here as the links of interest where you can read more are:
Here are a couple pics of the smallest unit Rotrex offers. On a type I I'm thinking of maybe integrating a serpentine pulley with longer belt rather than an additional pulley on the crank pulley. All just thinking out aloud for now, but may be quite interesting as an alternative to turbo/traditional superchargers.
Hehehe, good bloke maybe but having spoken to the owner's wife on occasion she has confidently dismissed the other two attributes 😉
On a serious note they are keen to get these things out there, but unfortunately I don't think they'll donate this one.....and I think Robert will notice if it goes missing 😁
i have installed a stack of those,you won't be disapointed.
great little unit.you will make 250 no sweet.and they sound cool screamin there head off.can't wait to see this one.
Al, I'm clueless on supercharging although I've been learning a far bit about turbo charging. Where does the supercharger sit in respect to the carbs? Is it the equivalnet of blow through or suck through? I guess its all just like a turbo with the exception that you don't have to have any plumbing from the headers.
Cheers
Steve
LIFE IN THE LOW LANEAll people have the right to stupidity but some abuse the pr
Al CES does all the pipe work for bullit cars from memory. MX5's with a Lexus/toyota V8 in the front. Nice power to weight and even more so with a Rotrex on it!!
I know of quite a few Celica guys who have Rotrex's fitted to the 1.8L 2ZZ Toyota engines. Make good HP and the big plus is you don't need a hell of a lot of room to fit them.
ACCEPT THAT SOME DAYS YOU ARE THE PIDGEON AND SOME DAYS YOU ARE THE STATUE
so whos gunna do a bolt on kit ? if you bolted it to a stock 1600 would that be totally stupid or would it handle if not pushed hard a give a little buzz?
matara wrote:Al, I'm clueless on supercharging although I've been learning a far bit about turbo charging. Where does the supercharger sit in respect to the carbs? Is it the equivalnet of blow through or suck through? I guess its all just like a turbo with the exception that you don't have to have any plumbing from the headers.
Cheers
Steve
Steve, although I still have research to do, aparently with carb/s it can be plumbed in pre (draw through) or post (blow through) supercharger. If used in blow through configuration the carb/s throttle shafts etc reportedly need to be sealed as per turbo blow through setup.
Re. kits etc, probably getting ahead of ourselves as I am really keen to do/assist with the development on a vw aircooled engine first to iron out the bugs/problems. Given Robert's ties with both Bullet and DAS Resto Haus, it is a good opportunity to explore its application with the humble little volksies.
Cheers
Al
PS will now start looking to build a type I (probably 1916 unless anyone has a good/affordable stroker crank) so if anyone has any parts they want to sell let me know. I have a set of Westi's sweet stainless extractors but nothing else! 🙂
matara wrote:Al, I'm clueless on supercharging although I've been learning a far bit about turbo charging. Where does the supercharger sit in respect to the carbs? Is it the equivalnet of blow through or suck through? I guess its all just like a turbo with the exception that you don't have to have any plumbing from the headers.
Cheers
Steve
Steve, although I still have research to do, aparently with carb/s it can be plumbed in pre (draw through) or post (blow through) supercharger. If used in blow through configuration the carb/s throttle shafts etc reportedly need to be sealed as per turbo blow through setup.
Re. kits etc, probably getting ahead of ourselves as I am really keen to do/assist with the development on a vw aircooled engine first to iron out the bugs/problems. Given Robert's ties with both Bullet and DAS Resto Haus, it is a good opportunity to explore its application with the humble little volksies.
Cheers
Al
PS will now start looking to build a type I (probably 1916 unless anyone has a good/affordable stroker crank) so if anyone has any parts they want to sell let me know. I have a set of Westi's sweet stainless extractors but nothing else! 🙂
Not an expert but here is my 2cents
I am nearly finished Supercharging my 1916 for the 356. Will post picks and drawings of all parts I needed to make to get it to going once I know it works.
I have used a roots type sc12 live the one steve1303 has used. Roots stypes are suited to suck through (carb upstream of supercharger). They have big robust veins that can handle the charge hitting the lobes at high rpm. These I think were even set up as suck through on the MR2 and corollas. BUT these centrigugal ones have much thinner impellor vaines. Everyone I have come across is up stream of the throttle body .
id be surprised if the seals and bearings in these things would handle a fuel mix thro them long term. the compressor wheels would be fine tho
nealry everything since that terrible period known as the 80s has been EFI
its only us behind the times fools playing wiht old vws still tooling round with carbs
point im just making is that nearly all the force fed toys out there now are made with fuel injection in mind which is only feeding air so they work well in blow thro not so well in draw thro but hopefully someone can get confirmation on that
aintgotitmusthaveit, the 4agze toyotas were draw thro setup but as theyre EFI engines they're only pumping air so no fuel is hitting the lobes
depends who u ask as to whether the SC12/14 can handle it
alot of the gemini crowd allegedly had dramas with the bearings failing, teflon coating lifting etc
as far as im concerned the fuel mix helps cool the intake charge. its failry minimal but every little bit helps
mine shows no signs of any of this but it has only done 3000kms since i built it but steves kombi fatso went for years untill the blower got a knock in one spot and ill bet that was age and high mileage more than anything else
helbus wrote:Would look nice attached to a Subaru EJ22. Blow straight into the manifold!
I so agree...am currently working on fitting a turbo to the EJ22 in my kombi...but i don't want to lose the low down torque...the grunt these things have...if so will supercharge🤪
Very interesting the way the internal friction drive works. I've seen a similar system working in reverse on huge variable speed reduction gearboxes that produced huge amounts of torque. Quite amazing the support they have from different manufacturers too.
Can't imagine that with the amount of R&D these guys would have done that they wouldn't have thought about the affects of fuel on seals and bearings let alone upsetting the friction/traction drive.
This would be an interesting project AL, good luck mate. Just out of curiosity does anyone know the cost of these things. I imagine they're not cheap.
Looks good BUT sorry to be a downer it's a waste of money!
A turbo will make more power faster at any rpm.
Also at those prices you could get a roller and have money for a manifold.
They do look good and I have seen some on fast v8's. It would look good and be different and drive like an aspirated car with a bit more zing. Keep in mind that a supercharger still heats the intake temps like a turbo and also needs the extra fuel and ignition retard like a turbo.
Well guys its been quite some time since the idea of supercharging the VW engine with a Rotrex unit first came into my mind and now we have had the opportunity to develop the setup on a customer's splitscreen kombi.
As Nick said, turbo would be much more bang for buck....but in this instance the owner of the bus wanted A) something different to what anyone else has (as per the rest of the restoration), and B) wanted an engine that was smooth, quiet, reliable with a bit of extra horsepower when needed.
Basically this setup will be running the smallest of the Rotrex superchargers with custom machined crank and alternator pulleys (using 6PV serpentine belt). Air con was also requested so to avoid running two belts, an engine 'faceplate' will be laser cut (mocked up here in mdf) to provide the mounts for the AC compressor and supercharger.
Intercooler in above pic will be a custom water to air unit (Bullet uses Plazmaman units but will have a look who else is available to fabricate one up)....the size above is the unit 'off the shelf' from Bullet. It will come down slightly and towards the supercharger a little. Clearance is pretty tight for most things on vw engines including ensuring we can get to the dipstiick (will be modified soon) and heater hoses can still run where required. Front 'faceplate' will be gusseted at the back and tie in with alternator stand and fuel pump mounting area.
Throttle body will be before the supercharger with inlet manifolds to be cut down and injector bungs welded in (with plenums welded on top). Longblock is being built and parts provided by Leons Motors (who will also do the injection (most likely Link ECU at this stage) with crank triggered signal used instead of dizzy.
Intercooler will be fed by Bosch water pump and PWR radiator (with thermo fan) mounted under the bus along with the engine oil cooler, supercharger oil cooler (small) and air con condensor (two thermo fans) all force fed air by the removal of the front chassis cross section and a scoop incorporated (plus a louvred belly pan to be fabricated) - air dams behind the coolers will force air through plus the negative pressure under the bus whilst moving will help draw hot air out.
This is where we are up to today - Rob is finalising the design this week and will then have the 'faceplate' laser cut out of 10mm steel (plus gussets etc)....and then pulleys machined. Heads and manifolds plus throttle body will arrive from Leons this week to complete the mockup process. Slowly but surely we are getting there.
Engine will be 2275cc type I case, CB wedgeport heads but the rest of the internals I don't have the specs on right now (will check with Andrew/Leon).
Looking good..............although I don't think using the wedports is a good idea for a supercharged motor.I would look at using a more 'solid' head like the eliminators....just my opinion though !
Yeah Craig, aluminium case. I've left the long block decisions up to Leon's motors as they will be doing the break in and tuning so we are just in control of the ancillaries.
Cheers for your comments though
Al
