TheSamba.com :: View topic - 40hp big bore with alternative supercharger options

Sun Jul 12, 2009 9:47 am

i don't know of anything that wont get to hot or fit correctly does anyone else? the vehicle its in is pretty heavy and some torque would be nice.

Sun Jul 12, 2009 11:09 am

Search this forum for "Pepco" and/or "Shorrock."

Mon Jul 13, 2009 10:01 pm

A Pepco won't provide much if any boost on a 40hp big bore kit. Vintage wise the Shorrock kit is perfect but rare, very expensive and usually requires a rebuild. There are some guys putting modern superchargers on. Do a supercharger search and be patient it is out there.

Wed Jul 15, 2009 12:59 pm

Why not a Judson? I have a big bore and a Judson and it works very well

William

Wed Jul 15, 2009 1:05 pm

sure will it work well...but the engine will be the same without judson ;)
a 1385cc engine will suck the same like a judson will blow.
did you boost gauge it? there you should see that the judson will make no usefull boost.

Wed Jul 15, 2009 1:11 pm

I'll check the boost gauge but I tought that the torque is still highter with judson + big bore than big bore alone

Wed Jul 15, 2009 1:20 pm

i will not bet on it.
maybee i bit at lower rpm, but don't forgett the blower needs 15-20% of the engines power to be driven.
i hope you push something over 3PSI everything less is not usefull with that blower and btw this is not much too.

Wed Jul 15, 2009 1:32 pm

Tx I'll check as soon as my car arrive

To make a long story short, I'm french, I leave in the US now and my beetle should be on the boat from Le Havre to New York as we speak :-)

William
www.oldspeed.net

Wed Jul 15, 2009 1:39 pm

oh,... I hope everything arrive well.

beautiful webpage. is that your engine? is that a judson for a 1200?

Wed Jul 15, 2009 1:42 pm

yes it's my engine. It's the correct Judson for my 65 1200 34HP (40 Us) engine

I miss my car :-)

Only bad thing is that all the major vw events are either in California or Florida

Wed Jul 15, 2009 2:37 pm

I would miss it too. nice build.
btw:
50cv+ 10cv for the big bore is a wrong calculation with blower, because the blower doesn't suck more without changingt the pulley.

chris.

Thu Jul 16, 2009 2:35 pm

something is weird because in the latest Judson documentation (71 or 72) they say that you can use a the judson on a 1500 and a 1600CC engine

William
www.oldspeed.net

Thu Jul 16, 2009 3:10 pm

Wow, a ~47% increase in horsepower? That's pretty impressive. Would my '67 be too late of a car to run one of these with any credibility? :lol:

- Scott

Thu Jul 16, 2009 11:33 pm

I think that are the jusons for 1600 that I mean....if you have one of those than is your 60HP right.
47% is very optimistic, but with the larger carb it alows more air come into the supercharger.
so if you only have very low boost with your big bore you could open the intake of the judson and put a 34 carb on it that will be make more air and so more boost. maybe than also the 1200 judson will be able to work on your big bore.

hmm 47% more power is alot with 3-6 PSI
I think I have about 90-100% with 14psi on my 36HP engine.
we will see during the next weeks on the dyno
:twisted:

Fri Jul 17, 2009 12:26 am

I have always been at a loss to see how overdriving a Judson for the 1500 & 1600 could ever have been achievable.

I'm also well aware of the Judson brochure page reproduced above and it's contents but it pretends overdriving the unit to be a simple procedure...it's not. The extra heat generated by the process has nowhere to go.

Fitting the larger 34pict carb (stock carb on a 1600) wasn't an option on the Judson as the stud spacing is too wide so the largest available carb was the 30pict.

Fri Jul 17, 2009 2:44 am

not to wide when you build an adapt-peace ;)

so the 1500-1600 kit is a oderdriven judson for 1200??? or am I wronk?

Fri Jul 17, 2009 3:04 am

grueni wrote: not to wide when you build an adapt-peace ;)

so the 1500-1600 kit is a oderdriven judson for 1200??? or am I wronk?

The stock Judson application is a tight fit add anything to the height like a carb adaptor and the aircleaner hits the decklid.

Quote: Yes Judson supplied the same sized larger pulley to overdrive for the 1500 & 1600.
Edit: That is what I was told...this now seems to be incorrect.

Fri Jul 17, 2009 5:30 am

good to know with the pulley. 1.3:1 for 1500-1600 and what is the ratio for stock 1200?would be interesting for me.
but to adapt an other carb is for sure not easy, but pussible. 28mm carb or 20,5-21,5mm venturies are very small to feet the supercharger.
judson is a very nice supercharger. only the heating problem sucks.

Fri Jul 17, 2009 8:03 am

the only way to know if the Judson is effective on 1400+ engine will be to dyno it with and without the Judson

Someone did it allready?

William
www.oldspeed.net

Fri Jul 17, 2009 9:12 am

grueni wrote: good to know with the pulley. 1.3:1 for 1500-1600 and what is the ratio for stock 1200?would be interesting for me.
but to adapt an other carb is for sure not easy, but pussible. 28mm carb or 20,5-21,5mm venturies are very small to feet the supercharger.
judson is a very nice supercharger. only the heating problem sucks.

I think if you look at this 1964 version of the one shown from 1971 you will notice the pulley ratio is given as 1:1.3 and a boost pressure of 6psi for the 1200.

The 1971 brochure gives the same pulley ratio of 1:1.3 and a boost pressure of 3 - 6psi. What this suggests is that Judson didn't actually provide a revised larger pulley to overdrive the larger engines.

The boost pressure refers to 3psi for the larger engines and 6psi for the 1200.