30/31 vac sig

[Lil Lulu]

Any port on a Brosal 30/31 that will give a proper signal for the Mexican Bosch svda? Last 3#'s on the dist. are 034. This is on a 1600 dp. Currently 009. OK but not great. Kinda Hoppity Hooper in transition until warmed.

Bought the Mexi for the bus but even though the seller said it was curved for that bus, the original 205p rebuilt was like butter compared. Thought I'd try it in the bug.

RB
_________________
'65 Beetle "Lil' Lulu"- Ruby Red
1600 stock from '71 bus

'72 Deluxe - Niagara Blue w/pastelwiess Camper Special 2L dual 40 Webers 002

'74 Hightop Weekender "Dixie" 1800 34 Del singles

[tasb]

You have a distributor and carburetor mismatch. That carburetor has only one vacuum port. You need a single vacuum only advance distributor like a 113 905 205 M or T.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[glutamodo]

Eons ago when I did that post on the H30/31PICT I only looked at the traditional vacuum advance fitting. Later on some people asked me about some of the other vacuum fittngs on there being OK for SVDA, and I did some looking at them and did a few tests - this one actually seems to be about right, but I never really went in-depth with testing on it.

[Lil Lulu]

Tasb- To be clear- The Mexi Bosch svda is a poor match for the 30/31? The 205M or T would be better? I used the 205p on my type4 2L w/40 Webers.

I may try Glutemoto's port just for fun. Anyone know what signal the Mexi Bosch requires. I have a vac gauge. The 30/31 is such a one size fits all that it doesn't really work perfectly for any one thing but semi-OK for lots of things. What I may do is get a re-man 34 pict 3 carb. Would be better for this engine I think.
_________________
'65 Beetle "Lil' Lulu"- Ruby Red
1600 stock from '71 bus

'72 Deluxe - Niagara Blue w/pastelwiess Camper Special 2L dual 40 Webers 002

'74 Hightop Weekender "Dixie" 1800 34 Del singles

[glutamodo]

I assumed you'd read that post I'd mentioned above about the traditional vacuum port on the H30/31PICT and just why it's not suitable for SVDA:

http://www.thesamba.com/vw/forum/viewtopic.php?t=185095

And yes, if you use that port, it's pretty much the same as the 1970 30PCICT-3 and that's the T (or M) distributor, with dual vacuum sources in the venturi.


SVDA needs a single vacuum drilling low in the carb body, much like the one I pointed out above, that goes to that angled fitting. The problem in trying to access it, is keeping the hose/line out of harms way from the throttle lever.

[Lil Lulu]

Yes, I did read that post but a long time ago now. It's just now I'm getting curious about the Mexi svda on the 30/31 since I have freed it up from the 2L in the bus.
_________________
'65 Beetle "Lil' Lulu"- Ruby Red
1600 stock from '71 bus

'72 Deluxe - Niagara Blue w/pastelwiess Camper Special 2L dual 40 Webers 002

'74 Hightop Weekender "Dixie" 1800 34 Del singles

[glutamodo]

SVDA is pretty much the same no matter what country made it. 009-esque centrifugal advance, plus a vacuum advance that requires a high vacuum signature found with a single vacuum drilling low in the carb body.

[volksnhousin]

You have something to possibly gain and nothing to loose if you try the svda. It would be silly to not experiment with the mex svda seeing how that is what you currently own.

I would install the svda, hook up a strobe timing light and watch the timing when you attach the vacuum hose to different ports… Which ever port shows the most advance at partial throttle opening (say a quarter throttle or so) is the port you use.

The final test of course would be driving the car. You use what ever port makes the car run smoothest at partial throttle.

Experiment around and let us know what happens.
Andy

[gt1953]

I have a real deal German 034 so that would not work to well with the 30/31. Ok I get that. Will the 034 work well with the solex 34mm dual carbed engine. Anybody?
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[andk5591]

Dont waste the time installing the SVDA with the H30/31 unless you try the mod that Andy (Glutomodo) mentioned. There is NOT enough vac signal. Your 009 will actually work better. When you rev the engine, with or with out the hose connected, there is no or damn little difference in the timing. The Mex will behave the same way.

This is not "I read it on the internet =, so it must be true". Went through this with my neighbors car a while ago. Had a German 034 on it and it never ran right and I knew why. FINALLY convinced her to let me throw an 009 on it and the car ran much better (not great, but better).
_________________
D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Lil Lulu]

Installed the mexibosch svda in the 1600dp. Holy shit. What a difference. No more hesitation when accelerating, no stumble off idle, no "aaaaaaaaaagh! We're all gonna die"when lurching from the parking lot.

Thanks to Glutamodo.

Now I use the 009 as a spare when on trips. I hate to change points when the #%@(*&@ rub block busts off in a driving rainstorm. (happened twice) Now i can just change out the distributor and go home.
_________________
'65 Beetle "Lil' Lulu"- Ruby Red
1600 stock from '71 bus

'72 Deluxe - Niagara Blue w/pastelwiess Camper Special 2L dual 40 Webers 002

'74 Hightop Weekender "Dixie" 1800 34 Del singles

[glutamodo]

So you used that angled vacuum fitting then? How did you route the hose over to the distributor? When I was messing with this on one my 62, I had it set up like this, but this was only a very brief test.

[Lil Lulu]

Yes, I used the angled fitting. No photos but I just used a direct, short piece of marine vac hose. Any reason I should use a metal line and route it such as your photo? I don't believe there is any chance of the rubber line collapsing. You can see the advance working smoother with the the light.

This little change has made driving in town effortless. Soon I'll put a trip on her and see what it does to mileage.
_________________
'65 Beetle "Lil' Lulu"- Ruby Red
1600 stock from '71 bus

'72 Deluxe - Niagara Blue w/pastelwiess Camper Special 2L dual 40 Webers 002

'74 Hightop Weekender "Dixie" 1800 34 Del singles

[glutamodo]

That's actually a plastic line in my photo. I just wanted to keep it out of harm's way of the throttle lever, plus give and an up-then-down-in-height orientation to it, like the "shepherd's crook" and loop style stock metal lines did, which was to prevent fuel from condensing and running down to the advance canister.

I'm glad it worked for you.

-Andy

[Bus Jerry]

I just tried installing the vacuum line in the front angled port , it worked, but its giving me 43 degrees advance at 3000 rpm , is this way to much? I have a stock 1600 sp running a solex H 30/31 and a 205 T dist. I kinda want to know before I take for a test run. I don't want to screw up a new engine.

[glutamodo]

You should not use the angled port for a vacuum-only distributor!!! You need to use that traditional one on the side of the carb for a 205T!

The 205T gives 32+ degrees of total advance and should be timed to 0TDC statically or with the vacuum line unhooked/plugged.

[Bus Jerry]

Point taken. I agree with you, but I get no vacuum out of that port. I have cleaned that port with wire and carb cleaner and there is no obstruction. I did have it timed wrong at 7.5 BTDC, and have changed that back to 0 BTDC. Once again I hooked the vacuum line to the side port ....no movement on the timing. Change to the front angled port and I get 36 degrees max advance. also the dist. is a rebuilt unit by TASB. and I have sucked on the line and moved the advance that way just to check. So here I sit, is 36 degrees going to be to much. I don't know,

[glutamodo]

The side port gave no vacuum? it should give a steady rising vacuum as RPM increases - which is what the 205T requires. That angled port will give something that is close to manifold vacuum, modified only by the interference of the throttle butterfly, which is NOT a steady rising vacuum - it gives high vacuum at low and medium speeds and a bit less at higher speeds, and is load dependant - and requires a vacuum canister that kicks in at much higher vacuum than the 205T (the 205T maxes out it's vacuum advance about the same vacuum as the 034 SVDA begins to advance!)

You say you probed the side port's fitting with a wire? I would also be checking the two places that the side port taps vacuum inside the venturi, the upper one at the extension pipe fitting in the middle of the venturi, plus the hole at the throttle butterfly.

And make sure nothing is messed up at the base gasket where the vacuum travels as shown here, this is labelled 34PICT-3 but for the lower drilling this is the same on all carbs.

Now, having said all of that, many years ago I did run a 205K along with a 34PICT-3 carb for a couple of years. I've heard of others doing the same as well... This is about the same mismatch as you're talking about. It does "work" and this is why - with the throttle set properly there should be no vacuum signal at idle, so the distributor will pull back. As soon as the throttle is opened though, a large vacuum signal will be sent to the distributor, basically making it go straight to full advance with no real "curve" At low and mid-range RPM/load it will always be totally advanced. Now at high RPM it "might" back off slightly, just depends on how strong the return spring inside the distributor is, but for the most part it's going to be an all-or-nothing advance situation.

It's not right, and since the distributor will be seeing 2 to 3+ times the amount of vacuum it would have in correct service, I would not expect the vacuum canister to hold up very well over time. In fact I'm surprised I didn't blow out (or is that "suck out" ) the vacuum canister on my Baja with the 205K!

One thing that might help a little bit is to relocate the vacuum nipple from the side of the carb to the angled fitting - the restrictor inside of it might give a slight lag and make tiny bit of an actual "curve".


-Andy

[Bus Jerry]

Boy did you nail it. The lower vacuum grove on top of the base gasket was clogged up. After cleaning it out and reinstalling it, I now have vacuum pull off the side port. It's about 28 to 30 degrees total, and goes up on a smooth curve and back down on a smooth curve. I'm hoping that this will give me better gas mileage and a bit more power to boot. Thank you so much.

[glutamodo]

You're quite welcome, glad it wasn't too hard to sort out.

-Andy