TheSamba.com :: View topic - Comparing stock Solex carbs to each other, and to the H30/31

Sun Mar 01, 2009 11:36 am

Both centrifugal and mechanical curves were a little different between those distributors. The Autostick needed a different power curve for drivability.

Sun Mar 14, 2010 3:32 pm

glutamodo wrote: Failer wrote:
John replies:

the article is outdated; since then we have come out with one for your carb

Cool, I knew from the limited experiments mentioned above,that modifying an H30/31 to work properly w/SVDA should be possible, but despite the info I put into this thread, I'm not really a carburator expert. I'm glad that someone who is has gone and determined and made the modifications needed to make the H30/31 work that way.

Of course, that leaves thousands of H30/31s out there that aren't appropriate for SVDA work. So this thread should still be of interest to them. I don't know what the mods needed would be, probably plugging the upper vacuum port, and doing something to the drillings at bottom, I think adding a couple of small extra drillings might do it (I wasn't equipped with any micro-drills for my tests)

I'm not sure if this topic rates a "Sticky' though, I am flattered, but I wasn't really expecting that. I mean, although I did put a lot of work into taking the pictures, then doing the various tests, it was something I spread out over a few months time. And I almost didn't even post this, or just trimmed it back to the basic "photo essay" it was going to be in the first place.

And one last set of statements here - there are always going to be "exceptions to the rule" you might say. I've seen a few carb/dizzy combos that worked very good together that I would not expect to work out. Then there's correct carb/dizzy combos that, usually because of wear, don't work at all. Last summer for a time I was running an old 034 SVDA in my baja, that's the one with a 30PICT-1 on a 1600DP. It ran OK, but after doing all these tests, I now know that the vacuum advance was doing very little most of the time, so basically, it was running like an 009. And I like how it runs with the "K" distributor better.

I never meant to indicate that the H30/31 was a complete piece of rubbish. Just indicate that it's not designed for any specific appliation, and that (unmodified) it is wrong for the application that many people are using them for (and some stores are selling them for), dual port SVDA or DVDA.

And now, Glenn did some mix'n'matching on his new engine (I'm also sorry to hear about the 1904 :cry: ) and found a good combo that worked for him.

One final thing, for those who might be interested, I noticed that CIP1 now lists a brand new EMPI :roll: brand 30PICT-1. I'm sure this is the first time you could get a brand new 30PICT-1 since Bocar discontinued production several years ago. And, of course, since I'm a fan of the 30PICT-1, espeicially the newer ones Bocar made, find that interesting. Has anyone bought/used/ seen one of these in person? I don't need one, I have an NOS BOCAR version on the shelf, so I'm not about to plunk down 160 bucks for one anytime soon. But am kind of interested in the quality of this. I guess it depends I guess on just who EMPI contracted with to make them. They look OK in the pictures. I wonder if they have a roll pin for the fast idle cam retainer like the BOCAR ones had, instead of the solid pin the German ones used (the roll pin holds up a lot better)

http://www2.cip1.com/ProductDetails.asp?ProductCode=C13%2D98%2D1288%2DB

-Andy

I have a stock 30 PICT 1 and a 009 which I was able to get running pretty well this past summer. After a long winter nap the stock 1300cc motor will start initially but quickly stall. After that very difficult to start and if I can get it started runs very rough and won't idle. I noticed that fuel is leaking from both sides of the throttle body. Decisions Decisions. Do I have the carb rebuilt and start searching for a rebuilt 113 905 205K dizzy (because of the smoother performance) OR cip1 have repro 30 PICTs and 205Ks for significantly less money overall. Any experience with this combo?

Sun Mar 14, 2010 10:31 pm

Back when I had a (German) 009 with my 28PICT on my 1385/40HP it ran just fine. Those old small-valve engines with their quick port velocities usually do OK with 009s and those simple carbs. The combo you have now should be OK. All you might need is just a little cleaning on the carb and it will be good again. I'd investigate that first.

Also, I've never seen any 205Ks sold at CIP1. They have an 034/205(SVDA) new, but no vac-only distributors like the 70/older cars used.

That EMPI 30PICT-1, you might look at my review I did of that separate from this one. It has a production issue, or rather it did on the units I tested. I've heard that it may have been addressed, but I'd have to see it myself or some good detail photos to know better. And the 30PICT-1 they sell is the 1500 version, not the 1300. It'll work, of course, but if you want the best fuel economy it's possible you might have to do some different jetting.

-Andy

Mon Mar 15, 2010 6:13 pm

Now that the garage is starting to get a bit more civilized (above 40F) I'll be kicking around trying to get the engine sorted. Good advice. I may try to pick up a 205K and keep the 009 as a spare. In all actuality, you're right the 30 PICT and the 009 worked pretty darn well together. But alas the carb may need intervention greater than my own amateurish skills can provide.

Mon Mar 15, 2010 6:13 pm

Now that the garage is starting to get a bit more civilized (above 40F) I'll be kicking around trying to get the engine sorted. Good advice. I may try to pick up a 205K and keep the 009 as a spare. In all actuality, you're right the 30 PICT and the 009 worked pretty darn well together. But alas the carb may need intervention greater than my own amateurish skills can provide.

Tue Apr 20, 2010 10:33 pm

I am currently running a single canister duel vacuum advance distributor with a Brosol H30/31 on a 1600 dp engine. This is the set up my bus had when I bought it... it also came with a Solex 34pict-3 carb. Not sure if it's
working. I have a sneeky suspicion the PO bought the Brosol because he thought the Solex was causing issues that were wrongfully diagnosed.

Would it be better to be running the 34pict-3?

Wed Apr 21, 2010 7:16 am

single canister dual advance - that's SVDA, and that is indeed an incorrect match with an unmodified H30/31 carb. The 34PICT-3 would be a better match.

Sun Jul 25, 2010 8:12 pm

Sp sb74 I have the h30-31 ,had the 009 with a very bad flat spot at take off , got a svda at a local vdub place. Flat spot was gone imediatly , and has been running great Ever since..now should I stcick with this set up or should I swap the carb ? For one better suited for the svda

Mon Jul 26, 2010 7:22 am

The only way an H30/31 will produce the vacuum needed to move an SVDA's vacuum advance is if it was modified. Unmodified, and your distributor is working almost totally on centrifugal - just like an 009. It could be your old 009 had something wrong with its advance - and the new SVDA fixed that part.
-Andy

Mon Jul 26, 2010 12:16 pm

glutamodo wrote: The only way an H30/31 will produce the vacuum needed to move an SVDA's vacuum advance is if it was modified. Unmodified, and your distributor is working almost totally on centrifugal - just like an 009. It could be your old 009 had something wrong with its advance - and the new SVDA fixed that part.
-Andy ok .. so if its running good will it hurt anything to leave it the way it is?

Mon Jul 26, 2010 2:49 pm

Yeah, probably just stick with it and call it good.
-Andy

Sat Sep 25, 2010 1:32 pm

Is this thread dead? I hope not. I have a 74 standard with a DP1600. As far as I can tell, because I dont see the numbers, its a single vaccum advance. It has one canister and one hose that goes to to carb. Im running a solex H30/31 now with the adapter plate. It runs great all the time. Especially once its warmed up. No flat spots. Once in a while though, I find that when I start the car, it will sound like its starved of fuel or maybe detonating. It will stumble and I can hear the engine knock once or twice, before I step on the gas and get the choke to engage. I can't figure if this is from my shitty napa fuel pump (which is my guess), or if its because of the carb/dizzy combo. Or maybe even because of the adapter plate. Or preheat/riser tubes jammed up? I used to have a solex 34-3 carb on it, same dizzy, no adapter plate. It always had a flat spot starting in first. It would run fine otherwise, except usually the idle would flutter up and down. Eventually I determined that this carb was shot when it wouldnt idle or drive without missing. So what I'm wondering is if this new combo is hurting my engine or not. And if you think the start up issue is from something other than the dizzy/carb combo. It doesnt seem like it would be because it has great power and response, and idles solid at whatever I set it at. Just curious, thanks in advance

-Dave

Sat Sep 25, 2010 7:32 pm

If it's just cold running issues I'd check your choke to see how it's set (too tight? sticking?) The preheat on the manifold, well it takes a couple of minutes of driving to really get hot, at idle it takes a few minutes more. If that's an issue for you, you'll be seeing frost on your manifold.

Single vacuum as in SVDA, or single vacuum as in vacuum-only? The numbers are not visible from the rear of the car, they face around towards the front. Vac-only, that's the one you want! The bodies on SVDA are taller for the centrifugal, and have a smaller canister than vac-only.

Mon Sep 27, 2010 10:46 am

Hate to beat this subject to death but I have some questions. I haven't messed around with the 30/31 that much, most of my experience is with the 34pict-3. I have a friend with a stock 67' beetle, he is the original owner. I believe the engine has been upped to a 1600 from its stock size on the last rebuild. He has had a hot start problem for awhile. He took it to a local shop who replaced the coil, plugs, wires, cap (not the rotor) points, condensor and the carburetor then told him thats the way VW's are. The original carb is long gone. I found the rotor was burned up and replaced it. This made a huge improvement. The car still has the original vacuum only distributor. I have had trouble tuning this carb. At first the volume screw did nothing when turned in or out. I opened the main jet to 125 and got some adjustability out of it. I am assuming the vacuum from this carb is sufficient to pull the large vacuum pot on the distributor?? He still has the hot start issue from time to time and I want to get it licked. Any thoughts??

Tue Sep 28, 2010 7:14 am

Thanks for the response, I do have an SVDA. From what I can see the from the numbers on the side (without a mirror), the last numbers are "03_" and I'm guessing that blank is a 4. Either way it runs fine, and I adjusted the carb again the other day and it sounds a lot better on the start up. I have a little trouble with mine on account of my elevation. I live at 8200Ft and I work at 7000 Ft. So everyday I get to work, the idle is high. And when I get home, the idle is fine. Since I have a 1600DP and a SVDA, I wanted to replace my beat 34-4 with the same carb. The shop I had order it biffed it. The guy never asked me my engine size, dist. model, SP or DP, or anything before he ordered it. I figured he had taken note of it while he was looking under the decklid. But he did not. So he got the 30/31. Thats why I never let anyone work on my cars. If I had half a brain Id have gotten one from Keifernet. Reguardless, I feel that any of those new solex's work great. Reguardless of the model, as long as its new. And you have the correct DIST. obviously. I havn't tried the Bocar's but I assume they are not as good of quality.

And as sunbugone said, I also have a hard start when its warm sometimes. But I've always seemed to have that. new coil new plugs new wires, new points, new fuel pump, new battery, new carb. Mostly preventative things, but still have a hard start when hot. Not always, but one out of six trys.

Tue Sep 28, 2010 7:52 am

Well, your 034 distributor and an H30, is running like an 009 - the vacuum really won't function much at all. But if it's running OK then I'd not be too bothered by that. It won't hurt anything which is what you asked previously.

Hard hot-start, at altitude not unusual. When it happens do you try holding the gas pedal to the floor at all?

-Andy

Tue Sep 28, 2010 9:02 am

yeah I noticed the hard start more so when I'm at this altitude. high altitude causes lower compression (correct?) I restored the car and drove it mostly around a thousand feet above sea level, so I never really had too hard of a time starting it. But yes, I do put my foot maybe half throttle and it takes maybe 3-5 seconds to start. Where as before I swear the engine wouldnt turn over more than once before it was fired up. Not a big deal, just something I noticed.

Thanks for letting me know about the dist. So its running only on centrifugal advance, correct? Does that mean that at full throttle, it is not advanced enough to burn all the fuel going into the manifold? Would that mean its detonating? or just not burning? I can not really notice any loss of power at those RPM's or speeds. I cruise at 55-65max. I supposed it would go a bit faster, but who wants to rebuild every 30K? And I'm happy getting 38MPG at 55MPH.

Tue Sep 28, 2010 9:10 am

glutamodo wrote: Well, your 034 distributor and an H30, is running like an 009 - the vacuum really won't function much at all. But if it's running OK then I'd not be too bothered by that. It won't hurt anything which is what you asked previously.

Hard hot-start, at altitude not unusual. When it happens do you try holding the gas pedal to the floor at all?

-Andy
Same set-up, same issues, although I am considerably lower than you.
approx 800 ft above sea level.
I do get the flat spot on take off, exaserbated by the AStick set up, but I had tried 3 (2 new bocars) carbies and the 30/31 was the only one that would let the car idle.
All the other carbs worked great on other engines, just not the one in the ASBug.
I feel your pain...
KC

Tue Sep 28, 2010 9:32 am

Orbison74 wrote:
Thanks for letting me know about the dist. So its running only on centrifugal advance, correct? Does that mean that at full throttle, it is not advanced enough to burn all the fuel going into the manifold? .

No, the vacuum side of thing helps mostly with the acceleration curve. If you go back to page 1 of this thread you'll find it explained in detail. But timed at idle to 7.5BTDC, the centrifugal should then give around 30 degrees total advance (and actually, you could probably get away with 32-35 total at your altitude) and that's fine. If it's running good, I'd leave it alone.

-Andy

Tue Sep 28, 2010 10:40 am

Thanks, I time it at 5ATDC. Its and AH engine, so all that I've read is to time it there. But I don't have my light with me, so Im not sure my total advance. Thanks for all your replies.