Guys,
Any advise on what to do with problems with Solex carbs, should I replace with Webers? If so, which models and where to buy. Thanks
Guys,
Any advise on what to do with problems with Solex carbs, should I replace with Webers? If so, which models and where to buy. Thanks
Replies sorted oldest to newest
I wouldn't replace them unless the throttle shafts are worn out and they are sucking a lot of air in at idle.............Bruce
Bruce, thanks for the reply, but say they are what would you replace them with, or should I get them rebuilt. Also what pertronix model ignitor should I use to get best performance. thanks
Don’t replace the Solexes, get them rebuilt. They’re pretty good carbs.
If you have your heart set on replacing them, the first choice would be a pair of Dellorto 40’s followed by a pair of Weber 40’s. Plan on something north of $800 for the pair.
The best Pertronix module for the best performance is a CB Performance MagnaSpark II system. You’ll never look back.
LOVE my Dells.
Hear ye, hear ye @DannyP, et al:
I really like my Dellorto DLRA carbs. Most guys who have them really like them. There's not a single thing wrong with them.
But...
they're getting pretty old. New ones haven't been available for many, many years-- and lot of normal replacement parts come from "across the pond", from secret vendors (ALFA1750 on ebay, Eurocarb in the UK).
Weber IDFs are just so much easier to deal with. New ones are available everywhere. Figure on getting them gone through, even if they are brand new. This shouldn't be a deterrent, because you'll want to rebuild any used carb you find, so I'd figure on spending the money either way. Float heights, etc. will be wrong right out of the box, and there will be crud and snotty grease on everything new or used.
The good news is Weber parts cost less than anything else and are also easily available everywhere. 99% of the good jetting information on the internet is for IDFs. Most of the carb-whisperer dudes are really Weber guys at heart. The IDFs can be made to work every bit as well as Dellortos.
The only reason to get Dells is that the idle jets are really easily accessible and they made a 36 mm size that Weber didn't (if you have a small engine). Dellorto also made a Tri-Jet 48, but good luck finding anybody who has any idea how to set them up (after you pay $1500 for a set of "rebuildable" used ones). If I wanted to run anything bigger than 45 Dellortos (or 44 IDAs) at this point, I'd get 48 IDAs with the 3rd progression port-- everybody has good tuning advice for these as well.
Most carbs can be made to work-- but whatever you get, even if they are new, you're going to need to strip them down to the bodies, clean them completely, and reassemble them, setting float height, etc. With that in mind, I'd look at what you've got to start, and buy some IDF 40s if you don't want to stay on that road.
Agreed 100% Stan. If it were me, I'd get some Spanish/Italian 40 IDFs if you can find them. A guy I know just got a 2-3 year old Spanish set for $500 a pair. I'm rebuilding them for him.
40 IDFs are perfect for a bone-stock 1600 up to about a 2110. Bigger motor than that get 44 IDF. For a small motor, get 28mm vents, and you're IN.
And you're right there's nothing wrong with Dellortos OR Webers.
There is a 36mm Weber IDF- there's just not a lot of them out there so you don't see them very often.
I'd rather have points than a brand-new Pertronix these days. They aren't particularly reliable or accurate.
.
Gordon wasn't completely joking when he said the CB Performance Magnaspark is the 'best Pertronix you can get'.
The problem is Pertronix makes the electronic module (that replaces points) but uses the same questionable quality distributor body that most of the inexpensive no-name distributors use. It's the distributor body (and its weights-and-springs advance mechanism) that determines the consistency of the spark and the shape of the advance curve. The Pertronix is notoriously weak in that department.
A number of us with Pertronix dizzies have had lingering firing and miss problems that were at first attributed to carbs, but that instantly went away when we switched to distributors that are mechanically better. The Magnaspark is a reasonably-priced alternative that seems to be much better built mechanically than the Pertronix distributors currently available.
I don't know for certain if the Magnaspark will fit on a 912 motor, but I'm sure CB Performance could tell you, or probably half the folks here.
Stay tuned.
.
@ALB posted:There is a 36mm Weber IDF- there's just not a lot of them out there so you don't see them very often.
I did not know this. Thanks for setting me straight, Al. In 20 years of "hobbying", I don't think I've ever seen a set. I see 36 Dellortos advertised about once a month.
@Stan Galat- The 36IDF was never part of any aftermarket VW 'kit' so you don't see them very often, but as I said, they are around. They would be the perfect size for a hotrodded bigbore 36 hp engine with Okrasa style dual port heads (which are made) or even a mild 1600. I don't think I've ever actually seen a set (or even 1 carb) at a swap meet or VW gathering; I'm pretty sure I just read somewhere that they exist and have seen them for sale on Ebay. As a matter of fact- https://www.ebay.com/itm/weber...9:g:lD4AAOSwS6FflEZF
I have no idea what they originally came on. Al
PS- just found out they'd be take offs from some Alfa Romeo...
And another PS - Here are New old stock for sale- https://www.dellorto.co.uk/sho...-idfs-new-old-stock/ Note that they're left handed carbs only (I'm guessing the Alfa they were originally on was a straight 4 or maybe a 6?) and 1 would have to be switched to work on an opposed 4. And surprisingly enough, they come with 32mm venturiis.
Just to keep your head spinning- there's also a 50IDF...
36 IDF AlfaSud Sprint
Total aside @ALB -- but have you seen Johannes Persson's (JPM) IDA kit? It adds a "tri-jet" stack similar to the Dellortos. He calls is the Raptor Power Jet kit. The idea is that the additional jet acts as a main-jet, with the IDA mains dropping a few sizes to become midrange jets, with the idles staying the same.
He's also got a trick grooved venturi setup that will increase the flow on a set of 42 mm vents by 19 cfm. This is enough of a flow increase that almost nobody would need to go to the 51 mm modification (although he's got the grooved vents for those as well).
It's super-trick stuff for the guys way, way out on the edge (big turbos, etc.) who don't want to go EFI.
@RCosta- thank you sir! I couldn't find where they came from this morning before heading out to do some work (was meeting my brother to finish a job).
Yes, I've heard of them, @Stan Galat. They're doing some pretty cool stuff these days- Johanne's on the cutting edge! Are the grooved venturis like the Berg modified units? They're supposed to drive like the smaller diameter and under full throttle give the cfm of the larger size.
And another tidbit I didn't know- the Alfasud engine is a boxer!
@Stan Galat posted:Hear ye, hear ye @DannyP, et al:
I really like my Dellorto DLRA carbs. Most guys who have them really like them. There's not a single thing wrong with them.
But...
they're getting pretty old. New ones haven't been available for many, many years-- and lot of normal replacement parts come from "across the pond", from secret vendors (ALFA1750 on ebay, Eurocarb in the UK).
Weber IDFs are just so much easier to deal with. New ones are available everywhere. Figure on getting them gone through, even if they are brand new. This shouldn't be a deterrent, because you'll want to rebuild any used carb you find, so I'd figure on spending the money either way. Float heights, etc. will be wrong right out of the box, and there will be crud and snotty grease on everything new or used.
The good news is Weber parts cost less than anything else and are also easily available everywhere. 99% of the good jetting information on the internet is for IDFs. Most of the carb-whisperer dudes are really Weber guys at heart. The IDFs can be made to work every bit as well as Dellortos.
The only reason to get Dells is that the idle jets are really easily accessible and they made a 36 mm size that Weber didn't (if you have a small engine). Dellorto also made a Tri-Jet 48, but good luck finding anybody who has any idea how to set them up (after you pay $1500 for a set of "rebuildable" used ones). If I wanted to run anything bigger than 45 Dellortos (or 44 IDAs) at this point, I'd get 48 IDAs with the 3rd progression port-- everybody has good tuning advice for these as well.
Most carbs can be made to work-- but whatever you get, even if they are new, you're going to need to strip them down to the bodies, clean them completely, and reassemble them, setting float height, etc. With that in mind, I'd look at what you've got to start, and buy some IDF 40s if you don't want to stay on that road.
I hear Webers are now made in Spain and are not up to par with the Italian units; still preferable to anything from China. I agree with you and Gord; Dells are killer but if I had a choice I would rebuild the Solexes. I am pretty sure there are a couple of great sources to get this done thoroughly.
@LI-Rick wrote- "you know you want them!"
And who wouldn't? I have a Berg 86 mm crankshaft and it almost seems a waste to only use it with 94's, but I can't afford those heads. And Nickies; the 101.6's would have to be Nickies. And find a set of those 50IDF's I was talkin' about earlier. And those would be the heads to dual plug.
Can you imagine- 240-250 hp, all in by 6500?
I whole heartedly agree with Plan A being rebuilding the Solexes. Since Dave retired out here, I don't know of a specialist, but I think any number of Porsche restoration services could handle the job.
This looks like a good place to start:
@Gordon Nichols posted:The best Pertronix module for the best performance is a CB Performance MagnaSpark II system. You’ll never look back.
Except that it doesn't have vacuum advance. Switching from a MagnaSpark II to a Pertronix SVDA cured the off-idle stumble my 1776 with dual Dell 40s had when I bought my Speedie. I got mine on Amazon, went for the Ignitor II distributor, coupled with a Flamethrower II coil and Flamethrower wires.
Do yourself a favor and order a spare module to keep in your parts kit. I had one fail during the warranty period. Pertronix shipped me a free replacement, but I still had to tow the car home.
That's strange; Pertronix modules tend to be trouble free for the most part. Install it and forget it.
@Impala posted:That's strange; Pertronix modules tend to be trouble free for the most part. Install it and forget it.
Not really. They're pretty bad.
@Stan Galat posted:Not really. They're pretty bad.
I agree with Stan. I’ve seen them used on a lot of VW and 356 engines and they tend to be sensitive to heat soak and premature failure. It’s ALWAYS best to carry a spare Pertronix module. You will use it eventually on an air-cooled engine.
Good note on the SVDA disti, though. When I was running a 009 and points I always yearned for a vacuum advance but the original MangaSpark worked really well and the MS II is even better, since it allows easy advance spring changes.
@Gordon Nichols posted:I agree with Stan. I’ve seen them used on a lot of VW and 356 engines and they tend to be sensitive to heat soak and premature failure. It’s ALWAYS best to carry a spare Pertronix module. You will use it eventually on an air-cooled engine.
So do I- another reason to work at getting underhood temps as close to ambient as possible. Feeding more air into the engine compartment than it actually needs will carry away latent heat radiating off the sheet metal (and engine itself), the engine will run cooler (cooler air entering the fan and carbs means the engine will be operating under proper parameters a larger percentage of the time) and the pertronix module (which should be better built to handle higher underhood temps but isn't) will last longer. If you look at it from the standpoint that it's not if but when the module will die and are prepared it won't be so much of a shock.
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