1915 carbs?

The single carbs you have actually are well suited for the size of engine, heads and cam you have. The engine was built as a package and everything is matched to be the best. Adding larger carbs without modifying the heads, compression ratio and or displacement will probably give you an engine that has less performance at worse or no increase in performance with increased fuel consumption at best. Changing carbs to larger ones would only benefit if the engine was built to begin with using carbs that are too small for the setup which isn't the case with your engine. If it works, don't fix it mentality will do you well in this instance. Save your hard earned money for something else..This of coarse is my opinion taken from my personal experience of doing this same thing and finding out the hard way for you. Good luck.

@GomerP-When bombing around in 3rd gear, how high does the engine go before it 'flattens out' at full throttle? Fyi- if it runs out of breath at 4500 rpm chances are it has a stock camshft. If it goes to 5,000 rpm (or thereabouts) it has an Engle W100, Scat C20 or C25 or something similar. If the thing zips to 5500 then it has something along the lines of a W110 or C35 (although I don't know if your 34 mm carbs are capable of that much power/airflow).

That said- While Jimmy's right in that it's probably a well matched combination, it's only a matter of time before the other carb is leaking. I've never heard of anybody bushing the throttle shaft area of those carbs- kadrons have the same problem but there's enough material in the casting to machine it for a bushing so they are fixable. If you're thinking you'd like to move up to Webers, a pair of 40 IDF's would be the right size, will give a smoother idle, could have a little more top end, and if set up and jetted properly will be the same (or even maybe a wee bit better) in the mileage dep't. 44's will definitely be too big.

Hope this helps. Al

What Al said. I'm not a big fan of the single throat dual carbs, BUT I installed a set of Solex 35 PDSIT carbs on a 1835cc sand rail and they simply work GREAT when jetted properly AND keeping the fuel pressure down to no more than 1.5 psi.

I really like Webers and Al is right, drive it and notice when it stops pulling.

The Weber 40s are a good fit for a 1915cc. And Webers like 3 psi for fuel pressure.

Having said that the dual singles are pretty much carefree, until the throttle shafts wear and leak air.

GomerP posted:

Questioning have a VS with a 1915  Currently running EMPI 34 single barrel duel carbs, one is started to show its age.. so I was wondering if it’s worth it to upgrade to 40 or 44 Weber’s  or stuck with the 34s and just replace/repair the worn out one?  Major air leak at the throttle shaft  linkage was set up poorly and causing it to bind for some time  

I am 90% sure I have stock heads, crank & Cam just set up with 94 jugs. 

@GomerP, you're at a fork in the road here. chances are, you're 100% correct regarding your engine-- in all likelihood, it's got a stock cam and heads with the Kadrons. One carb is worn out, so you're going to have to buy something. Now is a good time to ask where you'd like to go with this car.

Most of us here are "more is more" kind've guys, and will point you in a "more" direction. I'd put Weber (or Dellorto) 40s on it, and figure I'll be buying better heads and a bigger cam later. @MusbJim however, seems to find happiness and peace letting his car just be a car, rather than trying to channel his inner Stirling Moss. If that's you, and you're just going to let your car be a happy little cruiser for the wife and grandkids-- then just replace the carb with another one just like it.

If you've got an itch in your brain, and want more. I'm so, so sorry-- but at least you found some equally addicted and tortured souls.

Hi. My name is Stan, and I'm a power junkie. 

Thanks for all it the input guys. I really appreciate it. 
currently the car runs well, if I ignore the air leak on said carb. I have a 3.88 R&P. 3rd gear is when the fun starts now at about 3K rpm as that’s when It starts to wake up. I think it runs out of steam around 4.5-5 k. Top end in 4th is not at all an issue as it will pull well enough up to and run at 80MPH with no second thoughts. Don’t get me wrong I would always love more torque in 2nd & 3rd as that’s part of the fun to me. So I am sure at some point I’ll start to think about some internal changes. Cam & Crank maybe??? Always like a stroked engine. But not this season. 

fork in the road for sure... replace or upgrade... always the toughest question.  🤔

It gets to be a slippery slope - both cam/crank require splitting the case. Stroker crank requires clearancing the case and likely new pistons.  New heads would be simplest upgrade - no splitting the case at least. But then you'd probably want a new exhaust.

WOLFGANG posted:

It gets to be a slippery slope - both cam/crank require splitting the case. Stroker crank requires clearancing the case and likely new pistons.  New heads would be simplest upgrade - no splitting the case at least. But then you'd probably want a new exhaust.

And so it goes........"While I've got it apart I might as well blah blah blah $$$$$$$"

@GomerP wrote- "fork in the road for sure... replace or upgrade... always the toughest question."

The carbs you have are at their limit (or almost) now and it wouldn't take much for them to be the limiting factor in a new, bigger displacement build. Put them on a higher powered engine and at some point the engine won't rev any higher , so it will be short of it's potential. If you think you may upgrade in the future, those 34 mm carbs won't really be of any use to you, so now may be a good time to learn how to tune Webers. Or replace the carb, and when the time comes build a new engine from all new parts and either sell the 1915 as complete or keep it under the bench as back up.

And by the way, watch out for what Stan tells you; he's got it baaad! I, on the other hand, am not like Stan at all, and don't spend every waking hour thinking up new combinations for more power and better driveability, debating (with myself or anyone who will talk to me) the merits of aluminum vs chromoly pushrods, forged vs cast pistons (and whether hypereutectic pistons with their smaller expansion rate so you can run tighter clearances with less oil use are really a benefit despite being slightly weaker than a good forging), trying to think up a new exhaust design, since the sidewinder does use primaries that are ideally way too long for the operating range most of us drive in, scanning Craigslist sometimes 3 times a day, drooling about what I could drill holes in should I ever manage to get that bench top milling machine at a good price used, and when I am able to clear my head of these things not constantly running gear ratio combos for friends through my head.

No, I'm not like power junkie uncle Stan at all... 

@Panhandle Bob wrote- "And so it goes........"While I've got it apart I might as well blah blah blah $$$$$$$"

It's called sinceitsapartitis and it's a very serious affliction (to your bank account and occasionally to your relationship with your significant other). Been there once (or maybe twice?) myself...

ALB. Man reading that was like being inside my own head.  All this started from chasing down an oil leak on the 1-2 side of the engine... After pulling the engine cleaning everything up pulling the heads and changing what i I thought was the cause (pushrod seals) bolting it all back together putting it back in the car only to now be able to see that it was the lower case bolt leaking between 1&2. Coming right out of the threads... pull the engine back out.. pull the head again.. and cylinders this time because you can’t get a wrench in that damn head bolt with them on. Release the case bolts all of them. Now waiting on a new gasket set to arrive as the tube seals didn’t really look perfect the second time... and that would just piss me off if they leaked after all of this. Any way engine is sitting waiting on parts.. I think man this would be a good time to.... $$$$ new heads? New carbs..(I know I need to fix one or upgrade)  boy I really like the look of that vintage speed SS hi flow exhaust... 

I wish I had a new CNC mill, I really miss my old lathe... searching Craigslist and Facebook market for a good second engine to start a full build on and keep the 1915 as is and as a back up. Because I am getting pretty good and pulling the engine now. And it would be fun to have a hot engine... 

Oh the addiction  

Ok, it sounds like you're in trouble (and fully one of us!) Just wait 'til we start talking gear ratios and the way of 5...

Don't put money into new heads as the carbs won't let any potential gains be realized. Did you take a look at the heads while it was apart- any porting work done? Valves bigger than stock? After that's sorted, will the exhaust (I don't know what's on the car) have enough flow to let the heads do their thing? And how about the cam- does it have enough duration to let the engine rev higher to make use of all this new found flow and power? And if all this is happening you might be able to push the compression a little bit for even more...

It's all a combination, and has to work together with the displacement and rpm range intended. That's the trouble with these things- with such a wide range in displacements possible, what works on a 1776 or 1835 to 6500 or more with power falls flat on it's face at 1,000, 1500 or 2,000 rpm less with a 2 liter, 2110, 2276, or 2332.

Uh oh. I detect the makings of another dual plug, 10.5-to-1 compression ratio project....

Pull that tongue out of your cheek Ed.....     

For street use (which is what most of us do); Dellorto 36's or 40's are killer. Reliable ad basically plug and play when set up right. The problem is finding them since they've been out of manufacture for many years now. Username alfa1750 on Ebay sells them refurbished; here's a link:

https://www.ebay.com/itm/VW-PO...2:g:MlYAAOSwgO9dOerh

Well that depends on what you are running on the street, doesn't it?

Webers are just as tractable on the street when sized and jetted properly. Dells are nice, but even they aren't perfect, ask the guys who run them. Personally, I'd ask Stan, he knows.

Weber 40s can run on a 1600 to about a 2110, beyond that displacement go with 44s.

 of course.. “ I know a guy”.  Hahah any recommendation on intakes and linkage for that set up?

Oh man y’all are killing me... I guess I did ask for opinions. But sounds like no real Consensus for what’s best for my 1915. 

I don’t need to ask; I’ve had Dell 40’s for 15 years...😉. The linkage, manifolds and air filters for that setup you can get from CB Performance.

Option 1: Replace your 34 ICTs as a pair, clean and jet them as the old ones were and move along.

This is the sanest option.

Option 2: UPGRADE to dual 40s. Jet them as required to run right on your build, and drive on, secure in the knowledge that when or if you want to go to ratio rockers or a bigger cam or new heads or other horsepower enhancers, your intake will not stand in your way. 

This way lies The Madness.

And I've had Weber 44s on a 2165 for the same time. Ask anyone how mine runs: Stan, Musbjim, Cory, Chris, Carey Hines, and many others. Your point?

@GomerP posted:

Oh man y’all are killing me... I guess I did ask for opinions. But sounds like no real Consensus for what’s best for my 1915. 

You're correct in the there is no real consensus.  That's because size isn't everything.  When I got my Speedster in 2006 Beck offered two standard engines, both of which were 1915cc in size.  One was a basic, engine tuned for reliability and decent performance and rated at 90hp with two one-barrel carbs whose type I can't remember.  It was intended to remain stock and was what it was, but would provide the owner with good service for a long time with minimal maintenance.  The second was a more potent 1915 that was rated at 125hp, and which could be further souped up if the owner so desired.  It had a more aggressive cam and fancy heads, along with two Weber 44IDF carbs.  It was perhaps a bit more maintenance intensive, partially due to the Weber carbs.  Despite the "conventional wisdom" saying that 44s are too big for a 1915, it had no flat spots nor did it bog down - assuming, of course, that you didn't have a (!@$%!#&%!!) clogged idle jet.  Mine was a great deal of fun for well over 50k miles and, outside of the aforementioned carb issues and one distributor problem, was quite reliable.

A bit more "maintenance intensive" is a bit of an understatement from you, Lane.

You know I love you like a brother(father?), but at least some of your problems were, ahem, self-induced.

Word has it that Lane had considered applying for Federal Grant re: How little brass thingy's disappear.

I have a 1904 with pretty big gene berg heads and upgraded cam. I have two sets of carbs (40 and 44). The 40s were on the car. Since the car sat for many years I am having Justin at black line racing in Utah rebuild the carbs. He suggested using the 44s for my motor. Have not got them back yet so we will see. My dad said the 44s did not run as well as the 40s but Justin seems to think with the correct jets they will work better.

@Alan Merklin posted:

Word has it that Lane had considered applying for Federal Grant re: How little brass thingy's disappear.

Ooohh, great dig Alan!

@Lane Anderson wrote- " ...The second was a more potent 1915 that was rated at 125hp, and which could be further souped up if the owner so desired.  It had a more aggressive cam and fancy heads, along with two Weber 44IDF carbs.  It was perhaps a bit more maintenance intensive, partially due to the Weber carbs.  Despite the "conventional wisdom" saying that 44s are too big for a 1915, it had no flat spots nor did it bog down - assuming, of course, that you didn't have a (!@$%!#&%!!) clogged idle jet...

40 IDF's will support somewhere around 135? 140? hp (there is a model off of a European car that Alfa on Ebay sells with a slightly different carburetor top that will produce another 20 or hp with a slightly larger venturi but VW kits get the lesser carb model) so unless you're looking for power in the 7,000- 7500 rpm range you are better off with the smaller carbs. With the 40's there will be more power and crisper throttle response throughout all but the top of the rpm range. You are right, Lane, with the larger carbs it would run perfectly fine with the jetting reasonably close (and having all the parts in them and not spread across the garage floor- I told you it would live on forever!) and at full throttle there may even a couple or few more hp at the very top end.

But that doesn't tell the whole story- where carbs that are too big for the engine fall short is right around the idle/main circuit transition (which is where we spend a lot of time when we're not driving the bag off it). At this transition there's usually a 500? 1,000? rpm rich area that is is extremely hard (maybe impossible?) to tune out. The upper part of this area (3000- 3500 rpm) is right where we mostly drive in town and cruising on the highway so that rich section translates into slightly less mileage than with the smaller carbs. It's why typically a smaller engine (and I put a 1915 at the top end of what is a 'smaller' engine) with bigger carbs will get mileage in the low to mid 20's while an engine of the same size with 40's (properly jetted) can hit 30 mpg, and I've heard of guys getting even higher. I had personal experience with this wondering why mileage in my Cal Look bug with the 1750 (older ISS 90's instead of 90.5's) was only in the low 20's. The close gears and 4.375 r&p may have had something to do with it as well, but I wanted it all!

An engine with even properly sized carbs running a step or 2 rich may seem to run well, with no flat spot or bogging. When you buy carbs, companies usually ship them with rich jetting intentionally so they can't be blamed for melting down your engine. It's up to you to jet them closer to what's optimal. Al

I averaged 25+ mpg, so the mileage was respectable.  I figure Pat Downs knew what he was doing when he set it up.

And yes Danny, some of the problems were self-induced, particularly the brass thingy incident.