Weber conversion manifold

[Tim R]

As Kevin says contact Jerome and ask but I know previously the demand was such that they only sold the manifolds with the carbs. Interestingly I opened up the Apollo air filler today after 7 years and many thousands of miles as I noticed the plugs getting a bit sooty and the car not flying along quite like it normally does. The filter was blocked solid with dead insects, grit and muck. If you've got one and haven't checked it for a while it might be an idea to have a look. I will do it every year in future! Tim R

 

[John W]

Smash, Your “can of worms” has resulted in the best discussion I've seen on Alpine carb set-up.

Alpine Innovations has a “curved manifold” that's a common replacement on other British cars. I, like everyone normal, am so appreciative of what they do, but the sales page also lacks explanation of the difference between “Ford Mexico jetting”, “Std Alpine jetting,” and “Alpine specific jetting.” The prices aren't that different (if a couple hundred dollars isn't significant), but nevertheless, what's the difference? If they explained that, I think their sales would go up like the sales of the Weber accommodating Series IV intake for an Alpine did when just going to a Weber was the best information.

Sunbeam Alpine and Tiger “gold portfolio (1959-1967) (a history book by any definition) page 72-73 describe the Alpine IV as “Most interesting of the mechanical changes is that the Alpine IV is now available with a 3 speed automatic transmission. This is obviously a concession to the increasing number of drivers who have never mastered the intricacies of a manually operated transmission or would rather not work so hard in heavy (i.e. city) traffic.”

The Borg Warner automatic and the “log” intake with single Solex carburetor of the Series IV HAD to have been the result of the “touring” (as opposed to the sports car) intention of the Rootes Group. Nothing (that I know of) better explains the recent discussion of Moss Motors reply to carrying Sunbeam parts previously carried by Victoria British.

I have the “log” intake, with downdraft Weber on my Series V (and Series IV) (that has never performed like the original Stromberg dual carbs, and I lived/and dominated{i.e. outrun anyone} on the dirt roads [in 1973] “in town” with a vast dirt/mountain road extension).

Were the Solex carbs and “log” manifold designed to “get around town?” I'd love to hear that discussion (in the vien of 65beam or Michael from down under).

What ignorance to silence 65beam. This isn't perfect (nothing is) but you put up with whatever anyone has become for what they are. Let it happen. To quote the license plate of the most “progressive” Alpine on the planet (what they would be like if made today) “Let it be”

Michael's aesthetic analysis of the “all that's available intake” (greatly appreciated) may be all that's allowed by the current “owners' of this forum. ''

“Touring” is great. We are so much more. “Let it be.”

I'd love to buy what Alpine Innovations has to offer, but the impression of the “owners” of this website make me hesitant of the influence on what I might get.

 

[Tim R]

John,
I'm from the UK and not sure I totally understand your post. If you have questions about the Club Weber set up, e-mail or call Jerome at Alpine Innovations (AI) and he will happily answer any questions that you have. My family have no connection with AI but are very satisfied with their products. We've replaced Strombergs and Solexes with this set up and like everyone else who has done this we have nothing but praise for the system. I have literally NEVER heard someone say a bad word about the AI Weber carb set up. It is far and away better than the Strombergs in every department, if you used to 'outrun' people before, you would certainly do so again with this Weber! When you fit it to an Automatic Alpine you completely transform the car from a slow plodder to a car that will happily keep up with modern traffic and cruise on the motorway perfectly happily all day long.
Best Wishes,

Tim R

 

[pruyter]

Hear hear to the post of Tim Raymond as shown above!

Regards,

Peter

 

[Bill Tippy]

Wow. Talk about perfect timing. I'm doing my conversion today, Pierce manifold and Weber carb. I've never really worked on an engine before and was afraid to even start.
I got the intake and exhaust manifold removed.
It appears that the old gasket is actually 2 gaskets
The replacement gasket (only 1 gasket) I got is no where as high of a quality as the ones I removed. Which came off perfectly with no damage.
Should I reuse one or both of the old gaskets, since they are so much heavier than the new one, and appear to be perfect?
The photos are both sides of the old ones.

 

[puff4]

The original factory setup is a thick-ish gasket combined with a metal shim-like gasket with raised rings around the intake openings. I don't think this setup is still available from vendors, but the idea was to both insulate the manifold from heat as well as allow independent expansion and contraction along the gasket surface, thus preventing leaks. The replacement gasket being offered by most vendors is a thick-ish one with metal on one side, much like the one on the top of the second photo above. I'd advise getting one of those from a reputable vendor rather than using a thin gasket.

 

[Bill Tippy]

The original factory setup is a thick-ish gasket combined with a metal shim-like gasket with raised rings around the intake openings. I don't think this setup is still available from vendors, but the idea was to both insulate the manifold from heat as well as allow independent expansion and contraction along the gasket surface, thus preventing leaks. The replacement gasket being offered by most vendors is a thick-ish one with metal on one side, much like the one on the top of the second photo above. I'd advise getting one of those from a reputable vendor rather than using a thin gasket.

The gasket I bought was from Sunbeam Specialties. Where can I get the one you described?

 

[RootesRacer]

The gasket I bought was from Sunbeam Specialties. Where can I get the one you described?

I too recently bought a manifold gasket (MG5) from SS and it lacked the sheetmetal piece. New material is brown instead of black is is perhaps a bit thinner than the prior parts.
I sent an email to Rick on it but didnt get a response.

Without the sheetmetal piece, I am afraid that the gaskets are going to have to be considered disposable. I used to get 2 or 3 intake removals per set in the past.

 

[alpine_64]

Speedy spares in the UK carried the 2 part gaskets with the seperate metal and composite parts

 

[hierogk]

John,
I'm from the UK and not sure I totally understand your post. If you have questions about the Club Weber set up, e-mail or call Jerome at Alpine Innovations (AI) and he will happily answer any questions that you have. My family have no connection with AI but are very satisfied with their products. We've replaced Strombergs and Solexes with this set up and like everyone else who has done this we have nothing but praise for the system. I have literally NEVER heard someone say a bad word about the AI Weber carb set up. It is far and away better than the Strombergs in every department, if you used to 'outrun' people before, you would certainly do so again with this Weber! When you fit it to an Automatic Alpine you completely transform the car from a slow plodder to a car that will happily keep up with modern traffic and cruise on the motorway perfectly happily all day long.
Best Wishes,

Tim R

Did the original Solex carburetor with PCV and brake booster ports on the intake manifold cause lean running on cylinders 1 and 4? If not, what is different in the design of the Weber that creates this issue? Sorry for my ignorance, but what is meant by "log" manifold? I am replacing my old Solex with a Weber now, but had planned on using my current intake so any help would be appreciated.

 

[alpine_64]

The log basically dumps the mixture from carb into a comon plenum that the runners then feed off. On the original rootes design the 1st and 4th runners used to get a leaner mixture.

Rootes redesigned it in about 66 so that the runners curvee into 2 pickups from the log.

 

[alpine_64]

Aftermarket log:

 

[puff4]

...and the petrol tends to condense on the cooler walls of the log plenum, which exacerbates the starvation in cylinders 1 & 4. Combine that Lean mixture with poorer cooling around #4 cylinder and you’ve got a recipe for a very hot cylinder... which is why we see so many #4’s with pitted cylinder heads from hot-spots. On factory log manifolds for the downdraught carbs they ran the hot water pipe through the manifold to try and alleviate the condensation.

 

[Bill Tippy]

I too recently bought a manifold gasket (MG5) from SS and it lacked the sheetmetal piece. New material is brown instead of black is is perhaps a bit thinner than the prior parts.
I sent an email to Rick on it but didnt get a response.

Without the sheetmetal piece, I am afraid that the gaskets are going to have to be considered disposable. I used to get 2 or 3 intake removals per set in the past.

RootsRacer I think you answered my main question. That the gaskets can be reused. I had pretty much decided to do that since mine are in great shape.
Do you use any kind of sealant with the gaskets?
If so, on all 3 surfaces - block side, manifold side, and between the two gaskets?

 

[RootesRacer]

RootsRacer I think you answered my main question. That the gaskets can be reused. I had pretty much decided to do that since mine are in great shape.
Do you use any kind of sealant with the gaskets?
If so, on all 3 surfaces - block side, manifold side, and between the two gaskets?

When using the 2 piece (the only experience I have), I siliconed the gasket proper to the head and installed the sheetmetal raised side out with a the tiniest ring of silicone around each intake port on the intake and then smoothed it and let it dry before installing the manifolds.
I have not experienced leakages on either manifold even after removing them and reinstalling them.
I reused the sheetmetal until it got rusty and I felt it would no longer seal the exhaust.

I may keep the sheetmetal from my current engine since the future is uncertain about the proper gaskets availability.

 

[Tim R]

In reply to Hierogk above,

Changing the carb to the Weber is good but changing the carb and manifold to the curved branch type, (such as sold by Alpine Innovations) is better.

Tim R

 

[husky drvr]

...and the petrol tends to condense on the cooler walls of the log plenum, which exacerbates the starvation in cylinders 1 & 4. Combine that Lean mixture with poorer cooling around #4 cylinder and you’ve got a recipe for a very hot cylinder... which is why we see so many #4’s with pitted cylinder heads from hot-spots. On factory log manifolds for the downdraught carbs they ran the hot water pipe through the manifold to try and alleviate the condensation.

There is also a log manifold design issue that tends to magnify any other existing condition which might cause a lean mixture in the end cylinders. Due to the firing order of #1>#3>#4>#2, cylinder 2 intakes immediately before cylinder 1 and cylinder 3 intakes immediately before cylinder 4. This pulse pattern tends to allow the inner cylinder to rob part of the end cylinder's intake charge. The cam timing has the inner cylinder intake valve still open when the end cylinder's intake valve starts opening. The A/F mixture has inertia flowing into the inner cylinder which must be overcome before any charge goes to the end cylinder. Also, the end cylinder has gotten a late start to pull in A/F mixture and has a longer flow path to pull that mixture to the cylinder. If considered in that light, the single carbs seem to be supplying a two cylinder engine. The twin carb setups has each carb thinking it is feeding a single cylinder. That is a simplified model considering the crossover porting and other effects.

The simplest ways to get around this issue are a new manifold design which is unlikely to fit the allowed space, a new cam design to change the firing order, or maybe installing a sequential port injection system.

 

[alpine_64]

or maybe installing an sequential port injection system.

Or just individual runner manifold.... Twin dcoe/dell'orto or mikuni etc... No need to go injection

 

[hierogk]

In reply to Hierogk above,

Changing the carb to the Weber is good but changing the carb and manifold to the curved branch type, (such as sold by Alpine Innovations) is better.

Tim R

Regarding Tim R post. Thanks for that advice, but you don't really say anything regarding the reason you feel the AI manifold is better than stock. Also, I remain interested in knowing if the original Solex set up designed by the Rootes engineers caused lean running in two of the cylinders. It seems that many of the Alpines with this set up ran very well for a very long time, but they did go back to twin carburetors on the Series V.

 

[husky drvr]

Regarding Tim R post. Thanks for that advice, but you don't really say anything regarding the reason you feel the AI manifold is better than stock. Also, I remain interested in knowing if the original Solex set up designed by the Rootes engineers caused lean running in two of the cylinders. It seems that many of the Alpines with this set up ran very well for a very long time, but they did go back to twin carburetors on the Series V.

The AI manifold is the only manifold designed (To My Knowledge) to have each cylinder runner have its own unique entrance into the plenum under the carb. It's the most likely option to provide near equal F/A charges to each cylinder, for that reason. As for the OE Solex manifold and end cylinder A/F mixtures, I doubt anyone has tried to do any real world testing on the subject. On the other hand, there are results found during tear downs that could be interpreted as having A/F mixture being a probable or contributing cause.

By design, the OE manifold has the PCV air entering the plenum under the carb. That design allows the air that flows into the induction tract, from the block, to mix into the A/F mixture before distribution to all cylinders. This PCV air can be compensated for with the carb's tuning. If the PCV flows into just a single cylinder runner, then the PCV air displaces part of the A/F mixture and fails to replenish the missing fuel for that cylinder's charge.

The OE manifold is certainly usable. There are too many Rootes' engines using that, and similar design, manifolds to think it's not a viable option. Most of what has been discussed is "best design" as opposed to "usable design". Every "engineered" part or system probably has some type of compromise included due to design choices.

The sV's return to twin carbs can probably be viewed as Chrysler's desire to market the Alpine as a "performance" car in the US. IIRC, the later Rapiers continued to use the Solex carb with the 1725. The Rapier 1725 wasn't rated to the same output as the Alpine V 1725, though.

Hope this helps. I apologize if this seems too pedantic, but I tried to answer your questions without any idea about your knowledge of the subject.