Zenith 36 WiP - 3 Carbs

mamoose124 · Mar 30, 2016

I have the original set of Zenith 36 WIP - 3 carbs for my 1962 Sunbeam Alpine. However, the PO installed a Weber carb which now will not stay tuned. I think the idle screw and throttle screw are worn to the point they wil not stay seated where they should. Accordingly, I either need to purchase a new Weber carb or fix my Zenith carbs. I prefer to do the latter but am having difficulty locating carb kits for the Zenith carbs. Am I out of luck here?

I don't like the Weber as the adjustment screws are on the inboard side of the carb are difficult to reach and it is hotter than blazes trying to tune it.

What about a set of dul SU downdrafts like those fitted on the old TR-3s?

Any suggestions would be greatly appreciated.

SoCal'beaming · Mar 30, 2016

Classic Sunbeam Parts shows the kits .... S.S. just has the gasket kits .... throttle shaft bores ... if badly worn may be an issue, through they can be sleeved. Here's a post that may be helpful if you decide to rebuild 'em

http://www.sunbeamalpine.org/downloads/wip-carb-rebuild.pdf
...... David

mamoose124 · Mar 31, 2016

Thanks, David for the reply. I contacted SS and they don't have the kits in stock and don't know when they will have them. Thanks for the URL on the carbs. As it happens, I already have that pdf. In fact, that document does verify that my carbs are the same.

If you learn more about where to get parts let me know as I would really like to get the original carbs back on the car. I sent an email to the Zenith in the UK in hops that they may have repair kits. We will see.

oLD lIMEY · Mar 31, 2016

Hi I went through the same thing. My Alpine was not running when I got it. I overhauled the Zeniths only to find when started the shafts and bushings were worn and leaking air. I couldn't get parts for then ( shafts and bushings) so I built up the shafts with nicosol (sp) but they still drew air so finished up putting Stromberg's on it. Did hear there is someone who dose it but very expensive. Also think there is a way of putting "o" rings on the shafts but never tried it.

mamoose124 · Mar 31, 2016

oLD lIMEY

What Stromberg (Model No, etc) did you install on your Alpine? I'm thinking of replacing my Weber and, perhaps Stromberg's would be the way to go. Would the model you installed on you car work for my 1962 Series II?

George Coleman · Mar 31, 2016

The Weber is the way to go if you don't want to be correct. They are easy to work on and once you set it up thats it, I can not say enough about the Weber conversion which is a good replacement for the Solex PAIA carb.

Here are parts and supplies venders.

http://weberjets.com/

http://www.webercarbsdirect.com/

http://www.piercemanifolds.com/

http://www.racetep.com/

http://sucarb.co.uk/?utm_source=Bur...ail&utm_term=0_44190cdc60-63f2085778-78333145

mikephillips · Mar 31, 2016

Try contacting Joe Curto to see if he can offer rebuild parts, or even do the work if they need rebushing. No guarantees he can help but he does lots of British carbs.

http://joecurto.com/

oLD lIMEY · Mar 31, 2016

mamoose124 said:
oLD lIMEY

What Stromberg (Model No, etc) did you install on your Alpine? I'm thinking of replacing my Weber and, perhaps Stromberg's would be the way to go. Would the model you installed on you car work for my 1962 Series II?

They are CD150s, you will also need a throttle linkage, see pictures. When picture is there click left or right to see carbs and linkage. I saw a linkage on ebay the other day. Tony.

http://s261.photobucket.com/user/beebelbrox/media/motorcycle art CD carbs 059.jpg.html

bernd_st · Mar 31, 2016

No Italian nor SU carbs on an early Series Alpine. Can help you with the shafts if interested.Send PM please.

SoCal'beaming · Mar 31, 2016

mamoose124 said:
Thanks, David for the reply. I contacted SS and they don't have the kits in stock and don't know when they will have them. Thanks for the URL on the carbs. As it happens, I already have that pdf. In fact, that document does verify that my carbs are the same.

If you learn more about where to get parts let me know as I would really like to get the original carbs back on the car. I sent an email to the Zenith in the UK in hops that they may have repair kits. We will see.

Hi Mike .... Thankfully my SII's Zeniths were in good shape and all they needed was a complete kit(2nd owner car) ... Not sure if you have these leeds/links but I'll post 'em anyways .... I've been thinking about these if mine ever go south, though I'd like to stay original. http://www.v-performance.com/products/air_fuel.html

Here's the others

http://www.sunbeam.org.au/?page_id=787

http://www.carburetters.co.uk/index.php

... I'm always Looking!

..... David

chazza · Mar 31, 2016

Interesting link about the Mikuni carburettors David!

I run 40 DCOE's on my car, which for a car that only runs on the weekend, are quite adequate and fun to use.

A pair of Mikunis to replace them would set me back about $2000 though

For that money I would probably fit a Megasquirt system and fit injectors and get better performance,

Cheers Charlie

RootesRooter · Apr 1, 2016

mamoose124 said:
oLD lIMEY

What Stromberg (Model No, etc) did you install on your Alpine? I'm thinking of replacing my Weber and, perhaps Stromberg's would be the way to go. Would the model you installed on you car work for my 1962 Series II?

You would be the first Alpine owner I know of to go from a Weber back to Strombergs. 'Set it and forget it' has a whole lotta appeal.

mamoose124 · Apr 1, 2016

Weber Carb

RootesRooter said:
You would be the first Alpine owner I know of to go from a Weber back to Strombergs. 'Set it and forget it' has a whole lotta appeal.

The problem is my Weber no longer stays in tune. I have tuned it over and over getting it working beautifully. Then, within 50 to 100 miles, it dies at a stop light. You have to pull the choke out to get the Revs up so it won't die while waiting for the light.

I think the idle screw and throttle screw are worn to the point that they will not stay set and back out over time with vibration. So, I either need to purchase a new Weber or something else. I don't like the Weber because all the adjustment screws are inboard next to the hot engine and manifold. It is difficult to get screwdrivers in there and it is hotter than blazes. Dual carbs like the original Zeneths or something similar where the adjustments are outboard of the hot engine and manifold seem like a good idea to me.

At this juncture, not being terribly knowledgeable about these things, I am looking for alternatives. So, any good suggestions would be appreciated.

SoCal'beaming · Apr 1, 2016

chazza said:
Interesting link about the Mikuni carburettors David!

I run 40 DCOE's on my car, which for a car that only runs on the weekend, are quite adequate and fun to use.

A pair of Mikunis to replace them would set me back about $2000 though
For that money I would probably fit a Mega squirt system and fit injectors and get better performance,

Cheers Charlie

Hi Charlie .... It's definitely a unique option .... I like the look of the 40 DCOE's much better then the Mikuni's .... I bet not many Sunbeam folks have seen Mikuni's on an Alpine though

... I'll look into the "Megasquirt" you spoke of .... sounds interesting. http://megasquirt.info/products/diy-kits/ms1/

.... David

NoBigTing · Apr 1, 2016

WANTED ZENITH rebuild kit

Please help me find a RBUILD KIT for my 1962 Sunbeam Alpine. Iam in Atlanta Ga. Thanks.

bernd_st · Apr 1, 2016

The only guy who used to do rebuild Kits for the Zeniths in UK doesn't have stocks anymore. Don't think anybody else has them at the moment. On the other hand the top gaskets can be home cut from normal gasket paper and the center ones can be cleaned and reused. Can help with the spindles as mentioned earlier ( throttle, Accelerator pump & Choke).Send PM if interested...

chazza · Apr 1, 2016

mamoose124 said:
At this juncture, not being terribly knowledgeable about these things, I am looking for alternatives. So, any good suggestions would be appreciated.

If I was in your shoes; for a minimum of fuss, whilst at the same time gaining some very good performance, I would buy a matched pair of weber 40DCOE's with a suitable manifold, such as the one Redline makes.

DCOE's are very easy to tune and adjust; all of the jets and other parts are easily available; the throttle spindles don't wear because they run on roller bearings and there are excellent books on the subject, which make learning about them and working on them a doddle. Send me a PM if you need more information.

The only downside is that they are not cheap and the manifold cost me $550. They are cheaper than Mikuni, however. Also; there is very little room for any air-cleaners; I managed to squeeze some sponge bug-catchers onto mine but they will not filter dust, so I keep away from gravel roads.

If you want stellar performance, programmable fuel-injection and a programmable ignition system, the Megasquirt is the way to go. Most of the parts can be salvaged off an old car, or purchased quite cheaply, except for the computer, which can be pricey if someone else makes it for you, but it is possible to build your own. Cost is about the same as pair of new DCOE's if you buy everything new. I have programmable ignition on my car - Megajolt - which along with the DCOE's works very well.

Downside is the time spent learning the system online, but your car can be programmed using a laptop computer. It also looks modern but like most things it is possible to camouflage the modifications; I recently saw a car which had DCOE's in place but not functioning, with fuel injectors fitted on the manifold side. The DCOES were used as throttle butterflies only. It also requires modification or replacement of the fuel tank and fuel delivery system. Doing something like this would only really be worth it if you use the car every day, which is why I haven't bothered,

Cheers Charlie

alpine_64 · Apr 1, 2016

chazza said:
If I was in your shoes; for a minimum of fuss, whilst at the same time gaining some very good performance, I would buy a matched pair of weber 40DCOE's with a suitable manifold, such as the one Redline makes.
Cheers Charlie

Charlie, if it was minimum of fuss, you would switch the single down draft weber setup. That's also available new with new manifolds from several vendors, secondhand rootes setups and now a newer ( and very ugly) performance version from webcon UK. That's the easiest way to convert get reliability, performance and minimum fuss.

2x dcoe for most people are not straight forward if they are of limited mechanical ability. Also while jets, chokes etc are all available they are not cheap and you need 4 of everything. There are ball park guidelines but they do vary.

Then there is removal or modification of the scuttle brace in the intake side.

Also you are rhd, the left hand drive setup also can have issues with steering box and m/c clearance.

I love dcoes and was very happy when I got mine setup correctly. But they are not the easiest or most straightforward setup you can switch to....

They are the best looking, sounding and performing though

beamdream · Apr 2, 2016

mamoose124 said:
Thanks, David for the reply. I contacted SS and they don't have the kits in stock and don't know when they will have them. Thanks for the URL on the carbs. As it happens, I already have that pdf. In fact, that document does verify that my carbs are the same.

If you learn more about where to get parts let me know as I would really like to get the original carbs back on the car. I sent an email to the Zenith in the UK in hops that they may have repair kits. We will see.

I`m one of those folks who likes to have some of the originality under the hood; as a Series 1 owner the twin Zeniths are quite workable so long as you don't have throttle shaft leaks, the gaskets you can make yourself and there is not a lot else to them, yes a bit of fiddling with syncing the throttle plates but that goes for any twin setup.

I agree the single Weber 28/36 is an excellent set and forget option for durability, reliability and minimum upkeep, but I just like the period look and sound of the Zeniths when they are working right.

Just my 2 cents.

bd

alpine_64 · Apr 2, 2016

beamdream said:
I I just like the period look and sound of the Zeniths when they are working right.

Just my 2 cents.

bd

A fair 2c ... I drove with the Zenith's daily for 7 years... Apart from the issues you mentioned they also have a habit of ovaling the throttle body around the butterfly and need to be bored out and new butterfly made ( much the same as with the throttle spindle issue) they also always weap fuel due to the way the body is designed ( like period 4bbl Holley's) ... If ... And it's a big if .. You rebuild them correctly and her them synced and balanced they sound good and perform well... But getting them to that point isn't easy and they still had a sketchy rep in period.