Author Topic: Upgrading my carb to a new Weber 32/36  (Read 590 times)

jon3000

  • Veteran
  • **
  • Posts: 61
  • Pilgrim 3000 Owner /Builder
Upgrading my carb to a new Weber 32/36
« on: January 17, 2021, 11:59:34 PM »
I have never been that happy with my 28/30 carb which I got with my donor engine. The engine is a 2 litre pinto as far as I knew these carbs were only fitted on 1.6.   I have started the process of upgrading my carb from an old 28/30 to a 32/36. It seemed pretty straightforward but the project is growing arms an legs! The car always seems to drink fuel so I am hoping to get a payback in fuel saving eventually ( at least that how I justify it!). 

The port on the manifold looks exactly the same as the old carb but the studs are not the same spacing! its close enough that simple adapter plate did not seem on the cards but now I am beginning to wonder about that! . I sourced a secondhand manifold on ebay. The water pipe connection was corroded and snapped in my hand when trying to get the pipe off. But I successfully transferred the vacuum  port connectors.

I am using an old Mototcraft ESC2 Ignition system, and it had a air intake heater and a temperature sensor, I have transferred the temperature sensor but the heater will never fit. The stepper motor was never present on my carb so no change with that.

So now I am considering removing the ESC2, which would also mean replacing the distributor to one with a vacuum advance but I am staying focused on fitting the carb for the moment.

The throttle linkages are a similar but different also the cable seems to be riveted to the spindle and threaded through the main part of the bracket. So I am currently trying to make changes to the linkage with it still in the car, although as I type this I am thinking perhaps I may be able unhook it from foot pedal and pass the cable in that way.

I have yet to consider the choke but I hope that will be the easier.

I will let you know about progress, when I  get a few of the new parts
« Last Edit: February 01, 2021, 11:03:49 PM by jon3000 »

Nigel Haldane

  • Full Club Member
  • Breeder
  • *
  • Posts: 330
Re: Upgrading my carb to a new Weber 32/36
« Reply #1 on: January 18, 2021, 06:45:01 AM »
I would try and keep the electronic ignition, they give better starting and there is little to no maintenance. Throttle cable and little things take time to get right.
Nigel Barnicle Midlands Area rep,
Midlands meeting, Please contact me and we can arrange something.

jon3000

  • Veteran
  • **
  • Posts: 61
  • Pilgrim 3000 Owner /Builder
Re: Upgrading my carb to a new Weber 32/36
« Reply #2 on: January 24, 2021, 01:00:40 PM »
Well, the new carb is in. The car starts fine (with the choke). Its pretty cold outside, its warmed up to -7C just now. I thinks its actually colder in the barn. I still need to top up the coolant as changing the manifold required reducing the coolant level.  My main concern is that the manifold gasket keep the air and water separate once it warms up and pressure starts to build.

I managed to modify the linkage to mate with the manifold and carb. The little plastic bushing on the small throttle shaft fell off a few times, and has now gone missing!. A second hand one is £10 +postage on ebay! So instead  I bodged something temporary with a small plastic cap, then ordered a tiny brass reducer and an M10 Brass nut, and I will make it into brass bushing for less than half the plastic crap!

Hi Nigel, I plan to keep with electronic ignition, its just that the ESC2 is a lot more complicated than just electronic ignition,It and its also probably 30 years old. I am only using a few of its features, as it is capable of controlling  stepper motor for idle control,  a heater and temperature sensor. It also has a vacuum port, so my distributor has no vacuum advance as it is done by the "magically" by the ESC2.  That said everything seems to be working great, so there appears to be no rush. It would take a while to unpick the ESC2 from my loom but it  would greatly simplify the wiring to the engine, with less to go wrong.
« Last Edit: January 24, 2021, 01:04:30 PM by jon3000 »

jon3000

  • Veteran
  • **
  • Posts: 61
  • Pilgrim 3000 Owner /Builder
Re: Upgrading my carb to a new Weber 32/36
« Reply #3 on: May 11, 2021, 11:31:03 PM »
I thought I should followup my experiences since the last post. I found that the pinto would run rough until it warmed up then it was fine. I kind of assumed it was just because of the cold weather, and needing a bit of choke adjustment.

However when it failed to improve with the weather. I tried removing plug leads one at a time. I found some made more difference than others. So the engine was not running on all cylinders equally, but running improved while driving.

Prior to upgrading the carb I had noticed 3 of the plugs were running rich and number 4 was lean to normal. Later I realized  the brake servo take off, (on the inlet manifold beside plug 4), was leaking making plug 4 leaner than the rest.

So decided to investigate and improve the engine running, I checked compression, I adjusted all the valve clearances. I checked the distributor and rotor arm changed the plugs leads and coil. Changing the coil improved things a little and I had a stronger spark but were not the issue.

I came to realize that the new inlet manifold was leaking,  (tested with a spay bottle of isopropol). I had bought the correct manifold for my carb secondhand on ebay. Whilst it looked great and was clean and shiny, on close inspection I found an issue, I placed a straight edge on the manifold. I found that it undulated at the fixings, clearly at some point it had been cranked to "11" and now instead of being held tight to the engine block the fixing points ensured that the was no compression of the gasket in the areas that counted, particularly on cylinder 1&4 where I had leaks.

Initially I thought about getting it skimmed, however I decided to have a go with leveling it with hand tools and some engineering blue as my guide. I used a plate of glass as my surface table. I have to say it worked better than I expected, it was not perfect as the glass was not perfectly flat but the curvature was gentle enough that it could be accommodated when tightened.

I did not want to go through the exercise again so I used a little smear of RTV on the gasket just to be sure  it would not leak again.

The improvement was very noticeable. I still had some classic "Weber" hesitation after first starting but it ran perfectly soon after moving off.

One of the things I did when installing the new carb was move the vacuum advance to the carb rather than the manifold. This is the recommended position, it did have the effect of retarding the timing at idle compared with before. After a bit of investigation I found that advancing the timing often helps with hesitation, I advanced the static timing from about 10 to just over 12, I noticed the idle speed picked up quite a bit, I think this indicated that not all the fuel was burnt 10 degrees.

After that I readjusted the carb idle and mixture screws again.

Taking the car out today and yesterday I can say it has improved a lot, the hesitation is reduced but still somewhat present for a short time  <  a mile .

I learned a lot since I started working on the carb/timing and I thought I would pass some of this on here.







« Last Edit: May 12, 2021, 12:02:08 AM by jon3000 »

Tom Burton

  • Full Club Member
  • Breeder
  • *
  • Posts: 149
  • such a nice man
Re: Upgrading my carb to a new Weber 32/36
« Reply #4 on: August 10, 2021, 07:19:43 AM »
Thanks for the update Jon
In my ignorance, I thought that like my Marina engine, the smoothing out when it was warm might have been due to the coke warming up and keeping it running 😏.

How’s it going now and are you getting much use out of it?
Tom & his Toy
aka Chairman Tom

jon3000

  • Veteran
  • **
  • Posts: 61
  • Pilgrim 3000 Owner /Builder
Re: Upgrading my carb to a new Weber 32/36
« Reply #5 on: August 14, 2021, 08:18:44 PM »
Hi Tom,

Thanks for your interest.

Its been going really well, I have clocked up about 2.5K miles so far this year driving it to work quite often. I have to be careful now as I took out limited mileage insurance at 3K miles. I think I will need to increase my allowance for next year :)

It is running really well now, it really is starting to purr now having thoroughly blown away all the cobwebs. I have been calculating the mpg as a measure of how the engine is running it seems to be 27 mpg. which seems good to me. I checked all the plugs a few weeks ago they all look perfect, and each very similar now so I am happy. I got the carb dialed in a bit better after I refitted the manifold

Its still a little uneven at start, I think the idle is a bit low at start up, but it settles in after a few mins.
.
It used to be uneven and with smell of unburnt fuel that's all gone now

Regards Jon