News:

SMF - installed December 2017.
Returning members - please use the 'Forgot Password' function when logging in to the new Forum for the first time. If you have changed your email address please let me know so I can update it.

Main Menu

Carburettor synchronizer?

Started by TTM, December 06, 2016, 08:56:07

Previous topic - Next topic

ivs

Hi,
P78 is the float setting tool for Solex carburetors, but not for 32PBIC, rather for 40 PIIs. I do have P78 and I'll check this afternoon if it works on my spare set of 32PBI-6. For sure the level will be different but could be marked beforehand. P78 is available at several Porsche spare sources.
Ignacio

TTM

Hello,

Nevermind the level engraved on the P78 level tube, it shouldn't be too difficult to use it with a Solex 32. Does yours come with room to fit the main jet?

Looking forward to hearing if yours fit your B32-PBI6 carbs. Thanks for checking.

ivs

So, I spent some time checking out this topic:
I took the Bristol 32 BI carb, a Porsche 356 32 PBIC and a Porsche 356 40 PII-4 from my stock,
As well as tool P-78. This is what I found:

threads: interestingly enough both German 32 PBIC and British have metric 8x1.00 starters so the attachment for checking the bowls would be the same. 40s have a different M11x1.00 that matches P-78 tool.

So in theory you could machine an extension M8 to M11 to use the tool. There is an M7x1.00 extension available, that is for the zeniths also used on porsches 356. At this point I also had a look at the factory preA and A model workshop manuals as those are the models that used the 32 solexes.
The method for adjusting the fuel high in the bowl is the traditional which involves taking out the top cover.
I also checked the potential attachement to P-78 to the 32's....the lowest level indicated by the tool will still be too high compared to the maximum that the 32 will need. So the tool is not usable.
32s have way smaller bowls compared to the big, deep bowls of the 40's needed for the S-90/SC/912 series and P-78 was design for those clearly. Also there is a good reason for this tool as 40s do have an outside bolt to regulate the float high without taking apart the top cover.
So, long story short, P78 won't work and in fact won't make much difference as you need to remove
the cover anyway.
Ignacio

Flyinghorse

#33
In the recent past I  have used a set of 3  main jet holder covers modified (drilled and brass tube soldered in ) for clear plastic hose to be attached that you clip vertically on the carb body  --they were lent to me by a fellow Bristol enthusiast and he had made small clips to hold them all upright. It worked quite well though crude and bear in mind the engine (in a Bristol 400) is on an incline anyhow.

How do you know that its not the needle valve thats faulty, or perished washer?  I just looked at a old needle valve I have spare & disassembled and its also possible for debris to trap there if your inline filters are not working.
I have also had the actual float get pin-holed in the past and it just sinks and the car ( a lotus elan on webbers 40) just runs super rough all the time.
It sounds like you have a more subtle issue though more detail might help. A lot of the fuel rails /washers are prone to leakage if not assembled correctly.

Speaking to a knowledgeable friend tonight he also mentioned that the height should be adjusted by different washer thickness rather than bending the tab.

Graham

TTM

Good morning,

Excellent information and feedback, thank you very much Ignacio and Graham.

I will remove all 3 carb covers and proceed with an in-depth inspection.
I may ask a mate with a lathe to turn proper fittings that would sit in place of the main jet holders, with provisions for connecting plastic tubes.

TTM

Good evening,

It turned out that the flooding issue was simply caused by a leaky needle valve in the second carburettor.
I replaced all three with new ones and adjusted them to the same height in their respective covers as the previous two fuel-tight ones and the problem disappeared right away.