Amazon: Swopping a Zenith 36VN to a Weber 34 - Any views?

[Othen]

Originally Posted by fishyboy

Hi all,
Given the rather leaky nature of the Zenith 36VN on my 1966 131 (https://www.volvoforums.org.uk/showthread.php?t=336115 and https://www.volvoforums.org.uk/showthread.php?t=312839) I am thinking about replacing it with a Weber 34 (https://www.skandix.de/en/spare-part...4-kit/1022670/), which seems to be a straight swap for the B18A engine.

Only minor modification is required to the rubber seal with the Volvo air filter and the actual filter (https://www.skandix.de/en/documents/...er-34/3000188/).

Has anyone any experience of making this swap. I found only one reference on the forum (Willsapples - https://www.volvoforums.org.uk/showthread.php?t=334485) but was rather hoping other users might have made this swap.

One question I have is that the Weber 34 has a 34mm throat size (where it joins the manifold) whereas the VN36VN is 36mm. Presumably this difference of 2mm should not cause any issues.

Phil

There has been some interesting discussion here Phil... here is my tuppence worth. I've just read your other thread, and my course of action would have been exactly as you have done: to get the original Zenith 36VN working properly. You seem to have achieved that (well done), but you still describe the issue as a 'ticking time bomb' - so you still aren't happy with it.

If that were my situation I certainly wouldn't start fitting other 50-60 year old Volvo carburettors, manifolds, controls and exhaust parts - the chances are that some of them wouldn't work properly and lead to an even more complex problem with non-standard parts on your Amazon. In that case the best solution (in my humble opinion) would be to fit a modern direct replacement (the Weber 34 you suggest, and a correspondent (Willsapples) in the discussion above confirms is a good fit and has worked well for the 10,000 miles). I notice the cost would be around £300, which seems expensive (to me, but then I'm a tightwad), but as it is a direct replacement there will be no further integration costs.

So, if it were me I'd stick with the original Zenith (now that you have fixed it), but if you aren't happy with it I'd go for the modern replacement (Weber 34) that a member of this excellent forum has confirmed is a direct swap. I certainly would not countenance fitting a twin choke carburettor in the hope of squeezing a few more horsepower from motor - that would be an expensive mistake.

I should add that I do not have any direct experience of this issue: my Amazon has the B18D motor with twin SU carburettors (which are easy to adjust and work very well - just as Mr Volvo intended 60 years ago).

Alan