Did Volvo ever sell the 140 with a single carburettor on a cast iron manifold with the dual exhaust? There was such a manifold listed on Ebay lately and I'd like to track one down closer to home (listing was Canada - I am in New Zealand). I have a 63 121 wagon but I am more likely to find parts from 140 series cars here. Amazons are pretty rare here.

Hi Neil, I tryed emailing you but it bounced, I have a manifold but are you trying to put a downdraft zenith on a 2 branch exhaust? because that won't work, the manifold fits stromberg and SU carbs.
Cheers
Hans

I have tried to email you using the address on your post without success. I live in Oz and have the gear you need to do this job.

Email me on mcclark1@bigpond.net.au

Tim Clarkson

In Australia, the single carb B20A became wide spread in 1973 when Volvo Australia seem to only sell base model DL B20A Auto cars with no frills, or GL B20E Auto. B20B 4-Speed cars in 73 or 74 are rare by comparison which was sad because nearly all the early models are B18B or B20B 4-Speeds.

You don't want a single SU/Stromberg manifold because they are terrible. Much better of with a twin manifold, it will still match the fuel economy of the single, but give more power. If you have a B20A and fit twin SU's, you would use B18D needles for the A cam model B18D (B18D had A or B cams)



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Three 164's, Two 144's, One 142 & a partridge in a pear tree.

Thanks for this answer. I am actually looking for the manifold for the B18A engine on my 63 Amazon wagon which currently has the original single zenith carb and single outlet exhaust. I have a selection of parts including a cast iron manifold with twin inlet/dual exhaust, a separate single outlet exhaust and a single alloy inlet manifold. I have a pair of SU's that are in need of a re-build and new needles. I just pickup up a new dual downpipe for a 940 which has the same flange and just requires a bit of cut & paste to shorten the vertical pipes by 100mm.

As my car is a vital second car it can't spend too much time dismantled. That is why I'd quite like to do any upgrades in a stepwise manner. If I can find a single carb/dual exhaust manifold, then I can upgrade the exhaust first and see how it goes before converting to twin SU's. I also understand that twin SU conversion alone is pretty pointless without putting in a better cam. I suspect that single carb with dual exhaust will offer some improvement in performance and economy over my current setup. Any comments?

I suspect that single carb with dual exhaust will offer some improvement in performance and economy over my current setup.

Yes it would. Practically anything you do to the exhaust side of the engine will give you some 'free' horsepower, but it would make a lot less difference to an engine with an A cam in it.

As my car is a vital second car it can't spend too much time dismantled.

It's only a dozen nuts to take what you have off & bolt on the twin SU setup to play with linkages & exhaust pipes, then swap back when you are sick of playing around.

The money you spend getting hold of a single SU manifold is a complete waste that could have been spent overhauling the SU's or getting a new exhaust system.

I have a pair of SU's that are in need of a re-build and new needles.

What needles are they? Are the late model SU's with floating needles? The fixed needles practically never wear out since they never physically touch anything.

I have.....a single alloy inlet manifold.

A single SU or a single Zenith downdraught? Sounds like you need actually need a B20E exhaust manifold if you really want to stay with the single Zenith downdraught.


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Three 164's, Two 144's, One 142 & a partridge in a pear tree.

Thanks for your comments.

My thinking with a two stage approach is that I don't think I can fit in replacing carbs, manifold, cam and exhaust system in a weekend along with family commitments. My SU's are also a long way off being usable. I do however have a rebuilt Zenith that will bolt straight on. If I can find a manifold to suit the single zenith and dual downpipe - I could replace the exhaust system and do that conversion easily in a weekend. Consensus seems to be that going from single to dual exhaust will be beneficial regardless of cam or carb mods.

The SU's I have are the earlier type with fixed needles - the problem I have is that the needles are missing. I also don't have the throttle linkage or the split choke cable system - another reason for not doing the full conversion just yet.

Correction on the alloy inlet manifold - I said "single" - I meant "separate". It is in fact a twin SU alloy inlet manifold. A B20E exhaust manifold would be a match with the alloy inlet and I did have one at one stage - on a 1972 142E parts car. I robbed the car of the overdrive and sold the rest to someone who wanted to set it up as a race car. I should have parted it out and kept the engine as well but I am sure you all appreciate how accumulated crap always grows to exceed storage space (much the same as expenditure always grows to exceed income).

The SU's I have are the earlier type with fixed needles

I prefer those, even for HIF's. If you get needles with hats, you can knock them off & sand a little of the knurling down to fit the fixed hole. There is a table I have seen somewhere that lists every needle used in A, B & C cammed B18B & B18D's that have twin SU's, but I'd likely get KD's (115HP 10:1 B18B), they seem to be close enough for anything up to a stock B20E.

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Three 164's, Two 144's, One 142 & a partridge in a pear tree.

If you're after economy the single Zenith is about as economical as a 120 will get. I quite like them, better than I like the single Stromberg in fact. The issue with the Zenith nowadays is that the casting of the carb distorts and they get very fussy about sealing to the manifold.

Twin SUs will work acceptably well with an A cam B18A. However if the camshaft is original I'd lay money that it is fairly well worn.

Personally if I went down the road of changing the camshaft, I'd do the whole lot in one hit. The head has to come off to change the cam. At that point you might as well change the manifolds and swap on the twin SUs. I don't see any real merit in an intermediate step with a single Stromberg.

The Volvo single and twin downpipe systems are identical, apart from the downpipe itself. The B18B or the B20 for that matter didn't get a bigger exhaust. One of the biggest changes you'll make is to put on a bigger exhaust. The most economical solution is the Simons kit which is now also available to fit the estate. That comes complete with a downpipe that actually just fits the car.

The B18B or the B20 for that matter didn't get a bigger exhaust.

I don't know what 120's had, but 140's got 3 different sized exhausts. The B18B/B20B cars got a 2" exhaust practically identical to the Simons system & B20E cars got a 2.125" exhaust.

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Three 164's, Two 144's, One 142 & a partridge in a pear tree.

For some bizarre reason the 120 never did, the exhaust on a Zenith carbed B18A with a single down pipe is identical to the exhaust on a twin SU B20B from the downpipe back.

yes they did, i think for some European markets and probably Canada. My 74 144 has the single carb setup with dual exhaust downpipe. Try Australia. They might have them over there. I am in Malaysia, and parts are far and few in between here, but I'll keep a lookout just in case.
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...and the bricks keep on rolling

Yes. that's the standard B20A. Probably more 145's than 144's have that spec but common on both body styles from the start of the B20 engine.