Weber carbs

[Flakey]

Evening
Does anybody know of a reason why I wouldn’t be able to fit triple Weber’s to a Raymond mays head in my aceca, I’ve seen images online of them fitted to Aces but can’t see any pictures of an Aceca
Thanks
Fintan

[dkp_cobra]

Fintan,
there is no reason. Look here: https://www.ruddspeed.com/rsx5501.html
Peter

[James Eastwood]

I have a Mays Mk3 head but no Weber manifolds, so I'm interested in this thread. I know the correct carbs are; 3 x Weber DCOE 40  (30mm choke, 110 main jet) or 3 x 1& ¾ SU. As specified by the Homologation document;

https://historicdb.fia.com/sites/default/files/car_attachment/1601035801/homologation_form_number_67_group_gt.pdf

I've never seen the Weber manifolds for sale, there was a web site advertising them, but I don't think they're still in business. Does anyone know of a source? I should be able to get a manifold scanned at work if there was a volunteer to loan one. This might enable people to have a set laser sintered or fabricated to at least hold the carbs in the correct position.

Also looking at Homologation document the Camshaft has 248 degrees duration which looks a bit short for a sports application, it's probably the standard Ford cam. Does anyone have any guidance on a better cam and how to get hold of one? Plus I have no information on what the exhaust manifold should look like.

Of further interest perhaps to some, is a chap on Youtube who takes one of these engines out to 2.9L, with a +0.120" overbore and a 4mm offset pin stroke increase. General consensus from some hot rodding forums is that a 0.125" overbore is the limit.

https://youtu.be/quw64BqWZks

Regards, James

[James Eastwood]

I've just caught up with the 'Zephyr 6 parts supplier' thread and have written to Chesman Motorsport with a manifold enquirey.

If anyone would like to loan a manifold to be scanned the offer still stands.

James

[Klassik Metall]

I'm currently working on RSX 5501 & can confirm that Webers were fitted on this car from new together with a Mays head.
The only real difference on the 2.6 cars was a different throttle pedal that uses a cable rather than a rod linkage.

Weber manifolds for Mays heads are available from Webcon in the UK but they are somewhat chunky looking when compared to originals.

Newman Cams, also in the UK can regrind the original Ford cam to give a useful power increase. Their regrind has a duration of
260 degrees, which they state puts the power within a useable rev band for a road car. The valve timing for this cam is 20/60/60/20

The exhaust for the Mays head was either the twin iron "Y" style manifolds or separate 3 into 2 steel headers.

Lastly, the YouTube video is interesting but I'm unsure why they're going to all that trouble & expense for such a small power increase.
These engines can easily make good power even with the iron head but the limiting factor is the original main bearing caps that crack
down the middle & the useless original clutch design. Both these problems were long ago solved by the late Greg Margetts of Competition Engine Services.
He once told me that a properly prepared engine with a flowed Mays head easily made 220 BHP, all without overboring or crank stroking.

Regards Luke.

[10kph]

Hello,
         do a Google search for Don Pither. He has a couple of books about Reliant Scimitars and Sabres.
    He produces some rapid 2.6 Sabres and gave me useful information about the 2.6 tuning. He also supplied correct Mays headgaskets. Your starting point is a mk3  block with the best crank, steel maincaps, Mays head with Ford Essex valves etc  with 45 deg seats and can be enlarged. 260 deg cam and it will rev safely to 7000.
        The steel caps are simple to make and cheap.I still have one which was a spare. It consists of a piece of steel 1" x 1!/4" section x 4 1/4" long with the cente 2 1/2" machined down approx 3/8" with holes for the main bolts either side. The maincaps have their bolt faces levelled and the raised centre section skimmed down to give a flat section approx 1" wide so that when the new steel cap sits on top there is 1-2 thou clearance. The clearance is essential to prevent loading on the bearing but the maincap still has some ' give'. Maincap studs need to be 1" longer and I think they came from the  Essex or 2.6 headbolts.
   Years ago a club member produced some webber inlets.
      Tony

[Flakey]

Speak to Chris at Chesman, they cast the inlet manifolds, I’ve just got a set of carbs and manifolds from them

[taffe9]

Unfortunately Don passed away some years ago, sad.
Regards

[James Eastwood]

Chris at Chessman sent me the prices for the Raymond Mays parts including the Weber inlet manifolds.

@ Klassic Metall Ref the Youtube video I can only assume the owner of the engine was going for torque rather than power, at one point the engine builder mention that the engine is to be used with a single carb (to each their own). You mentioned clutches, what is the clutch problem solution pls?

Thanks for other info gents.

[Klassik Metall]

Yes, I saw in the comments that the Youtube engine is only going to run a single down draft Weber, that just makes all the other modifications seem even more strange!
As you said, to each their own.

Greg Margett's clutch modification was to machine off the deep rim of the original flywheel, (which has the additional benefit of lightening it) and re-drill/tap new holes
for a larger diameter diaphragm clutch. The original bronze spigot bush was also changed to a suitable bearing. Of course this also means changing the release bearing
and modifying the operating fork slightly.

Greg used to sell all the parts needed for this conversion and I believe the clutch pressure plates were specially made to his specs. In the past he had also experimented
with fitting stronger coil springs in the original clutch, to stop it slipping on tuned engines. The results weren't very good however and resulted in a very snatchy engagement
which he thought would soon break the transmission.

[James Eastwood]

Duly noted thanks.

I'm not big into originality when it comes to clutches, I'd fit a diaphragm clutch, which are lighter and more readily available. Something like an uprated TR6 clutch plate which is also 8.5" might be a good donor. I have an uprated 8.5" MGB clutch on my Bristol engine, it does mean changing the dowels from two to three though.

Those Zephyr flywheels are massive by today's standards, I wonder if not only was the car heavier, but with post war fuels not being so consistent, perhaps the large flywheel smoothed out the odd incomplete combustion event?