last year I accuired a re-coned Weber 36DCD7 and manifold from E-bay as the twin Strombergs/Rapier engine combination that were in the car when I got it last year are a mess (amongst other things only the rear carb is connected to the choke!). the car failed its MOT last week as one of the problems was a leaky exhaust (head to manifold). My Question is....
1. Would this be a good opportunity to fit the Weber?
2. Is this a good move?
3. Will it fit the Rapier head ok?

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Sadly they appear to be rarer than Rocking Horse poo now but David also recommends in his book the Weber 32/34 DMTL which may be available and might give similar results. As mentioned earlier the 1592 Series 3/4 manifold will be needed along with modifications to the manifold cut out to remove the bridging piece and open out the the orifice. You may find one through the club mag, or someone might just have an old unit in amongst stuff they're selling at the National. They will be highly sought after.

Try Ebay

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I'm not sure what 'Sunbeamowner' is saying is rare.
If you have a Weber carb which came with a manifold to fit the Alpine/Rapier engine (and they are the same), give it a go. If it's supposed to be water-heated, try without - your Stromberg installation won't have the water feed/return provisions. You will have to figure out some throttle linkage mods I guess.
Eddie Zetlin, and others, certainly say that the twin-choke downdraft Weber - notably the 28/36 - work well. I can't say whether the 36DCD7 will be as good.
Note that SV Strombergs are fairly easy to find, so if the Weber is no good, you should be able to fix the Strombergs and the exhaust manifold. You can get a stainless steel replacement, but the iron one is almost as good - and quieter.

[quote="Chris Barker"]I'm not sure what 'Sunbeamowner' is saying is rare.
Sorry for the confusion but I was just replying to Major Ed Spin on the "Rarity"of these carbs. Ebay has a kit for auction on a regular basis.

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Also just to put a cat amongst the pigeons. What does the forum think of this set up ?

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Hi eddie, I'm in the middle of reworking a Holbay head, I down loaded a chamber mod from the Vizzard Bible, checked the scale was correct by the size of the valves, then stuck the paper to a sheet of steel. After cutting it out & drilling the holes for the valve stems to locate it in position, in some places it is allready bigger(in the head) than the template. The original page specified this diagram was for the 1725 cc alloy head. Advice needed as weather to proceed or not. Have already flowed the head as per the Chris Mcgovern book.

I have the book, and it says that the mod is not suitable for a Holbay as most of the modifications have been done

Hi Dave, Your Holbay head already has had plenty of material removed from around the Inlet valve, so this is is going to help gas flow considerably. Arguably any more material removed now will yield only a very small increase in flow since the valve is not shrouded anymore.

The danger is by removing more material you will induce stress cracking between combustion chambers and possibly the water jacket as well causing reliability problems. The size of the exhaust to inlet looks to be optimal as well, so I would say this is a good rework anyway. Holbay knew their stuff. I would concentrate now on raising the compression ratio ( 10.5 to 1 max ) and also investigate the use of Rimflo valves which should yield better flow than the standard items. Don't use too strong a valve spring if your valve train is not up to it, the whole thing is a tad on the fragile side at the best of times. Keep head ports the Holbay size too, don't get tempted to open these out, it has a negative effect. Good Luck with it let us know what happens.

By the way guys the rarity object is the Weber 28/36 DCD. Out of production, for a number of years. There are still plenty of Twin Choke Webers suitable for us though, the 32/36 DGAV being the most promising. I took my new one in it's box to the Sunday meet of the Surrey group and I could have shifted a lorryload by the reaction I got.

Dave, try one of these on a 1592 manifold with no water heating, on your rebuild, bet you won't take it off again.You can fit a number of plenums or air filters to this carb with no bonnet fouling. A cold air intake to the grille will ensure dazzling performance.
Hope to catch up with you all at Warwick.
Be There.
Regards Ed

As a further note to all, the subject of cams came up yesterday, I would advise keeping the cam standard. The use of longer timings and overlaps on even the fast road cams tend to kill the bottom end whilst adding very little at the top end. With it's standard cam any Alpine performs very well right up to the red line whilst being very flexible at the bottom. Pulling cleanly from 20 mph in top gear. This is one thing Rootes definitely got right, adding higher compressions to this set up yields far more than breathed on cams. Perhaps we'll have a thread on cams later, but as Vizzard notes " The manufacturers have far more R&D budget available to test different cam grinds than the likes of Piper and Kent and rarely get it wrong. The best cam ever made for the A series for e.g. actually came from B.L. and there were hundreds made by everyone, Uncle Tom Cobbly and all."
Makes sense really.
Regards Ed

OK this is off topic but it illustrates the way David Vizards book makes my mind work in relation to obtaining more hp from the Rootes engine.
In order to get more air and fuel into the cylinders, we make the cylinder head flow more easily.

This is a lot of work, and it has to be done very carefully or we get blown head gaskets or worse, cracked heads. Forget superchargers and induction ramming for a moment and think about valve lift. If we could open the valve further there would be better flow, so how do we achieve this. Well remember the Mini Cooper ? There was a really neat mod done on the cast iron rockers, which looked a lot like ours. The work went like this :

Remove the phosphor bronze bush, enlarge the hole in the casting, and then replace with an oversize eccentric bush that moves the pivot slightly towards the pushrod, ream to suit rocker shaft. Drill out the bush oil holes.

The rocker now provides more lift from the same camshaft, and better breathing without touching the head. The only thing to watch out for is valve springs becoming coil bound but this is pretty rare.

For the A series you can buy 1.5 Ratio Titanium Roller Rockers that look like a modern work of art, a simple bolt on mod that provides large power increases across the board. Wouldn't it be nice if we could do that too ?

Best regards Eddie

Well I went ahead and fitted the Weber. What a difference! The vibration has gone , the tickover is spot on, the power is way up and she runs much sweeter. Still a bitch to start from cold though.

I take it you mean the 36 DCD7 ? Yes the cold running bitch is about right. The 28/36 DCD suffers the same problem.
So that means you got it right !! Enjoy
I'm hoping that the 32/36 DGAV has this problem nailed since the choke mechanism relies on two simple strangler flaps.
Simple usually works better.
Regards Ed.

On the subject of valve lift, is it possible to do this mod on our rockers?
Are there any other rockers that could be used, or would the re manufactured mini "work of art" be a candidate for conversion?

Dave
Roller Rockers are available at

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I noticed them the other day.
It might be worth noting Jarrids comments on the SAOCA about them though.
Pete

Before you all rush off to change your rocker ratios, give some thought to the fact that the valve-train loads and the cam pressure will rise with the SQUARE of the ratio. So +15% will increase loads by over 30%.
And those nice roller rockers are £30 each

Even I'm amazed this sort of stuff is available for our "little " car. A word of caution though as Chris noted. Our valve train is on the fragile side so the eccentric bush idea is not that good. It wasn't successful on the Cooper either, which is why forged rockers came about. As for the Roller rockers, these are certainly not the sort of thing to buy on a whim.

You need to do your homework ( Buy Vizards book , all this sort of thing is discussed in minute detail ) I'm just trying to illustrate the sort of ideas that can start making you think out of the box.

You need to know exactly what you are trying to achieve and the best way to economically bring it about. I'm not that taken with the billet aluminium idea for a rocker arm for eg. If you ever venture into valve crash ( remember what Chris said about stresses multiplying, well he knows what he's talking about I can assure you ) the result won't be pretty. This is why Titanium is used for the definitive article. You wouldn't have a lot of change out of £500 for this type of set up.

Then you need to factor in the special hollow push rods that are required to drive them.
So don't rush out to do this just yet. There are other cheaper routes of getting better air inhalation so we'll move back on topic now.
Regards Ed