From: TMo5018257@aol.com
Date: Sun, 1 Nov 1998 17:06:05 EST
Subject: [imps] Re: Carbs
RE air intake on Mk1 -
I think what Nick means is that there is the pipework built into the Mk1 exhaust manifold for hot air transfer to the automatic choke, which come to think of it could possibly be used to 'pre-heat' the air coming into the carburettor.
Trouble is that I'm not using a standard exhaust manifold (and I don't think I've got any more Mk1 manifolds).
I have got an 1.25inch SU with a modified manifold to fit the Imp (not one of those elbow-type adapters, as they seem to have icing problems too). I remember previously that it ran rather rich, indicating that the needle was wrong. Has anyone any ideas about correct needles?
Cheers,
Tim.
From: Nickcleak@aol.com
Date: Sun, 1 Nov 1998 18:09:28 EST
Subject: [imps] Re: Carbs
> there is the pipework built into the Mk1
> exhaust manifold for hot air transfer to the automatic choke, which
> could possibly be used to 'pre-heat' the air coming into the carburettor.
that may help but are there any auto chokes still around in working order ?
I meant the dual position of the air intake snout as described in the ROOTES workshop manual ...
Nick ...
From: Nickcleak@aol.com
Date: Sun, 1 Nov 1998 18:09:26 EST
Subject: [imps] Re: Carbs
Hi Gary ,
> No, it didn't.
Yes it did !
Have you a workshop manual ? It mentions the hot and cold position of the air intake snout ... the hot position is as you mentioned below ..
> The snout of the air-cleaner went to a "specified" position
> just forward of the engine. [...]
I guess the temp of the air going into the snout in the hot position would be around 50 degrees C ... it's between the two exhaust manifold branches ..
The air filter casing would be heated by other radiated means so little heat would be lost ...
> One 'invisible' tactic would be to [...]
Hmmm as long as the heat didn't soak into the carb causing bad hot starting due to fuel vapourisation . I know there is a heat insulator flange ...
But wouldn't the standard metal type gasket transfer enough heat ?
I still say convert to twin Strombergs if you can , they do everything better ...
Nick ....
From: Gary Henderson
Date: Mon, 2 Nov 1998 13:03:06 +1300
Subject: [imps] Re: Carbs
Hi Tim
That pipework is indeed present on auto-choke Mk 1s, but has an OUTSIDE diameter of 1/4" . Not much air flows through there....
Cheers
GaryH
From: Gary Henderson
Date: Mon, 2 Nov 1998 13:58:20 +1300
Subject: [imps] Re: Carbs
Hi Nick
I sort of generated a reply on another message, before this one came down:
I'm about 2 km crowflight or 6 km by road from my workshop manual right now, but the Owner's handbook has no mention of a 'winter' position; mine was usually in the position exactly as given in line illustration #6964. I've had to slew it a couple of degrees outboard now to clear the manifold-heater feed pipe.
The Haynes manual has a sectioned drawing of what I presume to be the later aircleaner (element common to Triumph 2000TC and some models of CF Bedford) but has a photo similar to Rootes #6964 for installation, showing the earlier air cleaner.
The prescribed snout position is not a long way from #4 exhaust, but seems oriented mainly to minimize inhalation of road-spray.
The heated manifold will have little effect on the full-throttle airstream, but ensures that any petrol droplets that get deposited will be flashed off at once. It doesn't leave little drips of diluted oil from the manifold drain now.
I don't see heat-soak from the head as any more likely to vapourize fuel in the carb. than from a water-regulated (better term, Rienk?) manifold. Also, the bottom of the Solex float-chamber is only connected via a plastic tube to the lower throttle-body.
Aren't the manifold-gaskets filled, with just metal outers? And probably (unless very recent) with asbestos? (I haven't disturbed my one since 1987.)
Forgive me pursuing this particular game to the death - it's just that I think the original Imp team knew what they were doing, so its only in a few fine details where things are actually 'wrong'. I still suspect that deliberate differences in pump fuel between NZ and UK may also have had an influence.
Cheers & thanks for your thoughts
GaryH
From: Gary Henderson
Date: Mon, 2 Nov 1998 13:18:27 +1300
Subject: [imps] Re: Carbs
Hi Nick
I'm interested in your last comment. My w/manual must predate the arrangement you mention. The early models had a simple straight-snout which went to a position just forward of the head.
My auto-choke is in semi-working order. Besides the fast-idle linkage mechanism having bagged out the 'bearings' in the housing, some @@#$* swiped a near-new choke-cover & spring off the car when it was innocently parked one Sunday afternoon. (The culprit must have known they were about $55 each at the time - couldn't get another one.) I got a Ford Laser choke-spring to fit into a 'dead' cover and shortened the lever inside to more-or-less suit.
It works about 80%. I think the water-heated manifold would allow a complete original auto-choke to give fully-acceptable results, and also not to break its main bimetal about every 20,000 miles!
If any of the go-faster crew have a good 30PIHT-2 or -3 that has lain dormant since the twim CDs first went on, I'm interested...
Cheers
GaryH
From: TMo5018257@aol.com
Date: Mon, 2 Nov 1998 04:56:16 EST
Subject: [imps] Re: Carbs
Gary,
>Autochoke working at 80%
Well, Speedy Spares in Brighton have got stocks of brand new autochoke carbs for sale at only £27.50. May be worth a call - 01273 417889... I'm beginning to sound like their PR dept!
Cheers,
Tim
From: Gary and Carol Henderson
Date: Mon, 2 Nov 1998 23:31:04 +-1300
Subject: [imps] Re: Carbs
Hi Tim
Thanks. And the exchange rate of the Kiwi $ against the pound may not be really better, but its less worse! Makes a new carb for $100 sound feasible. Don't suppose you have a fax number or eMail address for them?
Cheers
GaryH
From: TMo5018257@aol.com
Date: Mon, 2 Nov 1998 05:45:33 EST
Subject: [imps] Re: Carbs
Hi Gary,
Speedy's fax no is 01273 412764 - plus whatever the international code is.
They should be able to fax you over a list of the bits they do... and they are fantastic for getting the parts out quickly.
Hope this helps,
Cheers,
Tim.
Date: Mon, 02 Nov 1998 22:12:40 +1000
From: Mike & Tich Marsh
Subject: [imps] Re: Carbs
>> No, it didn't.
>Yes it did !
>Have you a workshop manual ?
Ah! 'energetic' debate... good to see ;) Also that rtfm applies not only to computer subjects :)
For what its worth I can distinctly recall seeing reference to Summer and Winter positions for the 'snout'. But where I read that, I've no idea since I'm pretty sure the export models had no such feature - the air being piped from the front. Perhaps this was a difference between export and the domestic article?
Mike
From: Paul Williams
Date: Mon, 2 Nov 1998 19:21:53 -0000
Subject: [imps] Re: Carbs
>I can recall seeing reference to Summer and Winter positions for the 'snout'.
Well, I've been through the Rootes manual and Parts List and there is no reference to a summer/winter flap. The manual also states that the 'snout' of the air cleaner should always remain in the same position ie. adjacent to the exhaust manifold. The manual may not be relevant to all markets/versions but I think all of the parts are included in the Parts List.
To illustrate this I've attached the relevant pages. (Sorry Franka:-))
Paul.
PS I tried to send the page from the WSM but it would have taken forever (3.96Mb). If anybody wants to see it, let me know and I'll send it to you personally.
Engine and Auxiliaries, Publ.no. 76601640
Attachment: Filters1.gif Plate F, section A (1034K)
Attachment: Filters2.gif Plate G, section A (1034K)
From: Nickcleak@aol.com
Date: Mon, 2 Nov 1998 15:10:08 EST
Subject: [imps] Re: Carbs
> Well, I've been through the Rootes manual and Parts List and there is no
> reference to a summer/winter flap.
My Maual is the Chrysler Version WSM 141 i bought it in 1971
The relevant page is Section C ( Fuel System ) 1st Re-issue Page 23 ...
It's not a flap but an alternative position of the top of the airfilter , It mentions that a new bracket 7100305 with 2 holes may be required .
> PS I tried to send the page from the WSM but it would have taken forever > (3.96Mb). If anybody wants to see it, let me know and I'll send it to you > personally.
I had a strange .mim file which was quite long . how do i read a .mim file ?
If you scan it , the size will need reducing to a .JPG file size of about 50k for a fairly detailed page .
Nick ...
From: Paul Williams
Date: Mon, 2 Nov 1998 20:41:50 -0000
Subject: [imps] Re: Carbs
>My manual is the Chrysler Version WSM 141 - i bought it in 1971
>
>The relevant page is Section C ( Fuel System ) 1st Re-issue Page 23 ...
>It's not a flap but an alternative position of the top of the airfilter , It
>mentions that a new bracket 7100305 with 2 holes may be required .
Yep, I can live with that. I've checked my later manual:-)
>I had a strange .mim file which was quite long . how do i read a .mim file ?
Strange, I sent the two pages as gifs. They came back to me OK!?? I've never heard of a .mim. If you want to see the page(s) let me know and I'll see what I can do:-)
Date: Mon, 02 Nov 1998 22:01:22 -0100
From: rienk steenhuis
Subject: [imps] Re: Carbs
Hello Gary, Nick, and all
> than from a water-regulated (better term, Rienk?) manifold.
Oim so 'appy now ;-)) , I just think that you may end up with too much of a good thing once the weather gets hot.
>Forgive me pursuing this particular game to the death -
I don't mind, I'm curious to see were it leads.
>it's just that I
>think the original Imp team knew what they were doing, so its only in a few
>fine details where things are actually 'wrong'.
I agree!
Sorry about butting in again, but how about fitting a small PGA cooler just above the carburettor inside the airbox? You know the ones that make IC's look like high tech hedgehogs? With the help of a few 5 watt resistors you might be able to get a fair bit of heat into the air stream and fairly quickly too.. The big advantage being that it can be switched off. The main disadvantage, that you would then have a bit of an obstruction in the airflow.
best
Rienk
From: Gary Henderson
Date: Tue, 3 Nov 1998 10:21:31 +1300
Subject: [imps] Re: Carbs
Hi Nick
My manual was bought in about 1968 by a friend who had an Imp at that time.
The Fuel System-Air Cleaner page is original issue; the text refers to Fig 19 which again is the early straight-shooter intake with the smaller filter element. The snout terminates about 4" to the right of the thermostat housing, passes over the #4 exhaust stub (again about 4" above it).
It's interesting that the factory did eventually take some action on this front!
My present solution works really well, but I'd still like a non-visible fix if I could devise one. (Call it a self-imposed loony challenge!)
Thanks for closing the loop on what the factory was up to in the latter days.
GaryH
From: Gary Henderson
Date: Tue, 3 Nov 1998 10:48:42 +1300
Subject: [imps] Re: Carbs
Hi Rienk
Too much of a good thing? But the Imp Sport manifolds were 'water-regulated' properly with cast-in passages. My Dutch NSU-Fiat 770 had all its intake passages cast into the head. And my old carburetted L300 4x4 had a full wet manifold, plus a small water-passage in the base of the Aisan carburettor, as well as the hot-water auto-choke gear.
My bit of trombone-tubing has much less thermal coupling than any of these.
Warming up an old TO-3 hedgehog heatsink in the airway has some appeal.
Great advantage: It can be happening before there is any engine heat at all.
Next stage: Measure the thermal resistance of a manifold gasket...
Cheers
GaryH
From: Gary and Carol Henderson
Date: Sun, 1 Nov 1998 14:53:19 +-1300
Subject: [imps] Re: Carbs
Hi Tim
A Mk.1 Imp Deluxe didn't have the facility for water-heating either. Well worth the effort though. (Mine uses a fairly simple fabricated pipework, clamped to the original manifold.)
Cheers
GaryH
From: Nickcleak@aol.com
Date: Sun, 1 Nov 1998 13:31:44 EST
Subject: [imps] Re: Carbs
> A Mk.1 Imp Deluxe didn't have the facility for water-heating either.
True , but it had a specific hot air intake didn't it , drawing air from around the exhaust manifold ...
Nick ..
From: Gary Henderson
Date: Mon, 2 Nov 1998 09:33:23 +1300
Subject: [imps] Re: Carbs
Hi Nick
No, it didn't. The snout of the air-cleaner went to a 'specified' position just forward of the engine. (OK, maybe the turbulence might have taken some warmth forward that far, but it really was quite some distance from the nearest bit of hot stuff.) A few years ago I tried re-orienting it in winter, so that it sucked from just inboard of the carburettor, in the gap between inlet branches 2 & 3. No operational difference observed! (OK, I didn't take measurements.)
There's certainly nothing resembling the 'stove' provided for a WINTER intake position on Hunters/Avengers/Mitsis.
The recent experiments show that much greater heat-transfer is required than can be achieved by mild thawing of the intake air.
One 'invisible' tactic which occurred to me, would be to replace the manifold gasket (or at least the inlet-side portions of it) with something of much better thermal conductivity, so that heat-soakage direct from the head is greatly enhanced. (e.g. use fully-annealed aluminium?) Could use heat-sink goo from the electronic industry on the interfaces. Probably help airflow as well, compared to the old asbestos-filled gasket.
Cheers
GaryH
From: Nickcleak@aol.com
Date: Mon, 2 Nov 1998 16:57:21 EST
Subject: [imps] Re: Carbs
Hi Rienk ,
Volvo have been doing something similar since 1985 with their 2.3 carb engines, there's a big electrically heated heat sink in the manifold under the carb...
it is certainly worth trying , how about 20w though?
Nick ...
From: Paul Williams
Date: Mon, 2 Nov 1998 22:51:15 -0000
Subject: [imps] Re: Carbs
How about fitting a diesel glowplug? It would probably have the same effect and not block the airflow. Fitting would be fairly simple as all it would need would be a threaded flange (and the wiring, obviously ;-))
Regards,
Paul
Date: Mon, 02 Nov 1998 23:53:21 -0100
From: rienk steenhuis
Subject: [imps] Re: Carbs
Hello Gary
> But the Imp Sport manifolds were "water-regulated"
> properly with cast-in passages.
Yes, and excellent heat-transfer I should think. When I did the measurements on Franka's stiletto, back during the holiday in '95, I would have been very grateful if I could have turned it of ! London traffic, outside temp above 30 celcius, watertemp in the red, general airtemp in the enginebay over 50 celcius, inlet manifoldtemp not measured but no doubt close to boiling, all 3 of us hot and bothered. Defenitely too much.
I appreciate that you need as much heat as you can get in there as soon as possible, which needs very good heat-transfer. But once the manifold gets to 50 or so, I personally think it's time to stop. Mainly because it's very difficult to get the heat out once it's there. Very little airflow there.
> Next stage: Measure the thermal resistance of a manifold gasket...
Are you aware that there are 2 different types? the standard one which is 2 bits of metal with filling inbetween, and the sport one which has just the filling. I don't know what the difference in heat transfer is. Anyone else?
best
Rienk
From: Hawes
Date: Mon, 2 Nov 1998 23:06:23 -0000
Subject: [imps] Re: Carbs
that's: 00 44 1273 421 764 with UK code
Roger Hawes
Date: Tue, 03 Nov 1998 00:14:59 -0100
From: rienk steenhuis
Subject: [imps] Re: Carbs
Hello Paul
> How about fitting a diesel glowplug?
Ehm.... I don't know, wouldn't that be the same as holding a match above the carb? How much do they actually glow? I'm rather ignorant on the subject of diesel engines.
Best
Rienk
Date: Tue, 03 Nov 1998 00:03:06 -0100
From: rienk steenhuis
Subject: [imps] Re: Carbs
Hello Nick
>Volvo have been doing something similar since 1985 with their 2.3 carb engines,
> there's a big electrically heated heat sink in the manifold under the carb
Why am I not surprised? :-)) Is it integral with the manifold or could it be taken out? Might be easier and more reliable than my idea.
> it is certainly worth trying , how about 20w though?
The biggest that will fit of course. It's just that the heatsink I was thinking of is 4X4 cm.
best
Rienk
From: Gary Henderson
Date: Tue, 3 Nov 1998 12:29:12 +1300
Subject: [imps] Re: Carbs
Hi Nick, Rienk, Paul
RadioSpares have a nice line of bolt-down wirewound resistors, up to 100 W rating. If only 20 W is what Volvo find necessary, that's easy to accommodate. (Was it only 20 W, or did they go for 20 A which is about 250 W? If 20 W, just using a small power transistor from the junkbox would be tempting.)
I think keeping the manifold surfaces warmer than the fuel-air stream is probably better both for performance and for behaviour than pre-heating the air to more than about 20 degC.
Paul Williams' GIF files showed a bewildering array of strange new filter arrangements! (Thanks Paul.)
Now my experiment motors smoothly towards summer...
Cheers
GaryH
Date: Mon, 02 Nov 1998 23:54:21 +0000
From: Roger W.Swift
Subject: [imps] Re: Carbs
Just as well you didn't attach another file this lot already took forever
Date: Tue, 03 Nov 1998 20:01:28 +1300
From: Hassall
Subject: [imps] Carbs
Gary
How about Impwerks down here in Christchurch? THey might have a carb available that would work out cheaper. Phone 03 3487979.
Or even Andrew McCrae used to have some bits 03 3495374.
THe Imp Club NZ said in the last newsletter that they were starting to hoard some spares so maybe try Tony Smith 09 8371901 .
Good luck
Matthew
Date: Tue, 03 Nov 1998 22:05:47 +1300
From: Kenneth barlow
Subject: [imps] Re: Carbs
I have got heaps of spare too, if I can help, let me know.
Kenneth
From: Mark Norman
Date: Tue, 3 Nov 1998 10:19:17 -0000
Subject: [imps] Re: Carbs
>>How about fitting a diesel glowplug?
> wouldn't that be the same as holding a match above
> the carb? How much do they actually glow?
[Mark Norman]
Has anyone come across camping hairdryers? - tiny little things that run on 12v. I have seen them used as demisters in kit cars (great for that purpose, because they don't need any air ducting, just wires) How about using one of them blowing into the intake, or for an invisible fit, take the heating element out & mount it somewhere inside the air intake (either before or after the filter).
mark
From: Gary and Carol Henderson
Date: Tue, 3 Nov 1998 21:56:31 +-1300
Subject: [imps] Re: Carbs
Hi Matthew
Thanks for info. I wrote to the Imp Club address some time back, but have had no reply so far.
Date: Tue, 03 Nov 1998 15:25:56 -0100
From: rienk steenhuis
Subject: [imps] Re: Carbs
Hello Mark, all
> take the heating
> element out & mount it somewhere inside the air intake (either before or
> after the filter).
I feel this thread is defenitely turning dangerous. The main purpose of a carburettor is to produce a highly combustible cloud of atomized fuel mixed with the exact amount of air. At certain RPM this cloud will extend beyond the throat of the carburettor. Any proposal to put glowing bits of metal there, is something that I do very much NOT recommend.
best
Rienk
From: TMo5018257@aol.com
Date: Tue, 3 Nov 1998 11:45:29 EST
Subject: [imps] Re: Carbs
Rienk,
I couldn't agree more!
I used to work in insurance, and they would go mad if they found out, especially if there was a fire!
'Water regulated' manifolds - fine. Turning the snout of your air cleaner nearer the exhaust manifold - fine. Glow-plugs, hot heatsinks/transistors & bits of hair-dryer - no way!
This all started because my Nikki carb appeared to be icing - it's not! The crummy air filter (cheapo pancake job) is getting condensation droplets inside and these are dropping down the top of the carb and killing combustion! Any ideas on that one?
Cheers,
Tim
From: Nickcleak@aol.com
Date: Tue, 3 Nov 1998 14:57:22 EST
Subject: [imps] Re: Carbs
> wouldn't that be the same as holding a match above
> the carb? How much do they actually glow?
white hot Rienk ! 900 - 1000 C ?
nick ..
From: Nickcleak@aol.com
Date: Tue, 3 Nov 1998 14:57:26 EST
Subject: [imps] Re: Carbs
> Paul Williams' GIF files showed a bewildering array of strange new filter > arrangements!
I only got a .MIM file whatever that is !
nick ...
From: Nickcleak@aol.com
Date: Tue, 3 Nov 1998 14:57:23 EST
Subject: [imps] Re: Carbs
> Is it integral with the manifold or could it
> be taken out? Might be easier and more reliable than my idea.
yes it's about 50 mm dia and finned on the inside under the carb ...
nick ...
From: Nickcleak@aol.com
Date: Tue, 3 Nov 1998 14:57:29 EST
Subject: [imps] Re: Carbs
> I think keeping the manifold surfaces warmer than the fuel-air stream is
> probably better both for performance and for behaviour than pre-heating the
> air to more than about 20 degC.
yes, bearing in mind the air cools considerably after passing through the carb due to the vapourisation of the fuel .
i believe the manifold heater is about 10A ...
nick ..
From: Gary Henderson
Date: Wed, 4 Nov 1998 10:19:04 +1300
Subject: [imps] Re: Carbs
Hi Rienk, Tim
Me too! My thoughts relating to bolt-down resistors, power transistors or what-have-you relate strictly to the outside of the manifold. Only the use of a 'hedgehog' heatsink would be acceptable anywhere in the internal airstream. (Not even a gross fault would get one of those to glow...)
When I get some spare time, I intend to explore the thermal-resistance of the manifold gasket, and the heat input required to maintain a sensible fuel/airstream temperature, a little further.
Congratulations on your 'free' water-injection setup, Tim!
Cheers
GaryH
From: Kristian Jonsson
Date: Wed, 4 Nov 1998 06:57:48 +0100
Subject: [imps] Re: Carbs
To all you living in to hot countrys!
There has been a lot of talk about preheating the air because of suspected carb iceing. For some reason, some carbs seems to 'ice up' more easily. Like two choke webers. Old Ford Escorts with two choke carb. in 0 to -5 centigrade is something I remember. But here in Sweden we have that weather for a long period. How do we manage?? We just buy a bottle of car de-iceing etanolbased stuff and pour it in the petrol tank. No icing and it mix with water so it will also take away water that can be in the fuel sustem.
You dont have that in the petrol stations?
Kristian Jonsson
Scandinavia
Date: Wed, 04 Nov 1998 08:40:20 +0100
From: Bert Clewits
Subject: [imps] Re: Carbs
Hi Kristian,
Yes I do the same in winter, but I just use blue spirit overhere in Holland called 'spiritus' it works like you say.
No more iceing up in the carbs.
I found that the little solex ices up quite a bit when the engine hasn't reached running temp (with the air intake towards the exhaust manifold)
Bert Clewits
From: Gary and Carol Henderson
Date: Wed, 4 Nov 1998 21:18:26 +-1300
Subject: [imps] Re: Carbs
Hi Kristian
In my case, it is not icing. I'm sure it's just failure of fuel to vapourize properly; some settles on the bottom of the manifold as neat petrol, to be delivered at the wrong time or else to drain out.
Your ethanol must have something else in the brew, to keep it miscible with petrol at low temperatures.
We don't have this stuff available on the forecourts here, not even in high country in winter.
Cheers
GaryH
From: Dave Edge
Date: Wed, 04 Nov 1998 04:02:00 PST
Subject: [imps] Re: Carbs
If anyone is looking for a device to warm the carbs on a cold day. I would think that the ideal candidate for donation is a Maestro, they have a heater element which warms the air going into the carbs. It is one of the reasons behind the unreliability of Maestros because the battery is under a lot of strain whilst the ignition is on and the engine is not running. Should be plently of Maestros in the scrappies though.
Dave
From: D.K. Pitts
Date: Wed, 04 Nov 1998 12:39:46 GMT
Subject: [imps] Re: Carbs
You can have it warm even BEFORE starting the car!!!!
(2 cents :-)) Darryl
>Warming up an old TO-3 hedgehog heatsink in the airway has some appeal.
>Great advantage: It can be happening before there is any engine heat at all.
Date: Fri, 06 Nov 1998 15:07:43 +0100
From: Bert Clewits
Subject: [imps] Re: Carbs
Impers,
Lot's of talk about carburettors and not many positive sounds about the single solex but..
I think (if in good nick) that it has a better cold start then the twin strombergs especially in winter.
I remeber in the sixties there was a renowned car test on the TV and the Imp was the only car which started at -30 degrees at once !
I do agree that they can have many faults, like worn spindels lose parts, failing springs, worn mixture adjustment screws, hardened accellerator membranes, lost copper insets, warped flanges etc.
I remember that many cars with twin Strombergs failed the dutch MOT (APK) on creating to much CO2.
The strombergs on my Stiletto's are OK, fuel economy is slightly better but I don't like the plastic fuel T piece and the sometimes leaking choke mechanism (there is no gasket between the two housings is there !) And they seem to get flooded for no clear reason (when hot)
Any comments ?
Bert
From: TMo5018257@aol.com
Date: Fri, 6 Nov 1998 10:02:44 EST
Subject: [imps] Re: Carbs
Hi Bert,
RE: Solex vs Stromberg
I agree that a Solex has excellent cold starting capabilities, but then the car doesn'y like driving on choke too much, and there is also the problem of stalling a junctions (usually due to a bung-up somewhere).
I also agree that the vast majority of Strommies are pretty worn out by now, after all the spindles run in the alloy bodies without a proper bush and most of them were fitted to 'Sports' models, and therefore usually driven hard.
However, there are a lot of equally worn out Solexes, and they are nowhere near as efficient as a good pair of Stroms. I have driven cars with these 'performance' Solex carbs with 24mm chokes and whilst they are quite impressive, they do lack the crisp but smooth pick-up of the Strom. Ray Payne (the god of imp-tuning) still swears by them, he says that for most fast road applications, nothing touches a good pair of Stromberg CD125s.
Regarding your plastic T piece, apparently MGB twin SU carbs had a brass union that can be cut down to fit with two small rubber link pipes. I haven't investigated this one yet, but it's on my list......
Flooding in hot starting situations is a problem with Stroms, it is usually just down to how they are set up. To be honest, I can never get the damn things right by myself, and I usually have them tuned and set up by someone who knows their stuff. They are are usually fine afterwards.
Cheers,
Tim.
From: Nickcleak@aol.com
Date: Fri, 6 Nov 1998 15:25:02 EST
Subject: [imps] Re: Carbs
> I do agree that they can have many faults, like worn spindels lose
> parts, failing springs, worn mixture adjustment screws, hardened
> accellerator membranes, lost copper insets, warped flanges etc.
> I remember that many cars with twin Strombergs failed the dutch MOT
> (APK) on creating to much CO2.
> The strombergs on my Stiletto's are OK, but I don't
> like the plastic fuel T piece and the sometimes leaking choke mechanism
> And they seem to get flooded for no clear reason (when hot)
and never being able to get the idle speed low enough , sometimes because the spring won't quite close them fully , any stronger and the pedal feels awfull !
I cured the flooding with the VITON (rubber) tipped needle valves ...
The choke disk only leaks if the float level is too high .
I have had a metal T piece for a long time , with proper rubber fuel pipe ..
They are forgiving carbs , make the car easy to drive , they damp out a lot i find compared with a fixed choke carb , you don't get that instant torque from the strombergs , as it takes a measured time for them to lift and supply the quantity of air required , unlike the usual fixed choke carb. Maybe that's why the single solex feels lively ...
Cold start is no problem at all with strombergs , it fires up within half a rev .. you need to adjust the fast idle cam to suit your preference , they all seem to be different !
However the 40 DCOE' s are really the ultimate , they do everything well !
including 45 mpg contrary to popular belief ...
Nick ...
From: TMo5018257@aol.com
Date: Fri, 6 Nov 1998 16:39:48 EST
Subject: [imps] Re: Carbs
Nick,
45 mpg from 40 DCOE's???????????????
What were you running them on, a curly edge MK1??
How on earth did you manage that?
Cheers
Tim
Date: Fri, 06 Nov 1998 15:36:32 -0700
From: Dave Edge
Subject: [imps] Re: Carbs
Nick,
I totally agree about the carbs, if a carburettor is correctly set up it will produce fuel economy to suit the weight of the lead boot applied to the throttle. If you all remember the 60mpg I was getting from my strombergs - well, after fitting the new needles (6f), guess what - I have dramatically reduced that.
Partly because I am currently running backwards and forwards to work with the choke on for about 3/4 mile, but the main difference is that when I press the throttle, it's more fun!
0-60 under 8 secs so far, just waiting for the new springs
Dave
>>However the 40 DCOE' s are really the ultimate , they do everything well !
>including 45 mpg contrary to popular belief ...
From: Gary and Carol Henderson
Date: Sun, 8 Nov 1998 00:10:45 +-1300
Subject: [imps] Re: Carbs
Hi Tim, Bert
Re the plastic T-piece: I don't know how well they last in use, but I do know that a 'brand-new' but long-time on the shelf one split end-to-end a couple of weeks after being put into service.
Small brass Tees can be had from engineers' supplies outfits; use with rubber-hose stubs petrol-proof, and with clips/clamps) as mentioned.
Re Solex-related stalling: If you disable the manifold-heating on the Sport setup, I think you'll find that CDs will stall too. My Mk 1 can idle indefinitely & still pull away cleanly, since heating the manifold.
To obtain CD bodies with least spindle-wear, look to Hunters - they had a decent quadrant for the cable.
What's this about a 'performance' Solex with 24 mm choke? Is this still in a 30PIH body? Anybody know the settings?
Cheers
GaryH
From: Nickcleak@aol.com
Date: Sat, 7 Nov 1998 07:47:30 EST
Subject: [imps] Re: Carbs
> 45 mpg from 40 DCOE's???
> What were you running them on, a curly edge MK1??
998 big valve R 17 in the Clan , i do a lot of long journeys ...
it's most efficient at about 75 mph ...
Below 3000 rpm it drops ...
Nick ...
From: Nickcleak@aol.com
Date: Sat, 7 Nov 1998 07:47:31 EST
Subject: [imps] Re: Carbs
> but the main difference is that when I
> press the throttle, it's more fun!
Yes , of course ! I drive with regard to fuel consumption these days. But it's nice to be able to have fun when possible :-)
> 0-60 under 8 secs so far, just waiting for the new springs
Some spec engine you have ! must be 115 - 120 bhp ....
do you have a low ratio Transaxle ? Maybe not as you got 60 mpg before ....???
The best i got from my 125 bhp turbo was 7.2 sec ... 30 - 50 2.8 sec
( measured with on board data logger )
nick ...
From: CKirkw00d@aol.com
Date: Mon, 9 Nov 1998 14:02:04 EST
Subject: [imps] Re: Carbs/Economy
Boys,
with reference to mpg and carb setups, it is well known to get over 40 with twin Weber and Dellorto carbs. This is when they are properly sorted and the engine is in good tune, driving with relative care also. The problem with the single 40 in your case is that some engine types can favour the single carb and others do not return the same performance. The mini goes well with a single 45.
My Stiletto has a 930cc with a combined inlet/exhaust manifold and a single Weber 40 on a sport cam. The performance figures are excellent, as good as my other cars with twin 40's but the fuel consumption is poor, around 25 mpg no matter how I drive. The reason for this is due to the type of engine causing pumping action within the inlet side. Imagine 4 cylinders drawing from two chokes and depending on how the firing order is.... it may not be balancing.
Remember that these carbs are designed for each choke to feed a cylinder. Andy Chesman did a lot of investigation into developing a head to minimise on the loss due to this pumping action. This reflected in the size of the valves and the porting specially for the single Dellorto. I have a copy of the article he wrote, very interesting.
Colin K.
Date: Tue, 10 Nov 1998 09:30:24 -0600
From: ABryson@sperry-sun.com
Subject: [imps] Re: Carbs/Economy
In normal driving I have always got more than 30 mpg even running the 5.05 top gear. I think the twins are more efficient than the single, I remember a CCC article in the dime and distant past testing single and twin 40's.
Regards,
Andy
From: Gary Henderson
Date: Tue, 17 Nov 1998 09:54:32 +1300
Subject: [imps] Re: Fw: carbs stromies
Hi Dave
I think they have just enough meat to be bushed - haven't done it though.
I have once successfully fixed a 30VN Zenith (on a Series 5 Minx), which definitely didn't have enough metal to take a bush, by reaming the holes out to just round, and sweating brass bushes onto the spindle & having them turned down to fit. (It was the blind-end which chopped out on these carbs, because the bearing-length was shorter than on the lever-side.) This is much simpler than making a whole oversize spindle!
Good luck in the dark cupboard
GaryH
From: Nickcleak@aol.com
Date: Mon, 16 Nov 1998 16:54:32 EST
Subject: [imps] Re: Fw: carbs stromies
I tried to do this in 1973 ... however , fitting the bushes is ok , but they have to be reamed in line , both bushes at the same time to ensure all is in line .. i could never find a suitable reamer , and it was not easy to 'line-drill' both holes so i gave up ..
Nick ..
From: Mark Norman
Date: Tue, 17 Nov 1998 10:10:51 -0000
Subject: [imps] Re: Fw: carbs stromies
I remember a method of fixing carb. bearings given in Practical Classics
a couple of years ago. I can't remember the exact method, and I will
have thrown out the magazine by now, so you might like to improvise on
this a bit!
What this chap had done was (something like) this:
Once the Chemial Metal has set, the spindle can be cracked free, the
washers cut away, and any excess Chemical Metal filed away to give a
smooth surface.
Since I can't remember all the details it would be worth trying this out a couple of times on some scrap metal if you do decide to do this. I think that whoever had done this said that it was quite successful. I'd guess that Chemical Metal probably sets harder than the metal the carb body and so would make a better bearing than the original hole, if not as good as bronze.
mark
From: Remas
Date: Mon, 16 Nov 1998 18:19:21 -0500
Subject: [imps] Fw: carbs stromies
I have a pair of stromies 125s on a standard 875, anyone know if there is a modern version, all this talk of leaking through the spindles has set me thinking.
would it be possible to machine the bodies and fit bronz bushes, I cant have a look at mine - I need to use it for work every day.
If some of you more knowledgable Impers think this is a viable proposition I will try and obtain another 125CD and have a stab at this.
I am toolroom trained and have some access to the machinery, and between me my colleges and the cupbord of extreme darkness I can get the job done.
Dave A