Hi Guys,

I have been searching around the board for a while but I'm struggling to find similar symptoms, so I have had to resort to posting again

I have recently been getting quite high fuel consumption. I did a full test today. I drove 60 miles, all highway, around 56-65mph sort of mark in my 1960 Plymouth Belvedere. Turns out I only got 14.6mpg (US gallons) This car has in the past returned well over 20mpg, usually around the 21-22mpg mark. I know a chromed, finned 1960 Plymouth isn't going to achieve the same sort of performance as a Feather Duster but 15mpg is not exactly good for my wallet, and she used to achieve far better.

I checked the plugs, they seem to indicate a slightly rich mixture but possibly nothing too drastic. The exhaust when idling tends to smell feintly of fuel. Also, when starting up, I get a slight soot deposit in the exhaust water vapours.

The engine appears to be running fairly cool, the ambient temperature today was about 70-80F and the radiator temperature just cracked 170F. Is this exessively cool? I'd prefer to be around the 200 mark.

My setup is pretty stock. The carb is single barrel BBS2985S, and alas wears a remanufactured sticker, but has worked well in the past. I understand this carb is for the manual transmission, though mine is an automatic.

It has a stock points distributor (I will upgrade to electronic when funds permit) with (as far as I know) no means to modify the vacuum advance. Pulling the vacuum hose (which is connected to the intake manifold, I thought they were supposed to go to the carb) has the revs die off, so it's definately pulling vacuum.

Since I am in the UK and short of money, I thought I'd ask the guys here before shooting off to order tools, parts, kits etc for anything. I'm suspecting either ignition advance or somthing running too rich. I thought I'd ask you guys first before diving into the problem. I'm low on cash and don't want to start blaming anything and ordering parts/kits/tools etc without a second opinion.

As always, your help and advice is greatly appreciated.
Thanks alot,
60Ply

Yup. Put in a new 180°F thermostat.
First-year carburettor...relatively primitive in terms of metering and such. They get the job done OK, if they're built up and adjusted correctly, though later carbs can give better economy.
No significant differences between the two; the vacuum spark advance port's location is slightly different.
The vacuum advance must be connected to the carb, not to the manifold — this, together with the maladjustments required to make the car start, idle, and run with the improperly-connected vacuum advance, could easily take a large bite out of fuel economy. Hook up the vacuum advance correctly, then reset your basic adjustments for tickover speed and mixture, then check and adjust ignition timing with the vacuum advance disconnected and carb port plugged, then reconnect the vacuum advance and do a final tickover adjustment.

Which spark plugs are you running?

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hey Dan,

I thought the manifold mount was a little unusual. Whereabouts on the carb should the vacuum hose be connected? I don't seem to be able to find a hose take off.

Also, for future reference and eBay scouting/swap meet searching, what carb would you recommend? Gas mileage is my highest priority, but again, I have limited funds at the moment.

I shall get back to you about which plugs shortly.

Thanks for your help,
60Ply

It is usually down on the 'base' of the carb, near the idle mix screw... in the later carbs it can be at the base or on the 'side' of the body depending on year and type.

Good luck,

-D.Idiot

So a little further investigation didn't do any harm. It' funny what you discover people have done when parts are unavailable and some unorthodox ingenuity apparently takes over.

I am guessing there should be a screw in adapter that takes the vacuum hose from the carb. When I pull on the throttle lever with my finger over the threaded port it is definately drawing vacuum. I can't believe this wasn't even plugged, unless there was a plug that has gone missing recently. I am guessing that sorting this will have somthing of a significant influence on the general operation of the engine.

Does anyone know what thread the adapter into the carb should be? I can machine one far quicker than I can have one delivered if I know the thread.

Also, the hose from the manifold, should I just plug that? Out of interest, what should go there? There is a boss in the casting on the intake (Number 6 cylinder) that appears to take somthing.

Again, thanks for your help,
60Ply

The reason why it's hiding from you is that in '60-'61, original equipment was a semirigid white nylon pipe with an inverted-flare fitting at the carb and at the distributor vacuum advance. It threaded in at each end like the fuel pipe connects to the carb. Starting in '62, a rubber hose was used instead, with a simple push-on nipple fitting. It's likely somewhen along the line your vacuum advance was replaced and the original threaded type couldn't be located. This meant using a rubber hose since the new advance had a push-on nipple, but the carb had none, so if you will look on the distributor side of the carb, about halfway up, you will likely see a plug of some sort threaded in. Unscrew this and replace it with an inverted-flare-to-hose-barb fitting. Or, simply install a short piece of steel brake pipe of — I don't recall — whichever diameter has the correct threaded fitting, then saw off the brake pipe to create a hose nipple.

UPDATE — we must've been posting at the same time. Yep, you found it. Guess they didn't bother plugging the carb port . As I say, I don't recall which standard steel brake pipe size has the correct threaded fitting, but it's one of them. 1/8" or 3/32", most likely.

The manifold vacuum tap was used on cars that have vacuum-operated heater/defogger systems. Your '60 should fall into that category. There should be a vacuum hose coming through the firewall if so. If your heater/defog has been failing to change modes when you push the buttons, now you know why! Other uses of this vacuum tap include providing vacuum for a brake servo and, on later cars, providing manifold vacuum for the operation of various emission control devices. On applications without any vacuum-operated accessories, a plain plug is threaded into the boss.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hi Guys,

Made a new fitting for the carb, have the vacuum hose hooked up as it should be. Having some trouble setting the idle. I can have the idle drop off through being too lean, but no matter how much I back the screw off I can't have it drop off for being too rich, before the screw appears to come out. Engine doesn't seem to respond much to whatever I do to the mixture.
Also, the throttle arm seems to foul the manifold when closed, so the revs may be a bit on the high side, quite possibly why the engine is so insensitive to adjustments at idle. Will get some numbers when I have borrowed a tacho.

Back at home (should be there in a week) I do have another carb, not sure what it is, but I'm pretty sure it's another remanufactured job. Came boxed with the car when I bought it.
In all honesty, I think I would be looking at a more modern carb set up and electronic ignition when I can afford it. This engine seems to have a lot of funny idiosyncracies that have been put in over its years in the UK and the more I can sort the better.
Recommended set ups/threads for economy? I'm only looking at carb/distributor combos, engine is in too good condition for a rebuild. And any recommendations for anyone who can supply the bits at a reasonable price are welcome.

Last of all, I have a Bosch distributor. I understand these are for Aussie slants? When were these first used, my engine is a 1960 in a Canadian built Plymouth (original right hand drive, makes #6 plug difficult to get to!).

Once again, thanks for all your help,
60Ply

Some carbs are like that...but given the other nonstock hookups you've described, I wonder if somebody has tried to create a PCV (closed or Positive crankcase ventilation) system. What's connected to the rear chimney on the rocker cover, and where does it lead?
That's certainly interesting and odd. Makes me wonder if maybe a thicker gasket is needed between the carb base and manifold.
Good plan. I may have a new (not "remanufactured") carb for you; is your throttle operated by a pull cable, or by a rotating rod?
Yep, those were used in Australian production from '63 through '70. Yours is likely from a '66 Australian VC model, as those were the only Australian Valiants sent in significant numbers to the UK.
Oh, cool, I didn't know you had a right-hooker!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hi Dan,

The crankcase ventilation is stock, I am running the original road draught tube. Incidentally, would there be anything wrong with fabricating a cap to fit this and take a PCV valve? With the valve cover off I do get some crank case fumes coming up whilst adjusting valves etc. Would prefer some ventilation when standing still (or backing up!).

The part of the throttle arm that fouls the manifold isn't necessary on my set up. It's that squareish bit with the hole in it (technical jargon), presumably for a different throttle set up. There's a small flange in that hole that fouls the manifold.

I would be very interested in buying the carb from you. Could you PM me some details? I am not sure what you mean by rotating rod or pull cable though. I have a torque rod running along the firewall behind the engine. Rods and bell cranks connect this to the carb. The throttle on the carb is connected to a bellcrank that pivots on a bracket mounted to the manifold, just under the carb. It is connected by a pullrod, basically a bent lump of steel. There aren't any cables, but there isn't really a rotating rod either (except the one on the firewall, but that appears to exist to transfer the motion from the right hand side. Right hooker again!).

I think she's a right hand drive because she was intended for Jamaica. That's where she was imported from in 65 anyhow. There's a 1960 four door hard top Fury around here that I believe has a similar story. No Slant six though [/quote]

Kuh-razy! I'm not familiar with the early RHD throttle control arrangements. Have you got a digital camera? Can you take and post some pics of your throttle setup so I can figure out which carburetor(s) will fit and work correctly with minimal hookup hassles?
Surely. First please see here, then post or e-mail pics of your throttle control arrangement, then we'll move forward on which carb to pick.
Ahhh...I think we've found the cause of your engine's tendency to smoke from the crankcase. RHD car from Jamaica? Pass de dutchie on de right-hand side and all (Wait...what? )
It'll be much easier to do so once you've put in a carb equipped for PCV.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hi Dan,

I have sent you an email with some pictures, to the email you use on the carb pages. I am afraid I still haven't mastered photo posting.

Thanks alot,
60Ply

There's quite a lot to see in these photos. Somebody's installed a late-production American-market inlet manifold (can't tell if it's iron or aluminium) in place of the 1960 original, and a late-American-production exhaust manifold as well. Your manifolds appear to have been installed with other than the correct span washers; it's a fairly good bet you've got some vacuum leaks at the manifolds-to-head junction, so is likely worth your while to R&R the manifolds using the good gaskets for the manifolds-to-head and the intake-to-exhaust (heat riser/hotbox) junctions. The span washers can be difficult to find, but they aren't impossible; I'll work on that. The original 1960 choke thermostat is used, which works OK but not great on the later exhaust manifold; there are better choke configurations (Kit #1231). You'll want to do the fuel line mod. The carb itself isn't the worst I've ever seen, but has seen better days and has been "remanufactured" at least once. It is spilling petrol from the bowl vent.

The throttle linkage appears to have been cobbled together entirely by hand, especially that bracket mounted to the flange where the EGR valve would've bolted onto the inlet manifold in this late inlet manifold's genuine application; the car's original inlet manifold had no such flange. The air cleaner attaching ring appears to have come from a parallel Earth in another dimension; I'm curious what sort of air cleaner is fitted.

I do see the throttle lever/inlet manifold interference you mention. I'm not sure what's causing it, though a thicker carb base gasket would fix it. Whatever which carb you wind up with, you will have some reëngineering to do on the throttle linkage. Shouldn't be a major operation, it's just that you'll be trying to hook up a carb looking for any of several factory linkage setups, to a linkage setup that I don't think came from any factory. If things get totally dodgy (ahem), I'd likely be tempted to take advantage of local resources and ring Burlen. They make and stock a good range of carb linkage parts (rods, pivots, bellcranks, etc.) with which you could rework the worst of that Rube Goldberg-y hash of a throttle linkage and build something cleaner and less problem-prone. Those bits used to be readily visible on their website, which they've completely revamped, as it seems, and I can't currently find them. (NB it's entirely possible at least some bits of your present linkage were cobbled together by hand at the factory...RHD models can't've been a giant priority at the time!)

(Lest you think I'm only noticing bad things, somebody has installed a later tandem brake master cylinder. A disc brake item, as it seems; I wonder if any changes have been made at the wheels.) Other questions to be answered in e-mail.

Your photos (downsized for connection-friendly posting) are posted below, per these instructions:

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hi Dan,

I should soon have the original intake manifold, the previous owner is sending it on. Using the original intake manifold would necessitate a rebuild of the throttle arrangement in any case. I would prefer to use the current exhaust manifold though, they are big old lumps and shipping them over isn't cheap. I'd intend to have the two manifolds bolted together and then lap the faces on a large surface plate till they were flat. Is that a reasonable way to go?

Yes the throttle arrangement is a little unorthodox, but I have never had a problem with it in use, seems to work quite effectively, if a little inelegantly. I feel I could design a pretty workable alternative to this however, a little more robust and reliable. Having said that, if it ain't broke . . .
I understand the original used the rotating bar arrangement? I see no reason why I couldn't produce somthing similar, though the firewall is simply a single flat sheet. I think that was done in 1994, when the car was given a complete restoration, so there are no mounts for the torque rod etc.

I would like to upgrade carbs, I would prefer to run a PCV to a road draft tube if nothing else. I'm guessing throttle configuration will depend on the type of carb, or vice versa.

The air cleaner is not the original. It is much flatter, though I do have an alternative which I believe is correct for this car. I shall post pics when I return to Bristol.

Also, I'm not sure if you did email me or not. I certainly haven't received any email.

Once again, thanks for all your help,
60 Ply

Nice. If it's in good shape, go ahead and use it if you like. It's made out of aluminium. There's nothing wrong with using the inlet that's on there now, mind.
Nothing wrong with that; they're actually preferable (less crack-prone).
Or some variant of that process, yeah. When you install the manifolds, they get bolted together loosely, then installed on the head, then the two get tightened to each other.
Yup, all upsides and no downsides to that.
Not yet, had to dash out for a doctor appointment, then stopped at the local for a pint and a bite.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hmmm,

My Rube Goldberg throttle linkages appear to use up some valuable bellcrank space. It appears I have no (!) rod going from the firewall mounted bellcrank to the transmission (Torqueflite 6) due to the unusual throttle linkage. Fine for a manual transmission but not for my auto. The car seems to upshift a little early on but I have never noticed any other problems. The again I am a fairly relaxed driver. This seems to be a strange way to fix a car, I find problems and then start asking what the symptoms are
What problems should I be experiencing, given no (apparent) link between throttle and transmission? Does the throttle linkage work to activate the kickdown?

Either way, I am definately going to be having some fun with steel, welders and drills to make some proper rods. I reckon I can do a pretty good job of returning the throttle arrangement to a more left-handesque arrangement with a torque rod.

Ever optimistic, I am looking forward to getting alllllll of this sorted, I was pretty happy with performance anyway