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Post by dave1800 on Jan 31, 2018 10:21:21 GMT
As long as you only take off the outlet cover (and have a new sealing ring available) then you can clean the filter without risk of flying springs etc.
If you feel more ambitious you may want to dismantle the pump and check the diaphragm and seals as they can deteriorate more quickly with alcohol in the fuel. Don't attempt it without a full overhaul kit though. Remember the seal stops the fuel finding it way into the sump (gearbox) so be careful.
If you have a pressure gauge you could check the pump is delivering the correct pressure and holding it steady to give you some idea of whether an overhaul is needed now.
An in-line renewable filter before the carb is a good and cheap investment and also allows you to see there is fuel without disconnecting anything.
David
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Post by paddymk2 on Feb 2, 2018 20:13:19 GMT
Remember these Triumphs and MGBs with their inline engines had hot air from the radiator being blown onto the carbs and the MGB (& I believe the Triumphs) used phenolic spacers between the manifold and carbs. This wasn't considered an issue with the crabs, hence the alloy spacer(s). As Andrew A has overcome a vapour lock problem by fitting the phenolic spacers on his high output and therefore hot running engine that looks like a good and cheap fix - it may even cope with 42C  I would worry about the wet cloth catching fire! David In that case when the Austin is at idle and the air is only being drawn through the engine bay by the (slowed) fan, wouldn't air also be drawn up past the hot exhaust and over the carby rather than blown away from the carby. The more I think about it the more I feel that the original lump of metal wedged in there as a heatshield might have helped. |
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Post by dave1800 on Feb 3, 2018 2:00:30 GMT
The air will be drawn from beneath the car, from around the front of the engine and grill and as you say from the hot exhaust over the float chamber, so that lump of metal acting as a heat shield most likely helped, but maybe only compensated in part for the wrong crankcase breathing set up.
What you need to consider is that the heat may cause vapour locks in the pipe leading to the fuel pump, the fuel pump itself, the pipe from the fuel pump to the car, the float chamber and the small diameter nylon pipe from the float chamber to the jet.
A weak pump would be more prone to not being able to overcome vapour locks especially on the inlet side. In fact the Mk1 cars used electric fuel pumps (mounted at the rear of the car) which can be less reliable but do not suffer the same way as they are not trying to suck fuel from the tank. If the float chamber fuel has evaporated the electric pump will chatter as the ignition is switched on and the float chamber refilled. However, as MGBs used electric fuel pumps and suffer vapour locks a change to an electric pump would only address part of a potential problem.
Routing of the pipes is important to keep them as far from the exhaust manifold as possible. You have already cleaned out the float bowl and jet pipe.
Remember also that many issues attributed to the SU carbs actually relate to the ignition system. A coil that is below par may prevent starting. (Also applies to the condition of the rest of the ignition system, distributor cap, rotor arm, plug leads, plugs etc. After a car has parked and the hot soaking taken place, on cranking the initial fuel delivery may be poor if the float level has fallen and the corresponding weak mixture needs a stronger than normal spark to ignite it.
But, getting back to your car without the PCV the mixture will most likely have been wrong. I would suggest that when you get the PCV components that you keep the set-up as standard. If it still suffers vapour lock work through each item. If you have a spare good coil that is the easiest thing to change, then check the fuel pump holds vacuum on the inlet and outlet (can test with a finger over the pipes if you don't have a gauge). You can then consider the phenolic carb spacer to replace the aluminium one and a heat shield for the float chamber.
Anyone else from a hot climate have any more ideas?
David
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Post by andrewa on Feb 3, 2018 9:02:18 GMT
No, but agree with you, one step at a time. Good luck!
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Post by dave1800 on Feb 3, 2018 10:19:34 GMT
I just found this, see posts #69 and #70. Post #73 suggests that in Australia with temperatures in the high 30s (degrees C!)that a well maintained Healey shouldn't suffer from vapour lock. One thing to remember is that a retarded ignition can raise the temperature of the exhaust manifold considerably - even make it glow cherry red in extreme cases. Also probably worth letting the engine idle for a couple of minutes if you have been driving hard to take some of the heat out into the exhaust before switching off. David Fuel vapourisationDavid |
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Post by paddymk2 on Feb 3, 2018 12:09:27 GMT
Hi - that link makes interesting reading and it does suggest that its easy to get too far ahead of yourself with solution - before getting the basics sorted. The Healy guy did have the standard heat shield and a new radiator. The car had previously been located inland in a very muddy/dusty environment so the radiator would have had a lot thrown at it. But I did get the radiator recored at www.southernradiators.com.au/ and that's as good as its getting. But I'm still of a mind that why not add the heat shield and phenolic block. I'm not really intending to drive on the 40+ days, but 30 yes. And yes I do live a the top of a hill and am familiar with letting my saab turbo cool down. Just out of interest is there any measure of L/s or CFM that should be expected to flow through the radiator? Paddy |
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Post by dave1800 on Feb 4, 2018 1:24:11 GMT
I agree no harm in fitting the phenolic spacer and a heat shield. I've not spotted any figures for the water pump output vs rpm. The insulating sock for the float bowl #70 in the link sounds interesting and I've heard good things about Joe Curto SU "koozies"There is also some interesting data on the MGB cooling system here www.mgb-stuff.org.uk/coolingtext.htmDavid |
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Post by dave1800 on Feb 4, 2018 23:50:10 GMT
Just a quick thought as you mentioned earlier there was not much air flow from the fan - the blades haven't been put on backwards by any chance? What is the gap between the crankshaft pulley and the blades?
David
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Post by paddymk2 on Feb 5, 2018 13:42:41 GMT
I was wondering about that. It does seem to be really ineffectual compared to a cheapie house fan. When I was putting it on it only fitted one way otherwise it seemed to foul on the radiator shroud. I had another look and it is the same as in the car manual. Sci Manual.pdf (234.32 KB) |
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Post by Penguin45 on Feb 5, 2018 17:51:20 GMT
Blowing outwards....
Chris.
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Post by dave1800 on Feb 6, 2018 1:30:36 GMT
It will still blow outwards I think at much reduced flow if on backwards?
David
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Post by paddymk2 on Feb 6, 2018 20:56:29 GMT
So does the fan fit backwards?
And other than that pic on the front of the manual is there a diagram showing orientation?
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Post by dave1800 on Feb 7, 2018 1:35:09 GMT
The best I can find is in the Oz Mk1 parts list. I can't find a fan on the UK parts list for Mk1/11 or 111 cars anywhere and there's no description in any of the BMC/BL w'shop manuals I own! Here is the link, under the engine section. A1800 workshop manualIt's not that clear and if anyone can post a photo it would help. It's possible over the years that a fan from another B series engine could have been fitted. I know the one from the Austin Cambridge (Freeway) my friend owns here can go on backwards. I believe the Oz water pump pulley is smaller diameter than the UK ones - not sure if the fans were the same. Looking through the Oz TSBs there was only one report about possible vapour lock but it was noted that it wasn't an issue with the 1800s (on the fuel in the 1960s) David |
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Post by paddymk2 on Feb 8, 2018 7:35:20 GMT
fan orientation.pdf (366.79 KB) Ok - so the fan is definitely in the right way round (actual blade are closest to radiator and frame is closest to the engine.)
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Post by andrewa on Feb 8, 2018 9:56:31 GMT
Good luck with your list of things to check / amend and obviously the right thing to do is get everything back to as good as new and go from there.
On my car I'm still on the original fan - have got into the habit of leaving the winter stat in (laziness- nothing else) with a little hole drilled in to do away with any possible air locks.
The gauge itself was checked when I had the speedo recalibrated as the speedo was all over the place.
The hottest the car has been is stuck on the motorway in a traffic jam for an hour in 35 degrees - very slow moving -if at all for some periods. The temp gauge gets a long way up but not into the danger zone at the top.
If the cars idling in the garage for a long time (15 mins or more) on a hot summers day (25 degrees c) the guage will go past the middle bar (if that makes sense) but only by a mm or two.
If the car is being worked really hard (flat out)but is fast moving it'll stay in the middle N range and then creep up a tad if you're then stationary - so I tend to let have a rest for a bit to calm down!
The cars got a new sender, an oil cooler (for what it's worth) and the aforementioned phenolic blocks.
At the risk of sending you off on a wild goose chase, quite a few owners have modified their cars with an electric fan - or even an additional rad at the front to help things. So some find it necessary and others not.
If you end up going down this route at some point in the future - after you've done the other bits..IMHO a neat arrangement is to keep the original fan in place and install a small electric fan on the other side of the rad to help suck the air though. It has to be small as there's not much room and just switch it on and off as required.
Hope this is of some use!
Cheers
Andrew
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