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Oil Pressure/ Ignition Cutoff?
Posted: Sun Nov 06, 2005 12:57 pm
by Packedup
Not entirely Minor related, although if cheap enough I'd be wanting to fit one if/ when I get a Minor
I'm looking for a switch that will only turn "on" when the oil pressure is high enough - So I can use a relay off it to power the coil. That way I hope to reduce bearing wear at startup.
Normal warning light switches are on till the pressure builds up, which is the wrong way round! I think some cars have both types built into the switch, but I'm not entirely sure on that (SD1 efi I think is one of them).
Sorry if that all sounds muddled, I know in my head what I want, but I don't know what to call it!
Posted: Sun Nov 06, 2005 2:04 pm
by RogerRust
You could set up the relay so that it was held off when the oil light was on most relays have normally open and normally closed contacts.
This would be fail safe because you could pull the wire off the switch and start the car in event of a switch faiure. Have you thought about what will happen if the oil light flicks on at tick over - whoops engine cut out. However you could make the relay latching so that it stays in the on mode until the ignition is switched off.
All in all its a bit complicated but possible.
My oil light goes off as soon as the starter turns - I ve just checked, so wouldn't make any difference to me.
Posted: Sun Nov 06, 2005 3:28 pm
by Packedup
RogerRust wrote:You could set up the relay so that it was held off when the oil light was on most relays have normally open and normally closed contacts.
Explain, please
I'm used to using a relay so a low power switch switches a large power circuit, never done anything else with them so not entirely sure how to rig it up to do what I want (if the oil switched worked the other way round it'd be easy).
This would be fail safe because you could pull the wire off the switch and start the car in event of a switch faiure. Have you thought about what will happen if the oil light flicks on at tick over - whoops engine cut out. However you could make the relay latching so that it stays in the on mode until the ignition is switched off.
If the oil light flickers at tickover then I've got more to worry about than having to restart the engine! But yes, I did contemplate setting it to stay on once on. It's the initial bit I'm struggling to get my head round, although I'm sure there's switches out there that would suit me just fine, if only I knew what to call them and where to look
All in all its a bit complicated but possible.
My oil light goes off as soon as the starter turns - I ve just checked, so wouldn't make any difference to me.
I don't currently have an oil light, the previous owner fitted a guage instead. Without backlight, and under the dash where it's hard to see. And it's a Triumph OHV lump, they're not known for havbing robust oil systems and bottom ends! I can try spinning on the starter till the guage registers, then pull out the choke, but that's a bit hit and miss and it would be nice to simply have a switch that takes care of it for me
The pickup takes a moment (well under a second) to put the light out, but then the crank isn't perfect and much against my will it only got new big end shells... So if a cheap solution is available it might be handy to sort that out as well...
oil pressure
Posted: Sun Nov 06, 2005 6:07 pm
by Willie
PACKEDUP....what you are asking for is a system like the pre starter solonoid
Minors i.e. my 1957 Minor has a pull switch to operate the starter which does
not need the ignition to be turned 'On'. Therefore, I can operate the starter
and after about three seconds the oil pressure gauge will read at least 25psi
at which point I could switch on the ignition and start the engine,if I so desired. Personally, I think you do not need your desired system unless the
bearings are VERY worn because there will be enough of a coating of oil on
the bearings to prevent metal to metal contact under normal circumstances.
Posted: Sun Nov 06, 2005 6:51 pm
by Cam
I agree with Willie. I think there is no need for such a system. If you REALLY want to do it though then convert the car to the earlier pull-start system, or put an ignition disable switch in (hidden somewhere) so it acts as an anti-theft device (cutting power to the coil) AND you can build the oil pressure up by trying to start while the switch is still 'off'. Then switch on and bingo!

Re: oil pressure
Posted: Sun Nov 06, 2005 10:30 pm
by Packedup
Willie wrote: Personally, I think you do not need your desired system unless the
bearings are VERY worn because there will be enough of a coating of oil on
the bearings to prevent metal to metal contact under normal circumstances.
The bearings are nearly new, and mid quality ones. But these engines (Cam, it's not a Minor I'm talking about right now!) are known for a bit of bottom end knock/ rumble on startup, although I'm concerned it's still there with the new shells but I get healthy enough pressure once everything's running.
Also I've got another OHV where the oil filter is placed "upside down" on the engine, and they're also very well known for premature bearing wear due to oil starvation at startup (mostly down to poor non-return valves in the filters) so it'd be handy to know how to cut the ignition till the pressure is high enough on that one too
You're right I suppose, a system where the starter can be run for a few seconds and then manually turning the ignition on would be OK, but it's still not as nice as an automated switch ;)
As for the pickup, it's going to be driven by the mechanically oblivious, so although the engine isn't as known for bottom end problems as the Triumph lump, I'd rather give it as much chance of survival as possible! At least, I would if such a switch or circuit isn't too pricey

Posted: Mon Nov 07, 2005 1:10 am
by Cam
I would not connect the oil pressure switch (via a relay or whatever) to the ignition as it IS possible that it might come on under mashed oil/hard cornering/low oil conditions which would cause the car to start kangarooing which is dangerous and VERY irritating.
If the engine is THAT bad to need such a device then I'd seriously consider assigning it to the bin and using a more advanced one such as perhaps a 1935 Morris Sidevalve!
But what's wrong with operating the starter with the ignition off? Surely that's got to be better than running the risk of the ignition dying on the road? If you are hell-bent on having such a system then why not a latching relay that once triggered (by the oil pressure switch) stays locked on until you turn the ignition off? This would overcome the problem of the oil pressure light coming on later on as it would have no effect, only when the ignition was FIRST switched on.
The B-series MG B engine has the oil filter upside down and they don't have probems...
Posted: Mon Nov 07, 2005 6:16 pm
by shaunb
Packedup
Every motorcycle I've had had a kill switch. After changing the oil I used to turn the engine over with the kill switch off and watch the return feed to the oil tank. Once you see a continuous flow of clean oil you were ok to fire it up.
Shaun.
Posted: Mon Nov 07, 2005 6:27 pm
by Packedup
Cam wrote:I would not connect the oil pressure switch (via a relay or whatever) to the ignition as it IS possible that it might come on under mashed oil/hard cornering/low oil conditions which would cause the car to start kangarooing which is dangerous and VERY irritating.
I've not seen the guage dip below 20psi since I did the bearings, so that shouldn't be too much of an issue. Also fitting a switch that's maybe around 10psi would help, the best I've found (Demon Tweaks site) can only be adjusted down to 15. And it's rather pricey for what it is, I just can't find anyone else that sell them.
If the engine is THAT bad to need such a device then I'd seriously consider assigning it to the bin and using a more advanced one such as perhaps a 1935 Morris Sidevalve!

Oh, if only! I should've known not to get another OHV Triumph powered car, but I was without transport and the price seemed right. I missed out on a 4 door Minor that would've been ideal, by an hour, and now I have to live with the curse of the death rattle

I'd love to fit a better engine, but insurance wise it'd have to be like for like - Meaning finding a good engine locally for a sensible price on a day I actually have money. Like that's ever going to happen...
What's really annoying me is I'm sure the knock is only from one or two cylinders, and it's as bad after new shells as before - Plus the old shells were worn, but didn't have any signs of extreme wear, oil starvation or other damage. Something is very wrong, the pressure when cold is about 80psi tickover, yet still it sounds like it's got dodgy bearings!
The B-series MG B engine has the oil filter upside down and they don't have probems...
Yeah, but BMC had more of a clue about designing relatively powerful and robust engines than the latecomers to the empire that was BL. What I feel like saying about Triumphs attempts at engines would either melt the word filter or get me kicked off this forum! ;)
I'll look into the suggestions so far when I feel more like it - I'm having a no getting covered in oil fiddling with seriously sick old cars day or three as of this evening

Posted: Mon Nov 07, 2005 6:30 pm
by Cam
I think the standard oil pressure switch on the A-series operates at around 8psi if I remember correctly.
oil switch
Posted: Tue Nov 08, 2005 2:40 pm
by Willie
YES... if I read full oil pressure on my gauge and then stop the engine and
quickly turn on the ignition again I can see that the oil warning lamp lights at
between 5psi and 8psi depending on the temperature
Posted: Tue Nov 08, 2005 3:26 pm
by paulk
Re Old triumph engines
We were always told to fit a remote oil filter housing (the right way around) and oil cooler. That used to be a must on the 6's but advisable on the 4's.
(ex Herald owner)
Posted: Tue Nov 08, 2005 4:29 pm
by Packedup
Already got a remote filter housing

Still seems to take a while to build up pressure after a couple of hours or more standing, and worse when cold. I'm not entirely convinced the filter is much good, and I can't get it fully pointing down, but there's also a faint bearing type knock when warm (always has been, even though as posted the old bearings didn't look that bad).
All in all I'm sick of the car, but I'm stuck with it so have to make the most of what I've got really.
Posted: Tue Nov 08, 2005 4:38 pm
by Cam
Why are you stuck with it?? Get rid and get a Minor!
I had a 1500 Midget (Triumph engine again) and detested the thing, so I sold it (only car I've EVER sold!).
Posted: Tue Nov 08, 2005 5:04 pm
by Packedup
Cam wrote:Why are you stuck with it?? Get rid and get a Minor!
It's worth maybe 500 - 600 with a full MOT in present condition (and the MOT is due next week), and I'd have to swap it for a Minor as I can't afford to flog it then wait for a car to come along. Quite simply I am most deifnately stuck with it for now, it's cheaper to keep saving and fixing little bits than to go out and buy a better car
Besides, I've still got my eye on that 2 door I mentioed a while ago - Then I can have a slow thristy rattly barge
and a nippy economical reliable small car
I had a 1500 Midget (Triumph engine again) and detested the thing, so I sold it (only car I've EVER sold!).
My condolences on owning one. Although one day I hope to have a fully restored (or at least solid tidy and all round good condition) car with one of those engines in it, but that'll be getting a full engine rebuild and extremely frequent services to keep it going...
Posted: Tue Nov 08, 2005 5:17 pm
by Matt
dolly 1500?
Posted: Tue Nov 08, 2005 5:23 pm
by Packedup
Matt wrote:dolly 1500?
What, my eventual resto project? Not quite, but close

Posted: Tue Nov 08, 2005 5:25 pm
by Matt
Herald
Vitesse
Spitfire
any others that used the triumph 4?
Posted: Tue Nov 08, 2005 5:30 pm
by paulk
Bond equipe
Amphicar
Spartan
Posted: Tue Nov 08, 2005 5:46 pm
by Packedup
Dolomite was the closest ;)
Let's just say every single part other than a few bits of trim are the same, and it carries the Triumph badge. It's also not worth the cost of a full service, but even though it's live rear axle, gutless, slushomatic and the term "powered" has to be used in the vaguest sense when applied to the 1500 engine, I still quite like it for some strange reason
My end goal is to have a nice economical pleasant to drive Minor, the car above, and maybe (space and funds permitting) keep the 2000 as well. Chances are I'll just stick to the first two though as aside from cash I don't really have the space for 2, let alone three cars
