rnk223 Posted April 6, 2022 Share Posted April 6, 2022 Hi, recently moved to Worcester and due to pandemic and moving not really had chance to sort my Herald engine. Car is fully restored, recon g/b, diff and rebuilt engine. Spent far more on car than it is worth. I cannot get the engine to run smoothly and despite building 3 mini engines in the past I am baffled by the Herald issue. The engine starts, but backfires a lot and bucks about on its mounts and then eventually stops after a few minutes running. Checked timing and appears to be spot on at TDC. Stripped Stromberg carb so many times it is now leaking petrol but nothing on the carb side seems to resolve the issue. It has Accuspark electronic ignition and coil but I seem to remember it also did the same thing on the original coil and dizzy. Have also refreshed petrol as I suspected it had gone stale so have counted this out as an issue. Anyone has any ideas as to what the issue is or is there a Triumph expert in Worcester who can help. I cannot drive the car at the moment as far too unreliable and no pull from engine. Quote Link to comment Share on other sites More sharing options...
RobPearce Posted April 6, 2022 Share Posted April 6, 2022 19 minutes ago, rnk223 said: Checked timing and appears to be spot on at TDC. At TDC? It should be approx 10deg BTDC static, adjusted to suit the engine (because nothing is entirely as it originally was). Try more advance. That said, it shouldn't backfire just because it's very retarded. That sounds more like a bunch of stuff. Double check the pulg lead order - it's not impossible to get it to run really badly with two of them swapped. Quote Link to comment Share on other sites More sharing options...
standardthread Posted April 6, 2022 Share Posted April 6, 2022 When you re-built the engine did you have the timing cover and gears off, if so are they put back on correctly? If it was running badly before the re-con did the previous owner have those gears and chain off, if so, did he re-set and mark the new ones correctly? From memory, there is a section on re-setting the gears etc. by setting two of the tappets at 40 thou. It's a while since I did it but the manuals cover it. Quote Link to comment Share on other sites More sharing options...
rnk223 Posted April 6, 2022 Author Share Posted April 6, 2022 When I meant TDC I have set it at 10Deg BTDC or there abouts. I thought i had this about right as the engine really does not want to know if I advance/retard as it splutters and stops. I have checked the firing order 1342. Should point out the car has never run in my ownership as I purchased as a box of rusty bits. with regards to setting the gears I set the engine to TDC and made sure the marks aligned on the timing gears and No4 inlet and exhaust were just opening/closing. So i think I have done all the obvious things? One thing of note is it must be running very rich as I always come in stinking of petrol fumes but cannot seem to address despite rebuilding the Stromberg and checking the float heights a least 3 times. Quote Link to comment Share on other sites More sharing options...
standardthread Posted April 6, 2022 Share Posted April 6, 2022 Is the distributor drive dog set correctly on the cam shaft? Its very easy for the dog to drop down one tooth out, or worse, to be set 180' out. The first engine re-build I did decades ago I made the mistake of putting the dog 180' out with the offset in the wrong place, so getting the distributor drive 180' out meaning cylinder 1 had petrol in it but the spark was going in to cylinder 4 causing misfire. Quote Link to comment Share on other sites More sharing options...
thescrapman Posted April 7, 2022 Share Posted April 7, 2022 Is I think a replacement fuel pump or an electric one? could be over pressure causing flooding Quote Link to comment Share on other sites More sharing options...
rnk223 Posted April 7, 2022 Author Share Posted April 7, 2022 Hi all, As per book I rechecked the timing. No1 piston TDC No4 piston valves just rocking between open and close on Exhaust and inlet. Distributer rotor arm pointing to No1. Set to 10 Degree advance. Nothing. Sucesfully killed the engine so I think I need to take timing cover off and go back to basics. If there is a Herald Engine expert in Worcester please drop me a line. As I say a Herald engine cant be more basic but i am stumped. Quote Link to comment Share on other sites More sharing options...
standardthread Posted April 8, 2022 Share Posted April 8, 2022 Have you taken the distributor and mount out to check the drive dog that connects it to the cam shaft has the offset slot in the top of the dog correct in relation to the two studs that mount it? And that the slot itself is above its centre line (the slot isn't central to the top of the dog). The dog itself sits in a slot on top of the oil pump drive so as well as getting it engaged with the cam shaft you also have to engage it with the oil pump. Could be that someone has fitted new timing gears and chain incorrectly and marked them so and you thought they were correct. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 8, 2022 Share Posted April 8, 2022 It is possible to check the cam timing without removing the timing cover using the equal lift method. From your description of having the valves rocking on #4 with 1 & 4 at TDC, it’s at least close anyway. New NGK spark plugs by any chance? If so take them out and fit something else. If they’ve been flooded /fuel-wetted (and it sounds like they have), they are likely done for ever. Nick Quote Link to comment Share on other sites More sharing options...
RobPearce Posted April 8, 2022 Share Posted April 8, 2022 5 hours ago, Nick Jones said: New NGK spark plugs by any chance? Ah, yes, the dreaded wet plug syndrome. Unfortunately NGK are still one of the better ones, although some cars are more sensitive than others. My GT6 runs fine on NGK for about six months then starts to misfire. It won't even start with Champion plugs. My Spitfire, on the other hand, doesn't seem to care what plugs I use. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 8, 2022 Share Posted April 8, 2022 Actually got a set of NGKs doing ok in my GT6. No idea how they ended up in there I usually avoid like the plague as they’ve caused me fair bit of trouble in the past, especially in my PI, which killed lots of them. Just saying don’t assume the plugs are ok just because nearly new…. Nick Quote Link to comment Share on other sites More sharing options...
Rosbif Posted April 9, 2022 Share Posted April 9, 2022 10 hours ago, Nick Jones said: Just saying don’t assume the plugs are ok just because nearly new…. Nick I have NGKs in my 13/60 no problems with them. I also have a known working set as spares, should I suspect the plugs I can swap them out for a set that do/did work. Same logic with coil and will be, when I get round to it, with the new distributor cap and rotor recently bought. Don't worry I'll check out the cap & rotor individually not both at the same time just in case... Quote Link to comment Share on other sites More sharing options...
rnk223 Posted April 9, 2022 Author Share Posted April 9, 2022 Thanks for all your replies. i went back to basics as I was never happy with the Cam that was fitted. I have removed timing cover and with No1 TDC and No4 rockers open and dizzy drive where I think it should be the timing mark on the cam drive is 180 degrees out see image 879. Have i set it all out by 180 degrees? Why do the No4 rockers and dizzy drive appear to be in the right place. Looking at images is the issue I have due to the fact that the cam is out 180Degress. I really struggled to find any timing marks on the smaller gear at the time i build the engine. Thoughts and have I done the obvious? Not sure as engine ran but albeit very badly! Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 9, 2022 Share Posted April 9, 2022 If you turn the crank through 360 degrees your timing marks will then line up…… https://m.box.com/shared_item/https%3A%2F%2Fapp.box.com%2Fs%2Fc7mpi50kfcrjo6djmz85 Page 1-126 covers the technique with markings and also the equal lift method. Yes, it’s the 6 cyl manual but same as 4 cyl for our purpose here. Quote Link to comment Share on other sites More sharing options...
standardthread Posted April 9, 2022 Share Posted April 9, 2022 (edited) 1 hour ago, rnk223 said: I really struggled to find any timing marks on the smaller gear at the time i build the engine. Look for the witness marks (staining/discolourations) on the backs of the gears to see how/where they have previously been fitted to the shafts to see how they should be fitted. Edited April 9, 2022 by standardthread Quote Link to comment Share on other sites More sharing options...
standardthread Posted April 9, 2022 Share Posted April 9, 2022 Try this link to download an official Works Manual for the Herald (and other Triumphs) that will show you how to set up the original gears and set up new unmarked ones. It's for early Heralds but they are all the same except pot sizes. Good luck. https://app.box.com/s/c970f3ab0c2635962ef5 Quote Link to comment Share on other sites More sharing options...
PeteStupps Posted April 10, 2022 Share Posted April 10, 2022 (edited) 21 hours ago, rnk223 said: Have i set it all out by 180 degrees? Why do the No4 rockers and dizzy drive appear to be in the right place. Looking at images is the issue I have due to the fact that the cam is out 180Degress. If you didn't use the timing marks during the build then presumably you could have put the cam drive gear on whatever way suited best. If no4 valves are rocking then the camshaft is in roughly the right place for no1 ignition stroke; the camdrive gear can go on 90 or 180 degrees 'out' from the timing mark position. But you might well be a tooth out. Echoing recommendations above, here's a good guide to timing the cam without marks: https://sideways-technologies.co.uk/forums/index.php?/topic/7770-equal-lift-on-overlap-the-other-cam-timing-method/ Personally I tied myself up in knots trying to do this with one dial gauge. Recommend not trying it late at night after a long day at work.. 🤯 Edited April 10, 2022 by PeteStupps Quote Link to comment Share on other sites More sharing options...
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