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Steve 13-60

are triumph engines really this rough?

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25 minutes ago, mpbarrett said:

Just a wild idea,
I wonder if its fuel starvation that starts to cut in above 3000 and then starts to miss and feel very rough....
is the fuel system the same? Have you used the same pump between engines? Poor flow from the tank to engine or fuel pipe starting to collapse.

Where are you located maybe some one from the clubs (CT or TSSC) could have a socially distanced listen to your engine...

 

Mike

(Cambridge)

Hi Mike, I did suspect the fuel pump so fitted a new one. That made no difference other than to overcome the old float valves and puke fuel out!

£30 and new valves later still no improvement.!

And it had too much pressure for the twin40's so bang went another £20 on a pressure regulator.

Thanks to folk on here making me think, I'm now hoping its a duff ign coil.....just gotta wait for the new lucas one to arrive.

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What are you setting the ignition timing to?  Suggest no more than 10ºBTDC static / idle and no more than 32º @ 4000 rpm

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9 hours ago, Steve 13-60 said:

I'm now hoping its a duff ign coil

It's definitely a possibility.  I've wasted ages before tracing down a roughness at higher revs that eventually turned out to be the (new-ish) coil.  

One thing I'd check is that you mentioned that you had the 'sort that uses a resistor', are you sure the resistor is all in place and wired up properly (not bypassed somewhere?), this can also cause problems.  Generally you'd be expecting to see 12v at the coil when the starter is engaged, but this should drop to ~6-9v or so when the engine is running (or thereabouts).

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39 minutes ago, richy_rich said:

Generally you'd be expecting to see 12v at the coil when the starter is engaged, but this should drop to ~6-9v or so when the engine is running (or thereabouts).

I don't think any Herald would have had this ballast resistor arrangement from the factory, though that is not to say it hasn't been added at some point.

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10 hours ago, Steve 13-60 said:

I did suspect the fuel pump so fitted a new one. That made no difference other than to overcome the old float valves and puke fuel out!

Sadly nearly all of the new mechanical fuel pumps sold as "suitable" are actually made for old Toyotas and such like and have operating pressures of 5 to 7.5 psi.  This is at least 2.5 x the highest that an SU or Stromberg can deal with regardless of the age of the needle valves.

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11 hours ago, Steve 13-60 said:

Thanks to folk on here making me think, I'm now hoping its a duff ign coil.....just gotta wait for the new lucas one to arrive.

Oh dear. 

I am very cagey about Lucas Coils these days, especially new ones. I tend to go for Bosch coils instead, as every time I have had an issue with a coil it has been a Lucas one!

Phil

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3 hours ago, thebrookster said:

Oh dear. 

I am very cagey about Lucas Coils these days, especially new ones. I tend to go for Bosch coils instead, as every time I have had an issue with a coil it has been a Lucas one!

Phil

Phil. That's exactly my experience with them too unfortunately. Older ones seem to last for ever but stuff made in the last 10 tears or so is pretty hit and miss.

PS hope you've managed to dodge any more volcanoes!

 

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Looks and sounds very nice there.

I am assuming that the engine pulls ok under load it's just the noise issue? I have had dodgy coils, spark plugs and fuel pumps where the engine would start and run fine but was like hitting a wall under load.

Otherwise given all the things that have been changed along the way I would think that something touching seems the likely problem as I have had this before.

On the small Triumphs it's been either engine or gearbox mounts going settling or coming apart.

At the front end I have had the exhaust touch the chassis and the sump can touch the steering rack although more on the 6 cylinder cars it's worth checking. At the back on overdrive cars the output flange of the gearbox or propshaft can touch the tunnel and the overdrive sump and speedo angle drive can touch the chassis mounting plate.

It is surprising how much the whole lot can move around. I have driven these cars fairly hard without the gearbox cover fitted on a few occasions and there's a LOT of movement even on good mountings.

Similar thing happened with my Scimitar which has a Rover V8 and gearbox. Started making an appalling din on hard acceleration which turned out to be due to the gearbox rubber mountings going soft.

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Just been for a test drive with the new mounts. Has made a difference to the noise but still struggling to rev, although I did manage to get it to 4500!

But it's to be expected it will be running weak on 1300 hs2s.

Gonna borrow my mates known good coil off his mgb tomorrow for a comparison. Then with the electronic dizzy.

And then gonna stick the twin 40s on for a play!!?

They are jetted for a 1.3 too but gotta be better than the su's eh ? And they are H type so are more forgiving than the non-emmission type.

Plus they are jetted for a 1300 alfa guiliette kicking out 90 horses and was hoping to be mear than with the work done on the 1300.

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Posted (edited)

Seems to run relatively smoothly, but a little too quiet, your AFR is also going really quite lean when revving past 2500rpm despite no load. I expect this is related to it not wanting to rev. Really should go rich when accelerating. Do your SUs have oil in the dash pots and springs in them? I'm guessing you didn't change needles since installing the 1500? The HS2s shouldn't limit things that much until the very top end (which a 1500 won't enjoy anyway).


For comparison, this is my standard (I think) Herald 13/60 engine, with twin HS2s and a 4-2-1 manifold. It seems to go alright, will cruise at 70 with overdrive...

https://www.youtube.com/watch?v=KTwKtg1bVC8
- David

Edited by JumpingFrog

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There's s light lope to the idle which might be the carbs out of balance.  The throttle stops need to be set for equal airflow at idle (preferably measured with a proper meter) and the linkage set so they pick-up equally too.  The latter is the harder part.

The AFR is interesting.  Assuming that's a proper wideband then it's going well lean as the revs pick up.  That will certainly dampen it's will to rev.  The quick and direty test is to pull the choke out when it goes flat - if it picks up and goes, you just found your problem.  David is right that the HS2s won't really hold things back - provided the right needles and springs are fitted.  Some early 1500 TC saloons were fitted with HS2 carbs and according to my SU book they had AAX needles with red springs.  The 1300 Spitfires (mk IV) had AANs also with red springs.  The 1500s with HS4s had ABTs, though that is a fairly pointless comparison.

Using Minty Lamb to compare profiles you can see that the AAX needle is a bit richer.........

AAN AAX ABT.jpg

  Not enough to account for the rapid leaning though IMO - can you confirm what springs are fitted, if any are fitted at all?  Lighter springs give leaner running and reduce the calibration range of the carb.

Going to be rude about your airfilters too I'm afraid......... good for induction noise (if you like induction noise) but not so good for airflow or filtration.  Quite good for chucking at squirrels.....

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Hi all, again, continued thanks for all your comments which are gratefully received.

I owe you all a pint, If we are ever allowed back in a pub!

The SU were bought off ebay (£36!!!) purely to start the 1300 after the rebuild before swapping to the 40's. But they do appear to be ok. Yep, the air cleaners are pants, but just needed something to stop debris getting in.

Yes, the A/F is going lean isnt it. I'll spend some time tomorrow playing with the mixture as best as poss without buying new needles.

I'll get it running as best as possible tp prove this new 1500 is basically ok, then fit the 40s and see how it responds. Then revert to the SUs. Main objective is to get it to run good enough for the trip back home to berlin on the 12th. Plan is to tow it on the A frame, but the autobahn stasi sometimes moan about using them. So if I do get stopped I need to be able to drive it! Last night it was struggling to maintain 60mph, not to bad at 50.... But 600miles at 50mph...eeeeek! If I can cruise at 60 I'll be happy. Hence why I fitted the OD box. Hoping to get it in at the Berlin classic car show in November (why not summer????? German sense of humour no doubt!)

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So, Young Jedi, begin to see the way you do!

Begin to see, if made no mistake you have, yet losing you are, then a different way you seek you should.   Yes.

 

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Interesting one. Some do, some don't.  Looking on the Canleys drawings, the Mk3 Spitty version definitely shows insulating spacers but the MkIV and 1500 do not.  Photos on the web are mixed.  Our Spitty IV carbs have no spacers.  My general take on it is that insulating spacers are a good idea, especially with modern fuel.  However, SUs (except HIF) with their separate float chambers are less affected by conducted heat than radiant heat than Strombergs.  Strombergs really need the insulators...….

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On 6/30/2020 at 9:43 AM, Nick Jones said:

I don't think any Herald would have had this ballast resistor arrangement from the factory, though that is not to say it hasn't been added at some point.

Agree, but earlier in the thread it was mentioned that "It's one that uses a resistor, was supplied with the Accuspark distributor kit."  I would definitely check what's going on, even if only to rule it out as a misconfiguration (ballast coil w/o resistor or equally a non-ballast coil with one) could cause problems :)

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The story so far today...

Played with the carbs. Front SU seems to respond slower than the rear upto 2000 ish. rear goes up about 5mm, front about 2mm. But giving it plenty they both went up the same.

Took it for a test drive and it would get to 5000....if I was brave enough...chickened out at 4600. But seemed to not have any problems....other than ITS BLOODY NOISY!!!

So probably not the coil afterall.

Swapped for the electronic dizzy - no difference.

Played with mixtures and got it to run at a better A/F ratio. So its probably running as best it will with the SUs.

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Ok, the video didnt work.

I'll try again later

, but latest update.....

We fitted the 40s and it ran ok, bit lumpy on tickover which turned out to be a fault on no4 choke. It floods on tickover but is fine once on main jet. And boy does it go when on all 4! Gets upto 4000 just breathing on the throttle. Tomorrow, I'll clean the carb and try again.

25 minutes ago, Steve 13-60 said:

 

IMG_20200701_162243.jpg

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Seems pretty encouraging then?

That vid does sound quite harsh as you get over 4000rpm but hard to judge - might be mostly wind noise.

Have you got any soundproofing under the gearbox tunnel?

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Not under the tunel and just the carpet on top.

Far better on the 40's but still bloody noisy compared with the mgb. But then the B has a proper body whereas the herald has a body with the structural integrity of an empty crisp packet!

I'll get there in the end, no rush, will only have to find something else to tinker with.

Am looking forward to fixing the 1300 tho and getting that back in, reckon its gonna fly once sorted.

Oh yes, spotted a core bung leaking....another panic order off to rimmer bros!

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Sounds like progress is being made.  Bear in mind that the 1500 is not the most revvy engine Triumph produced - they are much more about torque and standard ones tend not to make old bones if revv'd much.  Whereas a 1200 or 1300 is quite happy spinning all day at 4000 rpm and will spin up to the 6k redline without fuss, the 1500 is usually shouting for mercy from about 4k onwards.  They really benefit from overdrive and a taller diff (3.89 or even 3.63) and with those fitted they make the Herald a really good nippy, usable car even on longer, open-road journeys.

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Indeed, it'll be ok should I need to drive it on the autobahn.

But the idea was to have a nice rev happy 1300.

Oil pressure was very low on tickover....about 10psi....I might just stick the oil cooler back on and lock the valve to always flow thro the cooler.

Running out of days tho!

But did have a pleasant day tinkering.....and being paid to do it by that nice mr boris!

 

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1 minute ago, Steve 13-60 said:

Indeed, it'll be ok should I need to drive it on the autobahn.

But the idea was to have a nice rev happy 1300.

Oil pressure was very low on tickover....about 10psi....I might just stick the oil cooler back on and lock the valve to always flow thro the cooler.

Running out of days tho!

But did have a pleasant day tinkering.....and being paid to do it by that nice mr boris!

 

An oil cooler is likely to reduce your oil pressure at tick over, possibly not a great idea. You might be able to fit different spring and/or a washer to the PRV to help raise the pressure?

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Already added a spacer. And the cooler did help maintain low rpm pressure for the short time had it on the 1300.

Folk recon a cooler isnt really needed, but I'm concerned about driving on the autobahn at 60mph for hours on end.

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