The Triumph Dolomite Club - Discussion Forum

I always appreciate tips from good people that help me save money.

I’m still in two minds whether to send the dizzy in to the doctor or not. Tony has kindly given me some springs to try out, and actually put the frighteners on me a bit today by telling me someone on this forum had their dizzy reconditioned by the doctor, and that the final bill was well over £300!

The car seems to run well at the moment, it didn’t miss a beat today anyway. Acceleration seems smooth and the car pulls well. Or so it seems. Maybe it could be better? Unfortunately I have no other experience of driving a sprint so don’t have any comparison. I’ll try Tony’s springs to see if there’s any noticeable difference.

Do I invest, what could be £300 +, into something that may make little difference? Or do I go for it and have the piece of mind that a recon brings, being that it’s another item on the car refurbished, and it has a three year guarantee.

Nice problems to have I suppose in the grand scheme of things.

Don't know. But as a corollary of an age old adage, if you can't tell if it's broke, why fix it?

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).

Yep. Fair point.

If you know of a place with a rolling road not too far away, they can tell you whether the ignition is advancing correctly, etc., and what the carb set-up is like as well. Won't be cheap, but won't be anywhere near £300. Most will give you an estimate for the output power at the flywheel. Though that mightn't be exactly accuratem as it's measured at the rear wheels and back calculated from losses in the transmission measured during wind-down.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).

Hi Bish, i am firm believer in "if it ain't broke? Why fix it" A good idea of Graham's to spend your dosh on a rolling road, that will tell you everything I wasn't going to say anything about the dist doc, but i have heard similar reports and one that it came back worse than it went in Also didn't want to accept that there was a fault? How true, i don't know although i have bought stuff off him and it's been fine. Glad your visit to Tony went well without hiccups

Tony

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NOW A CLUB MEMBER 2017057

Bish,

I got a recon distributor from the doctor for my sprint because my old one was absolutely knackered. I posted at the time the vacuum advance was not attached, when I fixed that it was stiff and the advance was not even close to spec. The mechanical advance was all over the place as witnessed watching the timing marks whilst increasing the revs. Finally when I stripped it down the base plate was distorted and the shaft wobbled around in the bushes like the proverbial piece of doo in a bucket used for toilet duties. Finally the timing scatter had to be seen to be believed. Having said all that apart from at tickover which was as lumpy as.. the engine pulled well and didn't miss. So for me it was a no brainer. The new distributor is superb, timing is rock steady and the vacuum and mechanical advance is smooth, no scatter BUT on the road if I am honest I can't notice that much difference, may be a little pickup from lower in the rev range.

If your timing mark is steady under a strobe, no scatter, and progressively advances with revs and your tick over is OK (from what I have been told a Sprint never ticks over dead smoothly at low revs - open to correction there!) and it seems to run OK then as others have said spend your hard earned else where. A good rolling road will tell you for sure and would let you get the carbs set up as well.

Roger

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1975 Sprint Man O/D in Honeysuckle Yellow
1971 Stag Auto White

Too many cars, too little time!

Thanks to you all for the reports on the doctor, your thoughts, and advice.

I think I’m going to hold off on the recon for now. I have some new advance springs which Tony kindly donated to my cause. So, I will fit those next time I get some free time, and report back. It will be interesting to see if they fit any better than the ones that are already there, and or, make any noticeable difference to performance.

The car currently idles well, and tickover is as smooth as I reckon it gets for a sprint. Like I say, the car revs up clean with no hesitation or flat spots. There’s is no timing scatter evident with a strobe.

I reckon the carbs to be set up well too. I have solid mounts, no air leaks anywhere, and I spent a good while with a small tube to my ear, fine tunning using Johnners excellent SU set up guide. I used a colour tune after tunning by ear and only had to raise the jets a couple of flats to get a rich blue flame. After a run the plugs are a nice light golden brown colour when removed and inspected. So, I think it’s pretty spot on. I don’t think I need a rolling road session - been there in the past and wasn’t that impressed.

The reason for all this palaver about the dizzy in the first place, is that I have clearly got noise paranoia! I was convinced it was the distributor. I was obviously wrong.

I will save my money for now, and investigate the valve clearances and timing chain when I take the car off the road for the worst of the winters salty roads. There is some top end noise there, but as Tony and I agreed, whilst having a joint listen on my visit to him this weekend, it doesn’t sound terminal.

So, for now, I’m going to keep driving and enjoying the warm autumn weather.

Thanks again, Bish.

Distributor noise paranoia update:

Well, I couldn’t resist a distributor advertised on eBay recently. It looked to have had a refurb including new vacuum can, and clamp. Plus NOS Lucas; points, condenser, cap & rotor.

Only trouble was, that there was a seized and rounded off HT lead screw within the cap. If I could get the screw out without damaging the cap it could be a good purchase.

Advertised at well under the distributor doctors quote for refurbing miine, I thought it would be worth a punt.

I soaked the screw in WD40 for a few days then had a go at drilling the screw, gently does it...

h

I drilled the whole is straight as I possibly could and gently tapped a cheapo mini screwdriver in. With pliers for grip and a bit of extra leverage, the screw came free.







Im chuffed with saving a genuine cap. Alun kindly supplied a couple of replacement screws.





The dizzy is a lot cleaner than the one I have on the car at the moment to say the least. Investigation of the springs finds them clean and snugly fitted to the advance weights.



Deffinately not slack like these on my noise paranoia inducing distributor.



There’s no play in the shaft whatsoever, so all in all I’m chuffed with the purchase. Hopefully I’ll get some free time at the weekend to fit it and see how it performs.

Nice tidy dizzy, let’s hope it performs as good as it looks..

That looks like a 45D vacuum unit on it. While it does fit, obviously, you may find that because the arm that moves the plate in the distributor is a bit shorter, it turns the disy round when fitted. That may mean the screws are close to one end of the slots in the base flange, and there's not much adjustment one way on advance/retard as the points wear or you fit different ones. In which case, it may be necessary to take it out and move it round one tooth.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).

Well saved Bish

Tony.

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NOW A CLUB MEMBER 2017057

Thanks for pointing that out Graham. I did wonder if the vacuum arm was a bit shorter than it should be, because I had to turn the base plate further round to locate the pin than I remembered on the other distributor. I’ll fit it and see how it goes. I may then just swap the vacuum can over with the one I have, if it turns out to be too much of a a faff.

Thanks again.

Graham

I’ve just found your thread on vacuum cans. Did you experiment any further? Is there any real issue with using the 45d can as opposed to a 44d can, other than what you have pointed out previously?

https://forum.triumphdolomite.co.uk/vie ... hp?t=35864

I did a bit, but didn't get far before a distraction set in. I tried drilling a new hole in one of the 45D vacuum unit arms, but I suspect it will be too far the other way now, i.e. about as much longer than the 44D one. But, when I get a round tuit, I want to see if I can fit a threaded collar between the can and the distributor body and a spring inside. And that will want a longer arm. So I may have a use for that modded 45D unity yet.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).

So that you can adjust advance and retard from outside the dizzy with a knurled nut, or similar? Like the 22d6 and others? I had that distributor on my Vitesse and miss that function, I thought it was a great idea.

I've got an A version done, but that has no vacuum unit, just the knurled nut replacing it with a spring inside to hold the arm with the plate on it in place. The arm being a long M3 setscrew with the head hammered flat sideways and a hole for the pin on the underside of the plate.

I didn't think not having the vacuum advance mattered, thinking it was mostly about emissions on the overrun. But some further research makes me question that assumption, and wonder about the aspect of economy when cruising at a constant speed.



Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).