The Triumph Dolomite Club - Discussion Forum

Hello again,
Knowing that the cam was timed perfectly, I had the opportunity while everything was set up, so I decided to set the timing statically, for the first time ever. In the past, I've always used a strobe timing light.
Being ex-military, I followed what the book told me to the letter, and set it just as the light went out while the crankshaft was set at 10 degrees before TDC.
Once it was all done, I decided to run the strobe over it to see if it really was at 10 BTDC, only to find it was somewhere around 7 or 8 BTDC at 750 RPM.
Figuring I'd made a mistake, I set it again with the same result. And a third time....same result.
So, I then set it with the strobe (@750 RPM) to 10 BTDC, where (& how) I've always set it.
So, if the static setting is indicating 7 or 8 BTDC on the strobe, does that mean I can set the strobe light setting (@ 750 RPM) to around 12 or 13 degrees BTDC?
I'd really appreciate any advice on this as I don't want to stress the engine in anyway that could cause damage, but I also want the thing to perform as it should.
Thanks & Cheers,
Rob
PS; Its fitted with a Pertronix Ignitor electronic ignition system.

The timing should be set with a strobe. Static is only an indication. You do want the ignition to right when running and not right when the car is standing static in the shed or parked in the street. The most important is do not exceed 32 degrees at a sprint at full revs. Even better is adjust to 32 at full revs and what you get at idle is what what you have. When that would mean it becomes 12 or 9 at idle then it is. You do not drive with the engine at 800rpm.

Jeroen

Yes strobe is the correct way. The difference will come from when you do it static youre turning the dizzy until the light appears to go out but you may move it a fraction more or less. The play in the drive gears will also lose you a couple of degrees. So static for initial set up then strobe for real world, as you now have it.

Tony

I tend to click the rotor arm back by hand so all the advance is gone with the crank set at the 10 BTDC mark and then rotate the dizzy body
so the light goes out. Then the static and running strobe results are much closer....and can be checked so that the slightest "advance" pressure on the rotor makes the static light go out...

But what the guys say about running figures is of course far more important...and do be very careful that you arent getting detonation, which will break the ring dividers on a Sprint piston. They aren't very robust in that area, so if you hear any sign of knock, back it off...and dont run it lean.

Jonners

That's why adjusting at max revs is the best. Less chance of pinking.

Jeroen

Agree on strobe timing, but just a query on Jeroen's comment on 32 degrees advance. That is what I run on my race engine, BUT to get that I had to file the centrifugal advance mechanism to allow that much advance. Workshop manual (1973) gives 10 static, plus 12-16 centrifugal at 2000 rpm plus (and 8-12 vacuum) which I always related (with vacuum disconnected for timing with a strobe) to mean max 26 degrees advance. However, I found varying amounts of wear in 44D4 distributors so the amount of mechanical advance may vary between distributors. Plus recommendations changed over time and the original under bonnet sticker on my 79 road car gives static at 8 degrees.

They are only a guide as Jon's comment about pinking is the important one. It is vital to get the carb mixture correct and to run on the correct octane. Standard in NZ are 91 and 95, but 98 is available and I always find that is so much better and worth the bit extra it costs. BP6EFS plugs set with a 32-35 thou gap (not the standard 25 thou) if using electronic ignition. If you can drive hard up a hill below 3000 rpm in 4th without pinking then you can increase the advance a bit, or decrease if it does pink. Change any of the above variables (octane, mixture, plugs) and you may have to make minor timing adjustments.

Geoff

Jeroen, Tony, Jonners & Geoff,
Thanks for answering.
Its good to know you Gents are here.
Cheers,
Rob

My distributor always tended to slip back towards retarded. I fitted a tab washer into the groove behind the R hand side fixing bolt so the distributor body can't slip back towards retard which is counter clockwise from above. KC