nicrguy1966

I'm advancing the timing and going for a drive to see how it performs in various conditions, from low rev hill starts to acceleration from 50-70 on the motorway. Even after adjusting the cam timing, with the ignition timing set to 'standard' low rev power was very poor. So far, each time I've advanced the ignition, overall performance has improved. Trial and error will continue through the winter months, with maybe another play with the cam timing when the weather warms up.

I flipped the sprocket, so I'm assuming a 1/4 of a tooth, but honestly, even with measuring everything several times, that could easily have been user error!

I'm still making minor changes to my ignition timing. Yesterday I advanced it slightly, and went for an hour's drive. Still no pinking, so I'll advance it a bit more before my next drive. I've packed the strobe away and decided to just set the ignition timing so the car runs its best. Out of curiosity, I might check what that setting is once I've found it (I'm actually expecting it to be exactly where it was when I wrote post #1, and all the work I did on the cam timing was a total waste of time, but let's see!)

My car only runs smoothly when it's way off spec (hence starting this thread). I've given up all hope of ever setting it to spec. I just want it to run well across a wide rev range. It's better now than before I started meddling, but I'm sure there are a few more horses hiding somewhere. A year ago I had no power at high revs and struggled to go above 70 mph in top gear, now it feels keen even at higher speeds than I'm allowed to drive. Low revs aren't quite right yet, hill starts are not my friend. Setting the ignition by ear (or for peak revs) seems to give me far better results than a strobe and any target 'correct' setting.

To avoid carbon monoxide poisoning, I'll have the exhaust pipes facing the open garage doors, although I should get a nice warm glow from the engine.

I can't remember. I'll have a good look and decide on a solution once the weather is warmer.

Luckily there's a good 2 metre air gap between my garage and the neighbours, so as long as I don't start at 7am on a Sunday, it shouldn't be too bad, no worse than mowing the lawn hopefully.

I'll have a good look at the linkage and see if there is a better solution, maybe a bulldog clip or similar on the accelerator cable. I'm not doing anything until it's at least 15 degrees outside, so a few months away.

Hopefully not as it would also be slipping when I drive, which it doesn't seem to do.

Yes, but the two carbs are linked by a common throttle control (unless you deliberately loosen the link between them), so adjusting the idle on one the accelerator cable is connected to should affect both (exactly like pushing the accelerator pedal)

I was planning on screwing down the idle adjustment on the carbs. Bad idea?

I'll be setting my ignition timing at 2500rpm as soon as the weather warms up a little. One scary thing is how loud the engine sounds at higher revs inside the garage. I know it must be even louder at >4k rpm on the road, but it doesn't sound as scary without all the echo and with (some) sound proofing between engine bay and cabin

That's what I'm currently doing.

Even after all my messing about, I'm pretty sure my engine is back at around 20 degrees BTDC. I've adjusted the timing 'by ear' a couple of times since changing the cam timing, each time slightly advancing the timing. With each adjustment, low rev power has improved, without power loss at high revs or pinking. I'll dig the strobe out again once the weather warms up. My current thoughts are around a new distributor in the new year.

Thanks for the suggestion, and I wish life were that simple, but I don't think the timing mark is incorrect for several reasons. 1) I felt the position of piston #1 and it matched the timing mark 2) I removed the crank pulley and inspected it, there's no sign of any issue with the rubber and it wasn't possible to move the mark. 3) The timing of the cam shaft was wrong in the opposite direction to the problem with the ignition (cam was too much ATDC, ignition is too much BTDC) 4) I've set the cam timing based on the TDC mark, and if it was as wrong as the ignition timing, I doubt the car would even start, but it runs well.

I'm very happy to wait for warmer weather! My garage isn't heated and I tend to damage my fingers much more working on a car in the freezing cold.

I know a 500 rpm idle is lower than standard, but the car used to be perfectly drivable at that setting. Now I have to really rev it and slip the clutch to pull away, and on one occasion when I needed to do a hill start, I was reving up to about 3000 rpm to pull away, otherwise as soon as the clutch bit, the car felt like it was going to stall. Once moving, the car is a better drive than before I changed the cam timing. Until I've tried a few different ignition timing settings I'm quite relaxed about this issue. It might be a very easy fix.

Given the sudden drop in temperature, I've not spent much time working on the car for a couple of weeks. Things still to do: 1) Recheck the cam timing now the cars done a few hundred miles (using balance point of 1 & 2 rockers) 2) Try various slight adjustments of the ignition timing to see if I can increase power at <1500 rpm without hurting the power at >1500 rpm. If not, increase idle speed from 500 rpm to 850 rpm. If I find the cam timing isn't perfect, I'm happy that I can repeat the process of adjustment without the 10 pages of help I needed last time!

So clean! Do you ever drive your car? 😁 I'm sure I could rearrange the leads to match yours if I wanted (and twist the dizzy body), but I'm not sure how it would make any difference to the running of the engine. Where I am is that I have changed the cam timing, and things seem a little better than before, but I still have a little fine-tuning to do before I'm finished.

Today's installment: Fixed the leaky hose Adjusted all tappets so there's no rattle Got the strobe out and found that my "roadside" setting was way off and retarded the ignition to around 16 degrees BTDC (any less than this and the engine started to sound unstable) Went for a drive. A nice smooth tickover at 500 rpm. Lacking a bit of power at low revs, but not as bad as it used to be when set to 13 degrees BTDC. A blip on the accelerator and I could pull away with no problem. At 2000 to 3000 rpm it felt like I had more power than before. I took it to a stretch of motorway and pushed it up above the speed limit without any issues. The lack of power I used to have above 3000 rpm seems to have gone, so nice acceleration in 4th gear from 70 to XX mph (just in case the police are watching!) I need to use the car Friday so I'll probably leave it as it is until after that, but I suspect I'll be playing with the ignition timing again in the next couple of weeks (and might even double-check the cam timing now I know how "easy" it is!). As an experiment, I plan to set the ignition to 13 degrees BTDC to see how it drives, but not until after Friday.

I like that idea a lot!

I'll be playing with it again after lunch. I'll first check the rocker gaps and replace a bad hose clip while the engine is cold, then fire her up and check/adjust the ignition timing. I know it needs to be retarded as there was pinking when I had a drive yesterday. I never had pinking before, as the engine seemed to like a stupid amount of advance, so something has already changed.

I agree with Johny. I have full adjustment of the distributor from firing at TDC to 20 BTDC just by twisting the body. I could do everything you described, but to get it to run smoothly, the spark would be at exactly the same time as it is now. Edit: I haven't actually checked the ignition timing since adjusting the cam timing, so it might already be "fixed" (wishful thinking).

Holding a feeler gauge, screwdriver and 1/2 ring spanner all at the same time is enough of a challenge for me!

So far nothing has been badly warn on the engine. I had a reconditioned engine fitted about 15 years ago and do fairly low mileage (3-4k per year).