Advance/Retard question

[Nanoose]

The Landy seems to be running well with the new electronic ignition I put on. I've got the timing set around 10 BTDC (only because it seems smoothest there). The truck fires right up, idles well and seems smooth. Driving it much quieter and acceleration seems a bit better, well better by Land Rover standards.

The one thing I've noticed is that if I have a long period of acceleration (like up a hill or long straightaway), it seems to die. It's independent of which gear I'm in and I'm pretty confident that it's not an electrical or fuel issue. I've also replaced the distributor and have rebuilt the carb recently so I don't think it's the vacuum advance or accelerator pump. I'm wondering if I've got the timing set incorrect.

Thoughts?

Thanks!

Dave

[JayGoss]

The Landy seems to be running well with the new electronic ignition I put on. I've got the timing set around 10 BTDC (only because it seems smoothest there). The truck fires right up, idles well and seems smooth. Driving it much quieter and acceleration seems a bit better, well better by Land Rover standards.

The one thing I've noticed is that if I have a long period of acceleration (like up a hill or long straightaway), it seems to die. It's independent of which gear I'm in and I'm pretty confident that it's not an electrical or fuel issue. I've also replaced the distributor and have rebuilt the carb recently so I don't think it's the vacuum advance or accelerator pump. I'm wondering if I've got the timing set incorrect.

Thoughts?

Thanks!

Dave

This is coming from a non-mechanic, so please take with a grain of salt. I've heard that you'll lose power on a long ascent (not die) if the timing is too far advanced. I've also heard that, when it's timed right, you'll advance to where it runs smoothest then back it off a little to where it's a little rougher. I did that with mine and it runs well up hills, etc. If all of this is accurate then maybe yours is advanced a little too much? Can't hurt to back it down to 7-8btdc then see how your performance is affected.

[Nanoose]

Thanks Jay, that was exactly the info that I was looking for!

The truck was really struggling today. Some of the same things I mentioned before and it got progressively worse very quickly. I finally pulled over about a mile from home and started pulling things apart. I discovered that the inline fuel filter was plugged. I bypassed that and things were much better. Can't wait to time it tomorrow. Yeah, it's not going to fly, but I'm optimistic things will run much better.

Thanks again!

Dave

[bmohan55]

This is coming from a non-mechanic, so please take with a grain of salt. I've heard that you'll lose power on a long ascent (not die) if the timing is too far advanced. I've also heard that, when it's timed right, you'll advance to where it runs smoothest then back it off a little to where it's a little rougher. I did that with mine and it runs well up hills, etc. If all of this is accurate then maybe yours is advanced a little too much? Can't hurt to back it down to 7-8btdc then see how your performance is affected.

That was exactly my experiance also. Had it timed to where it started and ran great at idle but lost guts under load, I retarded it a bit (all by ear as I have no timing light yet) and now I'm not grabing for third near as much.

[brucejohn]

Looking at those markings

Okay, so really dumb questions since I finally broke down and purchased a timing light.

My 82 series III 2-1/4 8:1 petrol has markings on the crankshaft pulley that look something like:

6(degreess) | | | | | 6(degrees).

Just insert the degree symbol where you see (degrees), right. So, the other day I set her up at TDC (assuming the middle mark means TDC) and started using 89 octane fuel (per the green bible which suggest 90 octane for TDC and 3(degrees) ATDC for 85 octane).

She is running quite well, starts way easier in the morning without even using the choke though it's in the high 20's -30's. My better half says quit fiddling with it (she wants me to get after our ski boat), but she has started dieseling when I turn her off (the rover not my better half).

She is not running hot (barely over the N and making me wish the heater worked better). I am thinking I'd just as soon run 87 octane than 89 so, after all this rambling the questions.

What do the marks between the 6(degrees) mean (So, I can head toward 1-1/2(degrees) ATDC, I guess)? And when say you "advance" the timing does that mean moving BTDC or ATDC?

[thixon]

You probably have your timing advanced a little far, which can cause dieseling.

Did you adjust your fuel mixture as well? If you get it too lean, this can also cause dieseling.

Concerning timing marks, IIRC center is TDC, the 6's should be +6 and -6 of TDC. Someone esle needs to confirm. Sorry, I've worked on too many brit cars to remember and can't remember what the timing pointer on rover looks like.

Here, read this link. Its not Rover specific, but its a good resource, and covers exactly what your asking. This way you won't be subjected to another long and boreing post of mine.

http://www.mgaguru.com/mgtech/engine/ro101.htm

[thixon]

That was exactly my experiance also. Had it timed to where it started and ran great at idle but lost guts under load, I retarded it a bit (all by ear as I have no timing light yet) and now I'm not grabing for third near as much.

If all you own to tinker on is old brit cars, don't waste your cash on a timing light. Tuning it by ear and trial and error is your best bet. Moresoe as you pack on the miles.

[scott]

beer time means more than time for beer

[brucejohn]

Travis... Thanks, great link.

I did also adjust the mixture so I will check that, I do tend to set it lean. I also believe the fuel here has ethanol, so that may be part of the dieseling too.

So, ATDC is retard and BTDC is advance, thank you again.

Does anyone know what the hash marks represent?
I am confident Travis is right the center one is TDC, but what are the other four?

6 | | | | | 6

Do the hashes represent 6,3,0,-3,-6?
I tend to obtain poor results when I adjust the dizzy by feel/ear, and I JUST bought the light.

[scott]

bruce,

poor yourself a beer, set it on the wing and adjust the timing so that the ripples are minimized at an idle. then retard it ever so slightly and have a beer

[brucejohn]

I will try that tomorrow Scott. What a great suggestion.

[bmohan55]

If all you own to tinker on is old brit cars, don't waste your cash on a timing light. Tuning it by ear and trial and error is your best bet. Moresoe as you pack on the miles.

Money that was to be spent on a timing light will now be "invested" in Scott's method of timing. Thinking I might have to "check timing" on a nightly basis...Gawd I love this board!

[brucejohn]

Money that was to be spent on a timing light will now be "invested" in Scott's method of timing. Thinking I might have to "check timing" on a nightly basis...Gawd I love this board!

Exactly. I am thinking Scott's method offers a great opportunity to learn and hone my skill at timing by feel and ear. I suppose I can use my new light to 'check' my accuracy so my money wasn't wasted?

But least this thread (which I hijacked from the original starter) lose focus on my original dumb question. Does anyone know what the hash mark on the crankshaft pulley stand for?

[scott]

Does anyone know what the hash mark on the crankshaft pulley stand for?

6 pack, 1/2 a 6 pack, no 6 pack, borrowed 1/2 a 6 pack, borrowed 6 pack, maybe?

[brucejohn]

poor yourself a beer, set it on the wing and adjust the timing so that the ripples are minimized at an idle. then retard it ever so slightly and have a beer

Scott...
I did pour myself a beer, set it on the wing and adjusted the timing so that the ripples were minimized at an idle and here is what I found...

There are two smooth spots on either side of a very rough spot. When I raise the rpms though she smooths right out, barely a ripple, (of course, by this time the beer was almost gone, too). According to my timing light this rough spot is a the first hash ATDC. So, I am trying it here for now, which I suspect might be 3 (degrees) ATDC right where the green bible says she should be.


I may learn this ear/feel stuff yet. Of course I will need to 'check' it again tomorrow. Cheers!