quick timing question....

[darkcat]

Ok so ive decided to check the timing on the chim.

I located the pointer and the approx 3mm thich white line on the front pulley, or more correctly the thick metal disk bedinf the front pulley (hope thats the right bit...)

firing the strobe at the pulley i see the line about an inch BELOW the pointer. I assume that means that it was running approx 20 degrees ATDC????

Im just asking as that seems so far off its mad, but please confirm that the TDC line should appear 8-12 degrees ABOVE the pointer, i.e BTCD??

help much appreciared ASAP!!!!

[jenkotvr]

8 degrees BTDC....dont treat the timing marks as gospel as they have been known to be wrong.

If it runs fine i'd be tempted to leave it be.....other than that i'd use a TDC tool to accurately identify and then re-mark the pully.

Good luck

[darkcat]

so im correct that the tdc mark (correct or not) should appear ABOVE the pointer when hit with the strobe, to indicate BTCD?

Its feeling a bit slugish since i fitted the new vacuum advance, so wanted to check to be sure.

[Ant.]

You need to tell us more about the engine, serp or preserp?

I think the serps timing marks were more reliably positioned.

[darkcat]

Hi Ant
Its a serp 400 HC ('96)


Ok turning the dizzy ANTI-clockwise makes the TDC mark move UPWARDS and past the pointer. this is moving towards (and into) BTDC, yes?

I went a bit far and it started and ticked over like crap so turned the dizzy clockwise a few degrees, started fine and the mark appears about 4 deg BTDC, i guess the marker isnt very accurate, but am i going about this the correct way??

Edited by darkcat on Sunday 9th May 16:37

[chris52]

The best way to check your timing is using an "advance Timing light".
First find true TDC there are a number of methods a quick search on here will find them for you.
Disconnect the vacume pipe and set the timing light to 28deg BTDC have someone in the car rev the car to 3500rmp if its ok your TDC should align with the pointer if not you adjust it by rotating the distributor slightly.
Job Done.

Chris

[darkcat]

I understand yes, all im asking is if the marker should appear above or below the pointer????

[chris52]

Above.If your using a standard non advance timing light.

Chris

Edited by chris52 on Sunday 9th May 16:43

[darkcat]

thanks chris
yes its an old standard strobe i found in the garage, attached between the dizzy and plug 1.

going for a test i a mo, i assume if i hear pinking i should retard a little?

[chris52]

darkcat said:

I located the pointer and the approx 3mm thich white line on the front pulley

I think you may be looking at the wrong mark here. The TDC timing mark is nothing like 3mm. This maybe a mark that someone has put on the pully for reference but that could be TDC or pretty much anything.


Chris

[darkcat]

rather than struggle.. heres a photo!

its not just a line... its a notch!

there are visible (just) graduations either side of it, so imho, it really hast to be tdc??

Edited by darkcat on Sunday 9th May 17:03

[spend]

The pulley assembly is keyed to the crank, and the pointer is cast into the timing cover. Unless you have bent your crank there's no way it can be far wrong The myths about badly set timing marks refer to preserps where there is a movable pointer you can set - the timing marks on the pulley/balancer are still keyed to the crank. Folks blame it on others because 'someone' put the thing back together wrong

[JKY]

That notch is NOT the timing mark

Timing marks are a bit further round and are conventional etched markings.Showing 12 degrees either side of tdc.

On my engine markings are a short way anticlockwise round from the notch - Leaading edge of the notch corresponds to about 30 degrees before TDC.

Edited by JKY on Sunday 9th May 18:28

[darkcat]

Ah ok JKY - thanks
shame its impossible to actually see the markings...!!

Looks like ill have to find tdc manually,
good job i have mondays free..!!

[JKY]

They are very unclear until you really clean them

This is what mine looks like - you can see where I have painted in TDC (the long cross), 8 degress BTC and if you look to the right you can just make out the notch

[darkcat]

excellent thanks!!!!!!!
Exactly what i needed :-)

ill get the sand paper and sticky plasters out in the morning.

i have a feeling i may be running about 30 deg btdc after this afternoon's mis-guided tweeking!!!!!

[blitzracing]

We used some acid based rust remover (you could use Genolite) to clean thoses marks up without doing to much damage.

[spend]

Imperial Leather (the whitish one) rubbed in the indents is the quickest/easiest highlighting I have found, and washes off afterwards

[Ant.]

spend said:

Imperial Leather (the whitish one) rubbed in the indents is the quickest/easiest highlighting I have found, and washes off afterwards

We don't wish to know what you rub into your indents thanks!

[darkcat]

eeeeeeew!!!

ended up using some silver touch-up paint. (couldnt find my tipex)
all timed and happy now :-)


Thanks for the help guys!!