Club 80-90 Forums

Hi

I am a bit miffed as to what way the dizzy on my 2ltr CU engine should be turned to advance and retard my timming.

I have just read on type2.com that the dizzy should be rotated Counter Clockwise to advance and Clockwise to retard. Which is how I imgine it to be but I have just read a thread on this forum that suggests if you want to advance your timing turn it clockwise.

Now with what little I know and the little info I have found on the web, I was under the understanding that having the timing advanced means that the spark is firing before TDC, i.e in advance of TDC. So in these terms one would have to turn the dizzy counter clockwise to advance the timing as the engine and the dizzy is spinning clockwise.

Confused

Dizzy anticlock to advance the timing clockwise to retard the timing, You are correct, advanced is before TDC, retarded is anything after the correct timing point. If you still have the correct double vacume distributor the timing should be set to 5 deg AFTER TDC which is to the right of the TDC mark on the timing scale.

Why do you need to retime the dizzy?

With leccy ignition There is no reason for the timing to alter, or is there?

Des

rugchucker wrote:Why do you need to retime the dizzy?

With leccy ignition There is no reason for the timing to alter, or is there?

Des

You are right with not having to alter it once set up but if it could be wrong in the first place then it may need tweaking a little!

Dunno

All I know is that when I had found TDC it was about 25% out, which was why it wasnt starting. I stuck a test light on it, rotated the engine to 5degs BTDC and then turned the dizzy CCW just until the light went off. Checked the position of the rotor arm and it was before cylinder 1

Anyway

It appears that my other post is now more important now

Cheers guys

bigherb wrote:Dizzy anticlock to advance the timing clockwise to retard the timing, You are correct, advanced is before TDC, retarded is anything after the correct timing point. If you still have the correct double vacume distributor the timing should be set to 5 deg AFTER TDC which is to the right of the TDC mark on the timing scale.

Sorry I am seriously confused now

I took my van to the garage and told the guy to plug the idle stablisation thingy together and pop the crankcase breather tube off and time it to 5 Degs ATDC.

I got my timing light today and went to check it and it was exactly 5degs BTDC (to the left of the "0" on the timing scale). I thought this cant be right so I loosened the dizzy and rotated it to the left (CCW), thinking this would advance the timing as above but my timing mark went to the left on the timing scale. It went to about 10degs BTDC.

Well I thought this cant be right. After what everyone has told me on this forum one should rotate the dizzy to the right to retard and to the left to advance.

The story ended with me having to rotate my dizzy to the right in order for me to move my timing mark from 5degs BTDC (left of the "0"), to 5degs ATDC (right of the "0")

Bloddy hell, if I need 5degs ATDC should this be to the right of the "0" or to the Left?

Cheers and sorry for being dumb

Forgot to say that my mark is TDC (I think), its the only knotch on the pully on a CU Engine

albertramsbottom wrote:I loosened the dizzy and rotated it to the left (CCW), thinking this would advance the timing as above but my timing mark went to the left on the timing scale. It went to about 10degs BTDC.

Yell it did as you expected it to. It advanced the timimg by 5 degrees.

albertramsbottom wrote:After what everyone has told me on this forum one should rotate the dizzy to the right to retard and to the left to advance.

Thats what you did! You advanced the timing by 5 degrees by turning it CCW (to the left)!

albertramsbottom wrote:The story ended with me having to rotate my dizzy to the right in order for me to move my timing mark from 5degs BTDC (left of the "0"), to 5degs ATDC (right of the "0").

Ok... Whats earlier, before or after? Before of course. So rotating to to left gives you timing more before (or earlier/advanced) and rotating to the right gives you timing after (or later/retarded).

Treat your timing scale as a clock face. Anything before 12 is early or advanced. Anything after 12 is late or retarded.

Yeah I have just worked that out

So where should my TDC mark be 5degs to the right of the "0" on the timing scale or 5 degs to the left of the "0" on the timing scale

Cheers

Sorry Im having a thick spell

The pulley mark is TDC, 5 deg ATDC is to the right of TDC on the timing scale if you have the original timing scale still fitted there should be a dot at 5 deg ATDC. Both vacuum hoses to the distributor need to be connected. Thats assuming you have the correct double vacuum distributor.

The red dot is the original timing mark

bigherb wrote:The pulley mark is TDC, 5 deg ATDC is to the right of TDC on the timing scale if you have the original timing scale still fitted there should be a dot at 5 deg ATDC. Both vacuum hoses to the distributor need to be connected. Thats assuming you have the correct double vacuum distributor.

The red dot is the original timing mark

Cheers bigherb, again

I thought so, but after checking and it was 5degs BTDC after telling the garage 5degs ATDC I had to look at everything I had learnt on this forum. I dont think there is a dot on my timing scale but it could have worn off.

My local garage are idiots, that meant my timing was a full 10degs advanced being set at 5degs BTDC

Thank you very much, oh and thanks for confirming that I have brought the correct oil pressure switch

You dont dissconect the "crank case vacuum"...

you dont in fact dissconnect the vac lines onto the dizzy advance unit (standard is 2, advance and retard)

If you have dissconnected the vac lines on the dizzy then 5 deg ATDC is wrong.. vac lines MUST be connected to set to 5 deg ATDC. BUT the vac unit must be working properly.. conect a tube to each side in turn and suck on it.. it MUST hold vacuum when you do, if it doesnt then its fubbared

Right well somone told me to do that on this forum. I didnt disconect the vac tubes though. Ill go and do it again with the crankecase breather connected.

And ill test the vacume unit as well. I understand that it shouldnt advance to any more 25degs. But does that mean 25degs ATDC or does it mean advance the timing which then my TDC mark on my pully wouldnt go any further than 25 degs to the left (BTDC)!?

Cheers

No harm in disconnecting the breather it would'nt make any difference, it only needs to be disconnected before adjusting the carbs.

Crankcase breather has NO effect on timing, wether its on or off...

Vacuum advance unit, dont get tied up with how far it moves timing.. does it actually work is the important bit....