vs v8 ignition timing

[cannibalrikman]

Hey commodore fans could someone clarify which mark on the block is 10 degrees BTDC. I can see the timing marks but I'm not sure which one is ten. I can see the TDC mark and the advance and retard marking. There are 4 little marks then a large mark, are these little marks 2 degrees each and the large one 10 degrees? Any pics or diagrams would be good. Cheers.

 

[dirt drifter]

yep u got it right. 2 deg per mark and the big one is 10 degrees

 

[deanos70]

on the topic
on the balancer you have the markings TC or 0 then to the left is 10 then to the right of TC you have numbered from 10 upwards
exatcly what mark on the balancer should line up with the long mark on the front of the block as in pic in this thread

geez i hope that makes sense
also shouldnt the timing be set with pins 5 & 6 bridged out on the diagnostic connector

 

[BlackVXGTS]

Sounds like you have confused everyone. The large mark on the engine scale is TDC (top dead centre) or zero degrees. That's when the piston is at its highest point on the compression stroke. The marks to the left are the advanced marks before TDC (BTDC) in increments of two degrees. Normal static ignition timing of 10 degrees BTDC would have the arrow on the balancer pointing to the fifth mark towards the left (from the large mark) when the spark plugs are fired. The marks to the right are the retarded marks ATDC or after top dead centre - not sure when (if ever) they are used.

 

[deanos70]

Thanks BlackVXGTS

mate i confuse myself all the time let alone any other poor bugger i talk too :hmmm:

thanks for your post i appreciate the help

but just to make sure i have it right,
in diagnostic mode the the arrow on the balancer should be pointing at the timing mark i have arrowed in the pic





thanks again

 

[cannibalrikman]

Thanks fellas for your help. I could have been a little clearer about the marks. Dirt drifter got what I was getting at. Cheers

 

[BlackVXGTS]

Thanks BlackVXGTS mate i confuse myself all the time let alone any other poor bugger i talk too :hmmm: thanks for your post i appreciate the help but just to make sure i have it right, in diagnostic mode the the arrow on the balancer should be pointing at the timing mark i have arrowed in the pic
thanks again

That's correct. Spot on.

 

[deanos70]

Thanks BlackVXGTS

much appreciated, will get it done on the weekend

cheers

 

[eko]

Once its advanced and sitting on 10btdc is there anything else to do what would the revs sit on once advanced to 10btdc on a manual

 

[Jxfwsf]

Jumper the diagnostic plug so it can be set to 10° BTDC, set it, then remove the jumper.
If you just spin the dizzy while it's idling in normal mode it's not going to be anywhere near correct.