setting the timing on a V8
setting the timing on a V8
Author
Discussion

V8ish

Original Poster:

370 posts

230 months

Friday 14th March 2008
quotequote all
Can anyone talk me through an idiots guide to setting the timing on the 3.9 V8 in my V8s?

I have the use of a strobe, so far the bolt at the dizzy is too tight to undo without the risk of damaging it or snapping it off inside.

Can you trusts TVR's TDC marks and where will they be?

Any pointers/tutorials appreciated.

Thanks

GreenV8S

31,027 posts

315 months

Friday 14th March 2008
quotequote all
Timing marks are on the front pulley, they are not to be trusted unless you have verified them mechanically.

V8ish

Original Poster:

370 posts

230 months

Tuesday 18th March 2008
quotequote all
okay, I have now adjusted the timing.

bearing in mind I run the car on Super Unleaded I have adjusted the timing to 5 BTDC. before it was close to 12 but had no pinking.

What settings do other people use on their V8?
thanks


Edited by V8ish on Tuesday 18th March 16:29

spend

12,581 posts

282 months

Tuesday 18th March 2008
quotequote all
There are several advance curves due to different weights in the dizzy, not sure if our cars all have the same ones never mind your V8S. This may affect the static timing figures wink

Dave

GreenV8S

31,027 posts

315 months

Tuesday 18th March 2008
quotequote all
V8ish said:
I have adjusted the timing to 5 BTDC. before it was close to 12 but had no pinking.
Why did you adjust it?

blitzracing

6,422 posts

251 months

Tuesday 18th March 2008
quotequote all
Ive been running 10' on bog standard unleaded no problems. You could probibly run a couple more degrees on Super and if it was running 12' with no pinking, then all's well. I think 5' is too retarded.

Mark

V8ish

Original Poster:

370 posts

230 months

Wednesday 19th March 2008
quotequote all
blitzracing said:
Ive been running 10' on bog standard unleaded no problems. You could probibly run a couple more degrees on Super and if it was running 12' with no pinking, then all's well. I think 5' is too retarded.

Mark
I actually based it on the Bible that recomended 4' which I thought was too retarded, so I went for 5 to play it safe.

GreenV8s- I adjusted it simply because 13' seemed way out, and it was running slightly lumpy on the top end. I have noticed a slight diferance but not massive. Think I will wait until I get in a a RR to get it sorted properly.

Edited by V8ish on Wednesday 19th March 08:30

rev-erend

21,624 posts

315 months

Wednesday 19th March 2008
quotequote all
I've used a degree wheel to mark 28 degrees on mine - as that is the rough max advance figure and set the timing to this fugure at 4000 rpm.

8 degrees is what I use at tickover and seems to often work out to about 28 degrees max advance.

I've heard others say find when it pinks and back off a bit ..

It's all a lottery really with the old dizzy systems..

4 degrees is not really ideal.

timshap

155 posts

315 months

Thursday 20th March 2008
quotequote all
I'm sure mines set at 45 degs @ 3000 revs and 16 @ idle pre serp 500

Tim

GreenV8S

31,027 posts

315 months

Thursday 20th March 2008
quotequote all
V8ish said:
GreenV8s- I adjusted it simply because 13' seemed way out, and it was running slightly lumpy on the top end. I have noticed a slight diferance but not massive. Think I will wait until I get in a a RR to get it sorted properly.
In that case I suggest you put it back as it was. For a typical engine you would usually be aiming for around 28-32 degrees total advance, with a standard dizzy giving 20 degrees mechanical advance 8 degrees static puts you in the right ball park, they'll often take 12 or more without a problem. The only reason to retard it would be to avoid pinking, and as you say it isn't pinking there's no reason to take the timing back that far (even if it was pinking you wouldn't take anything like that much off). I don't know what problem is causing the lumpy top end but excessive ignition advance isn't a likely candidate and all you'll be doing by retarding it is losing power. (I'd be thinking in terms of cam wear if it was mine.)

Edited by GreenV8S on Thursday 20th March 18:04