Timing!

[Fontofall]

Hi, not been on here for a while! but here goes. What's the opinion on the best degrees timing btdc for a bus. The motor is a 1600, mild cam, twin dell 36's, all the seals and tin are in the right places. I cant remember whether it should be 28 or 32? We're always quite loaded and I don't want to run too hot if possible. Thanks in anticipation.

 

[Bobster]

It depends more on your dizzy tbh. And whether it's a vacuum advance or 009 ?

If you're talking about 28 or 30 I'm assuming 009, I time mine to 30degs at full advance

 

[Bluesnailman]

I've been having a few problems with running (turned out to be blocked jets), and spent a lot of time looking at this.

Assuming 95 octane fuel, and I believe regardless of distributor, 30deg at max advance is about right for either svda (vacuum plugged) or 009. 28 is probably a little bit low, but at 3500 rpm your coil won't be spitting out accurately enough for you to tell much diff between 28 and 30 is my guess. If your running super you could probably go to 32 Deg with confidence, but with 95 Ron I felt happier at 30.

I can't see a cam making to much difference to this rule of thumb, unless it's wild, would think it might have more influence on the curve - happy to be corrected though.

I ran a check on what idle advance I had and it was way off, about 10 or 11 deg and sounded and ran bad at low speed. So you might have to dial it back it bit to get a compromise at higher engine speeds or buy a new distributor (a 123svda - wonderful)

 

[Fontofall]

Thanks for the replies, yes its an 009, no vaccum.