[Jeff H]

I just got the car and when I checked the timing it was set at 38 degrees initial advance with no vacuum advance hooked up. I was told it's an L88 cam in the engine and it has a Holley 800 DP with no choke. It idles(when it idles) like it has a ton of lift and the exhaust is very rich. Does this sound right with the timing or could it have jumped the chain? It does run ok when it warms up and sounds powerful when you rev it, but that much advance doesn't seem right. Anybody fool around with built big blocks like this? Thanks, Jeff.

[68RS]

I run 36 deg. on my BBC for street use and about 39-40 deg. when racing with "good fuel". If it isn't knocking, I would say that you would be OK.

My homepage....
www.kdsi.net/~malandk

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[Jeff H]

Yeah, but is that at idle or total advance at 2xxx rpm's? I've never seen a car with 38+ degrees advance at idle, but I'm new to heavily modified engines. The vacuum advance is disconnected too.

[mccorry]

Are you sure that it is really 38 degrees? I have seen before where a balancer ring will spin and give an erroneous timing reading. You could be at 4 deg. BTDC....but the timing mark will show 38 deg.

Just a thought....

[darrell]

I doubt you have 38 deg at idle... I have a heavily modified bbc 454 .. . 12 to 14 with idle.. with the vacuum capped of... adjust the card with a vacuum gauge... i run a 850 DP.. close the 4 corner screws and open 1 1/2 turn out.. the adjust all four for max vacuum... 36 to 38 total advance would be correct.. but not at idle...

[Jeff H]

I'm going to check it again, but there is no vacuum advance connected so that has nothing to do with it. My timing light has the adjustment knob so while it was idling I put the light on with it set at 0 and I couldn't even see the timing mark. As I turned the knob up, the timing mark started to come into view and didn't zero out with the timing mark until the knob was at 38. The mark was moving around quite a bit too. Could it have jumped the chain? When you rev it, it runs pretty good.

[mccorry]

Again.....sounds like you balancer has slipped and is giving you bogus timing indication. The outer ring with the timing groove can sometimes slip on the rubber insulator. I have seen this a couple of times. Try to get another balancer to try...see what the timing reads then...

Steve

[Kevin]

My Camaro did the same thing (35 degrees) when the distributor's inner shaft was all crudded up and got stuck in the advanced position. Pull off your cap and see if you can get the rotor spin back a little. If it does, pull out the distributor, take out the inner shaft and polish it up. Fixed mine.

[Jeff H]

I checked the timing again this weekend and once it's warmed up it's at 30 degrees advanced at idle with a total advance around 44-45. It's pulling 10-11 hg(?) of vacuum through the carb vacuum port at idle(12-1500 rpm). It runs strong so maybe the balancer ring did slip some. The vacuum at idle seems ok for an L88 cam. It doesn't seem to knock or ping but I have to take it for a drive(once I get my tags) for the real test. I'm not too big on the Holley 800 DP without a choke though.