Lucas octane boost

[David K.]

Gentlemen; I recently purchased a 15oz. bottle of LUCAS brand "octane boost" & added it to a full tank of gas (Shell 91 octane with no ethanol in Canada) on my '65-L76. The slight pinging which I had experienced on hard acceleration prior to the addition of the octane boost has gone away & I feel that the performance has increased somewhat, but there's no way to really measure that.
My question is as follows - can the use of this octane boost cause negative issues with my spark plugs (fouling?) - (running AC-45's) the engine or the carb....? Thanks in advance !!

[Bill L.]

Re: Lucas octane boost

David:

I have used it in my '66 big block (390 HP) coupe --- added to 93 octane here in Georgia --- no adverse effects in any way shape or form ---

I tuned the car out so it would not ping etc on todays pump gas -- got most of it out by messing with timing and points etc ---- near perfect but adding the octane boost it never had any issues again ---- I used one bottle per "HALF" tank of gas .......

Regards
Bill

[Jim T.]

Re: Lucas octane boost

Ever try airplane gas bought at an airfield?

[Michael W.]

Re: Lucas octane boost

David-

The Lucas product is on the long long list of marginally effective products. A full bottle of the booster in a tank of gas will raise 91 octane to 91.3 octane. That's it and not the 94 octane the advertising seems to promise.

If that's all you need to eliminate detonation, I'd sooner tune it out through remapping the advance curve. If that doesn't appeal, 94 octane gas is available at many Petro Canada stations.

[David K.]

Re: Lucas octane boost

Thanks guys;

Unfortunately; the Petro Canada 94 has ethanol in it. Guess I'll stick with the Shell 91 with no corn fuel. I have tried all the airports in the area (within 40 miles), and no-one is willing to sell the 100LL to the public. Seems the authorities clamped down on these guys....unless someone knows otherwise for the Montreal area ? Let me know ! Thanks !

[Michael W.]

Re: Lucas octane boost

Thanks guys;

Unfortunately; the Petro Canada 94 has ethanol in it.

I'm from Montreal originally and have been running E10 in my cars for over 20 years. Not one problem...............

[Joe C.]

Re: Lucas octane boost

You are better off using this product if you are on the ragged edge of detonation, but backing off the timing a degree or two will solve your problem much more cheaply:

http://www.wildbillscorvette.com/octanesupreme01.htm

[Frank D.]

Re: Lucas octane boost

I'm from Montreal originally and have been running E10 in my cars for over 20 years. Not one problem...............

And no snake oil products added I bet. Those additives' purpose is to thin your wallet -- that's all...

[Joe C.]

Re: Lucas octane boost

And no snake oil products added I bet. Those additives' purpose is to thin your wallet -- that's all...

All of them except the TEL additive that I posted a link to. Diminishing returns, however, if you are looking to raise your PON more than about 2 points.

As I said, back off the timing a bit and the ping will go away. Shouldn't notice much if any change in torque.

To answer the OPs question: The use of additives should have no effect on your plugs.

I'm surprised that you're getting detonation with a 327/365. What are your valves lashed at? If they're too loose, you'll build more cylinder pressure. If they're lashed at .025/.025, it's almost impossible to make an L76 rattle because the cam is so inefficient at low RPM's that the cylinders don't build pressure until after 4000 RPM. Of course, your timing might be screwed up. What can you tell us about your timing? It should be at 12 degrees BTDC vac advance disconnected and plugged, idling at 800 RPM. All 26 degrees of centrifugal advance should be in by 2350 RPM, for a total of 38 degrees WOT spark advance. I'll bet that you lost the bushing on the advance limiter slot and you're getting 30 instead of 26 mechanical advance. What vacuum advance can are you using?