The Stovebolt Site Forums The Shop Area Engine Shop 22-deg spark advance??

> Do I have a problem ...?
Today I hooked up my sparkling new HF timing light with the advance dial on the back. I had to advance the dial 22-deg to see the BB. (actually 24-deg) I had not moved the distributor.

I stopped when I saw the amount of spark advance and came in to ask the experts. I haven't installed new points or condenser yet.

+ I've never heard it spark-knock / ping
+ Engine was cold and at idle when I checked timing
+ Choke was open
+ Octain selector on zero
+ Easy to start -- doesn't push back like the timing is advanced too far
+ 90 octain non-ethanol gas
+ Runs cool with a 160deg thermo

I haven't hooked it to a vac gauge yet, or done a compression test. Haven't measured gap on points.

My plan was to set the timing to the BB and use the octain selector to fine tune the timing. The octain selector goes +/- 10deg.

What's my next step?

Some background ...
OK, I admit: I'm an idiot.

I've owned my '54 3104 with '54 235 + 1959 848 heads for fifteen years. Not many miles in the first ten years. About 1,000mi/year in the past four of five.

Except for rebuilding the carb, adjusting the valves, new plugs, and changing the oil - I haven't touched the engine or ignition since I bought the truck. Runs strong.

I figured that I'm probably pushing my luck, so I'm installing new points, condenser, rotor, and setting the timing before I drive to the Daytona Turkey Run.

Thanks for your help,

- Lonnie

Sounds like a lot. But I have no idea how accurate the light is. 10-12 degrees advance with modern fuel is about right. If it won't ping under a load and it accelerates OK you might be fine. I don't use a light much just a vacuum gauge and a drive test to set mine. Set to max vacuum, back off a bit and drive up a hill. Works every time. Course I have a gauge and a hill both at hand. Any one else?

Did your truck come with a 216?

It's a 1954 truck. It's had a 1954 235 block with 1959 head since I bought it 15 years ago.

I'm sure that it has had some replacement parts over the years. I believe the intake is from a 261. Rear end is 1950. Don't know about the flywheel or distributor.

I'm using the same HF timing light that you have. Can't check the accuracy. My old timing light from over 40yrs ago is broken.

I'll play with the vacuum gauge tomorrow. And yes, Gus, I have the same HF vacuum gauge that you have!

Don't want to introduce another variable by replacing the points.

- Lonnie

When using a dial back timing light, you have to turn the dial on the timing light until you find the top dead center or 0 mark in order to tell what your actual advance is. If you are using the BB as a reference, then you are getting false information. I am pretty sure there is a mark on the flywheel denoting TDC, but I don't know what it looks like offhand. Digging for that info righ now

From what I can find the tdc mark could be either a triangle or a UC mark. Another way you can do it is to find out what timing setting the BB is suposed to be. For instance, if the BB is supposed to be 4 degrees before top dead center, and you turn the dial on your light untill the BB lines up, and the dial reads 5 degrees, then you are at 9 degrees BTDC. Sound like something is aways off there somewhere. I would use a vacuum gauge and time it that way. Perhaps the variety of parts being used is throwing you off

Bolter2 -

> How can I check the accuracy of the dial settings on my $25 HF light?

Even if I set the dial to zero and rotate the distributor until the BB is under the pointer, if the dial markings are wrong I still won't know if the distrib is at the correct setting.

The pointer on the knob on my light rotates counter-clockwise below zero. Perhaps the knob is on wrong. If so, that would cause a false reading.

I have not moved my distributor from the position that it was in 15 years ago.

When I hooked up the timing light with the dial at zero, I couldn't see anything on the flywheel.

I advanced the dial to 24deg and the BB was directly under the pointer. I was trying to determine what the current distributor advance is before I start moving the distributor.

I "assumed" that the dial allows one to time the engine to a specific degree by retarding the flash that amount of degree. When the BB is under the indicator, the light is retarded 24-deg and the engine is advanced 24-deg.

I dunno. Maybe I should read the directions.

At least I did double check to make sure that it was hooked onto the right spark plug lead. It is. #1 and #6 have the same 24-deg advance.

- Lonnie

Bolter2 -

I just read your second post. That might be a way to adjust the knob if it is in the wrong position. Just need to learn what degree of advance the BB is on a '54 truck Thriftmaster 235.

If it's way off, I may just return the light.

- Lonnie

I edited my previous post as you were reading it I think! I am not familiar with that particular timing light. My Snap On light dial starts at 0 and you can't turn it below that. As was stated earlier, it will be easier and more accurate, I think to set the timiing with a vacuum gauge