View Full Version : Bugeye 948 ignition timing help please

09-25-2010, 09:33 AM
As I mentioned in a previous thread on oil pressure, I got my Bugeye started for the first time in 25 years - I never knew a sound could sound so sweet! I am finally down to a small punch list. I really need some help on timing now. I know there are three ways to time this engine, and I have questions about each.
1) I was going to try and time with a timing light, but my book only says "not specified" for this process. For those of you that use timing light, can you tell me what the degrees are and how you do it? Is the vacuum line disconnected during this process? What is the correct dwell angle? Neither of my manuals tell how to time with a timing light for a Mark 1 - is there a reason for this?
2) I have used vacuum timing before on my TR6, but I do not understand how to use it on my Bugeye. Can someone give me specifics, including where to tie into the vacuum system and what reading I shoud get?
3)On the static timing, I just plain don't understand the directions. Is there someone who can give detailed instructions in words I can understand? This applies to methods 1 and 3, but can someone explain to me how to read the "timing teeth" on the timing chain cover-there is conflicting information in my manuals?
Help on any of these would help me tremendously. Thanks,

09-25-2010, 03:41 PM
HI Kevin
I have never done the timing with the vacuum gauge, but here is a web page that explains it. It is for a Triumph but should work: Vacuum timing. (https://automotivemileposts.com/garage/v2n8.html)

Glad you got 'er going. A big thrill isn't it!

ps: it made me smile when you used the term "punch list."

09-25-2010, 03:49 PM
Also, Kevin: Here is a web page that might help with static timing: Les Bangston's article on timing. (https://www.custompistols.com/cars/articles/ignition_timing.htm)

And here is John Twist's video that shows how to static time: John Twist's awesome static timing video. (https://www.youtube.com/watch?v=hpp67aqwM2Y)


09-25-2010, 05:49 PM
Kevin, don't worry about static timing - that is for before initial startup. You are now to the point of needing a timing gun or the vacuum method. Not sure about timing marks on a 948, but hopefully someone will chime in.

09-25-2010, 09:38 PM
Hook up timeing light.

Disconnect and block vacumn advance.

What you want is 5 degrees advanced, on a BE that is the center point of the three. The large is 0, middle is 5 degrees, third is 10 degrees.

When you get it set to 5 degrees I will be pleased to give you a tip to get it dialed in to suit your specific engine.

I have used a light since about 1963, works every time.

09-26-2010, 04:25 PM
One of things that LUCAS did right is putting the adjuster wheel on the vacuum advance.

If the car starts and runs and you don't have a timing light (for dynamic timing) or 12 volt clip light (for static timing) then.......

Drive the car. If it pings when accelerating, turn the timing adjuster to retard. (clockwise) .. ELEVEN clicks is one degree. .. Drive more. Repeat until the ping is gone,

If it DOESN'T ping, advance the timing using the adjuster, until it starts pinging, then go back a little.

09-26-2010, 10:58 PM
LoL you did it Bill, that was my second step to get it dialed in for the engine condition and age of parts, etc.

You know I think I would get everything just right a lot easier if I did not have a bonnett.

Hap Waldrop
09-27-2010, 05:58 AM
You may not even have vacuum advance on your distributor on the Bugeye, depending on the model year and distributor. Some real intelligent engineer at BMC thought it woulf be easier to have the timing pointer and mark on bottom pulley on the bottom, so you probably have to jack the car up and put it on jack stand to set the timing. There will be a pointer there and it will have different degrees on it, one being TDC, if you have a dial backtiming light, the TDC mark is theonly one you need, by 3000 rpm all the advance will be in, so someone mantaining 3000 rpm form inside the car and you move the dial to the point where the marks line up, that is where you are currently timed, to change tthe timing loosen the squeeze clamp on the distributor to just the point where you can move the distributor, clockwise will advance your timing, counter clokwise will retrard your timing. Depending on what you compression ratio is is where you an set your timing, I ould start off at around 32 BTCD.

The only time I mess around with the blocking the advance off and doing timing at idle is if I not getting all advance I suspect I would need at 3000 rpms, if everything looks normal at 3000 rpm, and the distributor has vacuum advance then you know it is working properly, and have just saved yourself some time, the early Sprites came with a 25D that had no vacuum advance and you may very well have that distributor.

09-27-2010, 08:53 AM
Oh gesh Hap, after all these years I learned even more that I don't supose I will ever need.