• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

timing marks

Share this page

R

Roberte

Member
Offline
On my BJ7 on the timing pulley there is a notch. There also is a spot of white paint separate from the notch. Is the notch the top dead center or the 6 degrees before top dead center that the timing is supposed to be set to?

Robert
 
TDC; someone else must've added the paint, but verify its location before relying on it for timing.
 
Hi Guys, I just got my BJ7 engine running about a week ago and took it out for its maiden run. I set the timing at about 12 degrees BTDC which I guessimate is about 3/4th inch on the pulley. It starts, runs and idles great, but it appears to have some detonation at the higher rpms. I've probably guesstimated wrong on the pulley, but I think I will have to back off the timing a bit. Dave.
 
I was aided in setting the timing on my BN2 by a Norman Nock article in his Tech Talk book. He lists the following timing measurements for stock diameter crankshafts: 100-4, 6 degrees before TDC, 5/16 inch on the pulley. 100-6, 6 degrees, 3/8 inch. Mk I, 5 degrees, 5/16. Mk II & Mk III, 12 degrees, 3/4 inch (Dave - good guesstimate). I believe the 100M with the advanced curve is 14 degrees but am trying to confirm that and will interpolate from the 5/16. Mike
 
Here's a method given to a Mini owner friend of mine that was given to him by a Mini Specialist Shop.
I hope I've got it right so if you blow your engine apart trying this I reliquish all liability. :smile:
Let the engine warm up. Loosen the distributor bracket just a bit so that you can turn the distributor while engine is running. Rev engine to 3000 rpms and hold there, turn distributor in advanced direction very slowly until the engine misses, the back off timing just a tesh, and you got it. Good Luck, Dave.
 
I went out and bought a Gunsen advanced xenon timing light to set mine up, I may never use it again, but at least it is now done and my friends can borrow it.

:cheers:

Bob
 
MikeAH100M said:
I was aided in setting the timing on my BN2 by a Norman Nock article in his Tech Talk book. He lists the following timing measurements for stock diameter crankshafts: 100-4, 6 degrees before TDC, 5/16 inch on the pulley. 100-6, 6 degrees, 3/8 inch. Mk I, 5 degrees, 5/16. Mk II & Mk III, 12 degrees, 3/4 inch (Dave - good guesstimate). I believe the 100M with the advanced curve is 14 degrees but am trying to confirm that and will interpolate from the 5/16. Mike
Click to expand...
I just installed a new flamethrower electronic distributor and need to set the timing. My timing light isn't adjustable. To confirm the proper way for my 57 100-6 is to set the timing 3/8" to the left (veiwed from front of car) of the TDC notch?
 
CessnaTPA said:
I just installed a new flamethrower electronic distributor and need to set the timing. My timing light isn't adjustable. To confirm the proper way for my 57 100-6 is to set the timing 3/8" to the left (veiwed from front of car) of the TDC notch?
Click to expand...

No! As viewed from the front, your engine rotates clockwise. A mark on the damper/crank pulley that indicates a BTDC(before top dead center) timing setting will be to the right of the existing TDC mark.
 
CraigC said:
No! As viewed from the front, your engine rotates clockwise. A mark on the damper/crank pulley that indicates a BTDC(before top dead center) timing setting will be to the right of the existing TDC mark.
Click to expand...

Thanks for the clarification.
 
Is that correct. Im confused. With the engine rotating clockwise i thought BTDC was before (to the left) of th TDC pointer?
Matthew
 
Bob_Spidell said:
Why not just buy an advance timing light; then, measure total advance and let idle fall where it may? If you have positive ground, a plastic case is best lest electrons escape and run wild on your chassis:

https://tinyurl.com/zybbqaq
Click to expand...

I borrowed an advance timing light and will adjust the timing tomorrow. I also looked into getting timing tape and learned you size the tape to the diameter of the pulley. Which brings up another question, how can the advanced timing light be 100% accurate with so many different diameter pulleys out there? I guess it's just a ballpark reading?
 
"I borrowed an advance timing light and will adjust the timing tomorrow. I also looked into getting timing tape and learned you size the tape to the diameter of the pulley. Which brings up another question, how can the advanced timing light be 100% accurate with so many different diameter pulleys out there? I guess it's just a ballpark reading?"


Diameter doesn't matter. The mark represents an angle, relative to TDC, starting at the center of the crankshaft, and intersecting the outer surface of the pulley. When looking at the front of the pulley, think of it as a wedge section.

Example: 10 degrees is still 10 degrees, no matter what the diameter is, so it is accurate - as long as the mark relative to TDC (or the TDC mark) is true.
 
CessnaTPA said:
... how can the advanced timing light be 100% accurate with so many different diameter pulleys out there? I guess it's just a ballpark reading?
Click to expand...

The only reference you need is the TDC arrow pointer on the timing cover and the notch in the balancer/pulley. For example, if you want 15deg of advance, you set that on the light's dial and rotate the distributor until the notch falls under the pointer with the engine running at the desired speed. I can't vouch for the accuracy of advance meters--might vary a little with brand and/or price--but with modern electronic components it's probably pretty close; and the whole electromechanical spark mechanism ain't exactly precision anyway, even with all the moving parts in perfect nick. Extreme inaccuracy could result if the outer part of the balancer--with the notch--has slipped on the inner part; i.e. the bonded rubber damping mechanism has failed (not unheard of).
 
Thanks guys that makes perfect sense now that I think about it. Well I set the timing and the car has never started so easily, 1/2 second push on the button and it starts. New plugs, wires, coil and electronic distributor really made the difference.
 
Back
Top