• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

MGB Question on timing and vacuum

Share this page

drooartz

drooartz

Moderator
Staff member
Gold
Country flag
Offline
Funny how things leave your memory after too many years. I need to check the timing on my 70 MGB, and can't remember if I need to check that with the vacuum line from the carbs to the distributor in place or with it removed and plugged. Been too many years since I tuned this car, and my Morris Minor has no vacuum line.

I have vague memories of removing and plugging that line with a golf tee for some tuning task, but can't remember why. 🤪
 
Disconnect it. And find that tee... 😉
 
I think it's still in my toolbox. ⛳
 
I need to look this up, but I seem to remember setting it to 32* at about 3500 rpm, so with all the mechanical advance in. Does that sound about right?
 
drooartz said:
I think it's still in my toolbox. ⛳
Click to expand...
Just like the Island of Misfit Toys, some of the things so anachronistic to their original purpose NEED to be at hand when no other "thing" is available.

A couple of 1/2" wood dowels can isolate a leaking heater core. Emery boards can clean a set of points.

drooartz said:
I need to look this up, but I seem to remember setting it to 32* at about 3500 rpm, so with all the mechanical advance in. Does that sound about right?
Click to expand...

As long as the dizzy is operating as it's supposed to. Did Jeff supply the dizzy?
 
Joe Reed said:
That's how mine is set, but I don't have vacuum advance.....mechanical advance only (DCOE carb)
Click to expand...
I kept the vacuum advance even with a 40 DCOE, but set the timing with it unconnected.
 
Jeff did the dizzy a few years and not many miles ago so that's in good shape.

I have a drawer of misfit tools like this. my grandfather was a piano tuner, and he had all sorts of made-to-suit tools. Guess I inherited that too.
 
Yup I have an entire little drawer of golf tees. :smile:

Also found my old notes for the car. I bought this car for the first time in 2011 (then sold it to my friend Paul, then bought it back from him) and I kept good notes in a little notebook. The notebook stayed with the car, so I could go back and see what I did in former tuneups. Back when I first owned the car I also made a little card with basic tuneup specs that was also still in there. Sure enough, I used to set the timing at 32* at 3500 RPM.

I'm glad I checked now, as the car is set quite a bit more advanced -- hopefully explains why it hasn't felt or sounded quite right. I'll get it reset once I can corral my helper again. I curse the engine designer that put the timing marks on the bottom of the engine. Really should get one of those kits to make a pointer on the top somewhere. Ah well, my wife's well skilled at watching me lie on the ground and lift my leg to let her know when to run the engine up. Should be able to get back to it this weekend and get the timing reset.

Plugs were the type I expected, and gaps were set pretty much on (tweaked a couple but probably just OCD to get them spot on). From a quick plug read it looks like I have the mixture set reasonably.

IMG_1443.JPG


IMG_1444.JPG



IMG_1445.JPG
 
Great that you kept a logbook! I know what it's like to try to recall what was done to which car and when, without one. 👍

As for tees, I'm obviously remiss in my restocking duties. This bin of bits was sat on my bench when a water heater line let go, it wasn't the most important thing there to quickly get removed, but the only drawer to get water in it was this one. BTW, this little cabinet is only slightly younger than I am.

SS2_5084.JPG
 
DrEntropy said:
Great that you kept a logbook! I know what it's like to try to recall what was done to which car and when, without one. 👍

As for tees, I'm obviously remiss in my restocking duties. This bin of bits was sat on my bench when a water heater line let go, it wasn't the most important thing there to quickly get removed, but the only drawer to get water in it was this one. BTW, this little cabinet is only slightly younger than I am.
Click to expand...
I'm so glad I did -- nice to be able to see what's been done, as the good Lord knows I won't remember! I thank my 11-years-ago self for writing this stuff down. I've got scattered notes on the Morris as well, need to get them written down into a notebook one of these days.

My cabinet's a youngin, maybe only 18 yrs old. I'm no golfer, but I did do a vendor golf outing a number of years ago and kept the tees -- specifically for old car work. Priorities you know.
 
Back
Top