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BT7 ignition timing

  • Thread starter Deleted member 21878
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looking to confirm what the timing should be on a 29E series engine.

my one manual showed ignition timing on BT7's as 10* BTDC static and 15* BTDC with the light.

in another manual it says only on 29F/4898 and later engines use the above settings. the earlier cars use 6*BTDC static and say nothing about a strobe light.

i just want to make sure i set my car properly.

Thanks
TL
 
OfficialTimingSpecs.jpg

From the official Bentley manual.

FWIW when I got my distributor back from Advanced, Jeff recommended this timing: "14 - 16 degrees BTDC at Idle vacuum disconnected".

However, the 35 degrees max is the proof of the pudding.
 
Thanks, i went by the Bentley manual but just happened to read this other manual yesterday. it is a Haynes manual.
 
Drone Dog said:
Thanks, i went by the Bentley manual but just happened to read this other manual yesterday. it is a Haynes manual.
Click to expand...

I've got the Haynes manual, too. If there's a conflict, would go with the official manual.

Plus what Jeff of Advanced Distributors told me jibes with the official manual.

Your distributor will be labelled as "DM6A" on the rim at about the 11 o'clock position. Those are the specs you go with.
 
Just timed my new distributor to 15 degrees BTDC @ 600 rpm with vacuum disconnected. This setting results in a max advance of 35 degrees BTDC at around 3000 rpm.

FWIW, I use an old style Craftsman fixed timing light and mark my crank pulley. Viewed from the front, marks are to the right of the TDC notch. 15 degrees = .82"; 35 degrees = 1.875".
Dimensions based on a pulley diameter of 6.25" with a circumference of 19.625"
 
Last edited:
One thing about Pertronix is that timing will change significantly after installation. My otherwise knowledgeable and meticulous mechanic/machinist used points to set static timing so the engine would fire on the first crank--it did--but when I installed the engine it would barely idle and would backfire ferociously when accelerated (bet it was down 40HP :wink-new:smile:. I think he put my Pertronix back in and didn't re-time the engine.
 
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