Distributor recurving?
 

I am rebuilding my engine 2.7....

specs:
Elgin MOD S cams
JE 9:8 pistons
PMO carbs 40

What should I recurve my distributor to = just S specs...?

thanks

I'd use 2.4 specs or 2.7 RS specs. Basically you want 35 degrees advance total and somewhere around TDC at idle. All 2.4 dizzy's had the same advance. RS is close to what the 2.4 was. I like to see full advance by about 4000RPM.

-Andy

35 degrees @ 4000 rpm with 9.8 compression is a formula for detonation.
That advise needs rethinking when the quality of today's fuel is considered.

4-7 @idle
18-20 @ 2000
28-30 @ 4800 max torque?
32-34 @ 6000
Easy? no, but this would be a fairly nice goal.

Thanks for the correction Henry. I should have noticed the high compression and made a disclaimer that I'm not an expert at the advance curves.

-Andy

Thanks for all the advise

I have decided to change pistons to

JE 9:5

to be on the safer side, cause it is true fuel octane may not be high enough....

so what would be the degree?

Henry gave you a nice curve in the above post. The main thing is to not exceed 35 degrees at any RPM.

-Andy

'74 Carrera stock distributor... will it need recurving...?

or is it best to install everyhting first then have it recurve when needed?

not sure what specs are on the stock bosch distibutor...

new engine being rebuilt specs:

PMO carbs
Elgin Mod S cams
JE 9:5

My plan for the PMO's is to go with the MSD 8981, stake my dizzie and program my curve.....

What do you mean by "stake your dizzie"??

Best regards,

Michael

Well...there are many interpretations.....:D

In this case however, I'll settle on a maximum advance figure (somewhere between 30-35 depending on A/F) mechanically limit the advance to that degree, then program the MSD curve up to that limit.....

I use an MSD 8981, with my distributor welded in the original full advance position.

The only problem is that the MSD gives a maximum 20 degrees programmable advance, so I run about 10 degrees at idle, ensuring I have 30 degrees total advance.

I really like the consistency and reliability of the MSD computer/CDI box combination.

Craig H