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Big Healey Timing Question

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67BJ8

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I sent my BJ8 distributer out for rebuilding. The restoration shop told me that when I get it back to not set the timing at 15 degrees advanced. He said that when using the unleaded fuels available now that you should leave the vacuum advance hooked up and set the timing at 25 to 32 degrees advanced when running at 2500 RPMs. Anybody familiar with this timing setup?

Larry
 
Hi, Nope, BUT I sure will be interested in seeing what the "technically-oriented" guys have to say!! Also, what if you use a 'lead additive'..?? Would this change their advice?
 
Larry,

If you time the ignition to 25-32 degrees(seems like a very wide range btw) at 2500 rpms, what is the resultant timing at 800 rpm? Perhaps it will come out to 15 degrees making both techniques correct.

Cheers,
John
 
I agree with John. The two different methods should be close to equivalent. Timing at 2500rpm is probably a little more accurate method. Even small variations of rpm at idle can cause large variations of distributor advance & it is hard to accurately determine 800 rpm or what ever rpm it is. However the wide range of 25 to 32 degrees leaves me wondering. I would be more concerned about not exceeding 35-40 degrees at 5000 rpm.

The commonly available pump unleaded fuels are lower octane than the leaded fuels & may require less advance to not ping.

Many ways to arrive at the same result.
D

[ 05-27-2003: Message edited by: Dave Russell ]</p>
 
Steve,

I have a no-lead head on the car so I should never have to use a lead additive. I will be talking to the shop this evening and will ask them
more about the timing.
 
Dave,

I made a typing error on the timing advance. It should have said 28 to 32 degrees advance. I talked with the restoration shop last evening. They said to set it at 32 degrees first and if it
pings to start backing it off a little bit. He
said that his recommendations are for using
unleaded fuel with no additives added.

Larry
 
related subject on distributors: Is there a place to buy the advance springs for the distributors? One of mine has a kink in it.

thanks
 
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