Reply With QuoteFrom what I understand haveing the timing locked at 36 will make it harder to start but thats it.
Whats the deal with running locked out timing vs centrifugal advance. Will an engine idle at 36 degrees of timing btdc? Looking for peoples thoughts on that.
From what I understand haveing the timing locked at 36 will make it harder to start but thats it.
It will idle GREAT exspecially if you have a large cam. Works real good with tunnel rams too. You'll lose some low end torque which isn't an issue with a jet. You may need some sort of start up retard as it will fight the starter.
I haven't done it to my boat because its not that wild. But the 468 BBC in race car dropped the idle from about 1800rpm to about 1100rpm after going to a lock distribtor. If you switch to a crank fire you'll do one step better yet. Bottom line it builds more vacuum at idle, should be more fuel efficient when putting through the "no wake" zones too.
Anyone else have any thoughts to share about this. Im trying to figure out if it would be worth doing. I guess i just need to try it.
Yes, it will idle fine, in reality it is actually closer to normal completely locked than it is with just mechanical. Because if you have both mechanical and vacuum advance, the vacuum advance will addd almost 20 degrees, so in reality running a locked distributor is closer to have both mechanical and vacuum, than just mechanical is. the only time it would be different is when you are at cruising RPM and there is no vacuum, which if there was it would be way up there in the high 40s low 50s. However, with a high performance cam that doesn't have much vacuum, running vacuum advance is pointless, because it doesn't work anyway. So in that case completely locked is better, unless you have super high compression, in which case you will want a start retard, or be able to turn the engine over before you turn on the spark.
However, an engine that has enough vacuum to run a vacuum advance canister (about 10 - 12 inHg or more) should run one, because in general it will be more responsive and more efficient with it and the mechanical advance. remember though, mechanical advance is strictly related RPM, where vacuum advance is related to manifold vacuum, which is also linked to engine load.
Did I answer your qusetion?
Yes you did. I do not have vaccum advance on mine though, only mechanical. I have an MSD dist. and am toying with the idea of locking out timing at about 34 instead of running 8 initial and 25 mechanical advance.
Let us know how it works out.
why would you want to do that?just curious.
If you do it make sure that you run a seperate swith to the coil so you can turn it over then light it
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