Corvette distrbutor

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chevrolet
corvette

#1

I’ve just completed rebuilding the stock 350 in my 73 Corvette…Mild upgrades, 9:3 pistons from 8"5, 327-350 cam, .030 over. Motor runs very good. With engine changes I set the timing by ear. When

I went to check where the timing was actually set at with a timing light, it was approximately 2 inches above the timing marks. Could I have installed the distributor a tooth off, or is that a myth?


#2

It’s possible to install it more than a tooth off and I would not advise setting the timing by ear on an older car in the world of unleaded gas. It may appear to run well because the timing is excessively advanced.
You may (?) get away with this during city driving but one high speed highway drive may do the engine in if there is too much advance.

Still running the stock contact point dist. or are you using the later HEI dist.?
Vacuum advance line connected to ported or manifold vacuum and are you disconnecting the line while checking the timing with a light?


#3

Where are you measuring two inches? Crankshaft pulley? Please say, “No.”

When you say, “above,” what do you mean? I’ve heard of before top dead center (BTDC) and after top dead center (ATDC), but I’ve never heard of timing that was “above.”

Please explain.


#4

dee book! dee book! You need dee book (repair manual)! Here are some instructions from dee book on your distributor: http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?fromSearchPage=true&pageId=0900c152800834e1&partName=Distributor&partId=0900c152800834e1
Maybe, the crankshaft pulley is notched wrong. Find TDC (top dead center) with a straw stuck in the spark plug hole, resting on top of the piston. Turn the crankshaft until the timing mark, on the crank pulley, approaches zero degrees. While turning the crank, watch the straw rise. When it stops rising will be TDC. Then, set the distributor.


#5

Moved distributor over a tooth, all is well.


#6

Moved distributor over a tooth, all is well.


#7

Great! You got ignition running on time. This illustrates that a smooth running engine can be WAY out of time. Good catch!