New engine setup mystery

Rancho Deluxe

Rancho Deluxe

Senior Member
Please check this conclusion….correct it if you can. It’s a mystery with a
shiny new rebuilt engine. Everything’s new, tight, fresh, and proper with authentic Model A parts. The distributor is authentic and in top notch condition. All great? No, the engine won’t run properly. It sounds like it’s timing is far too advanced. We’ve checked and rechecked this and set it up carefully and correctly. It won’t run anything close to normal unless the timing is set to the fully retarded position. Today we tried it with the distributor cam reset back (Clockwise) about as much as the width of the rotor blade. I’d guestimate that as 7 to 10 degrees retarded from the nominal normal position. That made the engine run much more normally and respond thru the range of timing lever settings. It was still sounding somehow odd but much better. Our reluctant conclusion as to the cause of this: The camshaft gear is probably meshed to the crankshaft gear incorrectly. One tooth off would account for the cam angle change. But how about the valve train timing advance? Would an engine run anywhere near normally that way? Are there any other possible explanations? Thanks fordbarners.
 
The timing gear mesh is fairly easy to check. Block up the engine, remove the timing cover and take a peek. there are 50 teeth in a timing gear so that's 7.5 ° per tooth.
 
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Might you have a B front cover on the engine? The timing pin location of the B front cover differs from the A, and my recollection is that it is more advanced.
 
Sounds like you are on target with your conclusion of the timing gear. I would check and make sure as Will has suggested that you don't have a B timing gear cover.
 
One way to check is to take out #1,#4 plug, look in #4 at valves,rotate crankshaft while watching #4 ezhaust valve, just as it is about to close #4 intake should just start to open(putting trans in 3rd gear and rolling car on level surface fwd--back makes it easy to see this event along with using bent wire to feel piston), the timing pin should feel the recess in the timing gear and #1,#4 piston should be at top when cam timing is correct ----this process should verify the gear is on the cam correct, the cam and crank gears are meshed properly and that the timing pin recess is in the correct place

does your timing cover have a oval boss where the timing pin screws in?
 
Don't forget that the steering column can be rotated. That will affect your timing as well, don't know bout 7-10 degrees though.

Mike
 
Well Barners, it's not the timing gear cover. The car is a '28 and the cover is correct. Sounds like it's the gear timing. So, severe retard setting for the distributor gets it to run pretty well, but what about the basic valve timing. That must be advanced also, probably by the one gear tooth value of about 7.5 degrees or so. What effect would you expect that to have on a new engine. It is firm and new, not broken in, but also not too tight. Rancho
 
Try to verify the cam gear timing as Kurt said.
If still in doubt then remove the front timing cover and look at the marks.
 
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