Timing gear set install question [Archive] - 460 Ford Forum

: Timing gear set install question


faber
12-22-2009, 06:58 PM
So I installed the timing gear set, and when the #1 piston is at tdc on the compression stroke my crank keyway (the 0 degree on a 3 position timing gear set) is at 12 o'clock position, but the cam sprocket gear marked with the dot is just to the left of 6 o'clock. they dont seem to line up perfectly no matter where i put the chain. is this ok?

69F100
12-22-2009, 07:39 PM
mine was like that after i got it d greed in but if I am not misstaken you have the retarded timing set my timing set is the same way I had to put the keyway strieght up at 6 oclock to get my cam degreed in right.I am sure if I am wrong on the timing set someone will let you now but don't do it like I did unless you are degreeing the cam in I believe you should be ok like you have it

Paul Kane
12-22-2009, 08:18 PM
So I installed the timing gear set, and when the #1 piston is at tdc on the compression stroke my crank keyway (the 0 degree on a 3 position timing gear set) is at 12 o'clock position, but the cam sprocket gear marked with the dot is just to the left of 6 o'clock. they dont seem to line up perfectly no matter where i put the chain. is this ok?This is because your 3-position keyway double-roller chain is a 1972-up timing chain set. Specifically, since the 1972-up engines have the crank advanced 4 degrees (as viewable in your photo), your 1972-up double roller timing set has the "1972 straight up" (which is actually 4 degrees advanced when compared to a pre-72 engine marked as "zero" so as to correlate with 72-up engines.

The fix is simple: remove the chain and reinstall the lower gear using the keyway that retards the crank ("-4" position on the gear). Once installed correctly, the crank gear dot, the cam gear dot, cam dowel pin, and the snout keyway will all line up.

Paul

faber
12-22-2009, 08:39 PM
This is because your 3-position keyway double-roller chain is a 1972-up timing chain set. Specifically, since the 1972-up engines have the crank advanced 8 degrees (as viewable in your photo), your 1972-up double roller timing set has the "1972 straight up" (which is actually 8 degrees advanced when compared to a pre-72 engine marked as "zero" so as to correlate with 72-up engines.

The fix is simple: remove the chain and reinstall the lower gear using the keyway that retards the crank ("-4" position on the gear). Once installed correctly, the crank gear dot, the cam gear dot, cam dowel pin, and the snout keyway will all line up.

Paul
I am totally confused now. I thought the pre '72 engines had straight up cam timing, and post '72 were 8 degrees retarded. I bought the timing chain set thinking it would bring it back to straight up just like the pre '72

so to clarify I would use the 0 setting to get rid of the 8 degree retard from the original timing set, but for degreeing purposes i would use the -4 position?

rmcomprandy
12-22-2009, 10:29 PM
Whichever keyway in the crank gear is directly in line with one tooth is the "straight-up" position. The dot should be on THAT tooth.

BOSS 429
12-22-2009, 10:44 PM
So I installed the timing gear set, and when the #1 piston is at tdc on the compression stroke my crank keyway (the 0 degree on a 3 position timing gear set) is at 12 o'clock position, but the cam sprocket gear marked with the dot is just to the left of 6 o'clock. they dont seem to line up perfectly no matter where i put the chain. is this ok?




X3 YOU HAVE THE WRONG TIMING SET

faber
12-22-2009, 10:52 PM
Whichever keyway in the crank gear is directly in line with one tooth is the "straight-up" position. The dot should be on THAT tooth.

THANKS!! This is the type of technical answer this retard (me) needed to get the cam timing un-retarded... I think it is right now don't you?

Paul Kane
12-22-2009, 11:06 PM
X3 YOU HAVE THE WRONG TIMING SETFaber does not necessarily have the "wrong" timing set, because either early or late 3-position crank gears can get a true pre-72 straight up position, depending on the keyway selected on the respective gear.

Even so, I do realize that my detailed & technical explanation is a bit much, and that rmcomprandy distilled that explanation to its purest essence thereby making easy for anyone to understand. :D

Paul

Paul Kane
12-22-2009, 11:09 PM
Addendum: Just because a timing chain & gear set comes in a box with a part number for a pre-72 straight chain DOES NOT mean that this is what you get. We regularly receive late timing chaine sets in early style boxes, usually with the CompCams chains and Summit chains. (The box may say pre-72, but the lower gear is keyed for 72-up...BUT you can still use a keyway on that 72-up gear which will set the timing to be the same as pre-72/straight up.)

faber
12-23-2009, 12:43 AM
Faber does not necessarily have the "wrong" timing set, because either early or late 3-position crank gears can get a true pre-72 straight up position, depending on the keyway selected on the respective gear.

Even so, I do realize that my detailed & technical explanation is a bit much, and that rmcomprandy distilled that explanation to its purest essence thereby making easy for anyone to understand. :D

Paul

:) yeah...I am a little green to the engine building... I do really appreciate all the help. I did learn about crank advance vs. cam advance! I am learning quite a bit building this motor!