2024/03/29 13:16:15
GTV6
Hi Guys
I'm putting my engine back together and thought I would check my cam timing.  Inlet centre is at 128deg ATDC, which is 18 degrees too far.  Has anyone seen this before?  Is there a known issue with timing marks on crank gears being out?
 
It's got me stumped and I've triple checked it.  Moving the setup by 2 teeth will fix it but I would like to know what's going on.
 
Thanks
Steve  
2024/03/29 21:30:08
martymexico
Have you checked with using another cam if you have 1 ?
I would try setting it up on another cyl and see if it lines up or move the dial gauge to the exh side as well to check where that is in relation to the inlet side.
2024/03/30 14:20:13
GTV6
No I dont have another cam that fits (long story a about undersize bearings) but I advanced it by two teeth and inlet and exh centres are now spot on.  Going to measure some other cylinders today.
 
The original stock cam was correct but is long gone so its not the crank key position.  I'm guessing that the cam keyway was cut for a 90deg V instead of the 60deg V in the blank.  The last non original cam that came out had a 3 deg offset key in it which maybe makes sense.  Two teeth is 18 deg, 90 v's 60 is 15 deg per side, difference being 3deg hence the 3 deg key....maybe.   But this time I have a 0 offset key so I should be 3 deg out if I'm right.  Maybe the cam manufacturer has accounted for this.   
 
I have sent an email to them to see what they know about it.
 
2024/04/01 11:28:37
MarkA
I just did a quick search and discovered a fun trivia fact; the Canadian Essex was a 90deg
 
If you have no joy with the manufacturer try John McCallum. He should be able to shed some light

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