The Ford Barn

PC/SR · 09-13-2021, 08:20 PM

TDC is determined by the position of the crank, not the cam. The camshaft timing will be off if the dot in not in the right place. If, as seems to be the consensus, you are off by one tooth,; when your crank is at TDC the valve timing will not quite be where is it supposed to be, I think retarded here. The car will still run, but not well for a stock engine. Heavy duty racers play with retarding and advancing the cam timing depending on what results they want.

aermotor · 09-13-2021, 08:24 PM

I replaced my two piece cam gear several years ago and apparently got it right. If I recall the crank gear tooth was marked on the back side of the gear - does not make sense. Then the installation was oriented to the keyway on the front side. It did come out slightly left or right of the keyway, don't recall which. I have no way of knowing who or where that mark was made. Several years doesn't help the memory.

John

aermotor · 09-13-2021, 08:36 PM

Quote:

Originally Posted by kursed30

I put the plate back on and and when I turned the engine over until the pin hit the dot. I took out the spark plug and it was TDC.???

TDC can be a few degrees left or right on the crank position. Watch the piston while moving the crank left and right and you won't see any movement from TDC. You can still be 1 tooth off when viewing TDC through the spark plug hole.

John

johnneilson · 09-13-2021, 10:12 PM

The key in the crank is in-line with the rod journal. Cam timing mark is not at TDC, it is to align with the camshaft. Key should be pointing toward the cam centerline.
The gears are helical, the correct timing mark will be to one side of the keyway, but if you follow that tooth, it will cross over the center of the key about halfway across the gear face.
Now as to advancing or retarding the cam, as mentioned it will run, but not at full potential.
As to racers, yes cam timing gets altered, usually to compensate for something or correct a custom cam.
J

Tom Wesenberg · 09-13-2021, 10:21 PM

The cam gear mark should fall in line with the right side of the keyway in your picture.
Your's right now is on the left side as you face the picture.
The cam gear should have a mark. Look behind the oil slinger.
Wonder if someone installed the crank gear backwards, as the mark should face the front.

https://www.fordbarn.com/forum/showt...+tom+wesenberg

See the link I just posted. Reply 9 is my picture showing the correct timing marks.

Patrick L. · 09-14-2021, 05:56 AM

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Quote:

Originally Posted by kursed30

another pic

It does appear you are off a tooth. Being off a tooth changes the valve timing, it'll either advance it or retard it depending. Changing valve timing can be a good thing if done a couple degrees, but, not by a whole tooth.
Advanced valve timing gives more low end and retarded more high end power.

aermotor · 09-14-2021, 06:08 AM

Quote:

Originally Posted by Tom Wesenberg

The cam gear mark should fall in line with the right side of the keyway in your picture.
Your's right now is on the left side as you face the picture.
The cam gear should have a mark. Look behind the oil slinger.
Wonder if someone installed the crank gear backwards, as the mark should face the front.
See the link I just posted. Reply 9 is my picture showing the correct timing marks.

Tom, I found the mark or marks where you described on two engines so I don't think the gear was put on backwards (if it can be). The mark is hard to spot between the slinger and gear. Hence the reason to install in relation to the crank gear key way.

John

kursed30 · 09-14-2021, 07:58 AM

Thanks for all the help. It took me forever just to get it that close. Guess Ill try again lol

PC/SR · 09-14-2021, 10:45 AM

It will be easier and faster this time.

Patrick L. · 09-14-2021, 10:47 AM

Its not too hard a job, but, it has to done. Practice makes perfect. [ smiley face]

kursed30 · 09-14-2021, 06:17 PM

how does this look now?

Dan McEachern · 09-15-2021, 02:23 AM

Ruth and John are correct- you were 1 tooth retarded. Just FYI, the centerline of the gear tooth at a point halfway from the front and rear of the gear aligns with the centerline of the crank key. Being a left hand helix, the tooth starting on the right hand side of the keyway is the one with the timing mark.

aermotor · 09-15-2021, 06:16 AM

Has any one else found a marked tooth on the front of the crank gear behind the oil slinger or is mine a mechanics made mark? I can just barely see it with a flash light. Les Andrews book shows this on page 1-138 paragraph 5. I think the drawing is slightly wrong but the narrative is correct.
John

katy · 09-15-2021, 10:35 AM

The tooth mark on my CCPU engine was on the front.

Ruth · 09-15-2021, 10:42 AM

Quote:

Originally Posted by aermotor

Les Andrews book shows this on page 1-138 paragraph 5. I think the drawing is slightly wrong but the narrative is correct.
John

See post #13.

kursed30 · 09-15-2021, 11:02 AM

So how did the last picture I posted look? I moved it one tooth over from where it was.

Ruth · 09-15-2021, 12:31 PM

Quote:

Originally Posted by kursed30

So how did the last picture I posted look? I moved it one tooth over from where it was.

By jove, I think you've got it!!

aermotor · 09-15-2021, 01:35 PM

Quote:

Originally Posted by Ruth

I think the keyway should be to the left (in your picture) of the cam gear mark.

The diagram in post #13 is off by one tooth, check the dot in relation to the key way. Compare that to post #9 in the thread titled "Timing Gear" - the dots are obvious with the slinger removed. The crank gear mark is hard to see with the slinger installed but it is there. Forget the key way as a reference and find the crank gear dot! Save yourself a lot of mental gymnastics trying to mesh the gears in relation to the key way. It is a lot of work if you get it wrong.

John

Dave in MN · 09-15-2021, 01:42 PM

Quote:

Originally Posted by kursed30

So how did the last picture I posted look? I moved it one tooth over from where it was.

I agree that you now have it correct based on the last photo. (Entry #31)

See attached gears. 25 teeth on the steel gear makes it easy to mark the centerline through the hole/crankshaft. See where the line passes at the key on the front surface for future reference. The marked tooth is clearly clockwise of the keyway.

Good Day!

Patrick L. · 09-15-2021, 01:51 PM

Quote:

Originally Posted by kursed30

So how did the last picture I posted look? I moved it one tooth over from where it was.

That looks 'more better'.

09-13-2021, 08:20 PM	#21
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,278	Re: A few timing gear questions TDC is determined by the position of the crank, not the cam. The camshaft timing will be off if the dot in not in the right place. If, as seems to be the consensus, you are off by one tooth,; when your crank is at TDC the valve timing will not quite be where is it supposed to be, I think retarded here. The car will still run, but not well for a stock engine. Heavy duty racers play with retarding and advancing the cam timing depending on what results they want.

09-13-2021, 08:24 PM	#22
aermotor Senior Member Join Date: Mar 2015 Location: Greenville, SC Posts: 1,099	Re: A few timing gear questions I replaced my two piece cam gear several years ago and apparently got it right. If I recall the crank gear tooth was marked on the back side of the gear - does not make sense. Then the installation was oriented to the keyway on the front side. It did come out slightly left or right of the keyway, don't recall which. I have no way of knowing who or where that mark was made. Several years doesn't help the memory. John

09-13-2021, 10:12 PM	#24
johnneilson Senior Member Join Date: Jun 2010 Location: 34.22 N 118.36 W Posts: 1,054	Re: A few timing gear questions The key in the crank is in-line with the rod journal. Cam timing mark is not at TDC, it is to align with the camshaft. Key should be pointing toward the cam centerline. The gears are helical, the correct timing mark will be to one side of the keyway, but if you follow that tooth, it will cross over the center of the key about halfway across the gear face. Now as to advancing or retarding the cam, as mentioned it will run, but not at full potential. As to racers, yes cam timing gets altered, usually to compensate for something or correct a custom cam. J __________________ As Carroll Smith wrote; All Failures are Human in Origin.

09-13-2021, 10:21 PM	#25
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: A few timing gear questions The cam gear mark should fall in line with the right side of the keyway in your picture. Your's right now is on the left side as you face the picture. The cam gear should have a mark. Look behind the oil slinger. Wonder if someone installed the crank gear backwards, as the mark should face the front. https://www.fordbarn.com/forum/showt...+tom+wesenberg See the link I just posted. Reply 9 is my picture showing the correct timing marks. Last edited by Tom Wesenberg; 09-13-2021 at 10:27 PM. Reason: Add information.

09-14-2021, 07:58 AM	#28
kursed30 Member Join Date: May 2021 Location: Omaha, Ne. Posts: 46	Re: A few timing gear questions Thanks for all the help. It took me forever just to get it that close. Guess Ill try again lol

09-14-2021, 10:45 AM	#29
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,278	Re: A few timing gear questions It will be easier and faster this time.

09-14-2021, 10:47 AM	#30
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: A few timing gear questions Its not too hard a job, but, it has to done. Practice makes perfect. [ smiley face]

09-15-2021, 02:23 AM	#32
Dan McEachern Senior Member Join Date: Aug 2010 Location: SF Bay Area Posts: 193	Re: A few timing gear questions Ruth and John are correct- you were 1 tooth retarded. Just FYI, the centerline of the gear tooth at a point halfway from the front and rear of the gear aligns with the centerline of the crank key. Being a left hand helix, the tooth starting on the right hand side of the keyway is the one with the timing mark.

09-15-2021, 06:16 AM	#33
aermotor Senior Member Join Date: Mar 2015 Location: Greenville, SC Posts: 1,099	Re: A few timing gear questions Has any one else found a marked tooth on the front of the crank gear behind the oil slinger or is mine a mechanics made mark? I can just barely see it with a flash light. Les Andrews book shows this on page 1-138 paragraph 5. I think the drawing is slightly wrong but the narrative is correct. John Last edited by aermotor; 09-15-2021 at 06:31 AM.

09-15-2021, 10:35 AM	#34
katy Senior Member Join Date: Jun 2015 Location: Red Deer, Alberta Posts: 5,042	Re: A few timing gear questions The tooth mark on my CCPU engine was on the front. __________________ If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn!

09-15-2021, 11:02 AM	#36
kursed30 Member Join Date: May 2021 Location: Omaha, Ne. Posts: 46	Re: A few timing gear questions So how did the last picture I posted look? I moved it one tooth over from where it was.