Author Topic: Timing gear dowel pin length?  (Read 4551 times)

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uniceptor

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Timing gear dowel pin length?
« on: December 28, 2017, 12:02:33 AM »
I'm building a 428 with a Lunati factory performance cam, lifters and timing gear set.  The camshaft included 2 timing gear dowel pins.  I installed the longer of the two for a single piece fuel pump eccentric, but the pin is still too short.  With the pin pushed all the way into the camshaft, it is just a little short of being flush with the surface of the cam timing gear.
Does this mean the pin is too short or the cam timing gear is not all the way on the camshaft?

a70eliminator

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Re: Timing gear dowel pin length?
« Reply #1 on: December 28, 2017, 06:30:52 AM »

I think you cam is back against the rear cam bore plug, put the bolt in and draw it up and the pin will probably end up protruding 1/8" proud is all that's required.

blykins

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Re: Timing gear dowel pin length?
« Reply #2 on: December 28, 2017, 07:39:07 AM »
Put the eccentric on, line it up, stick the cam bolt in, and run it up like you're tightening it up.  If the pin doesn't protrude into the eccentric, report back. 
Brent Lykins
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uniceptor

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Re: Timing gear dowel pin length?
« Reply #3 on: December 28, 2017, 11:31:44 AM »
Confirmed that the dowel pin is not long enough.  Got out the calipers and measured.  The long dowel pin is 1.375" long.  When the pin is installed all the way into the camshaft, it only protrudes 0.938" from the camshaft.  The cam timing gear is 0.960" thick.  The fuel pump eccentric is 0.165" thick.  If I have my math right, I need 1.125" protruding from the camshaft to be long enough for the eccentric.  This would equate to about 1.550" pin length. 
Is there a longer pin available? 
Is there a recommended way to keep the pin from going all the way into the camshaft?

blykins

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Re: Timing gear dowel pin length?
« Reply #4 on: December 28, 2017, 11:40:31 AM »
Did you try putting the eccentric on and tightening the bolt up?  The pin doesn't typically extend all the way through the eccentric.  Sometimes there will be just enough sticking out of the cam gear to keep the eccentric from spinning on the bolt.  Doesn't need much.

If you are confident with your measurements, you can put a little ball bearing behind the pin.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
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uniceptor

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Re: Timing gear dowel pin length?
« Reply #5 on: December 28, 2017, 11:45:58 AM »
Yes, installed eccentric and pin does not engage eccentric at all.  Eccentric wants to spin when I tighten the bolt.   I like the idea of a small ball bearing if I can find one laying around the shop.

scott foxwell

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Re: Timing gear dowel pin length?
« Reply #6 on: December 28, 2017, 11:54:58 AM »
Install cam gear and eccentric, line up holes, push pin into hole just flush or just past flush with eccentric. Tighten bolt.
-OR- put pin in cam, leave it long, install gear and eccentric over pin, push pin in flush or just past flush with eccentric, tighten bolt.

blykins

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Re: Timing gear dowel pin length?
« Reply #7 on: December 28, 2017, 12:26:30 PM »
Install cam gear and eccentric, line up holes, push pin into hole just flush or just past flush with eccentric. Tighten bolt.
-OR- put pin in cam, leave it long, install gear and eccentric over pin, push pin in flush or just past flush with eccentric, tighten bolt.

Ford cam dowels aren't always a tight fit (unless it's a Cleveland cam).   I could see how the pin could float or move deeper into the cam and if the cam bolt clamping force wasn't sufficient, it would let the eccentric spin.  Probably a slim chance of that happening, but I would feel more comfortable with a setup that would keep the pin from moving.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
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www.customfordcams.com
502-759-1431
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scott foxwell

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Re: Timing gear dowel pin length?
« Reply #8 on: December 28, 2017, 12:30:38 PM »
Install cam gear and eccentric, line up holes, push pin into hole just flush or just past flush with eccentric. Tighten bolt.
-OR- put pin in cam, leave it long, install gear and eccentric over pin, push pin in flush or just past flush with eccentric, tighten bolt.

Ford cam dowels aren't always a tight fit (unless it's a Cleveland cam).   I could see how the pin could float or move deeper into the cam and if the cam bolt clamping force wasn't sufficient, it would let the eccentric spin.  Probably a slim chance of that happening, but I would feel more comfortable with a setup that would keep the pin from moving.
If it's going to move, what's to say it won't move out?
I'd bet a dollar to a donut that the cam gear will spin enough to at least put pressure on the dowel once the engine is running. BUT, if not, some red Loctite should solve that problem.

blykins

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Re: Timing gear dowel pin length?
« Reply #9 on: December 28, 2017, 12:33:40 PM »
It can't move out dude.....the cam bolt washer holds the pin captive.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
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uniceptor

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Re: Timing gear dowel pin length?
« Reply #10 on: December 28, 2017, 12:40:54 PM »
Interesting that RockAuto offers a Camshaft Hardware Kit http://www.rockauto.com/en/moreinfo.php?pk=5580249&cc=1119844&jsn=1194
that has what I think is the correct dowel pin (3.090" x 1.50") and summit racing only offers the short dowel.
Going to see if any of the local auto part stores have the correct dowel, now that I have measurements.

scott foxwell

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Re: Timing gear dowel pin length?
« Reply #11 on: December 28, 2017, 12:41:21 PM »
It can't move out dude.....the cam bolt washer holds the pin captive.
LOL...you're right dude...so it does.  ::)

blykins

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Re: Timing gear dowel pin length?
« Reply #12 on: December 28, 2017, 12:48:39 PM »
What's the rolling eyes for?
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

blykins

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Re: Timing gear dowel pin length?
« Reply #13 on: December 28, 2017, 01:00:57 PM »
Interesting that RockAuto offers a Camshaft Hardware Kit http://www.rockauto.com/en/moreinfo.php?pk=5580249&cc=1119844&jsn=1194
that has what I think is the correct dowel pin (3.090" x 1.50") and summit racing only offers the short dowel.
Going to see if any of the local auto part stores have the correct dowel, now that I have measurements.

Most cams usually come with a short dowel and a long dowel.  I just went and measured, the long dowel is 1.5".   If you can't find any local to you, let me know and I'll throw you one in the mail.  I've got a million of them.
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

shady

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Re: Timing gear dowel pin length?
« Reply #14 on: December 28, 2017, 01:45:54 PM »
I have used the ball bearing method. When I did mine on a Comp cam, after everything was tightened up I could push the dowel in past the eccentric with just my finger, so I would never trust it not to move, hence the ball bearing.
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