timing gears - The 1947 - Present Chevrolet & GMC Truck Message Board Network

justinburnett · 03-23-2011, 07:25 PM

So I'm putting my engine back together and I don't know where to line up the cam. THe hear on the crank doesn't just have a dot, it has a bunch of +4,-4 stuff. There are 3 keyway slots and it is in the +4 position so do I line the cam hear timing mark with the +4 then? Someone please confirm for me that I am right, and then tell me what it means. Thank you.
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Cramitthefrog · 03-23-2011, 07:52 PM

Those marks are for advancing or retarding the cam so many degrees, but there should also be marks to install it straight up.

justinburnett · 03-23-2011, 08:08 PM

I didn't pull it because I don't have a tool and the gear 's in great shape. If I leave it it +4 what happens? Is that going to hurt my low end torque to have the cam advanced?
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wyattglock · 03-23-2011, 08:09 PM

The marks on the cam and crank gear should line up. If you can see the +4, -4 marks on the crank gear there should be a mark roughly 120 degrees from each. I don't know what else has been done to your engine, but straight up is usually the best way unless you have a real hot cam and a good set of heads.
One question, what kind of timing set are you putting on? I just did an Edelbrock set and it had a circle at TDC, a square at +4, and a triangle -4.

justinburnett · 03-23-2011, 08:41 PM

I left it where it was. I can't find a press for the gear anywhere. I already had all the pistons in or I'd drag the crank down to a machine shop, unless I'm totally screwed if I don't, in which case I'll tear the whole thing apart now. I put in a new RV cam, if that matters.
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justinburnett · 03-23-2011, 08:42 PM

I don't know who made it. It was on there before.
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I could maybe use a balancer install tool and a piece of pipe to press it on, couldn't I? Maybe that would be a good idea. I don't know if I should have a short duration cam advanced. Thoughts, feelings, better ideas? I don't want to throw this in and have run crappy or have little power.

Tx Firefighter · 03-23-2011, 09:18 PM

To install it, put the crank gear in your wife's oven at about 400 degrees for half an hour or so. Using good thick gloves, slip it on real fast while still hot. No tools required (other than gloves and a stove).

justinburnett · 03-23-2011, 11:30 PM

I'll give that a try. I thought metal expanded when it was hot. Will let you guys know tomorrow.
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jrcaprai · 03-24-2011, 01:18 PM

Quote:

Originally Posted by justinburnett

I'll give that a try. I thought metal expanded when it was hot. Will let you guys know tomorrow.
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Exactly... is there a 0° mark ? the best method is a degree wheel such as
http://www.summitracing.com/parts/SUM-G1057/

Tx Firefighter · 03-24-2011, 02:32 PM

If you heat a gear it grows both inside and out. You can slide it on by hand until it cools. Then it fits with the proper interference fit. Trust me. I've done it a bunch of times.
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justinburnett · 03-24-2011, 04:00 PM

Gotta get it off first which is proving harder than I thought it would. I'll get it though.
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justinburnett · 03-24-2011, 05:33 PM

Made a ghetto gear puller out of some bar stock, nuts and bolts. Slid right off. Got it lined up on 0, pressed it on with a harmonic balancer tool and some pipe, couldn't use friend's oven cause the house was locked. All in all it worked good and I'm glad I did it.
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wyattglock · 03-24-2011, 05:49 PM

Now that you have done that, try and get your hands on a degree wheel. A good degree set will have a dial indicator. You can indicate off the rocker or the top of the valve and get your high point for top dead center. That will get you dialed in pretty good. Then make sure the engine is at TDC and install the distributor. Use a timing light and you should be able to get that thing running great in no time. I prefer the timing lights that have the advance dial on them.

03-23-2011, 07:25 PM	#1
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	timing gears So I'm putting my engine back together and I don't know where to line up the cam. THe hear on the crank doesn't just have a dot, it has a bunch of +4,-4 stuff. There are 3 keyway slots and it is in the +4 position so do I line the cam hear timing mark with the +4 then? Someone please confirm for me that I am right, and then tell me what it means. Thank you. Posted via Mobile Device

03-23-2011, 07:52 PM	#2
Cramitthefrog It's always something Join Date: Jan 2011 Location: Carson City N.V. Posts: 59	Re: timing gears Those marks are for advancing or retarding the cam so many degrees, but there should also be marks to install it straight up.

03-23-2011, 08:08 PM	#3
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears I didn't pull it because I don't have a tool and the gear 's in great shape. If I leave it it +4 what happens? Is that going to hurt my low end torque to have the cam advanced? Posted via Mobile Device

03-23-2011, 08:09 PM	#4
wyattglock Registered User Join Date: Jul 2010 Location: Lafayette, IN Posts: 622	Re: timing gears The marks on the cam and crank gear should line up. If you can see the +4, -4 marks on the crank gear there should be a mark roughly 120 degrees from each. I don't know what else has been done to your engine, but straight up is usually the best way unless you have a real hot cam and a good set of heads. One question, what kind of timing set are you putting on? I just did an Edelbrock set and it had a circle at TDC, a square at +4, and a triangle -4. Last edited by wyattglock; 03-23-2011 at 08:15 PM. Reason: Getting kids ready for bed while playing on internet

03-23-2011, 08:41 PM	#5
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears I left it where it was. I can't find a press for the gear anywhere. I already had all the pistons in or I'd drag the crank down to a machine shop, unless I'm totally screwed if I don't, in which case I'll tear the whole thing apart now. I put in a new RV cam, if that matters. Posted via Mobile Device

03-23-2011, 08:42 PM	#6
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears I don't know who made it. It was on there before. Posted via Mobile Device I could maybe use a balancer install tool and a piece of pipe to press it on, couldn't I? Maybe that would be a good idea. I don't know if I should have a short duration cam advanced. Thoughts, feelings, better ideas? I don't want to throw this in and have run crappy or have little power. Last edited by justinburnett; 03-23-2011 at 09:02 PM.

03-23-2011, 09:18 PM	#7
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: timing gears To install it, put the crank gear in your wife's oven at about 400 degrees for half an hour or so. Using good thick gloves, slip it on real fast while still hot. No tools required (other than gloves and a stove). __________________ I'm on the Instagram- @Gearhead_Kevin

03-23-2011, 11:30 PM	#8
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears I'll give that a try. I thought metal expanded when it was hot. Will let you guys know tomorrow. Posted via Mobile Device

03-24-2011, 02:32 PM	#10
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: timing gears If you heat a gear it grows both inside and out. You can slide it on by hand until it cools. Then it fits with the proper interference fit. Trust me. I've done it a bunch of times. Posted via Mobile Device __________________ I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 03-24-2011 at 02:33 PM.

03-24-2011, 04:00 PM	#11
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears Gotta get it off first which is proving harder than I thought it would. I'll get it though. Posted via Mobile Device

03-24-2011, 05:33 PM	#12
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: timing gears Made a ghetto gear puller out of some bar stock, nuts and bolts. Slid right off. Got it lined up on 0, pressed it on with a harmonic balancer tool and some pipe, couldn't use friend's oven cause the house was locked. All in all it worked good and I'm glad I did it. Posted via Mobile Device

03-24-2011, 05:49 PM	#13
wyattglock Registered User Join Date: Jul 2010 Location: Lafayette, IN Posts: 622	Re: timing gears Now that you have done that, try and get your hands on a degree wheel. A good degree set will have a dial indicator. You can indicate off the rocker or the top of the valve and get your high point for top dead center. That will get you dialed in pretty good. Then make sure the engine is at TDC and install the distributor. Use a timing light and you should be able to get that thing running great in no time. I prefer the timing lights that have the advance dial on them.



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