Degreeing cam, can I reset it?

[Jonk67]

Hi all, long story short, local shop built my 333 stroker and degreed the cam the first time but the cam gear dowl pin had to come out. months after I picked up the engine. They reinstalled the timing gears (not sure if they had to remove cam, doubt they'd remember now months later).

I marked the cam/crank gear with a (black) marker for where they were lined up when first built/degreed, now it appears that when they reinstalled they didn't degree it again and simply lined the standard dots (white) up on the gears. I don't want to leave it like this and leave power on the table from the degreed settings. Can I simply rotate it to get them to line up or do I need to remove the gears/chain, rotate and reinstall the gears/chain with the black marks lined up? I don't want to haul it back to them again as it was a miscommunication for the first fix and they didn't charge me anything to fix the roll pin.

Jon

 

[tarafied1]

do the black marks line up when you rotate it? How did they degree the cam before? an offset dowel bushing in the cam gear? I'm confused about your question. It looks like the black marks will line up if you rotate the crank a little...

 

[Jonk67]

They didn't use an offset dowlpin or cam gear all is the same as originally built. The pin was simply too short the first time to work with my eccentric so they had to pull the pin and put a longer one in but then the timing got reset apparently.
That's what I'm wondering is can I simply rotate the crank until the black marks line up and still be at TDC and ready to start but degreed. All I've read is that you'll get the max out of your cam setup if degreed, just enough knowledge to confuse myself...
Jon

 

[tarafied1]

I think I get your question. Are the heads on? Can't tell in the photos, if not you can put an indicator on the #1 piston and rotate until it's at TDC. But that really isn't important now. The dowel should be the same location (degree wise) if it's just longer, so yes you can line up the black marks. The cam and crank are tied together by the chain so you won't throw anything off by rotating it. If they degreed it properly to begin with your okay. All that means is they checked the position of the cam lobes vs the pistons and they should have checked all 8. If the cam is ground okay, then they didn't have to do anything. If it was off a bit, then they would have used an offset dowel or indexed the crank sprocket if it has offset keyways. Clear as mud?

 

[tarafied1]

The only reason I could think TDC is important to you is if your installing the distributor so you can set the initial timing. If it's already in, the engine doesn't care where it is (in relation to TDC) when you start it.

 

[Jonk67]

Thanks Craig, heads are on, dist. isn't in yet, wanted to be able to just drop the dist. in set at #1 and do initial fire up but need to put all the covers on with gaskets first so I wanted to fix the degree issue before install and didn't know if I'd screw something up by rotating it. Just looking for affirmation from anyone more knowledgeable than I on degreeing.

So if I can check piston position through the sparkplug hole (set a pencil, etc. in the hole and mark?) then rotate to line up the black lines, should the pencil move up? I'm guessing to put the piston at the top?
Jon

 

[tarafied1]

It's not entirely necessary to line up the marks unless you just want to check them. Once you have the timing cover on and harmonic balancer you can then line the timing marks up there to install the distributor. Your going to have to adjust it with a timing light once it is running but that will get you close enough to start the engine. With the timing chain marks lined up now you know your on the compression stroke of the #1 cylinder. It's really hard to tell TDC with the heads on. The crank can turn quite a bit (several degrees) while the piston is up there. Without an indicator I don't think you can be sure exactly where it's at for timing the ignition. I'd just line up the marks to make yourself comfortable they line up and put the timing cover and balancer on, adjust as need to to get TDC or a few degrees before, then drop in the distributor. Remembering that the hex on the oil pump drive shaft will need to be close and that the gears are on an angle so the rotor will turn as it drops into place. If you want help I can look at Saturday after the show.

 

[2ndgen]

Thanks Craig, heads are on, dist. isn't in yet, wanted to be able to just drop the dist. in set at #1 and do initial fire up but need to put all the covers on with gaskets first so I wanted to fix the degree issue before install and didn't know if I'd screw something up by rotating it. Just looking for affirmation from anyone more knowledgeable than I on degreeing.

So if I can check piston position through the sparkplug hole (set a pencil, etc. in the hole and mark?) then rotate to line up the black lines, should the pencil move up? I'm guessing to put the piston at the top?
Jon

Hmmm...
1) As others state, rotating the engine will not affect camshaft timing (which is what degreeing measures) once the timing chain is installed.
2) Your original black marks do not line up with the keyway... which is the standard reference point. I too agree that if you rotate the engine the black marks will line up and verify that cam timing has not changed.
3) Verifying TDC (with a piston stop, not a pencil!!!) is important to make sure your timing pointer and the marks on the balancer are correct - not for distributor installation.
4) For stabbing the distributor, you want to be TDC on the compression stroke, not the exhaust stroke!!!
5) you want your initial timing to be about 8 degrees BTDC for initial start, then tune for maximum vacuum/RPM. Stock timing is for stock motors!

Good luck,
-Rory

 

[Jonk67]

Hmmm...
1) As others state, rotating the engine will not affect camshaft timing (which is what degreeing measures) once the timing chain is installed.
Good luck,
-Rory

Ok, so if it was degreed properly the first time when I made the black marks and turning the crank lines the marks up again then I just need to verify TDC and #1 on compression. One pair of marks or the other should be my starting point and apparently one of the times it got moved.
Thanks, Jon

 

[tarafied1]

yep, the cam turns two to one, thats why we emphasize TDC on the compression stroke (when both valves are closed). You can rotate that baby all ya want, the marks will eventually come back together.