Re: Timing sprocket marks
[Re: Dart 340]
#67273
06/04/08 09:53 AM
06/04/08 09:53 AM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
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Posts: 515
Dayton, Ohio
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yes marks can be off. i recently built a 360. used a Mancini roller set and the marks were 4 teeth off. that put my valves 68 degrees adv. till it broke a valve face off and exploded my motor. each tooth on the crank gear is 17 degrees. i am not saying anything bad about Mancini because everybody gets a bad part sometimes. it's weather the make it right or not that counts. at this point they are working with me. so compare yours to other brands to make sure yours is marked right. i will enclose a pic (if i can downsize it enough) to show correctly marked and not.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: 79powerwagon]
#67274
06/04/08 09:55 AM
06/04/08 09:55 AM
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Joined: Apr 2008
Posts: 1,195 Snowing in the north!
Dart 340
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Posts: 1,195
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Quote:
Yes, it happens all the time, thus the use of offset keys, eccentric bolts, etc. It it really only important if you're building a high-speed/high-power race engine. A stock street engine won't be an issue. You think they get that precise at the factory when they're throwing that stuff together?
Well that's what I figured, but if the centerline of the lobes lines up with TDC I can't see how it would matter too much. I know after market parts can vary also. Hell I'm just happy I tore it apart to see what was wrong before real damage happened. You know, you really should use the right width key in the key slot too..... well water under the bridge, it's fixed now.
Thanks for the info.
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Re: Timing sprocket marks
[Re: Dart 340]
#67275
06/04/08 10:03 AM
06/04/08 10:03 AM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
Joined: Feb 2003
Posts: 515
Dayton, Ohio
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yes i agree. i didn't have another gear set around when i put it together to check. so this is what happenes when you run 4 teeth off.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: 65cuda]
#67276
06/04/08 10:48 AM
06/04/08 10:48 AM
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Joined: Apr 2008
Posts: 1,195 Snowing in the north!
Dart 340
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OP
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Joined: Apr 2008
Posts: 1,195
Snowing in the north!
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Quote:
yes i agree. i didn't have another gear set around when i put it together to check. so this is what happenes when you run 4 teeth off.
Holy crap, that's awful!
My marks are off like one tooth-ish. But I did check valve position and tdc and it's where it should be when both valves are closed so I'm going to assume this is good enough to go. The marks are just kind of weird on this set. they look more like the letter o than a real mark......
Very sorry your engine crashed. Hopefully it's on the mend now.
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Re: Timing sprocket marks
[Re: buildanother]
#67279
06/04/08 11:19 AM
06/04/08 11:19 AM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
Joined: Feb 2003
Posts: 515
Dayton, Ohio
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i agree there is a speck of a mark in the correct place but i couldn't see it when i put it together. they put the big mark matching the cam gear on the keyway. if i built motors offen i might have thought hey the mark isn't always on the keyway. but who am i to question they way they make gears. heck there is 3 keyways. i know what they are for but i couldn't tell you where they should put the correct mark. all i wanted to do was make it dot to dot. this cam pistons and rockers were all happy together before. so i didn't worry about degreeing it. i bal. the bottom end and put on a new timming set, BM flex plate,new harm. bal. and thought i was good to go. as you can see there isn't much left of my KB107.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: Dart 340]
#67280
06/04/08 11:22 AM
06/04/08 11:22 AM
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Joined: Jan 2003
Posts: 13,595 md
mopars4ever
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,595
md
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Quote:
Isn't dialing in pretty much the same as finding TDC and center of the lobe? So would you have to use and offset key if it is off?
Maybe in a round about way. I guess you can do it that way if your just looking for O degrees advanced/retarded. But I wouldn`t. Mike
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Re: Timing sprocket marks
[Re: 65cuda]
#67281
06/04/08 11:24 AM
06/04/08 11:24 AM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
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Posts: 515
Dayton, Ohio
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Dart 340 i looked at the valves at TDC too and they were closed. so i guess that isn't a good indcator.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: Dart 340]
#67283
06/04/08 12:07 PM
06/04/08 12:07 PM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
Joined: Feb 2003
Posts: 515
Dayton, Ohio
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i don't know i guess it was just advanced enough to hit it as it was closing. it ran petty good i just had some lifter noise. and i was trying to figure that out. got 39 miles on it doing 45 MPH when BANG and everything was quite and i was coasting.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: 65cuda]
#67284
06/04/08 12:15 PM
06/04/08 12:15 PM
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Joined: Apr 2008
Posts: 1,195 Snowing in the north!
Dart 340
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Snowing in the north!
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Quote:
i don't know i guess it was just advanced enough to hit it as it was closing. it ran petty good i just had some lifter noise. and i was trying to figure that out. got 39 miles on it doing 45 MPH when BANG and everything was quite and i was coasting.
Good god, that is not a pretty sight.
Spun mine over by hand a bunch of times. Hope that it's good to go.
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Re: Timing sprocket marks
[Re: Dart 340]
#67285
06/04/08 12:35 PM
06/04/08 12:35 PM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
Joined: Feb 2003
Posts: 515
Dayton, Ohio
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nope it is ugly. makes me sick. the car is all done and now it doesn't have a motor. but a redo is in progress. Dart 340 did u use any clay to check for clearance?
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: 65cuda]
#67286
06/04/08 12:45 PM
06/04/08 12:45 PM
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Joined: Apr 2008
Posts: 1,195 Snowing in the north!
Dart 340
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Quote:
nope it is ugly. makes me sick. the car is all done and now it doesn't have a motor. but a redo is in progress. Dart 340 did u use any clay to check for clearance?
I would puke.....
No I didn't, but I have put a couple hundred miles on the car since I bought it a few at over 5,000 RPM. The guy that built mine used a 5/32 key in the cam way instead of 3/16 and also used a bad conical washer with no loctite so the bolt came loose and I lost fuel pressure. Tore it apart and that's what I found. I just was checking timing and that's what I came up with, marks off, or what appears to be the only marks I can find, were off like half a tooth to a tooth. I put a TDC finder in the no.1 cyl and put the piston at exactly tdc then checked the valves. Preload was good and they appeared to travel correct during rotation so it appears the cam lobe is pretty close to center...
I don't honestly know how to check it any other way.
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Re: Timing sprocket marks
[Re: MoparforLife]
#67288
06/04/08 01:39 PM
06/04/08 01:39 PM
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Joined: Feb 2003
Posts: 515 Dayton, Ohio
65cuda
mopar addict
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mopar addict
Joined: Feb 2003
Posts: 515
Dayton, Ohio
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that is right. i have had to learn way more about timming sets than i wanted to. it has a -4 and a +4 keyway too but the marks for them. they are almost ivisable too or i would have figured it out . maybe. if you look hard at that pic. you can see a pine needle on the ground it's a good closeup. it's a crazy except for the few with blowers or specal setups. probably 98 % of the people just put them in straght up or dot to dot. Comp Cams web site says they gring them 5 degrees advanced anyway so why advance it more. i know there is a group of builders out there that has a reason. just not us reg. guys. so my finished car sets there waiting for a new heart.
65 Cuda 360,3.23 SG-13.97 @99.4, 88 D100, 2000 Kota Qcab, 71 Duster 416 11.84 @110., 73 Imp ,(2)72 & (1)71 Dart Swingers GarysMocars Legendary Dealer
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Re: Timing sprocket marks
[Re: MoparforLife]
#67289
06/04/08 02:12 PM
06/04/08 02:12 PM
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Joined: Apr 2008
Posts: 1,195 Snowing in the north!
Dart 340
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OP
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Quote:
The problem with the multi-keyway gears is just what is pictured. The marks by the keyway are usually not the ones that are used to line up. There usually an index timing mark. There really won't be a whole bunch of crank and cam position change. a couple of degrees one way or but not a 'few teeth' one way or the other.
Well I'm hoping since mine ran well before I took it apart it will be fine once I fire it up tonight. I didn't change anything. Maybe next time I have to tear it down I will go through the instructions from Edelbrock and actually degree it.
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