Need advice 360 timing chain cam/crank slightly off
#3090955
11/01/22 02:48 PM
11/01/22 02:48 PM
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Joined: May 2013
Posts: 133 Parsippany, New Jersey
340challconvert
OP
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OP
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Joined: May 2013
Posts: 133
Parsippany, New Jersey
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Need advice 360 timing chain cam/crank slightly off
Purchased a 360 from Mabco to put into my A66 340 Challenger short term while I pull the 340 for a rebuild. I bought a hp version with flat top pistons and installed hp cam sited as a 272 cam Cam specs; 272-272 duration 454 lift 110 lobe separation 52 degrees overlap, 216 216 duration @ .50 Power range 1500-5200 Considered the largest "stock" cam for this engine
In going over the engine for parts install; the timing marks are slightly off. I call the manufacturer and he stated to leave the chain as is.
Pistons are flat top 30 over, no valve notches, piston to deck measurement is not a stock (deep in the hole) 360 with the higher compression pistons it measures out at about .087 below deck with number 1 piston at TDC.
I am no expert, and I have installed cams years back always aligning timing marks; is there a reason for the manufacturer to alter the timing in this manner with this hp cam and flat top piston? Pic of timing chain sprockets and Number 1 piston at TDC Any thoughts appreciated.
Last edited by 340challconvert; 11/01/22 02:52 PM.
1970 A-66 340 Challenger convertible
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: 340challconvert]
#3090956
11/01/22 02:49 PM
11/01/22 02:49 PM
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Joined: Aug 2011
Posts: 2,872 Pattison Texas
CSK
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master
Joined: Aug 2011
Posts: 2,872
Pattison Texas
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You need to degree the cam with a degree wheel
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: CSK]
#3090988
11/01/22 05:18 PM
11/01/22 05:18 PM
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Joined: Aug 2003
Posts: 43,303 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,303
Bend,OR USA
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You need to degree the cam with a degree wheel The first solid roller cam I bought and installed for a customer was ground 10 degrees retarded I've also had 10 sets of Cloyes BB Mopar timing sets that came with the wrong cam gear My message is never trust any part to be correct, especially with any Hi Po parts in your motors You'll need a solid lifter, a degree wheel and a dial indicator with 1.0 inch reading with an extension long enough to reach the lifter cup The quickest way to check the cam for proper lobe timing is to check the lobe separation angles at .050 before and after max lift on the lobes with the solid lifter, check the intake lobe first and then check the exhaust lobe second, if the intake lobe is correct (installed straight up) at max lift at 110 ATDC the exhaust lobe should be 110 BTDC at max lift, if the cam is installed 4 degrees advance the intake lobe center should be at 106 ATDC and the exhaust lobe should be at 114 BTDC I always check the lobe lift also before checking the LSA on the cams Cloyes made a batch of BB upper cam gears that would not align dead nuts straight up and down with the crank gear, if the cam dot was to the drivers side of the motor the cam was retarded around 12 degrees and the motors would run like crap If you moved the cam gear so the crank gear dot was to the passenger side of the motor it is was closer to being install correctly Take your time to make sure the cam is installed correctly on the lobe separation angles, you don't want it to hurt parts or have it run like Doo Doo Let us know what ends up with this problem please
Last edited by Cab_Burge; 11/01/22 09:57 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: 340challconvert]
#3090992
11/01/22 05:52 PM
11/01/22 05:52 PM
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Joined: Dec 2009
Posts: 20,668 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,668
in a cattle trailer down by th...
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Looks like you have the cam at least one tooth off. And BTW that is #6 firing, not #1.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: Guitar Jones]
#3091005
11/01/22 07:37 PM
11/01/22 07:37 PM
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Joined: Oct 2005
Posts: 4,961 WI
Dcuda69
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Looks like you have the cam at least one tooth off. And BTW that is #6 firing, not #1. Agree on both points. Line those dots up, then get the degree wheel out to find out where the cam actually is. Good luck!
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: Dcuda69]
#3091267
11/02/22 09:08 PM
11/02/22 09:08 PM
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Joined: Aug 2006
Posts: 2,537 God's Country Maryland
GODSCOUNTRY340
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master
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God's Country Maryland
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I just lined up a straight edge on his pic from center of crank bolt to center of cam bolt and both dots are off. Looks like you have the crank spun too far past TDC. Back it up and both will most likely line up.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: AARCONV]
#3091288
11/02/22 10:34 PM
11/02/22 10:34 PM
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Joined: Dec 2009
Posts: 20,668 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,668
in a cattle trailer down by th...
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They make an offset keyway They make them in 2°-4°-6° & 8° off sets.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: GODSCOUNTRY340]
#3091290
11/02/22 10:36 PM
11/02/22 10:36 PM
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Joined: Dec 2009
Posts: 20,668 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,668
in a cattle trailer down by th...
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I just lined up a straight edge on his pic from center of crank bolt to center of cam bolt and both dots are off. Looks like you have the crank spun too far past TDC. Back it up and both will most likely line up. Cam turns at half speed, that is still a tooth off.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: Need advice 360 timing chain cam/crank slightly off
[Re: GODSCOUNTRY340]
#3091388
11/03/22 12:46 PM
11/03/22 12:46 PM
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Joined: Jan 2003
Posts: 15,526 Omaha Ne
TJP
I Live Here
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I Live Here
Joined: Jan 2003
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Omaha Ne
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