Cam installation
#2107531
07/10/16 09:58 PM
07/10/16 09:58 PM
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Joined: Jun 2005
Posts: 368 Jacksonville, Fl
426runner
OP
enthusiast
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OP
enthusiast
Joined: Jun 2005
Posts: 368
Jacksonville, Fl
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I'm installing a stock, resto cam in my 426. Intake CL is supposed to be 112. I've checked it multiple times and mine is measuring at 106. I found TDC 2 different ways... with a stop and using the dial indicator. Both were right on. How can it be that far off? What factor would create this 6 degree difference from advertised? The crank I have was a Swap meet find. It was used but was still very nice and is still std/std. There was something very unusual about it that I didn't notice until I went to install the balancer. The portion of the snout that accepts the balancer is machined further into the crank than normal and has a 2nd key- I had a spacer made from a timing chain sprocket to fill the space- I posted this years ago when I first ran across the issue but no one had a solid answer. I can't help but think this mystery crank has something to do with my CL issues. Now for the really stupid questions... Are there cranks that have adv/ret built in? Am I using a Mopar crank meant for something else besides a street hemi? Please help. I am NOT bolting this thing up again without everything right and without ANY uncertainty of what's going on.
Later, Sandy
'70 HEMI Road Runner B5/B5, 4 spd
"Sandy's Garage" on Facebook
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Re: Cam installation
[Re: SportF]
#2107649
07/11/16 12:53 AM
07/11/16 12:53 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I had a cam that the key way was off by 23*.. just for kicks I lined the dots up... the valves crashed the piston... but I run that cam after I degreed it(SB) EDIT When I bought the cam from the mopar dealer the box had been opened and taped closed.. so I assume the guy before me just tried to line up the dots on the chain set and it crashed and he took it back
Last edited by MR_P_BODY; 07/11/16 12:57 AM.
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Re: Cam installation
[Re: AndyF]
#2107652
07/11/16 12:57 AM
07/11/16 12:57 AM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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You might mockup the #1 rod/piston & get it at TDC & see if the crank snout keyway is at 1:30. other than that as said retard it 6 deg as needed. EDIT I'd see if both the sprocket dots are clocked the same in relation to tooth root position if you have another known good timing chain/gear set,same for the cam keyway or dowel pin (I ain't up on BB's) compared to another cam. all that is left is the clocking position of the lobes on the stick. moving (1) tooth is 15.6 deg on the crank (SB)
Last edited by RapidRobert; 07/12/16 06:15 PM. Reason: bored
live every 24 hour block of time like it's your last day on earth
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Re: Cam installation
[Re: SportF]
#2109825
07/14/16 10:38 AM
07/14/16 10:38 AM
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Joined: Jun 2005
Posts: 368 Jacksonville, Fl
426runner
OP
enthusiast
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OP
enthusiast
Joined: Jun 2005
Posts: 368
Jacksonville, Fl
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Thanks for the input. Guess I'm stressing over nothing. Got a higher end, billet, 9 keyway timing set. With this new set lined up on the the "0" marks the cam centerlined @ 108. Adjusted the sprockets and BOOM... right on the money, 112 as desired.
Later, Sandy
'70 HEMI Road Runner B5/B5, 4 spd
"Sandy's Garage" on Facebook
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Re: Cam installation
[Re: 426runner]
#2109831
07/14/16 11:13 AM
07/14/16 11:13 AM
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Joined: Dec 2005
Posts: 1,495 Shelby mi.
JAKE68
pro stock
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pro stock
Joined: Dec 2005
Posts: 1,495
Shelby mi.
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I would have left it advanced for a street motor.
JAKES AUTOMOTIVE
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Re: Cam installation
[Re: JAKE68]
#2109847
07/14/16 11:38 AM
07/14/16 11:38 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I would have left it advanced for a street motor. I would bet that cam was meant to be installed at 106-108.. its a 112 LSA
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Re: Cam installation
[Re: 426runner]
#2109901
07/14/16 01:52 PM
07/14/16 01:52 PM
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Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
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Put the timing cover/timing indicator on with the damper and a degree wheel if the damper is not marked 360*. Reset the crank to #1 TDC using the degree wheel and check the damper/indicator. Check the damper to see if #1 TDC is correct on the timing tab (or close). This will tell you if the keyway is in a non-stock location and you can adjust cam timing and timing marks accordingly. Cam timing using a degree wheel set to #1 TDC will be accurate, regardless where the keyway is. Use the adjustment in the timing set to put the cam where you want it.
If the results don't match the theory, change the theory.
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Re: Cam installation
[Re: MR_P_BODY]
#2109953
07/14/16 03:17 PM
07/14/16 03:17 PM
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Joined: Jun 2005
Posts: 368 Jacksonville, Fl
426runner
OP
enthusiast
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OP
enthusiast
Joined: Jun 2005
Posts: 368
Jacksonville, Fl
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I would have left it advanced for a street motor. I would bet that cam was meant to be installed at 106-108.. its a 112 LSA LSA? Found it... Lobe Separation Angle. The paperwork that came with the cam clearly says intake centerline is 112 DEG. OK, now I'm all stressed again.
Last edited by 426runner; 07/14/16 04:59 PM.
Later, Sandy
'70 HEMI Road Runner B5/B5, 4 spd
"Sandy's Garage" on Facebook
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Re: Cam installation
[Re: 426runner]
#2110013
07/14/16 05:31 PM
07/14/16 05:31 PM
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Joined: Nov 2007
Posts: 277 MN
Willie68coronet
enthusiast
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enthusiast
Joined: Nov 2007
Posts: 277
MN
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He bets it's meant for a 106-108 INSTALLED centerline. Not lobe separation.
'68 Coronet 500 w/ Indy EZ-1 headed 446, 727 trans, 9" rear First day at the track with SUV street tires and no traction: 1.688 60', 7.24 @ 101.79 in the 1/8 mile
Great customer service from: DominicThumper Carbs, B3 racing engines, Porter Racing Engines, A-1 torque converter's, Quick Performance, Racer Brown Cams, R&R Performance, Manton pushrods
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Re: Cam installation
[Re: Willie68coronet]
#2110022
07/14/16 05:42 PM
07/14/16 05:42 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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He bets it's meant for a 106-108 INSTALLED centerline. Not lobe separation. Correct... its a 112 LSA(lobe separation angle) cam but in MOST cases they will say 106 or 108 installed degrees... its no big deal but the lower installed degree will make more low end power... for a street car I would want the low end power since you dont tend to rev to high.... but this is just my opinion
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Re: Cam installation
[Re: 426runner]
#2110066
07/14/16 06:54 PM
07/14/16 06:54 PM
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Joined: Aug 2003
Posts: 43,157 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,157
Bend,OR USA
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Thanks for the input. Guess I'm stressing over nothing. Got a higher end, billet, 9 keyway timing set. With this new set lined up on the the "0" marks the cam centerlined @ 108. Adjusted the sprockets and BOOM... right on the money, 112 as desired. if that cam is ground on a 112 lobe seperation angle and you can install it with the intake lobe center at 106 to 108 I would do that The reason being advancing the ILC makes the motor have more bottom end(low rpm power under 5000 RPM) Once you get the intake lobe center were you want it(108) take the time to check the exhaust lobe center to make sure it is ground on a 112 LSA also If it is ground on 112 and you have the intake lobe center in at 108 ATDC the exhaust lobe should be advanced the exact same amount, it should be 116 BTDC One degree either way is not worth worying about, if it is more than that then send it back and try another one
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Cam installation
[Re: 426runner]
#2112328
07/18/16 10:59 AM
07/18/16 10:59 AM
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Joined: Jun 2005
Posts: 368 Jacksonville, Fl
426runner
OP
enthusiast
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OP
enthusiast
Joined: Jun 2005
Posts: 368
Jacksonville, Fl
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I will be installing at 108. Thanks for all the input. It got me researching and confirming. Moparts (you guys) has yet to let me down.
Later, Sandy
'70 HEMI Road Runner B5/B5, 4 spd
"Sandy's Garage" on Facebook
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