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BB rocker arm shaft defection #2725244
12/18/19 10:58 PM
12/18/19 10:58 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline OP
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Cab_Burge  Offline OP
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Bend,OR USA
I'm assembling a bracket race 440 stroker motor with a set of 440-1 heads with a set of T&D single shaft 1.70 ratio rocker arms on both valves. it has a Jones solid roller lifter camshaft with .180 offset intake cup lifters along with the T&D offset intake rocker arms.
The cam card calls for .393 lobe lift on the intake lobes and .401 on the exhaust lobes, with .018 or tighter valve lash so that calculates out to be right at .650 net intake valve opening and .665 net lift on the exhaust valves.
I degree the cam in off of the lifters and then check the lobe separation angles(both intake and exhaust lobes) with light checking springs on the #1 valves along with checking the valve to piston clearances( it has .100 + PtoV clearances thumbs). It had right at 5 degrees intake lobe advance and same amount on the exhaust side using a Cloyes 9 way timing set using the 4 degree advance keyway up
I decided to set the valve lash cold on both valves using top dead center on the firing stroke and then redo them all using the race way, EO set intake lash, intake opens to max lift and starts to close set the exhaust lash with the heads torque down with the race valve springs and Manton series 5 pushrods. I saw a bunch of differences on the lash between those two methods confused I'm sure the rocker arm shaft deflecting causes that when the valve springs push down on the cam shaft and up on rocker arms work
I ended up having to remove the heads to grind additional intake pushrod to head clearances on five of the intake port castings :wrench
Once I had the valve train set up the way I liked it I decided to check the net lift with the lash set .012 cold on both valves, I measured between .712 and .715 on the #1 and 2 intake retainers and .735 on both #1 and #2 exhaust valve retainers shock
I had set those heads up with the valve springs to have between .060 and .080 to coil bind with the smaller net lift so it was time to check them on the heads, I decided to check #2 first and found that by tightening up the intake valve opening by .060 on the intake valve and then checking it with a good dial indicator I was able to cycle it to max opening and still see a small amount of clearance between the valve spring coils with no noticeable hard spots while rotating the motor over. I then did the same on the #2 exhaust valve the same way and hit a hard spot just before max lift, NO GOOD down
I'm now going to check every valve spring now on the heads using the rocker arms on those valve springs and remove the shims needed to get .060 from coil bind on all 16 springs. This motor had been run a short time before me taking it apart due to a spun rod bearing in it, It had 275 to 285 lbs. close pressure and right at 725 lbs. open with the calculated valve lifts, Shame on me for not checking the actual lifts before when I installed those heads and camshaft on his short block blush tsk
I hate making mistakes, especially on a race motor like this puke Never, ever ASSUME anything on motor builds tsk

Last edited by Cab_Burge; 12/18/19 10:59 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: BB rocker arm shaft defection [Re: Cab_Burge] #2725253
12/18/19 11:36 PM
12/18/19 11:36 PM
Joined: Oct 2006
Posts: 1,262
New York, USA
Chargerfan68 Offline
pro stock
Chargerfan68  Offline
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Joined: Oct 2006
Posts: 1,262
New York, USA
Thats great that you caught that before it was run like that. But, i’m not sure how you end up with .712+ lift with .400 lobes with 1.7 td’s? I applaud your attention to detail and always pay attention to your posts.


1.50 60Ft. , 10.75@ 127MPH Hauling 3900 LBS.
Re: BB rocker arm shaft defection [Re: Chargerfan68] #2725348
12/19/19 10:55 AM
12/19/19 10:55 AM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline OP
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I'm going to recheck the lobe lift off of the pushrods on both #1 and #2, my notes from degreeing it are out in the shop and I think the lobe lift was as advertised on the cam card.
I'll have to use a ball and cup pushrod to do that,the T&D use a ball and ball pushrod. I have a bunch of different lengths ball and cup pushrods in stock so that is not a problem, the hard part is getting the pushrods straight and traveling like they should with the rocker arms in place so you don't get a false reading wrench


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: BB rocker arm shaft defection [Re: Cab_Burge] #2725360
12/19/19 11:59 AM
12/19/19 11:59 AM
Joined: Jan 2016
Posts: 216
America
WedgeFED Offline
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Re: BB rocker arm shaft defection [Re: Cab_Burge] #2725401
12/19/19 04:13 PM
12/19/19 04:13 PM
Joined: Oct 2007
Posts: 4,205
New York
polyspheric Offline
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New York
Never mind


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Re: BB rocker arm shaft defection [Re: polyspheric] #2725421
12/19/19 05:37 PM
12/19/19 05:37 PM
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Posts: 289
St.Pete,Florida
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lancer493 Offline
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St.Pete,Florida
Cab, I am interested in hearing what you find out about your actual valve lift situation.With the numbers that you posted, seems like you have an effective 1.8 rocker arm ratio at that lobe lift.Possibly actual lobe lift is different from cam card specs.I ran into a similar situation with my build.As you mentioned, dial indicator measuring geometry plays important part in this, sometimes very difficult to accomplish.Please post your findings,as mentioned they are always very helpful.I gotta know where you found an extra .050".I seem to have lost actual effective rocker arm ratio/valve lift by using rocker arm geometry correction. Had to go from 1.5 to 1.6 rockers to put things back into perspective. Good luck here, Bill

Re: BB rocker arm shaft defection [Re: WedgeFED] #2725431
12/19/19 06:30 PM
12/19/19 06:30 PM
Joined: Jul 2019
Posts: 194
Springtown Pa
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Ray408G3Hemi Offline
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Springtown Pa
Originally Posted by WedgeFED


Cool Video, Can't speck to the flex on the BBM's but I've seen that same thing done on the G3 Hemis, stock vs Stanke .187 wall thickness., 4130 Chrome Moly, , Vs Manton .250” wall thickness 4130 Chromoly steel. ...............real EYE opener..


1963 Thunderbolt 496FE 10.80 (still a work in progress)
1968 Mustang slow a$$ 428 FE
1971 Boss 351 Mustang 11.20@115mph
1993 Lightning 10.61 @ 129mph 408Ci A3 headed NA
1996 Viper GTS
2001 Lightning 8.99 @ 155MPH 5.4 Mod Motor
2009 Ram 9.65@144MPH 463CI G3 NA
2010 Challenger 9.91 @ 139MPH 408CI G3ci NA
2019 F150 (local dealer's Lightning package) ..11.90s

Re: BB rocker arm shaft defection [Re: WedgeFED] #2725480
12/19/19 09:34 PM
12/19/19 09:34 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline OP
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Cab_Burge  Offline OP
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
That video is on a B1 head with 3 additional rocker arm hold downs, work
I didn't try to find out how much difference in lash there was between setting the lash at TDC versus the race way, maybe I should work
I use to set them when the exhaust valve opened set the intake lash, then rotate the motor over until the intake valve opened all the way and just closed and then set the exhaust.
Dominic, Thumperdart, found out with a solid lifter race cam that his motor was bending the parts with under 350 lbs. open at max lift so he came up with setting the exhaust lash after the intake valve opened fully and started to close as well as setting the intake lash when the exhaust valve started to open ended up with minimum lash change compared to the old Mopar decal way work
Time to eat, I'll add more later tonight on this subject.
I verified from my notes on the cam lobe lift, it was .384 on the #1 intake lobe and .393 lobe lift on the exhaust lobes off of the lifters that are being ran in this motor. I had the dial indicator stem sitting in the pushrod cup so the lobe lift might be slightly different there than measuring directly off of the lobes shruggy These lifters do have the .820 wheel diameter, not the.old smaller 750 diameter lifter wheels.
The lift at the retainers varied from a low of ..709 up to .715 with the lash set at .012 at room temps of 70 to 78 F on the intake retainers and from .727 to .740 on the exhaust retainers with the lash set at .012 at room temps.
I ended up having to remove valve spring shims (.015 up to .060) from 5 of the exhaust valves which gave me .060+ to coil bind measured at max lift and none from the intake valves work
I have one motor running now with the paired shaft Jesel rocker arm set up on a set of 4401 heads, I like that system up a bunch up
I'm still working on this motor and hope to finish it this weekend luck

Last edited by Cab_Burge; 12/19/19 10:30 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)






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