Re: 590 Purple Shaft wiping lobe
[Re: Leigh]
#808243
09/19/10 11:42 PM
09/19/10 11:42 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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I always run a fine wire brush on a drill through every lifter bore to polish it up a little and reduce friction/hold oil on the wall like a cylinder wall, move the drill up and down to creat a cross hatch pattern like a cylinder also. Also if you rotate the engine over you can watch every lifter rotate as it goes over the lobe. If one don't rotate you can scuff the bottom of the lifter a little with some scotch brite or cover the entire lifter in electrical tape except the bottom, then hit it lightly with the sand blaster to give it a way to grip the cam. Another thing you can do is polish the sides of the lifter, again this is to reduce friction. One other thing I do to make sure the lifter bore is straight enough is to put blue dye over the bottom of the lifter, put it on the cam (NO OIL ON EITHER ONE) then rotate the engine a few revolutions and see if it wipes the blue off by the edge of the lifter, if it takes it all the way off the edge of the lifter it needs a straight hole drilled and bushed, this is less of a problem with crappy chevy lobes on a mopar cam (like mopar performance cams) but get some real lobes like a comp XE HL and this becomes more critical. Following thease precautions I have built a lot of engines, most of them flat tappet and never lost a lobe yet
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: 590 Purple Shaft wiping lobe
[Re: Leigh]
#808244
09/20/10 12:10 AM
09/20/10 12:10 AM
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Joined: Apr 2006
Posts: 4,220 West Plains, MO
DrCharles
master
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master
Joined: Apr 2006
Posts: 4,220
West Plains, MO
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Quote:
Dummy it up. Sharpie a line on top of each lifter. Turn the assembled engine over. Which ever lifter doesn't rotate, swap lifter holes until they all do. Thanks to Jericogtx.
When you say "assembled" do you mean with pushrods, rockers and valve springs in place? (In other words, will the lifters rotate if only sitting on the cam with no spring pressure)?
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Re: 590 Purple Shaft wiping lobe
[Re: MRBELV2]
#808246
09/20/10 01:44 AM
09/20/10 01:44 AM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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yes you need to make sure it is rotateing the same way it will be when the engine is running.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: 590 Purple Shaft wiping lobe
[Re: HotRodDave]
#808247
09/20/10 03:19 AM
09/20/10 03:19 AM
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Joined: Jul 2008
Posts: 30,431 Florida STAYcation
BeEtLeJuIcE !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,431
Florida STAYcation
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IS THIS another reason to BUSH the lifter bores ? (never done it myself) ON any motors I am going to be doing ...I am going to put a dab of white paint on each lifter top ... so when running you can look-down into the valley and see if they are spinning properly. Real light spring pressure ? ... I have heard opinions that say that toooo light makes the lifter skid .. instead of spin. NEVER had a cam problem .. and hope never to.
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Re: 590 Purple Shaft wiping lobe
[Re: BeEtLeJuIcE !]
#808248
09/20/10 01:01 PM
09/20/10 01:01 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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If you are running a super agressive mopar specific lobe then it is a good idea to check the lifter bores at a minimum, you can use my low buck method with the dye on the bottom of the lifter or you can have them checked at a machine shop. They need to be checked to make sure they are perfectly verticle over the cam lobe, not tilted front or back or even side to side.
As for checking the lifters for rotation while running, that is a great idea however, I would still check for rotation by hand upon instalation of a cam. It only takes a few minutes.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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