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Lifter help!

PostPosted: 30 May 2006 9:07
by Chrippa
Hi!

I just have a question about my camshaft! Im running a 340 with solid camshaft, i dont have the specs on it!
I had the engine out this winter and checked it and i found out the timing chain lacked oiling. So i fixed that the stock way, one of the bolts that hold the camplate should have a 2mm hole right trough it. I didnt loose any oil pressure on this mod as it still lies around 75 psi.
My wonder is that i have heard that Mopar engines have a problem with sufficient oiling in the lifter gallery and now i wonder if my little mod could have a bad effect on my engine?

Anybody have clue? Better to ask before i grind the cam down?

/Chrippa

PostPosted: 30 May 2006 9:25
by ianandjess
gday chrippa
the cam lobes are lubricated as the oil drains back through the holes in the valley if your lifter bores arent badly worn there should be littlle oil leaking out from around the lifters anyway
cheers ian

PostPosted: 30 May 2006 11:50
by dave-r
The lifters themselves get plenty of oil. They sit in a main oil galley.

PostPosted: 30 May 2006 11:57
by dave-r
Oh. There should also be an oil slinger on the crank timing cog. It throws oil up over the chain from a small pool of oil in the bottom of the timing case. At least thats how it works on big blocks. Excuse my lack of knowlege on small blocks. :oops:

PostPosted: 30 May 2006 12:50
by Chrippa
I have an oilslinger on the crank, its not in the foto though!

Thanks for the help , i dont think its going to be a problem, but its better to check before the engine falls apart ;)
Wouldnt be so nice if the cam wore down just by taking a couple of spins around the block ! :)

PostPosted: 30 May 2006 12:54
by ianandjess
thats correct dave small blocks also have an oil slinger wich seems to be missing in chrippa's picture
cheers ian

PostPosted: 30 May 2006 13:23
by dave-r
I think the cam lobes get most of their oil thrown at them from the crank and rods below. As well as oil running down the valley from the heads. The camshaft bearings and lifters are both oiled directly.

The most important thing to prevent cam lobe wear is to make sure the lifters are free in their bores. With the pushrod removed they should be easy to lift with a finger and they should drop all the way back down easily under their own weight. They have to be free to rotate during operation otherwise both the lifter and lobe wear out fast.

However if the lifters are too loose in their bores (some side play) you can loose oil pressure and in the worst cases the lifter can dig into the lobe slightly. Blocks that have had big roller cams in them often wear the lifter bores into an oval shape because of the strong side loads.