Camshafts

Robert Harris bob at bobthecomputerguy.com
Sat Apr 3 13:52:28 GMT 1999


My point perzactly Bruce.   I've ran across his input many times from do'ers.
Latest was when I was talking to the man who put dual plugs in his 460 heads
who had a number of conversations with him about it.  I agree with you about
rag riters and have not met many of them that do anything other than spout
advertising.

If you start from a known accurate baseline such as obtained from a reputable
cam builder or author, and you know how it works, then you can do things that
ain't posed to work cause you found the twist.   Ignorance of how things work
is bliss only to a salesman.

I personally put Rhodes Lifters on a Kettering 429 and noticed an immediate
improvement in milage and low end drivablity - so I KNOW they work.  From
Vizard I found out how and why.   

A Vizardian twist.   Excess overlap and to a lessor extend late intake closing
are primarily responsible for loss of low end power on using a long duration
cam.   If you put Rhodes ( other ) lifters on the EXHAUST only, you can regain
about 75% of that loss.  Why - understanding that the reduction in duration
comes primarily at closing - means that using a leak down lifter on the
exhaust only - trims a bunch of overlap at low rpm.  A nice advantageous
change is made in both the lobe center and timing as the lifters closing
duration is increased with increasing rpm.

Another Vizardian note.  Unless you markedly improve the oiling system - you
will never gain the full lift and duration of the leak down lifter.  Huh??
Aeration.   If there is any air in the oil, the lifter won't fully pump up.
Remember these little suckers use a lot more oil than stock lifters to work.
So if you don't clean up the aeration in a stock system by at least a windage
tray and scraper, you don't get the full advantage of the lifter.

So maybe there might be some good in talking to a reputable cam builder as Dr
Bruce suggests or RTFBing prior to buying into something.  Just a thought.

1963 Ford C-600 Prison Bus Conversion "Home"
1971 Lincoln Continental 460 "Christine"
1972 "Whale" Mustang awaiting transplant
1978 Dodge Long Bed Peeek Up "Bundymobile"

Habaneros - not just for breakfast anymore



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