When a valve sticks, it sticks at least partially
open. The cylinder instantly looses all power.
Because the valve is open, the valve clearance is
grossly excessive. If there is a muffler on the car,
you should hear a sudden loud tapping. I would also
expect to see visible signs of "pounding" between the
end of the valve stem and the rocker. Often the
adjuster ball will jump out of the cup on the end of
the pushrod & land on the edge of the cup. This may
leave a witness mark or may crack or fracture the cup
causing it to fail later.
Greg Solow
The Engine Room
Sports Car Specialists
Santa Cruz, CA 95060
831 429-1800
------- Original Message -------
>From : Michael Moore[mailto:mmoore@mtmcpafirm.com]
Sent : 6/29/2014 12:18:54 PM
To : fot@autox.team.net
Cc :
Subject : RE: [Fot] Valve Clearance, sorry for long
winded question
What would be the effect of sticking valves, not
catastrophic in nature.
At end of straight, every run, last week at Mosport,
#4 cylinder went cold and
I had to pull over and wait a minute for it to come
back, sometimes turning it
off.
At track I changed fuel lines to split to each carb,
change facet fuel pumps,
removed regulator, rebuilt rear card, put in new
distributor, cap, peteronix,
coil and swapped wire with some old used ones.
Nothing worked.
After weekend found the top of #8 push rod came off
when I removed rockers and
rod was slightly bent. Engine builder thinks top
coming loose was cause as it
may have been jamming up and holding valve open
Installed new carter pump, new regulator, and Y
splitter at home.
Put it in dyno the other night, after replacing rods,
happened 1st pull again,
then we switched plug wires, and could not get it to
occur again.
However, at high rpm, say over 4500, when
accelerating hard, it would start to
break up.
We seemed to solve some of the problem with needle
swaps and adjustments. But
I wonder if at high rpms valves are binding.
Builder has great reputation, I trust him, he has
been helping for no charge.
he removed some valve springs and sees no signs of a
sticking valve.
Thanks
Mike
62 TR4, Race car
63 TR4, Street car
Mike & Becky Moore
6050 Ruhl Road
Fairview, PA 16415
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