In regard to TR-3 & 4 lifters and cams. It is true that the original cam lobes
were flat and not taperred. I do not believe that the original lifters were
flat. I had purchased OE> lifters from the TR dealer, Kramer Motors in Santa
Monica back in 1966 when I put my first Kastner "D" cam in my Morgan. I am
quite certian that the new lifters that I bought had a "crown" to their base.
We have found over the years, almost every single wet sleeve engine which
we torn down had at least 2, sometimes 3 lifters that were not rotating.
Usually these lifters were near the rear of the block. The wear pattern they
wouldl develop looked like a butterfly on the bottom of the lifter. They had
been occilating, not rotating!
We did some research with the cam grinder that we have been working with
for over 35 years now, and have concluded that if the cam lobes are reground
with a taper, & the lifters are ground with a matching taper, then the lifters
will rotate reliably and cam and lifter life will be dramatically exteneded.
This of course assumes that the lifters are at least Rc 55 or so as were the
originals.
Thecam lobes are tapered in pairs, each pair tapered toward each other so
as to match the offset of the lifter bores from the cam lobes.
This requires grinding the cam lobes in two different set ups with the grinding
wheel of the cam grinder set to taper 4 lobes in one direction and 4 lobes in
the other direction. Thus the thrust developed by the cam/lifter offset is
equel and the only fore and aft load on the cam is from the oil pump drive
gear. .
All of the cams that we have had reground in the last 30 years have all
had tapered lobes.
Greg Solow
The Engine Room
----- Original Message -----
From: Jerry Van Vlack via Fot
To: Mike Harmuth ; FoTTriumph
Sent: Friday, November 17, 2017 4:49 AM
Subject: Re: [Fot] Peugeot lifters 504
The discussion on lifters is of interest to me. I?d like to see some
independent verification of the recent statement regarding lifter bore being
at some angle relative to the cam bore.
What I believe is the bores are perpendicular to the cam bore but offset from
lobe centerline to facilitate lifter rotation. I recently did some research on
cams and lifters for the wet sleeve engines and have concluded that factory
stock cams and lifters are ground flat and lifter bores are offset to
facilitate lifter rotation. My bases for the conclusion is via verification at
a cam grinder that the stock lobes (and my Kastner D cam) are ground flat by
installing several OE cams between centers in the cam grinders equipment and
sweeping a dial indicator across the lobes and the heals which verified dead
flat grind.
With regard to lifters I took several used but known to be OE lifters that
were in good shape and placed them end to end, there was no rocking and they
mated as though they were lapped together. I did the same with new lifters from
a well know supplier and placed them end to end and they rocked showing a
slight radius. These radiused lifters combined with a flat cam are not matched
for lifter rotation and can lead to rapid cam and lifter wear. If using a cam
that has a taper ground lobe with the radiused lifters you will get rotation.
I have no idea what effect on wear an offset lifter bore has with a tapered
lobe cam and radiused lifter. Maybe someone else can comment on that.
Perhaps this is old news to many racers but I suspect that some engines have
been built with mismatched cams and lifters that led to rapid cam and lifter
wear which was wrongly blamed on oil and break-in procedures.
JVV
From: Mike Harmuth via Fot
Sent: Thursday, November 16, 2017 8:47 AM
To: FoTTriumph
Subject: Re: [Fot] Peugot lifters 504
"And they've been used in at least one 1296 Spitfire engine, where they're
much larger in diameter than stock."
Now you have my interest, I have a small block 1296 block with worn lifter
bores and my engine builder couldn't find a slightly larger lifter. I'm
guessing he didn't look at a Peugeot parts catalog. Does anyone have a lifter
part number or a spec so I can investigate bringing this block back from the
dead? It was mentioned that the TR bores holes are not parallel to the block,
are the small journal 1296 bore the same?
thanks
mike h
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