[Fot] Do(o)med or flat lifters?
tr4racing at googlemail.com
tr4racing at googlemail.com
Fri Aug 31 16:42:50 MDT 2018
Camshafts with an angled lobe are maybe available in USA but totally uncommon in Europe.
No camshaft grinder would angle the grinding wheel to grind 4 lobes in one direction and the 4 other lobes the other way.
They are all ground parallel to the shaft.
And so the tappets need to be flat to rotate with the cam lobe offset.
Well, the cam is now running with the tappets I've got from Tony Garmey but they have been flat ground as the tappets showed the first gentle signs of pittings at the center.
In one or two years, I report how they look.
Cheers
Chris
-----Ursprüngliche Nachricht-----
Von: Fot <fot-bounces at autox.team.net> Im Auftrag von Larry Young via Fot
Gesendet: Freitag, 31. August 2018 17:17
An: fot at autox.team.net
Betreff: Re: [Fot] Do(o)med or flat lifters?
Greg,
Thanks for posting this. I have seen the same thing in "virgin" engines, but have not taken so many apart. I was hoping you or Glen or someone with more experience would chime in.
- Larry
On 8/30/2018 1:20 PM, Gregmogdoc--- via Fot wrote:
> I bought my 1964 Morgan +4 new in 1965. When I first took the engine
> apart to modify it for more power at around 16,000 miles, there were
> two lifters in the engine that were not rotating! They had
> "butterfly"
> wear patterns on the bottom of the lifters caused by the lifter
> oscillating back and forth. So this is a fault in the original
> production of the engine.
> Over the years, whenever I have taken apart what I believe to have
> been "virgin" engines, I have ALWAYS come across 2 or 3 lifters in
> each engine that have not been rotating. When they don't rotate, they
> eventually pit and fail, then damage the camshaft.
> The original cam lobes were flat, not tapered, and relied on the
> offset of the tappet bores in the block from the center of the cam
> lobes to induce rotation.
> It was not enough! All or our cams are ground with a taper to the
> lobes that matches the offset of the lifter bores in the block to the
> cam lobes. This means that 4 lobes have a taper in one direction and
> 4 lobes are tapered in the other direction. The tappets are ground
> with a crown to match. Since we have been doing that, all the lifters
> rotate consistently, and if the lifters are hard enough, we do not
> have excessive wear problems unless poor quality oil is used or the
> break in procedures and not correctly followed.
>
>
> Greg Solow
> The Engine Room
> Sports Car Specialists
> Santa Cruz, CA 95060
> 831 429-1800
>
>
>
> ------- Original Message -------
> From : fubog1 via Fot[mailto:fot at autox.team.net]
> Sent : 8/29/2018 4:08:02 AM
> To : tr4racing at googlemail.com;
> pegandbobm at aol.com; rkrantz77 at comcast.net; fot at autox.team.net
> Cc :
> Subject : RE: Re: [Fot] Do(o)med or flat lifters?
>
>
> #1 cause of failure- dirt 40+%.
>
> #2 cause of failure- assembly error 40+% (note assemblers
> responsibility to ensure parts are to spec)
>
>
>
>
>
>
>
> This is part of the problem with rebuilt failures, it isn't all
> "defective parts".
>
> HTH
>
> Glen
>
>
>
> problems came in when people used aftermarket parts or tuning parts.
>
>
>
>
>
>
>
>
>
>
>
>
>
> -----Original Message-----
>
> From: Chris Marx via Fot <fot at autox.team.net>
>
> To: tr4racing <tr4racing at googlemail.com>; pegandbobm
> <pegandbobm at aol.com>; rkrantz77 <rkrantz77 at comcast.net>; fot
> <fot at autox.team.net>;
> Fubog1 <Fubog1 at aol.com>
>
> Sent: Wed, Aug 29, 2018 5:37 am
>
> Subject: Re: [Fot] Do(o)med or flat lifters?
>
>
>
>
>
>
> #AOLMsgPart_1.2_51b0e82b-6923-4884-aaee-ebe3d9794a06
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>
>
> Let me add:
>
> Standard means….from factory
>
> Tuning means…..from so called “experts”
>
> I don’t know how much experts they are but one thing is obvious.
>
> In the past, Triumph seems not to have much trouble with
> camshafts…..problems came in when people used aftermarket parts or
> tuning parts.
>
> This is always suspicious to me.
>
>
>
> Cheers
>
> Chris
>
>
>
>
>
> Von: tr4racing at googlemail.com <tr4racing at googlemail.com>
>
> Gesendet: Mittwoch, 25. Juli 2018 07:54
>
> An: pegandbobm at aol.com; rkrantz77 at comcast.net; fot at autox.team.net;
> Fubog1 at aol.com; tr4racing at googlemail.com
>
> Betreff: AW: [Fot] Do(o)med or flat lifters?
>
>
>
>
>
> I had a look around German forums and it seems to be a difference
> between tuning and standard engines.
>
> Standard – flat
>
> Tuning – domed.
>
>
>
>
>
>
>
> Von: pegandbobm at aol.com <pegandbobm at aol.com>
>
> Gesendet: Montag, 23. Juli 2018 22:17
>
> An: rkrantz77 at comcast.net; fot at autox.team.net; Fubog1 at aol.com;
> tr4racing at googlemail.com
>
> Betreff: Re: [Fot] Do(o)med or flat lifters?
>
>
>
> Not an expert but I WILL GUARANTEE the lifters in my air cooled German
> made VW Formula Vee engine have a slight radius/angle. I check this
> before each
> rebuild to ensure they have not flatten. Pre-Trump
> I think Germany was still considered part of Europe>
>
>
> Bob
>
>
> -----Original Message-----
>
> From: Ron KRANTZ via Fot <fot at autox.team.net>
>
> To: Christian Marx via Fot <fot at autox.team.net>; Fubog1 at aol. com
> <Fubog1 at aol.com>; Christian Marx <tr4racing at googlemail.com>
>
> Sent: Mon, Jul 23, 2018 1:46 pm
>
> Subject: Re: [Fot] Do(o)med or flat lifters?
>
>
>
>
> The reason for a slight angel on the lifter is to keep it from digging
> into the ramp on the cam lobe due to an aggressive acceleration
> design. Typical American (cannot say what European mfg. does) lifters
> have approximately a 60 inch radius. I even have an additional edge
> radius put on the lifters. The cam lobes have a slight taper side to
> side for rotating the lifter. Lift on a cam is limited by base circle
> radius which in turn is limited by cam bearing diameter. Then you get
> into duration and how fast you can get the valve open. All the
> Triumph "flat"
> tappets I have ever seen have a slight radius. The rules say you must
> retain the same type (flat, roller, mushroom) lifter as stock. My
> question is "how flat is flat". Rule does not say the lifter has to
> rotate. If a lifter has a 0.75 inch radius across the lifter diameter
> and no taper on the cam lobe,you can keep the lifter from rotating and
> accelerate the cam opening very fast. Think about that.
>
>
> On July 23, 2018 at 8:46 AM Christian Marx via Fot
> <fot at autox.team.net> wrote:
>
>
> This may be true for American engines.
>
>
>
>
>
>
> All European engines have no angel in the Cam shaft.
> And all the tappets, lifters, rollers, are flat. Dead flat. No light
> with an edge on it.
>
>
>
>
>
>
>
> So maybe this is just an American thing?
>
>
>
>
>
>
>
>
>
>
>
> Cheers Chris
>
>
>
>
>
>
>
> fubog1 < fubog1 at aol.com> schrieb am Mo., 23. Juli 2018, 15:40:
>
>
>
> This is well covered in many engine-building books &
> I've discussed it at length with several camshaft
> engineers over the years.
>
>
>
> It's my understanding that the lobe should have a
> very slight angle ground in, and the "flat" tappet
> really isn't, it's very slightly convex.
>
>
>
> This will give it rotation, if it doesn't rotate it
> will wear.
>
>
>
> There could also be spring pressure or lubrication
> issues?
>
>
>
> In any case I would discuss it with the tappet
> supplier before doing anything, at the least make
> sure that they are sufficiently hard to begin with
> and can be reground.
>
>
>
>
>
>
>
> Glen
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> -----Original Message-----
>
> From: Christian Marx via Fot < fot at autox.team.net>
>
> To: fot at autox. team. net < fot at autox.team.net>
>
> Sent: Mon, Jul 23, 2018 6:04 am
>
> Subject: [Fot] Do(o)med or flat lifters?
>
>
>
> In the past we had this discussion.
>
>
> I've bought some high quality lifters from USA, made
> from tool steel I suppose. 400$ they've cost..... and
> started to fail. On 3 of them, the very center does
> show e few pittings. Also visible that only a small
> part of the Cam is used.. The cam is okay
>
>
>
>
>
>
>
>
>
>
>
> The machine shop will grind the lifters dead flat, as
> they should be, they say.
>
>
>
>
>
>
>
> Cheers
>
>
>
> Chris
>
>
>
>
>
>
>
> Am 18.07.2018 02:12 schrieb "fubog1 via Fot" <
> fot at autox.team.net>:
>
>
> Yes, lacking access to a Cam Doc, you can use a set
> of V or bearing blocks, a degree wheel, dial
> indicator, and a bit of time, checked at 5 cam
> degrees, works fine.
>
>
>
> I'm still old school though, I plot them out on graph
> paper!
>
>
>
> That will give you the lobe profile but most folks
> don't have the full specs on the cam, usually just
> advertised lift and duration.
>
>
>
> Since the tip of the lobe usually starts to go away
> first, a simple lift measurement will reveal the
> worst, best done with a dial indicator cuz some
> (cheap) cams are ground on different base circles.
>
>
>
> Generally, ramp wear is unusual if the tip is still
> OK, although there can be exceptions.
>
>
>
>
>
>
>
> Glen.
>
>
>
>
>
>
>
>
>
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>
>
>
>
>
>
>
>
>
> -----Original Message-----
>
> From: timmmurphh < timmmurphh at gmail.com>
>
> To: 'fubog1' < fubog1 at aol.com>; rbtr3a < rbtr3a at cox.net>
>
> Sent: Tue, Jul 17, 2018 12:38 pm
>
> Subject: RE: [Fot] Cams
>
>
>
>
>
> By degreeing the cam using increments of 10
> crankshaft degrees (5 camshaft degrees) and then
> plotting the results in Excel, it is possible to get
> a very accurate picture of the profile of the cam.
>
>
>
>
>
>
>
> I’ve attached a spreadsheet showing an intake and
> exhaust lobe comparison two years apart of our
> Kastner G3 cam for reference.
>
>
>
>
>
>
>
> Tim Murphy
>
>
>
> #317 TR4
>
>
>
>
>
>
>
> From: Fot <fot- bounces at autox.team.net> On Behalf Of
> fubog1 via Fot
>
> Sent: Monday, July 16, 2018 6:31 AM
>
> To: rbtr3a at cox.net; fot at autox.team.net
>
> Subject: Re: [Fot] Cams
>
>
>
>
>
>
>
>
> Generally any obvious wear or pitting would make it
> unserviceable, but the wear isn't always so obvious.
>
>
>
>
>
> You can measure the lift and compare to spec, that
> will show any worn lobes, but the best way is to find
> someone who has a "cam doctor". It's a machine that
> sets it up and measures the complete profile.
>
>
>
>
>
> Usually if there is anything apparent that suggests
> that there may be problems, there are...
>
>
>
>
>
>
>
>
>
>
>
> Glen
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> -----Original Message-----
>
> From: rbtr3a--- via Fot <fot at autox.team.net>
>
> To: fot <fot at autox.team.net>
>
> Sent: Sun, Jul 15, 2018 6:47 pm
>
> Subject: [Fot] Cams
>
>
>
> How do I determine if a cam is good or bad. If there
> are any marks on it does that make it bad. I do know
> that two of the lifters has pitting on the surface.
>
>
>
> Ronnie
>
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