[Fot] Re TR4 camshafts

Larry Young cartravel at pobox.com
Sat Oct 28 09:11:33 MDT 2017 

Pat,
You should be able to send the cam back if it doesn't match the specs. 
Any cam should be within a few thousands of the stated lift. That is one 
reason I would thoroughly degree a cam before installing it. Otherwise, 
you are left with "Trust Me". Most of the time, it is the seat-to-seat 
duration which is off, usually greater than spec and often 10 degrees or 
more. 0.050 numbers are more accurate, but you rarely get those from UK 
grinders.

Most people treat the cam card as if it is sacred, but the numbers are 
just educated guesses. The conventional wisdom is that the advance 
should be increased at longer durations. This keeps the most important 
timing event, intake closing, from getting too far out of whack. A 110 
intake center would be 0 advance if the lobe separation is 110, because 
separation is in cam degrees and the events are in crank degrees. If the 
duration is greater than stock, I would set the intake a few degrees 
less than 110. I have a couple of pages at my website that discuss 
degreeing cams and what to do when you have no cam card - 
http://tildentechnologies.com/Cams/Tips_Takes.html
  - Larry Young

On 10/25/2017 10:25 PM, patrickmannion1--- via Fot wrote:
> Hi Duncan, John and all,
> I sent the proper information to Newmans in June and again this week 
> but haven't had any response.I was wrong when I posted the lift 
> figure, on Monday. When I didn't get a response from Newman in June 
> with accurate timing events I through my notes in a box and misread 
> them the other night, the lift was actually .015" less than specified 
> in lift at cam which would be .022" less lift at the valve.
> The total lift, rise figure at TDC, and the figure at which max rise 
> should occur did not match what their website specified. The two 
> sentence response from them was like a politician saying "trust me", 
> it only stated
> "The best way to set the camshaft is that you have maximum valve lift on the
> inlet 110° after top dead centre" with no other information to second verify events
> In the past when we've ever had a figure on a timing card that didn't 
> match our cam grinder would get back and be able to say, check timing 
> events at this lift and verify by checking lobe centers and he would 
> give you ways to verify that all was correct. His cams always worked 
> great.
> I have three different types of cams, I'm going to plot and graph them 
> later in the week but will just use a camshaft from now on from a 
> source I trust.
> thanks for you responses
> Pat Mannion, Santa Cruz
>
> ---------- Original Message ----------
> From: Duncan Charlton <duncan.charlton54 at gmail.com>
> To: Triumph 'Friends of Triumph <fot at autox.team.net>
> Cc: patrickmannion1 at netzero.com
> Subject: Re: [Fot] Re TR4 camshafts
> Date: Tue, 24 Oct 2017 06:50:56 -0500
>
> Hi Patrick,
>
> You didn’t say whether you determined how many degrees of 
> advance/retard you’re putting in by setting max lift at 110˚ ATDC. 
>  Confirming that figure ought to give you some confidence that what 
> they’re telling you is in the ballpark.  2 to 4 degrees advance seems 
> appropriate for a street engine.
> Since you've been in the business for a while (I’ve heard your name in 
> Morgan circles for many years) I assume you already have the tools and 
> knowledge to do this, so I won’t go into a long-winded description of 
> the process, but for those reading this who haven’t done this before: 
>  put a degree wheel on the crank, zero it at true TDC and measure lift 
> at the cam or at the valve using a dial indicator, starting a few 
> degrees before max lift and ending a few degrees after max lift to be 
> sure you’ve found mean maximum lift.  Do this for both intake and 
> exhaust and calculate the midpoint between those two mean maximum lift 
> points.  That gives you the cam's “zero” point.  Decide whether to 
> advance or retard a few degrees from zero.  Advancing moves torque 
> lower down on the rpm scale (but also decreases intake valve to piston 
> clearance).  I find I have to plot this on paper so I can make sense 
> of it and to make sure I don’t move the the wrong direction in 
> altering the valve timing.
> Newman overstated lift by 34%.  Wow.
> Duncan
>
>     On Oct 23, 2017, at 2:48 PM, John Styduhar via Fot
>     <fot at autox.team.net <mailto:fot at autox.team.net>> wrote:
>
>     ​Follow the instructions for setting the cam and you will be
>     fine.  An adjustable cam sprocket will make the job easier.
>
>     On Mon, Oct 23, 2017 at 11:54 AM, riverside--- via Fot
>     <fot at autox.team.net <mailto:fot at autox.team.net>> wrote:
>
>         Yikes!   I  have always had great success with Dema's cams.
>         I hope his shop survived the fires.
>
>         art de armond
>
>         -----Original Message----- From: patrickmannion1--- via Fot
>         Sent: Saturday, October 21, 2017 5:11 PM
>         To: fot at autox.team.net <mailto:fot at autox.team.net>
>         Subject: [Fot] Re TR4 camshafts
>
>         Hello all,
>         I have always nearly always built Triumph TR4 engines with
>         cams from Dema Elgin Superlobes in Santa Rosa. Occasionally I
>         had installed other cams supplied by customers that had a
>         valid timing card supplied. I decided with the English pound
>         being low vs the Dollar I would try the PH1 Cam from Newman
>         Cams in England. I had heard good things about their PH1 cam
>         as being a great street cam.
>
>         When installing the cam. Information on there website stated
>         peak cam lift was .295" (it is only .220") resulting in a lift
>         at the valve being .120" less than stated. Starting off with"
>         incorrect lift figure all valve event figures on the website
>         are wrong. After several emails I got a two sentence email
>         saying ,set Intake for max lift at 110 degrees ATDC and the
>         cam will work,
>
>         After doing lots of engine modifications I would like a more
>         scientific answer than the cam will work. Has anyone used this
>         cam or a Newman cam before, or found that the information
>         supplied by Newman was incorrect. I hate to eat the cost of
>         the camshafts I bought or incur the cost of sending them back
>         to England, but I would have no confidence in using a camshaft
>         without having a correct timing card for the camshaft. -
>         thanks
>         Pat Mannion
>         Santa Cruz California
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