Camshafts

[nylen]

Do anyone know which checking height the duration are measured of the original TR 5 or TR6 camshafts.

For example TR5 has duration of 280. Is the checking height 0,4 mm or what?

[Anschutz]

http://hottr6.com/triumph/tr6cams.html

 

This web site might help, also I believe rocker ratio for 5's and early 6's were 1.5

All measurements are in inches so you will need to convert for mm

Edited December 4, 2011 by Anschutz

[nylen]

Thanks,

 

I know this website. I am not asking for the Rocker ratio am asking for what the on this website call Advertized duration. The Checking height for Duration @0,050 is of course 0,05" = 1,25 mm but what is is for Advertized Duration???

[Dennis Devon Group]

Hi

 

This site may be of help. Regards Dennis

 

http://www.rbracing-rsr.com/camshaft.html

[nylen]

Thanks,

 

That´s a nice website but that website doesn´t tell me how they measured at Triumph. We have made some measurments and this what I got for a TR5-cam no 307689:

 

Inlet 0,3 mm checking height, 270º,

0,5 mm 254º,

1,0mm 209º.

Lift on cam 6,35 mm.

 

It looks like Triumph measured at 0,2 mm or something like that.

 

Bengt

[Dennis Devon Group]

Hi Bengt

 

Your figure of 0.2 mm looks about right. Whats your reson for checking your cam? I have my original 150 TR5 cam in the garage as I have just fitted a Kent TH6 to my 5, I know my old cam is the 307689 as I bought my car in August 1973.

 

Regards

 

Dennis

[D1070]

like the trumpets Dennis,

cheers,

Laurence,

[TRTOM2498PI]

Hi Dennis,

 

How are you getting on with the trumpets ?

 

Have you done a power run with and without plenum ?

 

I am interested as I have a tuned TR6 on PI.

 

 

Cheers

[nylen]

Answer to Dennis,

My reason for checking camshafts is that if you want to have a new cam or even if you just discuss camshafts there must be a standard how to measure. If you tell me that you have a camshaft with duration 290 it doesn´t tell me anything if you don´t know the checking height.

You mention Kent Cam TH6. On there website they give you Duration 280 for this camshaft but on which checking height. 0,2 mm or what?

 

If you look at another supplier of camshafts, www.webcamshafts.com you will find that the give you two values. One just for advertise??? and one called Duration 0,050". Here the checking height is 0,05" = 1,25mm.

[Tom Fremont]

Hi Nylen,

 

The last (2) camshafts I installed commenced to open their valves at precisely the prescribed angle at the specified operating clearance; i.e. 41 degrees BTDC @ 0.014" clearance ( duration 292, 41/71/71/41 timing ), once I got it timed in of course, and F/L centerline checked out correct as well ( 105 degrees in this case ).

 

My next camshaft ( different engine ) will be a 150 spec, so I expect its #1 inlet valve to open @ 35 degrees BTDC set to 0.010" clearance.

 

Happy with your Webers ?

[nylen]

Answer to Tom,

 

Yes am happy with the Webers. Now running with a cam with specification as below. I have 165 hp on rear wheels at 5500 rpm and good power from 2000 so its ok. I use a cam called TG 076. Made especially for my engine. PI camshaft figures here just for information as we made the measurements.

I know that you can have more hp from a TR6-engine but if you like to have the car on normal roads I think I have made a good compromise.

 

Duration

Type Inlet/outlet 0,3mm 0,5mm 1,0mm Lift on cam Standard rocker Roller rockers 1,65

PI-cam inlet 270 254 209 6,35 9,5

TG076 inlet 280 260 235 7,6 12,35

TG076 outlet 270 256 228 7,3 11,6

Edited December 8, 2011 by nylen

[nylen]

See above

Edited December 8, 2011 by nylen

[nylen]

I am trying to attach a Excel file but I give up.

Edited December 8, 2011 by nylen

[Dennis Devon Group]

like the trumpets Dennis,

cheers,

Laurence,

 

Thanks Laurence see you soon, I now have my rolling road figers from Mike Tarr, but need to return for finale adjustments.

[Dennis Devon Group]

Answer to Dennis,

My reason for checking camshafts is that if you want to have a new cam or even if you just discuss camshafts there must be a standard how to measure. If you tell me that you have a camshaft with duration 290 it doesn´t tell me anything if you don´t know the checking height.

You mention Kent Cam TH6. On there website they give you Duration 280 for this camshaft but on which checking height. 0,2 mm or what?

 

If you look at another supplier of camshafts, www.webcamshafts.com you will find that the give you two values. One just for advertise??? and one called Duration 0,050". Here the checking height is 0,05" = 1,25mm.

 

I did notice that the 0.050" is quoted on the web page I posted.

I said I have a Kent TH6 cam not exactly true I got them to custom grind to TH6 characteristic as I have 1.65 roller rockers and did not want to be to lumpy on the lower end.

[Dennis Devon Group]

Hi Dennis,

 

How are you getting on with the trumpets ?

 

Have you done a power run with and without plenum ?

 

I am interested as I have a tuned TR6 on PI.

 

 

Cheers

 

 

I had my 5 on the rolling road last week i am returning next week as the metering unit is to rich from 2400rpm up, this will be the final adjustments to mixture and my 123 Tune USB distrbutor, I must say I am very inpressed with the flexability in plotting the curve to your engines characteristics. at the moment I have 177bhp flywheel with 167lbs ft torque.

 

Photo of mod I have recreated on my current metering unit so as to adjust the maximum fuel screw, it consists of a piece of speedo cable inserted into drilled holes and soldered, i have modified the end by the distrbutor to have locking nuts,will take a new photo.