Cam specs for timing

[saggy]

Hi all,

I've been onto Moss and they are very prompt and helpful with advice on degreeing their camshafts. However, they quoted the number of degrees at .300" full lift.

But I'm trying to find the cam degree/timing figures at .050" tappet lift which is quoted on cam spec cards these days as believe more people use it as it's more accurate rather than the 'dwell' over the top of a fully up lobe - bit like the dwell on a piston measured with dial gauge as it goes through TDC.

Anyone know where these .050" tappet lift figures might be found please. BTW it's a TT1004N for a 4 cyl 8v 4A.

Thanks, Saggy

[john.r.davies]

Saggy,

Forget the magic number of degrees and use the "Equal lift on overlap" method.

It's been discussed here and elsewhere on t'Net'.

John

[Guest ntc]

The numbers do apply http://www.burtonpower.com/tuning-guides/tuning-guide-pages/camshaft-fitting-timing.html

 

http://www.kentcams.com/information-faq.asp#5

Edited October 28, 2013 by ntc

[Andy Moltu]

Unless they have done the measurements there may well not be a figure.

Most manufacturer give a figure for degrees after tdc with no1 inlet at full lift.

 

Using a dial gauge it is a pretty straightforward to find the max lift of the cam - using the gauge to measure the mid point of say 10 thou' before and after the max lift. (just as you might to identify true tdc) (rather than just measuring max lift which may well cover a few degrees)

http://www.leicestertr.co.uk/Technical/camtiming.htm

[saggy]

The numbers do apply http://www.burtonpower.com/tuning-guides/tuning-guide-pages/camshaft-fitting-timing.html

 

http://www.kentcams.com/information-faq.asp#5

Cheers Neil - thank you for that.

I also note that I & E clearances are large at .022" and .024" as well.

Regards, Saggy.

[Stanpartmanpartwolf]

Same old Kent Cams Ford crossflow profiles, designed for dished pistons & flat heads-- not great.

All these cams are ground at 108deg lobe centre angle & can be installed anywhere within +2 or -6 degrees of that figure without any ill-effect.

In fact ALL cams for our cars have LCA's between 105 & 110, from standard to race spec; narrow (100deg) angle cams tend not to suit.

Don't waste time & money on Vernier wheels, etc- TR engines are remarkably insensitve to cam timing variation- the longer the duration, the less the effect.

Only gross errors make any tangible & quantifiable difference on the dyno.

Whoops...there goes another myth........

 

Also I have yet to see any TR exhaust valves grow by 0.002" when hot, so check your lash hot & cold, then set it at 0.022" all through.