What cam am I running? How to find out?

[V12man]

Is there any way to find out what cam is in the car without removing it from the car - valve covers and cam timing chain covers are removed already, but I don't want to remove anything else.

Anyone know how to do this? is it even possible?


Guy

[jluetjen]

Plot the lift at the valve, or at least the maximum lift by setting up a dial gauge, zeroing it when the valve is closed and then measure how much lift the valve has. Do it for one of the exhausts and one of the intakes.

This will help you to narrow the choices of the type of cam that you have. When you drove it, at what RPM's did the engine's note change and did it really start to pull hard? Does the engine serial number match the car? What's the type number on the engine. Both of these can be found at the base of the fan shroud on the right side.

BTW -- Welcome aboard!

[Flat Six, Inc.]

I measure the cam timing also......you can usually make a pretty good guess.....

[V12man]

Thanks for the ideas and the welcome - I have been following this board for months, so much that I am well addicted to it - just an update on what's happening

The motor is a 71 2.2 T (according to the serial number) in a 67 chassis.

I met a previous owner some weeks ago - strange co-incidence, but that's another story - and he said the car had S cams in... So I got to wondering... (car is much bastardised, and I have never opened the motor in the year I have owned it - so I have no real idea what is in there - but it's sure to be non-stock)

Then 10 days ago a chain tensioner started failing (did not appear to slip) and I have installed replacement tensioners - with the help of a few friends - last night. (the tensioners we replaced were 930 tensioners... so who knows what else is in there... Motor also appears to have 2 aluminium looking cylinders, and 4 cast iron ones... go figure...)

At the same time, we measured the Inlet & exhaust valve lifts, and it appears to be an S cam, (matched within 0.1 mm of spec)so we have set the cam timing to match, and will close up and complete tonight hopefully (this is woman dependant.....)

And for sure I will check again for valve/piston interference by turning the motor by hand - but the acid test will be to see if it runs.... and if it breaks - well then I get to buld it properly.
It only has to last this year (club time trial events only really) while I get the chassis and brakes sorted - so far:

New bushes front and rear
New torsion bars (33 and 23mm)
New sway bars (23mm SRP front and rear - rear still has to go in - front is in, but untested (torqued it up last night too - before the friends arrived)
New 23mm master cylinder (which meant new front hard brake lines)
Boxster brakes front and rear (mmm... fun engineering that was getting brackets made up to fit the old struts and the rear...)
New shocks - front and rear - slightly shorter and valved differently from stock.
Turbo tie rods
Longer rear wheel studs
All new syncro rings and one new slider in the 'box

Still on the plan for this year:
Wevo shifter bits
New engine and transmission mounts

and that's about it - so far


Blue skies

Guy

[jluetjen]

Great! Let us know how it turns out.