8 replies to this topic

[tucker]

Hi all

I have searched the posts and done a bit of research - just need a bit of confirmation from the experts if possible!:

I intend to check cam timing on my new motor ASAP. It's a KENT 296 Cam which the website says should be 106 deg. advanced of TDC.

I plan to purchase a timing disc to measure this.

Is there another tool that I need? e.g. if it is not 106 deg. do I need another tool to correct it? I have in mind some sort of key but there seems to be disagreement about which are the right kinds and whether they are even necessary. I also have no idea where to get one.

Many thanks

[Big_Adam]

From various books I've seen and read then a Dial Test Indicator is a well used too. It's plonked on top of the block (head removed) then the engine is turned by hand until the dial reads to a TDC (the dial reads up and down, so keep going up until it starts going down....if that makes any seance).

The "key" I believe you are referring to a woodruff key. Depending on your timing chain set up your more than likely going to need an offset one.



A woodruff key lines into the sprocket for the timing chain gear (see the little cut out key ways in the sprocket wheels). Then when the engine turns so does the sprocket rather than spinning round. An offset one is stepped one way and is used to get the timing .... ... close. It's never dead perfect but it means you can time up using dot-to-dot on the duplex/simplex chain wheels. An adjustable timing chain or belt would be the best of options but they cost 3 times the amount of a regular chain set up.

edit,

Oh and if you want an offset woodruff key give Kent Cams a call and they should sort you out.

Edited by Big_Adam, 27 February 2007 - 12:16 PM.

[tucker]

Many thanks mate.

So from this I understand that, provided I have a timing disc, I need no other tools just to check the CAM timing.

However, if I want to correct it I will need an 'offset woodruff key'. The best place to get this is Kent Cams.

Finally, the DTI is a tool for determining TDC and this is helpful to ensure that all of your other timing measurements are correct. This will be just as useful for doing the ignition timing.

However, I think that you can determine TDC just by turning the crank and watching the relevant piston (I'll be using No. 1 for everything) reach the point where it finishes rising and the point where it stops rising and then measuring exactly halfway between the two. Is this correct?

Many thanks for your help.

[Big_Adam]

Offset Woodruff, yep. Phone Kent Cams and tell them your cam spec then they should be able to advice on a key.

DTI is actualy a tool used on mills. Just happens to work well for finding TDC. Yes you can just turn the engine by hand. Hell when I changed my timing gear I just plonked a screwdriver in thro a spark plug hole and turned the engine back and forth to find TDC. Be careful when you restart the car tho as the oil pressure might go.

[The Matt]

However, I think that you can determine TDC just by turning the crank and watching the relevant piston (I'll be using No. 1 for everything) reach the point where it finishes rising and the point where it stops rising and then measuring exactly halfway between the two. Is this correct?

Yeah, but it is more accurate with a DTI, that's all.

If you are going to the effort of setting the timing I still say that a decent second hand vernier set up would be useful. But you can do it with offset wooruff keys. I believe Minispares.com sell them, but I have never used the offset keys myself.

You also need to measure where the peak lift of the camshaft is in the same way (I use an old carb return spring on the pushrod to pull the follower/rod back down under a bit of tension).

[rob3]

You will need a DTI to determine the maximum lift point of the cam lobe your measuring so you check the timing

[Bill USN-1]

click here

[tucker]

Many thanks all.

I will trawl through that and try to figure out what I need to do.

I'm pretty confident that when this engine was put together it should have had the correct cam timing so I'm hoping to just check it's in the right place - have this confirmed - and move on!

Excellent.

[Big_Adam]

good luck with it man,.