Originally Posted by stanglife (Post 10453058)

Glad to see you're back. So sorry for your loss.

Originally Posted by Neil Harvey (Post 10453160)

I just watched your video of the cam timing. Unless you did this for practice, you did a huge amount of un necessary work.


Piston to valve clearance checks. I think I have this written up on our web site about doing this.


This can be done when you first have the case bottom together. Fit up one cylinder with one piston and one head. No piston clips required at this stage. You will need a degree wheel fitted and before you fit the one head, TDC the degree wheel with your dial indictor directly on the piston.

Now fit the one head with the valves loose in the head. No springs. Hold the valves in place with a rubber band or similar. Don't worry about them falling , they will stop at the piston. Exactly what you are measuring.

Turn the engine until you have 20° BTDC. With the dial indicator on the tip of the valve, zero the indictor with the valve up against the valve seat. Now drop it slowly until it touches the piston. Record this number. Repeat this every 5 or 10° until you go past TDC and are at 20° ATDC. Do the same for the Exhaust valve. Now call your cam supplier and ask them for the valve lift at those same crank degrees at the timing you wish to use. They will know the Intake and Exhaust centerlines at the lift at TDC you may be wanting. They will also be able to tell you the valve lifts at those crank degrees. You subtract the numbers they tell you from what you measured and this is the clearance at each degree mark you used. If its too close, change the cam timing to suit or machine the pockets/change pistons.

This may seem long winded, but I promise you its far quicker than doing a full assembly, then taking it apart again. Once you have done the math on paper and established you have clearance, you build up the engine one time.

As for the cam timing way you did it, another way is to place the cams where the rocker is on the backside of the lobe, or I guess with the cams you are using, where the dots are up and down. Fit your rocker arm and do the lash as you did. Now turn the engine until you are approx. 90° BTDC. The more valve lift at TDC may require this position to be further from TDC. Put the pin into any hole and turn the cam until the dial indictor reads the lift you want. The engine wants to be BTDC. Pull the pin and slowly turn the engine until you are just before TDC. Find a hole close and insert the pin. Now turn the engine until you feel you have taken all of the play out of the pin in the hole. If you are not at TDC, try another hole. If you go past TDC, do the same but turn the engine back past TDC and then turn the engine clockwise making sure you take all of the chain slack out. This way, you are up against the pin in the hole and the cam is where you want it.

Another simple tip when turning the engine, use a long breaker bar. It makes the job a lot easier.

Hope this makes sense. Cam timing is the easiest part of building these engines and these engines have to be one of the easiest to time. Too much is made of this and has put unneeded fear into many. Just have to make the process easier and eliminate repeating, trying to get the number you want.

nh

Originally Posted by Robert59095 (Post 10652544)

Hi, Kav -

I rebuilt my 2.7 10.5:1 twin-plug last Winter. Watching your wonderful videos on your engine build was a warm recollection for me. I might add that I used my surface plate and sand paper on every surface that needs to keep oil in the engine, particularly the chain housings and the surface on the case. 2000 miles and no leaks, other than the fact that I am learning how to use the silicone valve cover gaskets. My friends that does lots of engines swears by them. He says 35 in-lb. on the nuts and he has never had a leak!

- Rob