21 replies to this topic

[ACDodd]

9.75:1 is perfect with 95Ron fuel and that cam.

 

AC

[Mini and Puck]

Sorry, the 3cc is the volume of the block at tdc. Flat top pistons.

[Mini and Puck]

Well, if anyone is still reading this saga....I have tried to get the cam timing set to 108. So I fitted a 4 degree, and got 105. I fitted a 3 degree and got 106. I fitted a 2 degree and got 109.5!!!! I mean what the ????? So I repeated the three degree and two degree woodruff key setup. Got the same readings. Has anyone heard of woodruff keys not giving the correct offset? I guess a two degree is incredibly small.... Of course a vernier timing gear would solve this,Mobutu that is an incredibly expensive option. My question is this. Am I better to go with the two degree at 109 ish, of the three degree at 106? I mean, 106 seems a bit much for a MG metro cam on a 998, even accepting that I am fitting a 12G295 head.

[Cooperman]

109 degrees ATDC will be fine.

[Spider]

I have had a few where almost at every turn you get a different result - cheap sprockets and chains will do that.

 

I'd suggest running with the 3 degree key (giving 106⁰).

[Cooperman]

I take 3 readings at each setting and average them. I also get slightly different readings each time.

it'll run fine at an initial of 109 or 106, especially after the chain has stretched a bit.

[Mini and Puck]

Right then! 106, with the 3 degree key it is!