3 replies to this topic

[Wright&Wright]

I've recently found out that the cam that I was given by my Dad's friend was a BMC 731.

From what I know this is a fast road variant. My Mayfair has a 998 engine.

However we've installed it just by lining up the points on the duplex gears when the piston is at TDC and then slotting the cam in to meet this.
I don't have any of these timing disks or a dial gauge. Will it still be all right as I don't know how I'd compensate for any necessary changes in the degrees of timing for the cam?!
It's basically gone back in the same way the old one came out.

Cheers

Greg.

[Cooperman]

If the dots line up with 1 & 4 at TDC it should be OK. One thing to remember is that an original 731 cam will not have the lobe for the mechanical fuel pump, so you will need to have an electric one.
For your information, with a correctly timed 731, the inlet valves should be at mean max opening at 110 degrees after TDC.

[bmcecosse]

It's not the greatest cam, especially in 998 .......... but timing dot to dot should be ok.

[mk1leg]

the 731 is a good starter cam especilly in a 998 when I first tuned a 998 way back in 1980 there wern't many cam options and my 998 went like a bat out of hell .........so good luck............