Leyland cam timing

[970s]

Hi, planning to fir a ST Leyland 544 cam in my S motor, any idea of what time in angle should use? should I take the 107.5 or 110?
thx!

Al

[Spider]

ST provide a figure of Full Inlet Lift at 110 degrees, however - and this is just my personal preference, - I time them at 105 - 106 degrees minus (or advanced) another 2 degrees if chain driven, for street use. If for comp use, then I use 110 to 112.

Advancing the cam timing brings it on the cam at lower revs, however it does so with a small loss higher in the revs. I don't like 'screamers' for the street.

[Vegard]

I remember that Vizard advised to advance this cam by quite amount from the ST setting. Don't quote me on it, but I seem to recall this while fitting one in my own 1132.

[mk1]

I have always timed in at 110° in my 1070's & have always been very happy with the results.

M

[36inter]

The 544 in my 1385 is timed at 106, not on purpose but because in 1979 when I built the engine it was the nearest I could get to 110 with a Leyland cam, their grinds were all over the place, I went through 4 cams from my local supplier and in the end picked the best of a bad bunch, cam lobe timings were all over the place. Adjustable timing gears were not readily available or too dear as I recall.

106 gave brilliant results and consequently I have heard that 106 is a popular setting for this cam.

Pete

[970s]

oaps! Now I really get lost in the timing of 544! any more advise I can get? Still not decided to put it in a 1293 or 970? but for fast road use only!

Al

[Spider]

oaps! Now I really get lost in the timing of 544! any more advise I can get? Still not decided to put it in a 1293 or 970? but for fast road use only!

Al

I'll just add then perhaps that you initially try setting as per ST's recommendations, then play with it, changing it around 2 degrees at a time. Make notes as you go and be very careful if you are going to advance it more than about 104 degrees (allowing for a safety margin) as there is a risk that the Inlet Valve can kiss the piston crown (though this won't usually happen until about 100 degrees or less). I have one of the belt drive kits with the movable peg (they call them 'vernier' kits, but they are not). On the kit I have, each hole is 2 degrees, you should then be able to change cam timing in about 40 minutes. Once you work out what you like, I'd then suggest going back to a chain drive, timed at you sweet spot however I'd suggest advancing it by a further 1 - 2 degrees again to allow for chain stretch.

This exercise will also give you a much bigger appreciation of the need for accuracy in cam timing as well as cam characteristics in general and the need for accurate grinds.

At the end of the day, it is your engine and it's best to set it up how you want and expect it to go.