roller rockers

[cav773]

Hi, quick question I have had my 1275 taken out to 1330 and am using an md286 cam. Would it still be worth using 1.5 roller rockers with this cam?

[DanGT]

Yes it would give you more valve lift and if set up correctly more power. It will with more lift mike it more ruth at low reves but with a 286 I would thin not to bad. I have run high lift rocker befor but never done a befor and after check.

[Cooperman]

I fitted 1.5:1 roller rockers to my 'S' which was then 1293 cc with a 286 cam, big-valve fully-flowed head, 11:1 CR and twin H4's. I gained all of 2 bhp at 5700 rpm and over which was measured accurately. I also believe I lost a bit at the bottom end, but that was not measured.
That's a lot of cash invested to gain 2 bhp and really it was not worth doing.

[guru_1071]

you should also consider that the roller rockers will solve the problem of the normal rockers rearing against the tips of the valves and also pushing the valves into the guides, so they also offer a reliability issue over 'mechanical' rockers, particually on high lift cams.

[Cooperman]

yes, they do reduce side-loads on the valve stem and hence reduce guide wear. Now, 1.3:1 roller rockers would be ideal for a 998.

[guru_1071]

Cooperman said:

yes, they do reduce side-loads on the valve stem and hence reduce guide wear. Now, 1.3:1 roller rockers would be ideal for a 998.

they could be made, trouble is there would need to be a minimum order qty for it to be a worthwhile thing, which has never happened, its like 1.3's for 1275's, nobody ever seems to want them