roller rocker kit

[eric]

Is it a good improvement for an x flow ?

 

Better acceleration or only less wear for valves guides ?

Do it cope with the standard Caterham rocker cover ?

 

Thanks for your advises

 

 

 

eric

[George C]

It wont make any noticable difference other than they look fantastic, but you wont see them! I found that the roller rockers wear (on 2 sets) and so any less wear in the valve guides has been replaced by a new problem. Best to fit an uprated rocker assembly of the original design which is available from Burtons or others. I have gone back to this set up on 170 bhp X Flow. I hope that helps.

 

George

 

 

 

[eric]

it helps

 

eric

[OliverSedlacek]

I know Roger King would say that the standard rockers are very good and the roller rockers add weight. I like them because I get a huge (seriously huge) increase in valve guide life.

[eric]

It could be a good reason for me to go for it !

 

eric

[Revin Kevin]

Eric,

There is some suggestion that roller rockers some times do not work well with high acceleration cams IE KENT 2X4 cams. Use standard rockers which you can lighten if you are feeling inclind with steel posts and spacers, I have found the standard shafts adequate although some people advise using a steel shaft. I would only use roller rockers with long duration cams.

 

Cheers

Chris

[eric]

quite interesting

 

eric

[Roger King]

Yes, there are issues using rollers with high lift, short duration cams such as the 234 and its relatives. I'm not the only one to have found this.

 

At the race end of things, the (high lift) roller set works well with an A8. With a 264 you wouldn't need the extra lift, so you'd choose the standard lift rollers but you usually find a problem with spring surge in the high 7000s which can be driven through until the valves start to behave again at around 8200. This is obviously not a good thing. The fact that this can be driven through suggest that its a resonance problem related to component mass and not simple valve bounce due to the springs being too weak (we found the same problem with several different spring types, although the exact point in the rev range would vary a little). Even changing the valve cap material from steel to aluminium would alter the mass of the valve gear enough to change the point in the rev range where this happened.

 

Now I admit that the 264 is much more racy than the 234, but I have also tried the rollers (std lift) with a 244 and had a succession of broken cams and followers (not due to coil bind which would be the obvious first place to look). These failures didn't occur immediately which suggests that the same problem is probably happening, but to a less noticeable degree.

 

For these reasons I have always avoided running rollers with the 2X4 family of cams.

 

There is NOTHING WRONG with standard rockers, particularly if teamed with a steel shaft and posts. They are certainly good to 8800rpm with a 264 and I have gone to 9500rpm with other cams. Smaller capacity Kent based engines have been taken to 11000rpm in the past, although with lower lift cams.