5 replies to this topic

[Alpenflitzer]

Engine SPI 1.3i, 53 HP, 1993 all original, nothing tuned-up.

Now i would like to change the present old stand rockers to roller tip rockers.

 

Does anybody know if there additional work to do ? 
Can I just fix it and drive away?

Could  the ECU make problems?

 

Minisport writes that the old assembly can just be taken off, new roller rocker in  and after adjusting the valves ready to go.

 

See   http://www.minisport...ckers-blue.html

[KernowCooper]

The risk is if you release the rockers the rear head bolts need to be undone and retorqued to fit. and there is the chance of head gasket failure. If your doing the mod to reduce side loading on the valve guides fair enough if your expecting a performance increase then there is better ways to spend the money as they wont do anything over the standard rockers for power

Edited by KernowCooper, 29 October 2014 - 01:29 PM.

[jaydee]

You need to release the load from the valve train, screwing the tappets adjuster up all the way so you have all the valves closed and no tension from the pushrods. Then carefully undo the rocker nuts in reverse spiral order.

Thats the only way to remove the rocker assembly reducing the chance of disturbing the cylinder head.

At refitting, once you have all the nuts back at the correct torque in spiral order (rocker post to head 30 NM, cylinder head 68NM) then re-torque again ALL cylinder head nuts in spiral order to 68NM. Now you can set tappets to specified clearance.

Good luck.

 

A word of warning must be added regarding rocker geometry.

Sintered rockers have tall posts, rollers use smaller posts, you have to adjust height placing spacers under them so you achieve that the rocker stays at 90° when at half of the valve lift (90°to the post at half of the rocker travel). 

Edited by jaydee, 29 October 2014 - 01:40 PM.

[Alpenflitzer]

Thanks for the good explanations what to do. This means that I could also polish the shafts, new guidances and sels.--- This becomes a winter work!

 

I have a second question:

 

Keith Calver offers special hardened high quality rocker adjuster screws.

http://www.calverst....cker screws.htm

 

If I replace on the old equipment only the rocker adjuster screws, can I simply take off the old ones and replace one after the other and then set to specified clearance?

Or does this mean additional work besides srewing  in and out the rocker adjuster screws and set clearances?

[jaydee]

Adjuster screws are not where the wear occurs

Sintered rockers wear a groove on rocker pads and the shaft wears in the posts as its not running on a bearing.

[Alpenflitzer]

Thanks a lot , I think I leave  everything as it is and in case s.th. happens to my rocker assembly I will do a general overhaul.

Up to now, the engine is running like a sewing machine and I hoped by changing to roller rockers that it will be even less noisy.

 

So, some more beer can be consumed next time Dortmund´s  BVB plays the championship.