I'm doing some research on rockers and engine capacity and also whether it may be worthwhile upgrading the rockers on my 998.
I understand that the 1.5:1 rockers are best used on 1275 units but also fit other capacities such as 998cc but theres usually torque lost down low.
My 998 has a 12G295 head fitted and has the stock cam.
Does anyone have any experience with the 1.5:1 rockers on a 998 and can tell me about some pros and cons?
Cheers!
joe

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-----Better is the enemy of good-----
-1976 Yellow Devil Leyland Clubman-
-1970 Morris Mini Van - Work in progress-

I tried the 1.5:1 rocker thing and found it was slid the torque curve too far up on the 998 (+100) to make it a nice car to drive on the road.

There will be pros for it, but not in my context in any case. Perhaps with a lot of engine development it would be an option.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

I don't even run 1.5s on a 1275.

Its not as pronounced.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

I'd stay away from 1.5s on a 998. If you want more lift than stock, fit 1.3 roller tipped ones. Or, put offset bushes in some 850/998/1098 pressed steel rockers.
Look similar to this- I used to make and fit them. This one has .044" offset.


[edit]
Can buy them here-
http://www.jonspeedracing.co.uk/index.p ... &cID=13895
They need reaming to size after fitting.
You also need to drill out the rocker post holes ~1.5mm, and push the rockers back before bolting down.
The most these bought ones will give you is about 1.28:1 ratio. Some people in UK or US say they give 1.5:1, but it's BS.

Mine gave 1.31:1, and their .044" offset was on the limit of what can be done; I pressed solid bronze into the rockers then bored them on the mill. The bought ones are not made this way.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.