ausmini
https://www.ausmini.com/forums/

Rocker Question
https://www.ausmini.com/forums/viewtopic.php?f=5&t=90712		 Page 1 of 1
Author:  jpodge [ Sun Oct 04, 2015 6:37 pm ]
Post subject:  Rocker Question
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
Author:  Mick [ Sun Oct 04, 2015 6:57 pm ]
Post subject:  Re: Rocker Question
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.
Author:  Morris 1100 [ Sun Oct 04, 2015 7:10 pm ]
Post subject:  Re: Rocker Question
I don't even run 1.5s on a 1275.
Author:  Mick [ Sun Oct 04, 2015 7:32 pm ]
Post subject:  Re: Rocker Question
Morris 1100 wrote:
I don't even run 1.5s on a 1275.


Its not as pronounced.
Author:  drmini in aust [ Sun Oct 04, 2015 9:28 pm ]
Post subject:  Re: Rocker Question
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.
Image

[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.
Page 1 of 1 All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/