Minute wrote:
doc, am i better off running the larger valves in my road 1380 head or std 1275 valves?
also, he gave me a set of pressed steel rockers saying they were measured as 1.5:1 how can i measure the ratio?
claeten
Run the Mk2 inlets that it has. 35.6mm dia.
No pressed steel rockers are 1.5:1.
Standard they are about 1.21:1 unless they are 1275 ones (oval pads) then 1.25 or so.
At one stage Minispares and MiniMania were advertising offset bushed pressed steel ones as 1.5:1. This is BS there is no way to offset them that far and have a working bush. They advertised this as they had no stock of their forged 1.5:1 rockers back then.
I used to make my own offset bushed ones (.044" offset, a fair bit more than the ones sold) and the best ratio I achieved with 1275 rockers (Simon K's) was 1.35:1.
850-998-1098 pressed rockers with my offset bushes got 1.31:1.
I still have all the lift figures I found with S forged, pressed steel, and sintered rockers, tested on a block & 1275 head with same RE13 cam, same pushrod and a new rocker shaft.
[edit] here's a rocker with .044" offset bush (bored in situ).
As you can see there's no room for MORE offset.

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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.
