You'll almost certainly gain a little, but perhaps not enough to be
noticeable in normal use (unless you put it on a rolling road.)
As for lightweight, you might be surprised. The roller rockers I have are
slightly heavier than the stock (pressed steel) items even though they
are made from alloy!
For a stock motor, there are lots of better value-for-money ways of
getting some extra HP. You didn't mention exhaust - do you have a
good set of LCB headers?
A little head work (i'm not talking big valves or race porting - just a
little
improvment on the flow rate) will produce much more HP than just roller
rockers and will probably cost you less. The same is true of changing cams
to one with a bit more duration and more lift. This is in fact the cheapest
route to more HP.
What the higher lift is giving you is an improvement in the CFM (cubic
feet/minute) of the intake system (head, valves). The CFM starts
increasing significantly when the valve lift is getting up towards 0.4 -
0.5".
With a stock cam and 1.5 rockers you are *nowhere* near this figure.
A warm cam and stock rockers will get you closer. A hot (full race)
cam and 1.5 rockers will see 0.5" or a little more.
Somewhere I have a graph of CFM vs lift for one of my heads. I'll see if I
can drag it up.
Mike
-----Original Message-----
From: Mark Endicott <endicott@nashville.com>
To: Spridgets <spridgets@autox.team.net>
Date: Tuesday, October 27, 1998 8:28 PM
Subject: Roller High Lift Rockers
>Spridgeteers:
>
>The newest Mini Mania flyer has a "High Lift Roller Rocker" assembly
>advertised. They don't say what the lift is but I believe that I have
>seen it before and it was a 1.5 to 1 lift. The original rockers are
>1.3 to 1 so I have been told. I am wondering if the lighter aluminum
>roller rockers with the higher lift would gain me a few horses on a
>stock 1275. The only other mod is K & N's with stub stacks inside the
>stock housings and very slightly modified SU's. Ideas and thoughts?
>
>
>Thanks
>
>--
>Mark
>70 MG Midget
>Nashville, TN
>
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