Interesting dissertation on Performance.... I agree on the porting cam and
exhaust system...
I did all of this except the headers..
I have found that over the years headers have generally improved... just
not as much as computers... so I have opted on my wives street 1275 in the
bugeye not to have the headers... the constant problems of welds cracking
and so on... just to much for Miss Kathy to bare.. She wasn't supposed to
know about the 9.5-1 pistons and the .080 thousands we took off the head...
so I simply port matched the stock exhaust manifold and cleaned it up in
general with a sanding roll..
The Cam springs and retainers with a 3 angle valve grind and some light
porting on the head really woke this thing up...
Great car.... Little to quick for her not to notice that it has more power
then a stock 1275.. She isn't impressed with the Heat that it builds so
the next project is a decent radiator..
Keith Turk BN2, BJ8, AN5, AN9,Bville Camero( Tuned the motor last
night..ouch.. this thing makes some serious racket...) last outing of the
year this weekend... still liking the 155mph estimate on a 153 current
record with the East Coast Timing association..."North Carolina or bust"
----------
> From: Mike Gigante <mikeg@vicnet.net.au>
> To: Mark Endicott <endicott@nashville.com>; Spridgets
<spridgets@autox.team.net>
> Subject: Re: Roller High Lift Rockers
> Date: Wednesday, October 28, 1998 6:43 PM
>
> 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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