Getting 120hp is pretty easy from a 1275, in fact 130hp for a streetable
motor is quite realistic.
Step 1: get a really good head. Cut no corners here as this is the real
secret. Get huffaker or comptune or someone like them to do the head for
you. You want between 127 and 130CFM on the flow bench at 0.5" lift.
As a comparison, the Longman GT6 head is very ordinary - 115CFM
as measured on the flow bench. It means that the engine runs out of puff
at higher revs as the head can't deliver the fuel/air mixture.
Don't get the huge inlet valves - if the head guy tells you you need 1.4"
inlet valves, go elsewhere. Over the past few years, my engines have been
producing more hp/torque with smaller valves and better porting shapes.
this also means the head is less susceptible to cracking b/n inlet and
exhaust.
BTW, tell the head guy you want it to run on pump fuel!
step 2: go to 40thou or 60thou overbore or even 73.5mm (there is no
substitute for cubic inches!)
step 3: use a 286 or higher cam. If you don't plan to drive it in traffic,
you could go to around 296 degree overlap cam. 286 is a very nice
streetable cam that still produces the hp given an excellent head.
optional steps:
get a stroker crank, for street use a offset ground marina crank or an 1100
(2" main) crank. Note with the 1100 crank you'll have to get a 4 bolt
flywheel.
I wouldn't do this unless you were prepared to get a steel flywheel made
to suit.
That'll do for now.
Mike
-----Original Message-----
From: type79@ix.netcom.com <type79@ix.netcom.com>
To: spridgets@autox.team.net <spridgets@autox.team.net>;
Andrew.Griffith@ReadRite.com <Andrew.Griffith@ReadRite.com>
Date: Thursday, 14 January 1999 9:59
Subject: 120hp
>Drew,
>Could you let us in on your secret as to how you are getting 120hp from
your A-series block? I have a little MK.II panting at the garage door
waiting in nervous anticipation.
>
>Jay Fishbein
>AN-5
>HAN-6
>Innocenti S
>
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