First of all, apologies for the inactivity as most of my updates are done via other social media, being a young’n and all...
However this deserves its own post on the forum as I am proud to present my 1256 project for the last year or so.
Just recently I have officially broken the 100 HP barrier with my fuel injected, turbocharged 1256.
Perhaps a world first on multiple fronts?
I wanted to replicate power levels achieved in the 70s by the HB/HC racers whilst maintaining a drivable car which retained the original engine with period modifications to the internal components.
The specifications are:
•1256 block
•1256 chevette head
•Mildly ported cylinder head
•8.5:1 compression
•Standard 1256 cam
•Hollow pushrods
•Heavily worked conrods (each rod 50g lighter)
•Conrods balanced end to end to 1.5g variance
•Crankshaft, flywheel, clutch balanced to 1g variance
•Lightened flywheel (from 5.9kg to 4.9 kg)
•High pressure oil pump
•Bespoke stainless inlet manifold
•Bespoke stainless exhaust manifold
•Bespoke stainless full exhaust system
•Oil cooler
•Baffled sump
•Garrett GT1752 Turbo
•45mm Throttle Body
•Electronic Fuel Injection/engine management
I have now had this engine broken in and tuned to produce
78.9 WHP @ 5070 rpm
96 ft•lb @ 2910 rpm
This is at 5 psi boost.
This is a 75% increase on both torque and power on top of standard figures. I have posted a graph of the new engine plotted against the standard guise.
It was lovely talking with some of you at VBOA this year and showing my car again. It was great to hear your thoughts on a very unique build.