I'm working on a project with a friend, converting a 1940's Ford 255CID
flathead V8 from carb and points to a Rochester TBI setup. The electronics
hardware side is done. The engine has an afermarket distributor with a
conventional VR pickup coil. This is connected to a standard Delco computer-advance HEI module that is firing an MSD box. In the pictures the advance weights are still present, but they have been removed and the advance bolted so the ECM cancontrol the timing.
The intake manifold has a huge plenum, look at pictures linked at bottom. We're using a 4.3V6 throttle body and injectors. It is a very mismatched setup on the engine/ cam/ manifold but this is what we have to work with.
We'll be using Cats RT Tuner and a wideband to adjust the VE tables.
This has been a fun project so far, but the real fun will be making it run
correctly. It will be an open-loop calibration, tuned for drivability first,
Well, today we got it running! The cam was an unknown but suspected of
being a rowdy grind. It is a fairly rumpy cam and my friend may put a stock
one back in the engine. We will have to see how streetable this one can be.
This was a 'test and evaluation' run with a garden hose cooling system
instead of a radiator and a gas can for a fuel tank. The rest of the car is
no where near being ready to drive so all we could do was adjust the idle
I started with a calibration for a 305. The tunnel-ram manifold required
more than doubling the delta TPS pump-shot to give a satisfactory rev when
the throttle is blipped. Cranking up cold is not easy. I figure after the
VE table is tuned with wideband maybe cranking AFR will become more tunable.
The engine had been in a barn for years and there was evidence of rust in
it so we were afraid it might need another rebuild. This run has proven
that it has compression and no mechanical problems. That was all we set out to do today so it was a success!
Still got to locate "true" TDC and make TDC marks on the pulley and timing
gear cover. The timing table needs to be adjusted to reduce the RPM-advance per advice from folks here and other flathead literature. We're using a magnetic-pickup MSD distributor (no built-in advance) with ECM controlled
Got to install exhaust manifold gaskets on one side at least, and then weld in an O2 sensor bung. Then the wideband datalogger can be used to make a decent VE table.
All my other EFI projects have been mild cams, and this one is probably a
60's era "three-quarters race" cam. Anyone have any experiances to share on
rowdy cams and speed-density systems? We're not going for max HP, just
streetability and uniqueness.
In the pictures below you can see the adapter plate my friend has fabricated to adapt the TBI to the manifold and hold a scoop that will conceal the works. We had to do some creative fuel line fabrication on the TBI to make it fit in the base of the scoop. Fitment of the decorative scoop is not 100% sorted out yet but at least the engine runs now!
The real details of tuning will have to wait until the car has a radiator,
alternator, gas tank, clutch linkage, brake pedal, drivers seat, tires and
wheels to name a few. :-)
Below is the engine as it is for the test-run. We test-ran it with a garden-hose cooling system...
Below is a close-up of the TBI on the engine...
Below is another view of the TBI and throttle linkage...
Below is the decorative scoop that will cover the TBI...
Below is the electronics panel. It will be hidden well in the car's dash area...
Rest of pictures are in this folder:
126.96.36.199 - /FlatheadEFI/
If the pictures do not show, please try later as they are hosted on my computer at home and if it is offline or down for a re-start they will be temporarily unavailable.