Project status....

[michaelmount123]

Which windage holes, Chris?

on the right and left sides of the main bearing webbing - not in a normal 944 block!

Yes, there are also windage ports in the main webbing between each cylinder like a 3L block, and 14mm head studs from the factory. Don't know how many of these blocks exist. Since there were only 7 (944GTR) cars, there can't be many. We have 2 complete engines and one NOS block. Once I get beyond this 2V engine, I'm thinking of a 944S 4V head adapted to the GTR block and intake manifolds. But, I'm getting ahead of myself....

[chris white]

Which windage holes, Chris?

on the right and left sides of the main bearing webbing - not in a normal 944 block!

Yes, there are also windage ports in the main webbing between each cylinder like a 3L block, and 14mm head studs from the factory. Don't know how many of these blocks exist. Since there were only 7 (944GTR) cars, there can't be many. We have 2 complete engines and one NOS block. Once I get beyond this 2V engine, I'm thinking of a 944S 4V head adapted to the GTR block and intake manifolds. But, I'm getting ahead of myself....

its interesting that they did the windage ports differently. a lot of work for a small number of castings!

[michaelmount123]

CoolantLeak.jpg (1.98 MiB) Viewed 3058 times

Interesting flaw...
Here's a photo of the GTR cylinder head surface that shows the source of a coolant leak. Although it only leaked when cold, it was frustrating to have to monitor the coolant level and refill between track sessions. The photo shows where the head gasket seal missed the corner of the water passage. A dab of additional sealant in the flawed area will hopefully address the issue.

[michaelmount123]

Finishing up the rebuild:

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[walfreyydo]

Curious why 2 injectors per cylinder and not a single larger injector? And assuming the standalone EMS is treating it like an 8 cylinder engine, having them fire in pairs, running full sequential? Can you shed any light on the custom fuel rail setup? I assume its modded in order to run dual injectors but any other reason?

Sorry if this was answered previously I have not read through the entire thread. If so, let me know and Ill go back through and do more reading. I almost dont know what I am looking at!

[michaelmount123]

Re the dual injectors: Porsche developed the engine back in the mid-1980's, some 40 years ago. At the time there were no large injectors available for motorsports. So what to do? Andial chose to run two 951 injectors off the Porsche shelf. It's currently set up to run both injectors simultaneously, and it does run sequentially as a 4 cylinder. The fuel rail is a custom piece to accommodate the dual injectors and the intake manifolds have been (beautifully) modified as well.

As an aside, the first generation 944GTR engine was developed by McLaren and used mechanical injection. The engine was deemed 'not ready' due to durability issues. Andial then took over engine development and converted to electronic engine control using a modified 962 Bosch ECU. They found the power and had success with the very early electronics. We're using MoTec due to the stability and capability of today's ECU's. Anyone notice the Kinsler DBW throttle actuator?

[four0four]

I'll give some of 'em a shot, but obviously other people know lots more

edit: oops, beaten by one!

Curious why 2 injectors per cylinder and not a single larger injector?

iirc that's from the original design. no idea how they were driven at the time, but wouldn't be shocked if they turned one off under low load conditions where a single injector would be difficult to control at such low duty cycle. would also be only partly surprised if it was difficult to source otherwise appropriately sized injectors at the time.

And assuming the standalone EMS is treating it like an 8 cylinder engine, having them fire in pairs, running full sequential? Can you shed any light on the custom fuel rail setup? I assume its modded in order to run dual injectors but any other reason?

You can see a cam sensor, but it doesn't look like it came that way. So I imagine fully sequential, no need to be more complex than that. Most ECUs'll let you be pretty flexible with what injector output(s) fire per event, so that simplifies things.

[ROB III]

Didn't see the Kinsler until you mentioned it....interesting to see a bit of Kinsler here...I did notice the skull and cross bones sticker on the last picture..... and surprised to see any cloth braided covering of a hose on a full race engine....there is always SO MUCH going on in these engines and the various stages that it easy to get absorbed into the details....Thank you!

[chris white]

I looked over this car at the WGI Historic Races last summer (it was not running well). I couldn't figure out how it would run well with the MAP sensor on the plenum before the throttle bodies. I couldn't see any MAP sensor connections after the throttle bodies....kind of hard to tune (unless I was missing something)

[blade7]

Cosworth fitted an 8 injector inlet on the 87 homologation Ford Sierra RS500 Cosworth. The 500 road cars didn't come with the ECU to run all 8 injectors though. So the RS500 road cars only ran 4 of the 8 injectors, the same as the standard Sierra RS Cosworth.