911 aircooled developments

[Turbo_pro]

Although advertising your parts on Pelican Parts may seen like a cool way around paying for advertising, if you want to sell your parts here, perhaps buying ad space or convincing Pelican that your product is worth selling, might be more ethical.

[jac1976]

Settle down

[Turbo_pro]

Originally Posted by jac1976

Settle down

Our host is gracious enough to supply this incredibly helpful forum for builders of all stripes. They sell advertising space and they sell Porsche parts at every performance level. Respecting their business seems like a pretty simple expectation.

[Bill Verburg]

Originally Posted by Turbo_pro

Our host is gracious enough to supply this incredibly helpful forum for builders of all stripes. They sell advertising space and they sell Porsche parts at every performance level. Respecting their business seems like a pretty simple expectation.

I see no issue here, Mr. Harvey's posts are informative and helpful, a real asset to the enthusiasts here.

[Turbo_pro]

Originally Posted by Bill Verburg

I see no issue here, Mr. Harvey's posts are informative and helpful, a real asset to the enthusiasts here.

Everyone calls on a different devotion to ethics....you do you.

[Bill Verburg]

Originally Posted by Turbo_pro

Everyone calls on a different devotion to ethics....you do you.

Thanks ever so much for your blessing, it makes my day

[Neil Harvey]

Had many responses to the above comments. To last in this business you have to have a thick skin.
Often that can turn into been critical of others. Something I work hard at not doing.

Project 24 is now at the top of our agenda. Its based using a Mag case with the through bolts, larger Oil pump and today, have decided to design a new Countershaft and Crank gear. The cost of new ones plus now the import tariff's makes these every expensive. 50% tariff's on anything steel out of Germany. Also give me the opportunity to change the pump gear speeds. Something I have wanted to do for along time.

This is going to be either a "hero or zero" project. I have for along time never understood the Porsche performance "wall". These smaller displacement engines have for along time been stuck at a certain performance level. I'm hoping to see if I can nudge that up a little.

Kinda the same thing with these more modern 4.0L 964/993 engines. We get to approx 100-105 HP/L and stall out. I have read of a 2V engine that makes over 120 HP/L but I have never been able to achieve these numbers with a 2V engine. Those are 4V numbers. Hence the drive to try and push the limit up.

I'll start to post photos of the parts we are using and some of the issues we are trying to solve.

[Old H2S]

Even if it fails it will be a win win for the data it provides..

[PeteKz]

Neil, you're a gentleman and a scholar, and I appreciate your contributions here. I look forward to seeing what comes out of your shop next.

[Billiam 911 2.8]

I believe the word is surrogate.

[Neil Harvey]

Received a Crankshaft today that had sustained a rod bearing failure. Only one journal and the adjacent mains looked in great shape.

Question was how did this happen and why. All I have to look at is the crank and the bearing shells. Thought I would pass along my thoughts for others that may have the same modified Crankshaft.

This crank has had a lot of material removed from the counterweights in what is known as knife edging. This is the worse thing you can do to these crankshafts. It does not spin in oil, as the oil is all stacked up on the one side of the inner crank case. You need that mass there as it counters the masses that go up and down and round and round. If you want to lose weight, lose it in the Rods and Pistons.

This is a classic 1st order failure. The crank was probably flexing and the bearing shell lost its clearance. An imbalance caused by the rotating masses on every revolution. These hard faced shells do not give you a 2nd chance. One they touch its curtains.

I do not know the early Cranks at all. I am not sure what percentage of counterweight they have. Not sure of they are under or over weighted but as soon as you add different Rods and Pistons you change everything.

My advice, do not knife edge these cranks. Lose the weight in the rods and Pistons.

[jac1976]

Man, I love this.

[Nk993]

Originally Posted by Neil Harvey

I have read of a 2V engine that makes over 120 HP/L but I have never been able to achieve these numbers with a 2V engine.

Is that the one with 4 camshafts but still 2V? Perhaps they changed the angle of the valves?


Do you have any rough specs on the UAE engine?

[Neil Harvey]

Project 24 is moving along at some pace now.

Have many of the new parts finished. Making custom parts takes time.

The Intake system is in design now and my thinking is to go against convention and make something different. Single central plenum is the idea at present. I was late to the Porsche game so I do not have much historical understand or knowledge of what has been tried in the past.

Did Porsche or anyone else try a single plenum Intake with the runners tipped inwards with mechanical Injectors pointing down? Have not decided what type of injection to go with. Electronic or mechanical. If its mechanical it will be with current high pressure and some combination of current high pressure pumps and Injectors.

Would be interested to hear if anyone tried to run the injectors "90°" to the port? The throttle plate will be some distance above so hopefully the fuel will atomize.

Learning every day.

[PeteKz]

Neil, I don't know the answers to your questions, but I do know from reading their technical books and papers that Bosch spent a lot of research over the past 60+ years to optimize the location and angle of the injectors in the intake tract, both to optimize fuel economy and minimize emissions. Therefore, I would try to copy the latest iterations of their work on 2-V Porsche engines. The last 2-valve heads were on the 993, right?. Since we are a quarter way through the 21st Century, I would not even consider an MFI.

[Henry Schmidt]

I am not an engineer of any sort but I have been around this stuff for 40 years.
Back in the day, there was an effort by a couple of different engine builders to change the angle of the entire intake to drastically improve the intake port flow characteristics.
The theory was, if you could straighten out the port you could find "free" horse power.
The idea was to machine off the intake flange and replace it with a bolted or welded flange with a 15 to 17 degree angle. In essence, when you looked at the engine, the intake leaned to the outside over the valve covers. On an engine with slide valves, you could open the slides, look down the intake and see the entire intake valve.
I believe Neil is talking more about angling the injector but my memory only offered this weird trip back in time. If that same memory serves me, the effort proved entirely fruitless.
BTW: I love MFI. I was entertaining the resurrection of the Falconer governor but alas, time is slipping away. It was an inovation designed by Ryan Falconer for the Corvette GTP car from the 1980s. I bought the project but have only built one engine using it.

[Neil Harvey]

Project 24 is all about trying something completely new and "off the wall". Its not about being safe.

I have said before, its a "zero or hero" type of build. Running the typical electronic low pressure Injectors is nothing new. I will learn nothing. My current thinking is to use current high pressure Injector technology and see if I can inject the fuel pre throttle plate and not into the Chamber. Never done such a thing before so its all about seeing if it can be done.

Over the past few years I have learned a lot about the new Fuel strategies so lets see if any of this can be applied to these old engines.

If it doesn't work, I have learned a lot and lost nothing. There is nothing "standard or anything done before" about Project 24 so why should the fueling be any different.

[Henry Schmidt]

The early RSR Porsche with MFI slides tried running the injectors above the slides and we tried it with EFI and encountered serious issues with creating a stable idle.
Neither effort proved to deliver a well formed throttle response. Full throttle, sure. Throttle transition, not so much.
Perhaps lofty injectors with butterflies will offer a different result.

[Henry Schmidt]

A few year back, Richard Parr (PMO) came to us with a plan to make an MFI throttle body that would place the injector above the head creating what was hopefully better fuel atomization.
It also got the injector out of the head where heat after shutdown tended to biol the fuel in the injector and fuel lines making hot starting iffy.
This design also allowed for MFI to be installed on head that lacked an MFI port. Machining an injector port in the short Carrera intake flange is challenging at best.
We were tasked with creating a user friendly linkage and the project proved to be effective but given the lack of MFI knowledge in the industry at large, it never became very popular. EMPI, the new owners of PMO, still offer the setup for those adventurous few with MFI in their DNA.

[Neil Harvey]

My post should have read "post" throttle plate as per the sketch. What I am about to learn is how DI results are changed by port injection. Direct into the chamber allows more time to inject the fuel, higher CR numbers and helpful with knock. How this is all changed by port injection I will find out.

Looking into how we may be able to help the injection timing with new cam designs. Project 24 is all about high engine speeds so maybe we will be limited to what is achievable. Lots to learn here.

Its hope that if this is successful, it can be applied to any of the 911 2V and 4V port injected engines.

I would love to hear from anyone who has tried this.