911 aircooled developments

[Neil Harvey]

Originally Posted by Walt Fricke

Neil - if, as you say, the CDI does a better job than COP, what (other than novelty, absence of a distributor, and maybe smaller wires?) is the attraction of COP? Because each plug can more easily be computer controlled? But that can be done with systems other than COP.

My only hands on experience is with an Electromotive EFI and waste spark system, with 6 coil packs for a twin plug system. Not COP. I assume it is inductive? Worked fine.

I believe the use of COP on these early engines is all about simplicity and cost. The Ignition energy is never considered first. Others will disagree and that's ok. I have proven to myself that these engines run so much better with CDI. It's a pretty simple measurable calculation to understand the energy levels available in coils. The energy levels available in CDI units is also calculable. Then understanding what happens when and after the plug fires will give you a better understanding of why in these big chambered engines CDI is better.

The problem with CDI is the cost. Typically you have to use a distributor and the wiring gets pretty intense.

To most, as long as the engine does not misfire the ignition is good to go. I get it. But there is a lot more to ignition than an engine that doesn't misfire. Our business is about finding performance and that is not always peak performance but throttle response as well.

This is my opinion and view and I know others will disagree. I'm ok about this, as the engines we installed CDI on, all ran better and that's all I need to know.

[Neil Harvey]

I have been using and selling M&W Ignition system for close to 25 years, I think. I have not found a better system both reliable and power wise for these early engines.

I see Wayne responded to the other gentleman's thread about CDI and Inductive. I leave it to an expert to explain the reasons.

We are going to make a full kit available for who ever wants either a single plug or dual plug system.

[Helix8]

You are always professional Neil which is why you have my respect. Thank you.

[Neil Harvey]

As we get more and more applications completed and tested we add to the Connecting Rod inventory.

These rods are for an engine we are supplying parts to. As this engine will make approx 320 BHP, there was no need for a heavier H beam rod. We designed this Rod to use the I beam section, with longer than typical CCL, thinner beam and BE section and the SE is detailed at 18.00mm and the piston will guide the rod. The assembly uses a billet piston so we can achieve the CR we require with the bore and chamber sizes. This allows us to use a stronger and lighter piston design and still guide the rod by the Piston. The standard boxed forging we wanted to use just does not have enough mass above the pin to gain the CR we require.

This rod with bolts comes in at 490 grams even with the added 9.50mm in CCL.

We have all of the standard Porsche rods available but we are trying to focus and offer the custom rod service where the engine is not limited by the older stock designs. We can add any additional features to any design if required.

[Jeff Alton]

Neil,

This may have been asked before, but who is forging the rods for you? I trust with your experience and tooling you are doing the big end sizing and pin bushing work in house.

ItalianRP.com based on what I could see on the rod?

Cheers

[Neil Harvey]

We use this vendor as our designs are proprietary.

We design the rod in house and supply a drawing based on the requirements the engine will need. In this case the performance level is low but the component weight is critical. We have a lighter steel rod but the budget did not allow for this level of spending. I have shown the lighter rod in the past.

Many times I see rods sold that are over engineered for the application. Weight is huge factor for me.

We offer the stock sizes in I and H beam designs along with the lightweight version. Our focus is to offer rods like this one that are designed for each application with other design features not seen in the "stock" rod design.

We offer the stock sizes in I and H beam designs along with the lightweight version. Our focus is to offer rods like this one that are designed for each application with features not seen in the "stock" rod design.

[Jeff Alton]

Neil,

Awesome, thank you!

Cheers

[Henry Schmidt]

Nice looking product. 490 grams is a great number.
Are they on the shelf or custom order?
If not what is the delivery time?
Are you making a 997 GT3 rod? 130mm 21mm pin?
My favorite rod for custom air-cooled application.
Pricing?

[Neil Harvey]

Originally Posted by Henry Schmidt

Nice looking product. 490 grams is a great number.
Are they on the shelf or custom order?
If not what is the delivery time?
Are you making a 997 GT3 rod? 130mm 21mm pin?
My favorite rod for custom air-cooled application.
Pricing?

Henry,

The rods pictured are custom. stock BE diameter to suit the stock 3.0L crank by rule, but the width is narrower, the CCL is 136.50mm and the pin is 18.00mm and designed to guide the Rod by the piston.

Delivery times are getting better. Italy was closed down due to Covid but the latest 3 sets of rods are coming in 4-6 weeks. It all depends on the features added. Pin oiling takes longer as does the lightweight Rods we also offer. Best to email me what you would like and I can quote and get you a delivery time, more exact.

We have made several GT3 rods designs, but never followed the stock dimensions. 21.00mm pins are more than needed if you use a boxed type piston forging. I know the deck heights of most of these engines, but If you email me you "block" deck height and the piston deck height you want, I can send you a suggestion of rod dimensions and piston dimensions. This would net you less weight going round and round and up and down. The longer rod will dwell over TDC longer and slower helping the gas exchange process and making up for poor head flow and induction numbers. It will accelerate away for TDC quicker pulling a harder charge into the inlet port. You get nothing for free here though. The down side will be the secondary balance forces will be slightly higher. F=MxA. We offset this by lowering the mass number with a smaller lighter pin, SE section, and a lot lighter Piston.

I am offering a service and parts where the Rotating assemblies of these engines is more current, lowering the weights involved, lowering the friction and increasing the sealing.

[Aircooled4evr]

Originally Posted by Neil Harvey

We are also making available these rods in some custom sizes and lengths along with custom Pistons. These kits will be available for all of the std air cooled rebuilds where the std deck heights are in play along with all of the std CR numbers.

TOP GUIDET and longer CCL rods.

"TOP GUIDET" is this to be understood as a narrower BE on the connecting rod? And if so, what does the oil pressure at the journal bearing say? (Or ... have I totally misunderstood the concept?)

Cheers, Mads

[Neil Harvey]

Originally Posted by Aircooled4evr

"TOP GUIDET" is this to be understood as a narrower BE on the connecting rod? And if so, what does the oil pressure at the journal bearing say? (Or ... have I totally misunderstood the concept?)

Cheers, Mads

I like to think I'm a better engine person than typist. I never have enough time to write and check what I write.

"Top Guidet" was a mistake. It should have said Top Guided.

Not sure your question? The oil pressure is unaffected. The concept has nothing to do with Oil pressure. Maybe ask the question in more detail and I would be happy to answer.

We are lowering the Rod weight at the BE, less mass and keeping the Piston straighter in the cylinder. This increases ring seal and cylinder pressure.

[Aircooled4evr]

Pardon! I didn't know I was making fun of a typo ...
English is not my first language, and I didn't see it!
no, I was simply asking what that meant, what is being done?

I was wondering if it could be the connecting rod being controlled via the wrist pin in the piston, and the BE "floating" on the journal bearing?
And if so, whether the oil has enough "resistance" there, when the connecting rod doese't sit close to the crank in the journal bearing?
Sorry, but I don't think my technical vocabulary allows me to ask more precisely ....

Mads

[dannobee]

Originally Posted by Aircooled4evr

I was wondering if it could be the connecting rod being controlled via the wrist pin in the piston, and the BE "floating" on the journal bearing?
Mads

They're more commonly called "Piston Guided Rods." Google for more information than I can give here. Both the good and the bad.

[Aircooled4evr]

That was a good advice dannobee! thanks.

[Neil Harvey]

Originally Posted by Aircooled4evr

That was a good advice dannobee! thanks.

Hope you got covered.

The advantages are basically the same for any engine but, the flat opposed engines do have added benefits.

All of our Rod and Piston designs typically have the rods piston guided, longer CCL, along with smaller pins and shorter comp dimensions.

We just this week finished a mod to a stock 911 2V engine for a customer who had us repair his crankshaft and rebuild the rods. We had to repair 2 rod journals after the bearings lost the clearance.

We changed this over to piston guided by machining the pin bosses and adding shims either side of the SE. This allowed us to narrow his BE and also required shortening the shell length.

Is it worth it. That is still an unanswered question. However, in this case the crank required repair, the rods required repair, new shells and all parts including the pistons were balanced checked. The machine work on the pistons was quick with the most time making up the shims.

Also, in this engine project, the same pistons were reused. This then requires the same wide ring package to be retained. One of the advantages of keeping the piston more straight in the bore is the opportunity to use narrower rings lowering the friction. Still I'm sure some gain will be noticeable as we have lowered some of the rotating mass weight too.

[Neil Harvey]

This week we also has several requests for a standalone Ignition system. One in particular seems to be required as the customer had his engine case narrowed twice, the second time to fix a screw up. This now makes the Distributor gear lash an issue. So ditching the Distributor and going to Crank triggering and multi coils does seem to be an option.

The other was to supply a solution for the 964 Turbo Ignition control unit that is no longer unavailable. Both of these gave me cause to believe that there is a need for another Ignition option that offers different functions as well. One we are considering is the ability to control the engine ignition as a safety device. Bring in Oil temp, Oil pressure and using these inputs as limp mode functions is something we can do.

These systems will be CDI. This is not a post I will get involved with going back and forth over CDI verse Inductive. That argument has been flogged to death. I have spend years proving to myself what works and what doesn't in these huge and massive chambers with cantered spark plug positions. Like all things in life, it's how the rubber meets the road.

I need to have the reasoning and experience to sell any of our wares. Customers today are well informed and have a huge library of knowledge at their disposal.

The system (kits) we are putting together will be both Wasted spark and sequential. Much to my dislike, I do understand that often wasted spark is the choice due to cost and simplicity. We are just going to make it as best we can. At least it will be CDI and wasted.

We have chosen two ECU's to drive the system. One with 4 Ignition outputs the other with 8. This then give us 3 for wasted and 6 for sequential. The CDI units will be the same. We have the coils already in testing to make sure they will work as required. These are coils that will require HT wires. The single output Coil is a proper CDI coil designed and made for CDI use. The other is a dual coil in a single body with low primary functions.

The kit will come with all necessary modules, sensors, mounts, finished harnesses, HT wires, mounted coils etc. A plug and play system. The cost, unknown until we get further into this and have completed the testing. What I do know is this will not be the cheapest solution, but hopefully one of the best.

[Neil Harvey]

Finally the parts are slowly coming in from our vendors. It has been extremely hard on everyone. Customers of mine and I'm a customer too of my suppliers. Getting material has been extremely difficult, as is machine time on special machines. These bolts are made of Titanium and on a swiss type machine.

These we printed so we can see the final fitment is correct, the case machine work is correct before we have the real ones made from very expensive material. We expect to the final bolts, washers and Nuts in house by November.

For all of us, the end customer and all of us builders, its starting to get better. But we have along way to go still. I have optimism that will go back to how it was, but then that is a fault of mine.

[Neil Harvey]

Our new Titanium through bolts are close. These are coming in two lengths. 911 and the later 964/993. The Turbo head studs are also in production. These are M12/M10 to give more anchoring into the case. These new Head studs go along with our existing 911 M10 studs. Both come with our Titanium 12pt nuts and washers. We sell these Head studs kits and include a set of hold own nuts as we use a 3/8 x 24 thread at the nut end. This is all about economy of scale as we have forging tooling that covers a multitude of uses.

The through bolts will allow the case halves to "lock" together and stop the case shifting without the need to use the solid dowel pins.

There is some machine work required but its on one side only and done when the case halves are bolted together with a alignment sleeve fitted. This will eliminate the need to line bore often required after fitting the solid dowels.

[blue911rsr]

My 3.0 case is at the machine shop now how much are the thru bolts and are the available now
Also does machine shop guy need a special tool or can regular machine tools be used?
Regards

[Neil Harvey]

Not available at present. Thread rolling and some other minor details yet to be completed. Yes all machine tools are common. Nothing that any machine shop either has already or can buy off the shelf.