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This is better than the new season of whatever on Netflix. Keep 'em coming!
42R stroker Crank is up next in a week or so.
Then cam design
Then 4.0RS airbox and decklid...
We wanted to have our ITB setup finished for this, but over the winter we'll get that going...
Then it will likely be time for videos of startup, dyno's and first impressions. The cage just got done from powder, light weight carpet is in, 19" BBS Monoblocks ready to go on (in addition to the E88 track wheels) and a repaint of the carbon hood and new rear 4.0RS Cup decklid
A little back story of how the 42R came about. The first engine built was 4.2L in displacement, (105.40mm x 80.40mm) and built to a level of technology similar to many others like it. The 42R morphed out of a 4.0L engine program designed to match and possibly surpass in some areas the factory GT3R race engine. This is our 40R engine platform that is now offered. Looking at the 40R engine we decided that a lot of the same parts and technology could be used to make a 4.2L version of the 40R. The 42R is the result.
The R platform is an engineering exercise to show case the engine technology and engineering level Dundon Motorsport has decided to invest in and offer to the Porsche community. We decided to offer a level of engine not presently offered outside of Porsche Motorsport. All of the parts included in the 40R and 42R engines are designed and manufactured for these engines. No Porsche Motorsport parts are used in either engine.
Unlike the first 4.2L engine, the R engines are designed as a totally new bespoke design based on the GT3 engine. Not one part of the original GT3 engine is left as stock. The engine case is modified, along with all new designed parts that make up the rotating assemblies. A new designed Crankshaft made from a different steel produced a lot stiffer and lighter design. The connecting rods are a new design and made from Titanium. A new Piston design also made lighter and more ridged with only two Rings and a smaller Pin. The weight saving here was required to allow the engine new 9000 RPM limit.
The cylinder heads are highly modified now with Beryllium Copper valve seats and guides along with Titanium Valves, Spring retainers and Locks. The air flow was increased to match the RPM we will run. Two new cam designs were produced for the Intake and Exhaust to make use of the extra airflow. Solid Cam Followers were designed as the hydraulic followers would limit the RPM. Lowering the rotating and reciprocating mass is essential if you want to run above 9000 RPM.
The R platforms have required us to look at new methods of manufacture as well. The camshafts are now modular allowing easier changes to be made for different applications. Different surface finishes have been utilized optimizing the friction levels as low as possible. Frictional losses are the easiest losses to overcome and gain back lost performance. The R engines have been from the design stage, considered as six individual one cylinder engines connected together with a common shaft. This way we considered and applied engineering to each cylinder and worked on producing the maximum performance from each cylinder, not from one six-cylinder engine. We know from past experience which cylinders are typically lower performers and focused our attention on them. By raising these cylinders up to match the others we gained back lost performance otherwise missed in building an engine.
Our Exhaust systems were approached in the same manner. Engineered and developed for each application and not a copy of another system. The results came as the systems were designed and built to match the engine they are fitted too.
Dundon 42R Stroker Crank,
The 42R crank is made from 300M/S155 steel, has ultra high strength, good fatigue resistance and excellent transverse properties and as such finds many applications in the aerospace industry such as undercarriage components, gears and shafts and has a proprietary heat treat.
In the 42R Crank, oiling is direct from the Crank Journals to the Rod journals. In the stock crank, Rods are fed
from #1 main and # 8 main. Oil winds it way through the crank on the inside
from front and rear to center. This isn't ideal and typically ends with rod bearing issues near the center of the crank.
We feed each rod directly with a straight path from each adjacent main. Keeps the oil pressure as even as possible at
each rod.
In addition we add counterweight over the stock counterweight as we balance/overbalance the crank
to help counteract harmonic forces. The stock cranks are notorious for oscillating and by making them lighter it takes less energy to make them oscillate worse. This makes the cranks break, or cause them to break other items (oil pump gears, push cam actuator bolts, flywheel bolts out, etc.) Most want to remove counter weight by "knife edging" for windage and so the engine revs more easily. Any benefit to reducing counterweight in a flat six engine are overcome by the longevity benefits and there isn't much if any windage to overcome in a dry sump flat 6 engine.
This is the heart of the 42R and is what the rest of the engine was built around.
Engine is being assembled, was delayed with a World Time Attack Challenge team that needed some last minute help!
Will discuss the Motec M1 plug and play engine management in the next few weeks, talks to all the modules via CAN and allows HUGE flexibility, engine protection strategies, motorsports traction control, and so much more. Also will discuss the Capacitive discharge ignition we plan to use...
So much with this project was designed from nothing and was typically only seen in full on race cars... Until now...
Some pics of the 42R Stroker Crankshaft.
Dundon 42R Stroker Crankshaft
Dundon 42R Stroker Crankshaft
Dundon 42R Stroker Crankshaft, notice that the counter weights are kept...
Last edited by Jamie@dundonmotorsports; 10-18-2016 at 01:35 AM.
Very nice work Jamie. Just to confirm, is this a stock GT3 crank that you guys have modified to your specifications, or have you machined this crank from scratch?
Additionally, is the intent to offer these engine packages to the public at some point down the road?
Very nice work Jamie. Just to confirm, is this a stock GT3 crank that you guys have modified to your specifications, or have you machined this crank from scratch?
Additionally, is the intent to offer these engine packages to the public at some point down the road?
This is a crank machined from scratch.
We're building engines now, the 40R and 42R are the pinnacle of what we're building and will be available after mine is finished!
Things are moving, we had to redirect resources a bit, GT4 headers/tune had to get finished (in the home stretch) and we've been focusing on getting the 991 GT3 finger follwer/cam products pushed through.
The 42R is in the small stuff that's big stuff phase. Just got the hardened heat treated and nitrided oil pump gears, engine is going together, but the first one is always the slowest...
We're back on it, will have some more pics up next week. We did find an interesting piece of info upon assembly. The liners were honed and coated and perfect. When pressed into the case, we measured them again as we want them as perfectly round as possible, they distorted slightly. For a three ring piston this isn't likely too big of an issue. Fora two ring piston we want it better. So we're setting up a new machining jig to essentially hone them how they'd be in the engine...
When pushing the envelope you gotta keep finding new ways to do things!
why don't you just buy the 4.3 or 4.5 litre tech which has been race proven in Europe for years instead of messing about with developing your own smaller capacity, is it a cost thing ?
why don't you just buy the 4.3 or 4.5 litre tech which has been race proven in Europe for years instead of messing about with developing your own smaller capacity, is it a cost thing ?
09-22-2016 | 12:38 AM
