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This rod as it stands now weights approx 100 grams less than the typical aftermarket version. The next versions that will be sold are losing another 20 grams.

Old 12-12-2019, 02:16 PM
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In our quest to lower component weights, we are about to test titanium bolts in these new lightweight rods. This is not something new. Pankl fitted to bolts in their rods back in the 80ís used in 24 hr turbo engines. Engineered correctly it poses no issues.

If we can lower the Rotating and reciprocating weights we can help with the crank harmonic movement. I am confident this will help in the life of the magnesium cases a lot.

Getting back into the air cooled world, we wish to offer a modern twist on these older engines. It seems to me that this is an area that has been forgotten about. I have studied what others are offering and in most cases the same historic parts are used.

I know this technology is more expensive so not for all, but my intention is not to compete against the common parts but to offer a modern up to date alternative.
Old 12-13-2019, 09:16 AM
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Titanium bolts

They were used on all RSR engines that had steel rods in the 70,s.They were reusable which was nice.
Old 12-13-2019, 09:26 AM
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Before my time but yes , the use of titanium rod bolts is nothing new. There is a terror in the minds of many about using titanium but when engineered correctly it adds huge advantages. We are making our new exhaust studs with titanium and the new head studs use titanium washers and nuts.
Old 12-13-2019, 10:48 AM
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HI Neil,
I love what you are doing with these new parts. It makes so much sense to design for the application and not just make new parts based on how the old parts were designed.
In on of your earlier post you show a rocker.



This looks to me to be a later 993 rocker that has been modified to accept the a screw type adjustment. Is this a service you offer? are these bushed to use standard rocker shafts or are they intended to use 993 cam housings and shafts?

Thanks,

john
Old 12-14-2019, 12:37 PM
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Yes, these are 993 rocker arms. We use these for adjustable types as they are stronger and lighter than 911 types. 911 rocker arms are cast and 993 arms are forged.

The arms are purchased new, undergo a ratio check, pad check, crack checking, machining for the threaded bushing, additional modification if used for 911 cam housings, and finally after ultrasonic cleaning, sent out for DLC coating. Upon return, the shaft bores are honed for the clearance we specify and finally get assembled with the bushing. We use new rockers only if they are to be DLC coated as there is minimal contamination prior to DLC coating. Used rocker arms have too much embedded trash which makes the adhesion of the DCL too difficult to be certain of.

We offer non adjustable types made in Germany but these are not intended for street engines. They require lash caps to be used for adjustment and stock valves are too long.

Everything we have developed is intended to be used as matched parts. Camshafts, Rocker arms, valve springs etc are all designed to be used as solutions for those wanting something more engineered.

The "new" A symmetrical 964 replacement cam just completed, is designed to be used with the new valve springs we have had wound, or the 964 and 993 springs. We have extensively tested the 964 valve spring and it is a very good spring made from very good material. The wire stress numbers are at its limit but as the spring is wound from superior steel, the stress numbers are ok. The same cannot be said for some of the aftermarket springs currently sold.

The new 964 cam will take the place of our existing 964 1/2 step version. We now have cam designs for engine up to 2.8L, 2.9L up to 3.2L, 3.6L up to 4.0L and another for engines above 4.0L. There is currently a cam design underway for engines 3.2L up to 3.6L.





Last edited by Neil Harvey; 12-15-2019 at 03:36 PM..
Old 12-15-2019, 03:33 PM
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It has been a crazy time lately. Indianapolis for PRI, then to Detroit, now in Florida for a break and back to LA just after new year. In the next few days I hope to post some photos of the parts we are continuing to develop for these air cooled engines.

All new valve train parts both steel and titanium have been made which we spent a lot of time testing, testing with new and some existing valve springs. We found some of the existing valve springs are very good when used in certain applications. Unfortunately these are typically over sprung.

Cylinder heads are subjective, which size is better, what porting is better etc. I have left this area to each engine, not saying you need this amount of air. It's not always about the airflow through the head. It has to be measured from the entry of the intake system to the back of the valve.

There is a development 2V cylinder head underway for these engines, but to redevelop something similar to what already exists is pointless. Bill @ Xtreme offers an excellent alternative to the stock heads. There is no point in spending time and money to come up with something similar.

The current 2V heads have just about reached their max flow, so managing the flow per crank position is an area that can be influenced.

Two new camshaft designs have just finished testing. One is the new "964" design to take the place of our 964 1/2 step. The other is for 4.0L+ engine sizes. As I have stated in past posts, all the new cam designs are "solid A symmetrical" and will be available only on new billets. The lobe designs are set but the LSA's can be changed when required.

The 2.9L engine that has just had all of the parts completed will soon be assembled and tested. I will hopefully be able to give some updates that project soon too. This engine uses the new lightweight rods, Piston design, camshaft, 993 adjustable rocker arms and the cylinders have the
softer seat pressures. The rest of the engine is pretty much "stock" using twin heads with typical port sizes, valve sizes, stock intake system and the mech fuel system.

Its important to me that we develop parts that can be used across a wide range of engine spec's.
Old 12-27-2019, 03:17 PM
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Those combustion chambers are pretty impressive.
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Old 12-27-2019, 03:48 PM
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This year my intention is to bring to this community more basic info on rebuilding these engines. Hopefully it will be of help, lowering the fear that some often have when starting this journey. I wont give away any secrets or modifications that are proprietary, rather focus on the best ways to tackle some of the required work.

I also will go deeper into the machining of the parts so you can have a greater knowledge of what is required, when and what in my opinion is the right way. Recently, a shop I am currently working with in the supply of custom parts had the engine case machined by a well known Porsche machine shop. The result was extremely poor with out of round main housing bores giving bearing clearances over spec of 0.004" in one direction. Mistakes can happen, we are all human, but the mistake was found after checking, not assuming it was done correctly.

Simple changes in certain areas of these engines can make a dramatic difference in the engines performance. An area I keep going on about is the over springing of the valve train. Some of these smaller engines produce less than 200 BHP, so any power regained is a huge plus. My beef is with companies that sell aftermarket valve springs without asking of giving any sort of data and reasons why you need them. Often fear of valve float is used as a selling point. BEWARE of salesmen who sell you stuff without having any reason for you using whatever they are selling.

We have conducted a lot of testing recently on valve springs and were pleasantly surprised just how good one of Porsche's stock springs performed. I intend to write a paper showing the results and giving an overall spring doc for many of the different engines. I cannot know every camshaft out there and how it works, but this should also give you an understanding of what goes on at 6000+ RPM, what questions to ask your cam supplier and what not to do when building your engine.

I have written a draft paper on the case assembly and what to do and look for. I will post this in the next couple of days. Then I will cover many of the areas often questioned. Head studs and their installation, Cylinders, measuring and the repair work, what to ask for and who best to be use in having your cylinders repaired. This is an area when knowing what to ask for will eliminate many of the poor results I have read about.

Cylinder heads and what to ask for, what info you should give the repair shop and what to look for when receiving them back. There are some really good shops doing this work and some others who are regarded as the go to places. This is not the place to compare or trash others work, rather to educate you on what to expect as rebuilt correctly.

The main thought process here is to educate, lower the fear level and show that there are many ways to do this work. Books that have been written often give no lea way or alternatives. You do have some tolerances in rebuilding these engines other than just the measurement tolerances. Hopefully understanding these will help and make this journey more enjoyable and rewarding.

Last edited by Neil Harvey; 01-05-2020 at 11:19 AM..
Old 01-05-2020, 11:17 AM
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Interesting that the Porsche valvespring was developed by an American company back when they couldn’t keep them from breaking on the 356. The vacuum used during the making process was key to keeping occlusions/voids to a minimum.
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Old 01-08-2020, 08:48 PM
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Quote:
Originally Posted by patkeefe View Post
Those combustion chambers are pretty impressive.
Shiny and clean maybe but very much old tech.

If Porsche designed them again today, they'd likely have:
Tighter valve angles reduce the surface area of the chamber,
Twin plugs to speed combustion,
Shorter exhaust ports to reduce head temperatures,
More squish area to speed combustion,
No or little piston dome to speed combustion and reduce piston temperature
Extra care in inlet port alignment (extra "sidedraft" and less downdraft for our flat 6!) to give greater swirl and tumble to speed combustion

When you consider how much money is often spent on these Mezger engines, I find it surprising no one has offered a modern design head with the above features. Not impossible as these features are readily seen on modern Ducati 2 valve aircooled engines for example.

Last edited by Peter M; 01-16-2020 at 11:04 PM..
Old 01-09-2020, 12:32 AM
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To follow on from where I last left off.

We are in the middle of an engine project that may be of interest. The car and engine are from a 1975 911 that was built to 2.5L S specs I understand. The owner decided he wanted an upgrade and came to us asking in his brief, “I want something custom, unique and not built from off the shelf parts”. This is our “wheel-house” type of work. We came alongside Autowerks in Huntington Beach CA., who are assembling the engine and other support work required to the chassis.

This became our 2.9L project, that followed on from the 2.8L engine project we did for Jeff In Australia. This is a lot more engine than Jeff’s, as the customer wanted more custom parts included.

We started off with the engine case that had been decked line bored back to standard by a well-known Porsche machine shop. It was so far out of spec when we first measured it. It was sent back for a re do. It came back to Autowerks no better and still misaligned and out of spec. No main journals were even round. It was a real mess. Always measure before you assemble and do not trust the work done is correct. This added to the build and delayed the assembly. We lined bore the case, this time correctly and gave the case back to Autowerks within days, not months. Now the assembly could start.

The case is fitted with our new Head studs that use a Titanium 12pt nut and washer. This case already had the dowel pins added, so it did not need our new through bolt with the center dowel included. This is a lot easier method of holding the main housing bore together with both assembly and disassembly far easier.

This engine retains the stock crankshaft with all the necessary mods and checks performed. One of our crankshaft Dampers is fitted along with a new 5 groove Alternator pulley. The Damper will help control the harmonics these engines suffer from and in doing so will hold the camshaft timing where its engineered then to be placed. This is one of the major power losses in these engines. The front of the crankshaft does the most movement, the 1st motion gear gets all of this as well as the timing chains and camshafts. All that noise and vibration ends up in the cam gears and valve timing goes out the window. Often heavy springs are used to try to dampen this noise, but they typically fail and just add unneeded pressure which is a power loss. This engine uses light seat pressures gaining back that lost power. More about this and the new springs we had wound later.

The Connecting Rods are our Italian made custom lightweight steel 420-gram rods coupled to custom Mahle made Pistons. The rods are custom designed for this project, with a custom designed beam, a CC length, and SE to match the short comp height pistons. The cylinders are 93.00mm bore with our sealing system added. We decided to use a GT3 Oil pump as this pump met the requirements we needed. The only requirements were some additional clearancing of the case and the relief springs and caps will be changed to allow for better oil pressure control across the RPM range.

This is the point of where the current assembly has reached. I will post further details of the rest as the assembly continues. I have many photographs that I will post of the components and as Autowerks assemble then engine will show this process as well. Some have already been posted but I will post more as this continues.

Last edited by Neil Harvey; 06-14-2020 at 08:34 PM..
Old 06-14-2020, 08:30 PM
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What did you do with the oil pressure springs and caps? Or was this still a pre-76 or 7 case which needed the pressure return modification?
Old 06-21-2020, 10:38 PM
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Originally Posted by Walt Fricke View Post
What did you do with the oil pressure springs and caps? Or was this still a pre-76 or 7 case which needed the pressure return modification?
If you mean the by pass mod, it was done. Caps and springs get selected once the engine is running.
Old 06-22-2020, 12:22 PM
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May I ask if your rods are rifle bored?, thanks.
Old 06-23-2020, 07:23 AM
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May I ask if your rods are rifle bored?, thanks.
Are you asking, do we pressure feed the pin with oil from the journal? Yes in some applications we do.

In some applications the pin coating along with the clearances we run is sufficient.
Old 06-24-2020, 02:15 PM
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Good to know!
Old 06-27-2020, 01:03 PM
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rods

Hi Neil.Your rods are like the Ti Crower rods I have bought for the last 30 years.You have to split the case to change rod bearings.My question is what is your opinon on the main bearings once you have split the case.Are you comfortable to reuse if they look well.Or are you like me and once they have been torqued and flattened they will never seat the same again & should be changed.That is how I was tought.When I CHECK a bore measurement I only use 15 ft lbs instead of 24 for the through bolts.I only trust the torque to 24 lbs.once.Thanks Fred
Old 06-27-2020, 04:56 PM
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Neils new rods

I apologize as my thinking can be a little pre-emptive.Neil,your rods are beautiful and only 10-15 grams more than the Ti rods I bought from Crower.Your new thinking for this old design is refreshing as well.A little more info on your new cam thoughts would be helpful as well.Keep em coming.Fred
Old 06-28-2020, 04:48 PM
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Hi Fred,

Ask me what you wish to know about our cam designs. I will supply certain info but not all.

Most of our "solid" applications (these include the air-cooled 911 engines) use an A symmetrical design. Any application that uses an hydraulic follower is of standard design. You cannot accelerate the valve too hard in these applications without compromising the follower. These include the some of the watercooled GT3 and turbo designs.

So far we have developed cams for the NA air-cooled 911 engine family for engines up to and including 2.8L, 2.9L, 3.0L, 3.4L, a "new 964 design" and a camshaft for engines above and including 4.0L. We are in the process of going back through all of the designs and fill up any "holes". Turbo applications have not be forgotten either. We have several designs for these applications. As we have developed complete engine solutions for customers, we have been able to design many engine components that we are now gearing up to sell. Many have been included in my past posts.

All cams come on new billets with DLC coated lobes. These are not cheap to produce. They require two designs for each lobe, an opening and a closing design. But the performance difference makes it worth while.

These are engineered and produced for their performance gain, so price should be expected to be higher than most other supplied camshafts. These designs are for those applications where engineering is the driver not guess work. In all cases we would want to know the intake systems airflow numbers to best match the camshaft. Its a waste of time thinking that "I want" this performance if you have no clue what the air flow numbers are.

With limited air capacity and volumes in many of these cylinder heads, managing and influencing what air is available has proven to give the best return.

All of our new products have been designed for and are focused on, all levels of this "Porsche aftermarket world". We are driven by one stipulation, they are designed and engineered for those engine projects where its understood that an engine the sum if its components.

Old 06-29-2020, 10:59 AM
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