911 aircooled developments

[Neil Harvey]

Unfortunately these engines are expensive to rebuild. More often it’s a restoration not a rebuild.

[Henry Schmidt]

Originally Posted by Dpmulvan

I would like to figure out a viable build for a 3.0 where you can get 250hp To 275hp without spending 6 grand on cylinders.

If 250hp and <6K for Ps&Cs is the bench mark, there are plenty of viable options.
Call or email and I'll walk you through them.

[Glenfield]

Originally Posted by Henry Schmidt

If 250hp and <6K for Ps&Cs is the bench mark, there are plenty of viable options.
Call or email and I'll walk you through them.

Post like that on a forum like this is akin to giving a vampire the keys to the blood bank! Must be a sucker for punishment ...

I called Henry with a 2 minute question a while back and he was incredibly helpful and selfless with his time (think we clocked an hour). Missed the opportunity on his 3.1s and a few other things but hope to bring him some business soon enough. Same goes for Neil and his insights and developments.

Lucky to have both!

[Neil Harvey]

I thought I would post an update on our new parts. Thought it might give everyone a break from the ever continuing discourse over CDI's, Head studs and the rest of the parts these engines are made from.

I was born in New Zealand and travelled to the UK and immediately got a job in Formula One. Not because who I was but where I was from. The guys that went before me did such a great job, all Kiwi's were considered the same. But you stayed and survived by what you did and how you did it. I was lucky enough to work during the Turbo days as well. Everything you built was prototyped, engineered and developed for a single use. Power and reliability.

We were one of several engine suppliers. We all did it differently and never did we get into arguments or heated discussion over who was right or who was wrong. That was decided on the track. But the common element in all of this was mutual respect for one another. Something that seems to be lacking in several discussions here.

This same ethos continues in me today. I design parts for a reason and a specific use. I put all my knowledge, experience and engineering ability into each part. I do not consider what others are doing. Its what I do that matters. If others do it better then I have more work to do. If my parts are better than the others, that comes from my efforts. Its not something we "sell" the parts do that. Our parts are sold by our input not how we compare ours to others.

We designed our own head studs many years ago. I remember a little yellow 914 pulling up to our shop and out jumped this guy along with his little dog. He wanted to look at our studs. I will not
disclose who that was, he knows. WE stopped making them until we got back into the air cooled game. We then realized we need a stud. So we went about designing anew stud. Not really because there was not one available that would work , but because our MO is to design our own parts. We sell these to who ever wants them but never do we get into competition over who's studs are best. WE included several new design elements into ours along with Titanium 12 pt nuts and washers. The Ti stuff works better in hot climates.

We are continuing with many new parts but the 991.2 engine parts have taken over somewhat lately. The air cooled parts will soon take the lead again. The new Cylinder head is in the works, this using 4 camshafts. Years ago I swore I would never build another 4 cam air cooled engine. Those engines were crazy difficult with gears and splines to time the valves. We designed a shaft that would allow you to time everything in the head without pulling shafts etc. But here we go again. I never seem to learn, I guess. Lessons learned will be applied for sure.

[Helix8]

Thank you Neil

[Walt Fricke]

Neil
Would a 4 cam setup allow an air cooled motor head to run 4 valves, and a spark plug in the center of the dome?

[Neil Harvey]

Not where I'm going. There just isn't enough mass to absorb the heat. I tried this years ago and failed miserably.

I believe others have tried this also and have not had the success that was expected.

These heads are air limited so managing that air is the only thing left to do. There is only so much room to fit valves within the head bolt pattern.

[Walt Fricke]

What, then, would be the advantage of four vs two cams?
Porsche did it with their 365 era 4 cam motors, which clearly produced good HP per liter. What made those heads flow better?

[Neil Harvey]

The standard 2V setup is limited to what the valve timing can be. It is really hit or miss when you compare it to todays control.

I do have air flow numbers on the early 4 cam heads we did years ago. We did port them after, as well. I swore I would never build another. From memory we built 6 of them. After the first one with all of the splines and gears to set the valve timing, we gave up and designed a camshaft with adjustable gears fitted to them. That made is so simple to set the valve timing.

I will have to dig through old files to see what they flowed. I seem to remember the ports been quite big. The intake ports were horrible, more of an oval to fit the Intake manifolds.

Our design is to retain 2 valves, a smaller chamber, and have control over the valve timing on each camshaft. We developed new camshaft designs for the standard 2V engines using non symmetrical lobes which have proven a step above the old designs we had. The recent 991 water engine work we did with finger followers and the cam designs will move over to this new head allowing us to modernize the 2V air engines.

Our recent larger displacement air cooled 2V engine projects proved we had an issue with air flow. The later engine head bolt pattern limits the valve sizes and the overall air flow potential so we had to think of another way to increase the engines efficiency. Time and money will tell if we are successful.

Or, it could end up in the ever increasing pile of "tried and that didn't work ideas".

[Henry Schmidt]

Hi Neil, I know you would rather I didn't post on your thread but I know you considered a stand alone liquid cooling system to cool only the heads, so why not follow that avenue? I think it would be cool if you could offer a four valve solution for the air cooled engine.
As for bolt pattern restrictions, why not go the direction used in air cooled aircraft engines. A system that bolts the cylinder to the case and the head to the cylinder.
It would require a special cylinder and head but I'm sure it could be manufactured.
Keep in mind, I'm not an engineer so these are legitimate questions from someone who wants to learn.

[Lukesportsman]

Always a good read from Neil. Still debating on trying some Cup cams (on Cup heads of course) for the Metzger turbo.

I sent email to you Henry and never heard back or missed it on the engine blocks as I still wait for the "new" ones to be sent my direction.

[Neil Harvey]

Henry, that would be similar to the 956 engine. Air cooled cylinders and water cooled heads.

My thinking always is to identify the problem and then try to come up with the simplest solution. Not adding complexity always is a good thing.

Others have tried this, one recently with oil cooling. I never did understand the reasoning for that when there is a perfectly proven water engine (GT3) available that would work great.

Adding another cooling medium requires adding additional systems. I'm just trying to use what air we can get more efficiently.

[Neil Harvey]

Work continues here with new parts.

The case through bolts are in production after testing. These are made from Titanium with nuts and stepped inserts made from the same. These have the center dowel holding the main caps together and stopping the creep that happens. The advantage here is many and, the case machining is simple and anyone can do it. I'll post some photos of the model in the next couple of days. At present we are modelling up the whole assy in the case to show the fitment. I need to remove the dimensions.

The head studs sold out and we are making more now. These are made from 17-4 SS heat treated with Titanium 12pt nuts and Titanium washers. The material used for the nut is far superior in these conditions over steel. There is no issue with galling either. We supply a small amount of assembly grease with every set.

Camshaft have also gone well. We received positive feed back on the new “964” cam design. This is a non symmetrical design that has opened up some hidden performance. The catalog of camshafts is getting bigger every month. We now have NA cams for the 2V engines, up to 2.5L, 2.8L, 2.9L, 3.0L, 3.2L, 3.8L and 4.1L. Some turbo’s are mixed in there too.

The camshaft designs we have done for the 997 and 991 engines will fall back into the earlier 2V engines. The shafts are modular with each component made separately and fitted to the shaft like a leggo set. In the case of the 2V engines, even the journals will be separate. A new valve spring has made it into our inventory as well. These give alot more variance to set and nose pressures.

The 4 Cam head is back in design after we had to stop with taking care of other engine issues. The 4 cam head uses a finger follower allowing for much better valve control and motions. These early 2V head are air limited, so managing what air we can get is the only thing left to do.

What I have come to like about these earlier engines, is the basic engine is well proven, a solid foundation that you can modify without issues. The newer engines, not so much. We have just completed a project to help the 991.2 engine from destroying itself. We did the same for the 991.1 finger issue as well.

Getting back to the 911 2V engines is like going on holiday. Its fun, easier to do and way more enjoyable.

[Neil Harvey]

Model of our Through bolt.

[Henry Schmidt]

Originally Posted by Neil Harvey

The head studs sold out and we are making more now. These are made from 17-4 SS heat treated with Titanium 12pt nuts and Titanium washers. The material used for the nut is far superior in these conditions over steel. There is no issue with galling either. We supply a small amount of assembly grease with every set.

Imitation is the sincerest form of flattery.
Thanks dude

[Neil Harvey]

Originally Posted by Henry Schmidt

Imitation is the sincerest form of flattery.
Thanks dude

No sure what that means. But anyway, we have been very busy with the continued development of solutions we get asked for. And some we did years ago that are now coming back around.

Like the head studs. We used to make these and sell them before anyone else did. We were the only alternative to the divilar studs.

We redesigned them after researching the nut and thread engagement issue. This is why we are now selling these kits with titanium washers and titanium 12pt nuts. The titanium is far superior to steel in this application.

The use of titanium is proving to be superior in a lot of other areas as well. The through bolts are made from titanium.

We recently were asked to "fix" the issue the 964 Turbo engine has with its ignition module. We developed a replacement kit that makes this issue be a non started now. Poor choice of words, opps.

The car runs far better, has a more modern system controlling the ignition and has the ability to program a curve. It also has the ability to change over to CDI.

Most will know I am huge fan of CDI on these large chambered engines. In all my years building these engines, I have never had anything be better than the CDI system we use. But we have to understand that CDI is a dying system especially finding the proper CDI coil.

A few years ago, we bought CDI pencil coils from Magnetti, but they stopped making them. This makes the twin plug conversion difficult requiring the distributor.

COP is popular and makes for a simple conversion so we are developing an Inductive COP conversion with coil energy of 100mJ. Still not as good as CDI but it does give those that want COP another alternative.

At present we are designing a way to mount the coils to the cam covers.

[faapgar]

I love you are doing this.If it is just a float fit like factory then even better.All the 3.0 RSR motors I worked on had these.It was a brilliant design as the center location at the halves that allowed oil to flow through had a fit of less than 0.001 thousandths .So as case would expand and contract it reduced wear between the halves.Neil,how much for these and will you have the special concave washers that are associated with this fitment.Ciao FRED APGAR

[reclino]

I am interested in your harmonic balancer, can you describe this a bit more. I am preparing for final assembly of my 1986 3.3 liter turbo engine. Do you have to cut a keyway in the crank to secure the balancer or is the locating pin and torque of the bolt able to handle the increased shear load? My engine is a pretty mild stock rebuild, with the primary goal to be durability, and a mild increase in power, depending on how much fuel my CIS can provide.

[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.

[Neil Harvey]

Originally Posted by reclino

I am interested in your harmonic balancer, can you describe this a bit more. I am preparing for final assembly of my 1986 3.3 liter turbo engine. Do you have to cut a keyway in the crank to secure the balancer or is the locating pin and torque of the bolt able to handle the increased shear load? My engine is a pretty mild stock rebuild, with the primary goal to be durability, and a mild increase in power, depending on how much fuel my CIS can provide.

We have fitted these to the early 911 engines but it requires some modifications. The front #8 bearing requires the front seal to be move inwards some so the damper overlap onto the crankshaft is correct. The damper is located by the same dowel pin.

You will also need a Alt pulley and belt tensioner as the damper is designed with a 5 groove serp belt.

If you are interested, best to email me direct through our web site.

Thanks

nh