Supertec latest

[Henry Schmidt]

She's packed up and ready to ship. This time to England.

This little 2.5 is destined for a 904 /6 chassis.
Some of the cool stuff.
66 mm crank, knife edged, cross drilled with 53mm journals.
This journal size allows for the installation of GT3 titanium Pankl rods.
Shuffle pins, Supertec modified Carrera pump
38 mm intake and 37 mm exhaust ports
47 intake and 41 exhaust valves with Eibach racing springs
Custom DC 80 cams
JE pistons 10:1
993 oil console
46mm PMO PMO High Performance Porsche 911 Carburetors & EFI & MFI Fuel Injection Kits
Bearings were coated by Calico Coatings (704)483-2202 ceramic coatings, teflon coatings, thermal coatings solutions with Calico Coatings
Fan shroud by Damon @ Series 900. (603)863-0090
The cam towers are 49 mm 4 journal. John at Dougherty Cams (530)672-2286 Dougherty Racing Cams
ground a small base circle to fit the early valves and then the cam towers were converted to six bolt lower valve covers for that vintage look.
Of course we used Supertec Head studs and Power pulley.

[356RS]

I'm sure you'll have another very happy customer with this little 2.5 masterpiece. I really like the lower cam tower mod for the early valve covers, not to mention all the normal Supertec internal performance parts. Glad to see you post the important vender's you deal with. Great work Henry.

[Henry Schmidt]

Thanks Mark.
It appears I forgot one of my best partners in these twin plug engines.
Aaron Burnham @ Rennwerks Inc. (805)240-6931 rennwerks@hotmail.com
These sweet little distributors are based on a Bosch distributor originally fitted on a BMW. Bosch electronics with a true vintage feel. Thanks Aaron

[BURN-BROS]

Aww, thanks Buddy!

[Henry Schmidt]

Originally Posted by BURN-BROS

Aww, thanks Buddy!

I thought you might appreciate a reach around.

[HawgRyder]

As usual with Henry's engines...it has caused the maximum amount of drool to run down my chin!!
Talk about setting the bar higher.
I looked at my forlorn project sitting in the garage yesterday.
This would look great in her.
Ah well....dreams....something to aspire to.
Way to go Henry.
Bob

[Tippy]

Originally Posted by 356RS

Glad to see you post the important vender's you deal with.

You beat me to it.

Good man......good man, to plug the other vendors!

[ajwans]

Is that the Smart Racing 0° oil filter console? Regardless of the
manufacture, can you explain for slow people like me how the oil
circuit now works?

andy

[Walt Fricke]

Andy

Simple. Oil fresh from the oil pump, which would go through the cooler, goes through a filter instead before it enters the galleries which lead to bearings and such. Porsche did this on their race motors, and then starting with the 964s on the production motors.

I've not gotten into motors as modern as the 964, but I believe it has another filter elsewhere. Because the engine mounted filter's job is to catch any debris which may have somehow gotten through the primary filter. Only the primary filter protects the oil pump.

On the 935 motors (and I suppose other race motors as well) Porsche used a special casting in place of the engine oil thermostat. It simply routes all the oil from the pump (less any the regular pressure system bleeds off) through the filter. I use one of these, and also had a stock thermostat modified so it worked that way also.

I see Henry has included a vintage oil thermostat (see the screw adjuster fitting sticking out the top). Did he also disable the thermostat stuff inside so that even cold oil gets that extra filtration?

[Henry Schmidt]

The oil console is from a 993. 993 107 057 00

The thermostat functions as usual. Without a thermostat you run the risk of exploding the filter with cold oil and high RPM.

[Geronimo '74]

Great looking engine, Henry, as usual.

The oil console is cool.
How do the engines cope without the cooler??
Is it usefull for regular engines as well?

[Henry Schmidt]

Originally Posted by Geronimo '74

Great looking engine, Henry, as usual.

The oil console is cool.
How do the engines cope without the cooler??
Is it usefull for regular engines as well?

Front mount remote cooler.
It can work on any engine as long as a proper cooler is added.

[Walt Fricke]

Geronimo

If your car is not a 964 or later (and they have this modification), you don't want to do this unless you race the car on a track. A front cooler good enough to handle the heat in the oil needs to be in a far better air stream than any fender mounted cooler could possibly have. So you need to replace the valance, or do substantial surgery on it.



I don't know of any stock class 911s which are raced or driven on the track where the engine mounted cooler has been removed. Cooler is better. And for dual purpose cars, having the engine cooler operating is a good idea in city traffic, as well as when the weather is really hot.

My track car, which has a filter instead of an engine cooler, has two 964 oil coolers mounted in ducts which approximate proper cooler ducting.





These cool very efficiently, even when just idling on the grid in hot weather, and the engine mounted cooler is not needed for cooling.

I used the base of an old cooler to be able to route, by short hoses, the oll which would come into the cooler to an oil filter attached to a standard (for the USA) aftermarket filter mount, and then ran the oil back into the cooler out passage.

I think I did this more from monkey see/monkey do than for any other reason. Porsche put a filter there on its early 911 race cars (an unusual design consisting of a bunch of pierced stacked disks in a housing), so that's what a proper race car should have.

A better rationale might be that the stock engine mount coolers can fatigue, crack, and thus leak, and perhaps running the motor up to 8,000 RPM before each upshift exacerbates this issue (by and large, the coolers on normally driven street 911s don't cause problems).

Other than the fact that they had determined that with their well ducted front cooler the 964 and later cars did not need the engine mounted cooler, I don't know why Porsche decided to delete it. Perhaps to mount pumps on that end of the right side cam?

For a factory race car, it makes sense to have a last line of defense against debris in the oil system from some not quite immediately fatal problem during a race. If you can nurse the car home at the Targa Florio, no doubt that would be worth whatever extra damage was caused by keeping it running. The stock oil filter, as we are often reminded, has a pressure relief feature, so if it gets clogged up, the dirty oil bypasses the filter and drops into the oil tank, and then into the engine. With a second filter, this bypassed guck can be filtered out, at least for a while if not too much of it.

A steel mesh filter in a stout aluminum housing, like the System 1, has no trouble dealing with any cold oil overpressure when the thermostat is replaced by a constant flow piece.



When the stock oil temperature thermostatic valve fails, it fails by bypassing the engine oil cooler (or the filter, if that is used as a substitute). I suppose that is why Porsche didn't use a thermostat on the 935s and other race engines where the engine oil cooler was not used.

All in all, I would think moving to this system for anything other than a highly modified race car would be misdirected effort and resources. But perhaps one could say that about much of what we do with the cars we love.

[Geronimo '74]

Thanks for the elaborate explanation, Walt.
I fugured as much, that for a streetcar that is not raced cooling would have priority over second filter.

[Henry Schmidt]

The simple answer to Walt's question is head temp vs oil temp.
If your front cooler/ coolers function properly the thermostat for the engine mounted cooler will never open.
That means that the cooling air generated by the engine mounted fan is wasted on a cooler that is not functioning. This wasted air could and should be used to cool the heads which rely primarily on air for cooling. Note that on the 964 and later air cooled engines, the cooling fan speed is reduced to improve air volume in an attempt to control head temps.
Balance is key when it comes to cooling an air cooled engine. More is only better when it functions better.

[gestalt1]

Great engine Henry! What cylinders did you use?

[Henry Schmidt]

Originally Posted by gestalt1

Great engine Henry! What cylinders did you use?

Mahle 90 mm Nikasil. We buy new sets of RS spec pistons an cylinders and sell the low compression RS pistons to street customers. The pistons are JE.

[Walt Fricke]

Henry

Of course you are right about avoiding wasted cooling air. Somewhere in my mind I knew that was the effect, I just didn't correlate it with why Porsche would have done that. Like you, I run the early engine air cover on my three race motors.

I am still a bit puzzled as to why Porsche added a filter to replace the removed cooler on production cars, though. Yes, it made use of the existing castings and so on, but you'd think they could just be plugged and the thermostat replaced with something which sent the oil directly to the galleries - sort of the reverse of the 935 fitting which routes it all through the filter. That would be cheaper.

Knock on wood, I've never found any debris of consequence in my reuseable filter, as the two filters I have on the scavange line before the oil hits the tank have contained the lamentable results of some engine explosions. On the other hand, that didn't really matter, as the engines were destroyed well before debris in the oil could have made matters worse.

[Henry Schmidt]

The 964 did as you suggest. They just plugged the holes. It wasn't until the 993 (with the notable exception of the 959) that Porsche added the filter. I assume they found some justification for spending the additional funds. (perhaps they got a debt limit increase and needed to waste the money on something)

[boyt911sc]

Henry,

What kind of chain tensioners did you have in this engine? Stock, mechanical, modified (ala Jerry Wood's), etc. Your works exemplify beauty and perfection. Thanks.

Tony