By Ron LaDow
First published 356 Registry Magazine, Vol. 28, No. 6 Available in PDF format at www.precisionmatters.biz
Clean oil helps engines live a long and enjoyable (for us) life. Most all of us want our engines to last as long as possible. As pointed out in the article Stock Oil Filtration Effectiveness (Vol 28-4, Nov/Dec 2004), in stock form, "92% of the pump output, oil and dirt, go right to the various engine bearing surfaces". The stock 356 oil filtration system was very good in the 1950s, but engine life can be greatly improved without ruining your car's originality by fitting a full-flow oil filter. There are various designs and methods available which will provide full oil filtration to your engine, and they all have advantages and disadvantages. As a 356 owner, you probably have more options than any other vintage car owner.
Breaking the Circuit
Figure 1 – The bypass oil system. The plunger (A) would cover the main oil galley (3) during warm operation.
By David Jones
Overall view of lines for full flow system. Engine out of car in this picture. Here's how to plumb a full flow filter while retaining the mechanical tach (for those with electric tachs, there are other options). What is described and shown here only works for late "A" , "B" and "C" cases. Earlier cases would have to be tapped at a different point for the oil to filter because of different internal plumbing of the 3rd piece. Placement of the oil filter is mostly a personal choice. I have seen them out in the wheel well and on the shroud. No matter where it goes it will need one line to pass through the ductwork somewhere. I personally favor putting it in the engine compartment off to the left in the rear corner on a bracket. High enough to be able to remove it in an upright position so one can fill it with oil before replacing it and so as not to spill more than necessary when removing. I also favor using the filter that is compatible with the VW Rabb...
By Ron LaDow Special thanks for contributions by Alan Klingen of The Stable and Neil Fennessey, Ph.D.
First published 356 Registry Magazine, Vol 28. No. 4, Nov/Dec 2004
Modern engine design, lubrication and filtration systems provide amazing engine life and no sacrifice in performance; that is a development of the last 10 years or so. We've got the stock 356 engine design and the lube system is fine, but the filtration system leaves a lot to be desired and can be improved. Several shops and parts vendors (I own one) offer modern oil filtration.
Along about mid-20th century, engine speeds were increasing, bearing clearances were dropping to about .0013 per inch of bearing diameter, oil pumps were becoming well-developed and the engine designers saw that providing pressurized oil directly to the bearings drastically improved engine life. But to be effective under vehicle accelerations, and to keep the height of the engine low enough for modern cars, the pump pickups we...
Text by Rainer Cooney, Ken Daugherty, Alan Klingen, Ron LaDow
[Editor: After 50 years or more, 356 sump plates often leak. Here is a range of solutions to the problem from some of the veterans on 356Talk, as posted in November, 2008.]
Alan Klingen: Over the years the plate develops waves on the sealing surface from the nuts pulling it down. When the plate is off I lay it on a flat steel surface, such as an anvil, with the inside surface up and hit the stud holes to flatten them back down. You should also check the center copper rivet to see if has become loose. If you need to use a sealant use a non-drying one that be cleaned off at the next sump service.
Ken Daugherty: We 'flatten' sump plates by turning them upside down of an anvil, placing the ball end of a medium size ball peen hammer in the stud hole and carefully smacking the hammer with another hammer. This reforms the dimple caused by repeated tightening over the years. Caution, do wear safety glasses in case ...
By Barry Lee Brisco
The 356 engine is often described as "air-cooled", but a more accurate phrase would be "oil-cooled". After all, cars with radiators are "water-cooled" even though ultimately that water is cooled by the air.
With that in mind, it's easy to understand why 356 owners are concerned about their oil temperatures during hard running on hot days. If the oil gets too hot, engine damage can occur. But how hot is "too hot"?
Starting in 1950 (Ludvigsen, Excellence Was Expected) or 1951 (Johnson, Authenticity Guide) an oil temperature gauge was standard equipment. Up until mid-1957, the various gauge types over the years — first MotoMeter, then Stork, and finally VDO — had numbered scales that ended at 250F / 121C (MotoMeter, shown at right) or 280F / 138C (Stork, shown below right). At around the time of the T1 / T2 change in mid-1957 the numbered temperature scale used in the VDO "combi" gauge—oil temp and fuel level—was dropped and a simpler scale was use...
By Joe Leoni
If you think your oil temperature gauge is not giving you an accurate reading, most likely either the oil temperature gauge or sender has failed. However, there is a third case where the sender and gauge are not compatible. The indication would be that the oil temperature shows hot with a cold engine, then the temperature decreases as the engine warms. [Editor: Brad Ripley emphasizes that currently available VDO senders will not work with an original gauge. New senders from Porsche (made by Beru) that will work look different and cost plenty.]
First, some background on the sender location in the engine compartment. In mid 50's and later cars, it is located just behind the distributor. In earlier cars it's hidden behind the fan shroud. Brad Ripley writes: "On late 2-piece case engines, the sender is threaded in the engine case above the flywheel. On early 3-piece case engines, the sender is threaded in the case at the lower left corner. Starting with ...
What oil filters will fit on a 356?
All of the following will fit:
AC P203, C315
Bosch - OX79
FIAMM FB1254 (Italian)
Fram C3P, PC10, C-988
Hastings LF130, 102
Knecht EN 108
Mann PF915, PF915N
Motorcraft FL 144
NAPA "Gold" 1010
Purolator PM3003, PM352, P70AC, T110, L20701
Wix 51010, PC10
List gleaned from the 356Talk Discussion List, largely from Mike Robbins, with additional input from Wulf Mšnnich and Stephen Dean.
Let me know if you find other compatible oil filters and I will add them to the list. Email Barry Lee Brisco, Website Technical Editor, at email@example.com .
And Don't Forget the Gasket...
David Jones, Process Analyzer Specialist with Premcor Refining offered the following information on oil filter gaskets:
"Be aware that the gasket supplied with some of these filters is not a rubber or neoprene type. The one with the Mahle ...
Recommendations from 356Talk Members
(Ken Daugherty:) One method to clean the 356 oil cooler is to turn it upside down, fill with lacquer thinner and let soak overnight. In the morning, drain it and then refill with Simple Green or Bleche White and let soak for another day. Then drain it and rinse thoroughly with hot water until it runs clear. Blow it out and refill with WD40 (it is a water dispersant) and drain and blow dry. Fill with clean motor oil and let stand until ready to use.
(Wyatt Blankenship, Tom Martinez, and other recommend:) Lanfried Ultrasonic Cleaning, 20730 South Main St, Carson, CA. Contact: Jerry Marquez. Tel. 327-8930.
(Alan Klinger at The Stable says:) Send it to Ultrasonic Cleaning in Carson, CA. They will get it absolutely clean, clean enough to FAA certify it. If you could see the process they is no way you can replicate it. They flush and filter the effluents with special solvents and they check the flushed solvent for de...
By Charles L. Navarro Provided courtesy of LN Engineering
Summary: What oil should I use in my 356?
[Ed: The question of "What oil should I use in my 356?" is often asked. Below is what Charles Navarro suggests, depending on whether you want to use traditional oil or a synthetic formulation.]
When in doubt, look at the label. Do not use an API SM or API CJ-4 motor oil in your Porsche 356. Also, it is best to use an oil that does not need supplemental additives!
Inexpensive Dino Oil: Kendall GT 20w50 or Castrol GTX 20w50 (or it's High Mileage formulation). I'm not a big fan of GTX, but if changed often, it's okay.
Good Dino Oil: Valvoline 4-stroke motorcycle oil 10w40 or 20w50. This oil is easy to find and comes with an API SF/SG/SJ rating.
Best Non-Synthetic Dino Oil: Swepco 15w40 "306" motor oil. Many shops who had been using Mobil 1 have switched to this and most if not all their problems (including bearing failures) went away.
Best Semi-Synthetic:Brad Penn Racin...
By John Wilhoit
We performed four comparisons using our latest 1925TR 356 engine with a stock Dansk muffler, the NLA Dansk Supersound muffler, the Bursch 1.5" header (with street muffler and race stinger), and the WR 1925TR Sport muffler. These tests were performed at Carobu Engineering in Costa Mesa, California, on their DTS engine dyno, in February 2007.
The 1925TR is very streetable but is by no means a mild engine. The peak power is at 6000 rpm and peak torque is around 5000 rpm. These are recorded during a full throttle sweep from 3200-6500 rpm in which the performance is recorded and calculated by the dyno at 100 rpm intervals.
The dyno also plots the fuel curve at 100 rpm intervals across the entire run using a lambda sensor. In the 356 engine there is always a dip (richness) in this curve just below peak torque, which is made worse by the use of a sport cam. The tuning and back pressure of the exhaust can help this (as you'll see in the tests), but it can't...