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Muffler Performance Comparison

September 27, 2010 | Troubleshooting & Repair | 0 Comments
Everyone has their favorite muffler in terms of the sound it produces. But have you ever wondered how your favorite muffler stacks up in terms of performance? Thanks to Alan of The Stable in San Francisco, you don't have to wonder any longer. Let's let Alan take it from here....   Click an image to view it full size Here are the results of my dyno test of 4 common mufflers used on the 356. The first one is the stock unit with its tail pipes. Second the Bursch street legal system that has the large oval muffler in it. Third the Euro sport system that is just straight pipes with a couple of resonator boxes in it looks very much like the 4 cam "Sebring" system. The last system is the Porsche "sport" type, which has a couple of tail pipes that exit under the body works. The test motor is a fresh rebuild 1600S, 356A, that is stock except for the NPR pistons and cylinders, Elgin 6607 cam much like a 356C cam, port matching, stock distributor set to 36 degrees ma...

New Engine Break-in Procedures

September 27, 2010 | Troubleshooting & Repair | 0 Comments
By Maurice P. Cruz, the Phillipines   Start-up / Break-in Guidelines 1. Spin engine without spark plugs to circulate the oil before start-up. 2. Use Bosch W6BC spark plugs (.46" extended tip electrode) or W5AC 3. Valve clearances : a. on a new engine, set at 0.008" for all valves for the first 30 - 50 miles b. then set valves to 0.001" more than standard or; c. after break in : set intake at 0.005" set exhaust at 0.007" (Ed: note that factory clearances are .004" intake and .006" exhaust and are preferred by many) 4. For break-in, set timing to TDC. After 2000 - 3000 miles, reset dynamic timing to 30 degrees total advance at 3500 RPM. 5. Keep RPM below 4000 - 4500 for first 500 - 1000 miles. 6. Drive at low but variable speed at cool temperatures 7. Oil temp should not exceed 210 degrees 8. Change engine oil and clean screen/magnet at : 50 miles, 300 miles, 1000 miles, 2000 miles, and thereafter...

How to Find a Bad Engine Cylinder

September 27, 2010 | Troubleshooting & Repair | 1 Comment
Harry Pellow: Try the Maestro's Patented "Binary Search" procedure to find your miss. This technique will narrow the problem down to the individual cylinder (orside) that's bad in two minutes, making it much easier to find and fix the problem. Before you do the test, you might want to check that the plug wires are installed properly on the correct plugs, the plugs are clean (or new), and the timing (low and high speed) are in the right ballpark. First find a flat, straight road with no traffic. Go there. Go to engine. Disconnect the downcoming linkage rod to one carburetor. Drive car on one carburetor. It'll drive poorly of course, but a good 356 oughta get up to 50+ mph, given long enough and flat enough. If it does do 50mph, stop. Connect the linkage arm you disconnected and disconnect the other one. Drive on the other carb. If one side only does 25-30 mph, you have a bad cylinder on that side. Stop. Get out an...

Cadmium Plating Tips

September 27, 2010 | Troubleshooting & Repair | 0 Comments
By Ron Scoma Call it what you will, Obsessive-Compulsive Disorder, Anal Retentive, being a craftsman, or just plain having no life; this is what I did to Cad plate stuff. Get a list of all items to be plated (thanks Maestro) Find the parts in the Bucket O' Stuff and count the items. Soak in orange cleaner to somewhat degrease, rinse. Soak in Carb Cleaner to really degrease, rinse. Soak in Muriatic acid to remove prior plating. DON'T let the acid come in contact with aluminum (tin foil) trays, I'm not sure why you shouldn't but the end results were very bad. You may not have a screaming S.O. shouting "where's the checkbook, I need to increase your life insurance ?" but still, even without that bonus, the effects were pretty bad. Neighbors in the unit next door were curious also... At this stage you have parts free of grease and oil. Blast with a 50/50 c...

Identifying Porsche 356 Heads

September 27, 2010 | Research & Identification | 2 Comments
 By Mike Robbins, Al Zim, Jim at Easy, Harry Pellow   Q: I have a 356 cylinder head of unknown origin. It has a stamp of 30/5. What kind of head is this, and how else can I confirm that? A: Although your Date Stamp of 30/5 infers about July, 1965 (week "30" in year sixty "5") and thus a 912 Head, the Factory did make other heads at the time too. Here's the quickest way to determine the head type, if the valves are stock and if you have a caliper or dividers and an accurate rule. If the heads have 31mm exhaust valves they are 356A or 356B. If they have 38mm intake valves they are N or S. If they have 40mm intake valves they are S-90. If they have 34mm exhaust valves they are 356C or 912. If the holes on ea side of the intake ports go through into the rocker chamber they are 356C. If those holes are blind into bosses in the rocker chamber they are 912. Read the numbers off the valves through the spring, or take the valves out. 91...

Spark Plug Recommendations

September 27, 2010 | Troubleshooting & Repair | 1 Comment
By Vince Cappelletti, Tom Farnam, Geoff Fleming, and Dan Schaefer Bosch Plug Old / New Part Number Equivalents (provided by Al Zim) Type OLD # NEW# Comment Platinum WR7BP 4232 Normal plug for 356 Copper W8BC 7503 W145T1 Hot plug use in VW Copper W7BC 7597 W175T1 Normal plug for VW Copper W6BC 7593 W200T35 356/912 leaded gas plug Copper W5BC W225T1 Racing plug Editor: The question of what plugs to use in our now 40-plus year-old cars is a frequent one. Fortunately, there are several good choices. Bosch WR7BP platinum (Bosch plug 4232) and NGK BP6HS or BPR6HIX are often used in the 356. Below are specific comments from several experienced 356ers. But if you buy your plugs from well known Registry advertisers they know what should be used in your car! There is no need to guess or listen to someone at an auto parts store who has never seen a 356 and is too young to know what a carburetor is. Additional ...

Twin Plug Ignition in the 356 Engine

September 27, 2010 | Troubleshooting & Repair | 2 Comments
By Ron LaDow I wish I could credit this properly: I'm sure it was in a Henry Manny F1 review in Road and Track: "If you need two plugs, there's something wrong with your chamber". It related to a Maserati, and is suitably snotty, but there's a point there. 356 engines improve with the addition of a second spark plug in each cylinder. They improve in overall efficiency, both power and economy. And since the application does not effect engine breathing (with the resultant compromises), it improves matters at just about every RPM which has been tested. Improved overall efficiency means a 356 runs stronger, cooler and with less fuel. Firing Later, and More Evenly, Maximizes the "Rod Angle" The reason has to do with the fact that the mixture in the chamber must burn at a given rate, not explode. The burning causes the pressure to rise in the chamber, and that's what pushes the piston down that hole, connected by the rod, thereby rotating the crank. Ideally, the pressur...

Calculating Compression Ratios

September 27, 2010 | Troubleshooting & Repair | 0 Comments
Text by Richard Peattie and Ron LaDow [Editor] Richard Peattie and Ron LaDow have both developed Excel spreadsheets that enable you to calculate compression ratios when building up an engine. Ron LaDow [First download Ron's spreadsheet (Excel file) for calculating compression ratios]  The spreadsheet will only calculate the compression ratio; the measurements are up to you. Enter values in rows with italicized captions, as follows in the upper section: "Cylinder Bore" is entered once in cell B-5. "Arbitrary", "Net" and "Head Chamber" volumes are entered in columns E, F, G and H for each cylinder. "Add or Subtract Gaskets" entered in columns C and D; each changes both cylinders on a bank as thatís whatís required. In the lower section, enter: "Head Chamber" and "Piston Dome" volumes plus "Deck Height" are entered in columns E, F, G, and H for each cylinder Add or Subtract Gaskets" entered in columns C and D; each changes both cylinders on a bank as thatís w...

Starting an Engine after Extended Storage

September 27, 2010 | Safety & Driving | 0 Comments
By Alan Klingen How to handle an engine that has been sitting for years First see if you can turn over the motor easily, if not then you need to dismantle the motor to play it safe. If you can turn it over then remove all the oil, sump screen and oil filter, then refill with new oil of your choice. Do a regular tune with points, valve adjust and plugs but leave the plugs out for the time being. You can squirt a small amount of oil into the cylinders if it make you feel better but only a very small amount! Just a couple of drops only! Note on the dip stick where the oil level is exactly. Crank the motor with the ignition off by grounding the point wire to the coil, this is marked #1 on the coil. You don't want to just leave the cap off because it will be sparking inside and if you have a fuel leak and you are not there to see it, well you know what could happen. Crank for a few seconds and then recheck the dipstick and see if oil is being drawn, if it is crank some ...

Big Bore Pistons: Torque vs. Horsepower

September 27, 2010 | Troubleshooting & Repair | 0 Comments
By Alan Klinger and John Wilhoit [Editor] Dave Brenny asked a question on 356Talk wondering if rebuilding a 356 engine using big bore pistons produce more low-end torque at the expense of horsepower at high RPMs. Two 356 engine veterans responded: Alan Klingen, The Stable: No single item will make a motor"scream": it is a function of all of its parts. You can make a 1200cc motor feel real good to 10,000 rpm and you can make a 2000cc motor be a very good low RPM motor. The basic items that make a motor rev freely are the design of the cam, the compression ratio, and porting. There are a few others that come into play like timing ignition curve, fuel management, etc. I have found the biggest limit to a 356 to make good horsepower is the design of the heads: they are in a word, bad. A 911 can deliver 100HP/liter quite easily and be drivable, but to get a 356 engine over 75hp/liter takes some serious effort (and expense). Of all the dyno testing I have done it seems th...