Building new Engine for My 1965 Mustang

Charlie Cheap

Active member
Just purchased a 1973 200 out of a Maverick for my 65 Mustang. The OEM 200 had to be bored .060" over to clean up...which is not a good idea. I drove it to Tennessee last summer for the M6A show, running 75 and sometimes better just to stay with traffic. It had no problems running up to and above those speeds. After the M6A show we went to Mississippi to visit relatives. It ran great, got 24.5 MPG running the AC all the way, but refused to start after stopped, unless we allowed it to cool. Mine is built for highway running not max power. I will remove the internal goodies to put on this motor as I am well pleased with its performance. Anyone else needed a .060" bore and finding the same problem? It works but has issues with cylinder-wall flex when hot. Hoping .030" bore will clean up cylinders but have a question. My 65 has 8.8 - 1 compression with 13cc dish pistons. The 73 looks like it has a lower compression when checking info pages. Is this true? Are the 6.5cc pistons the way to go? About 9-1 or 8.5-1 seems like a good road static-compression for a car not racing. With my cam that comes to just below 8-1 dynamic-compression. My dizzy is one I built with BWD SELECT parts and Pertronix conversion with a dual-advance (swing-weights-vacuum) modified with the 925D spring, manifold vacuum and Ford 9mm wire wound plug wires feeding Autolite AP46 plugs gaped at .040". A MSD .8 ohm ignition resistor puts a little more primary voltage to the ACCEL 42,000 volts coil, while the lowest ohms wires reduce that voltage as little as possible. With higher input the coil puts a little more to the plugs plus it has about 10K higher ability than the OEM. Better coil, more primary volts, Pertronix, the best available parts, tuned right, and platinum plugs...works.[image]img1743[/image]
 
Hi Charlie Cheap, I am sorry but your above post was placed in the wrong tech section (Coming of the New Forum Upgrad) so it wasn't seen by many of the forum members. I am sure you have solved and found the answers to your questions by now, but just in case you haven't or for the benefit of others that may read this post here goes. Yes the late 1969 and newer heads have the larger 62 CC Combustion Chambers so your 1973 block and head have aproxamately 1 point lower CR (Compression Ratio). Yes your 1965 engine stock with a 52 CC Combustion Chamber giving it 8.7 to 1 CR. As far as I know all 200 short blocks have the pistions setting .019 or more down the hole you need to measure this. Yes the 6.5 CC dish or the flat top pistions are the way to go for the very best combo the block should be zero decked to get close to the proper quench distance of .035 to .050, when the block is zero decked you can run 8.7 to 9.2 to 1 CR (many people have built street motors 9.0 to 1 with excelant results at sea level) can work very good on regular 87 pump fuel depending on your local condistions air temps, altitude, type of driving, etc. 9.5 to 9.7 to 1 CR could also work with premium 93 grade fuel. The Camshaft spec's also having some effect too. Best of luck and hope you are doing well.
 
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