Major Problem

[lark55]

Hi Leonard - I was curious what you are going to do for pistons. I have an early partial flow 259 that I am thinking about putting in a champion and I would like to increase its performance. Are these off the shelf pistons ?

[Skybolt]

Hi Leonard - I was curious what you are going to do for pistons. I have an early partial flow 259 that I am thinking about putting in a champion and I would like to increase its performance. Are these off the shelf pistons ?

They are but not in the USA. They are an off the shelf part in Australia. That is where I learned about them. The GM Holden six cylinder, designated as " a red motor" by locals, was made in the millions. It is a popular engine to learn hot ridding on and for many a regular means of transport. I'm using a 0.040" over 186cid piston. giving me 3.6625 bore. The alloy is a low expansion formula and I'm using Hastings moly rings made for a 0.040" over Dodge 273. The wrist pin is 0.223 mm smaller than a Studebaker piston so the New piston is honed to fit the locked in rod Studebaker pin. The piston also sits higher in the bore for better squish. I can get them from the manufacturer in Taiwan. They are an ISO certified company and supply piston to most major Asian vehicles. In the USA they only supply to aftermarket companies for pistons for motorcycles. There have been posts about these before.

[Skybolt]

Soo, if bored out an extra .125" or so for sleeving, in addition to the desired .100" oversize, will that total .225" or so cause other problems with that oil gallery, i.e. restrict flow?

No idea. Never had to do this before. If anyone has information on this please enlighten me/us. I don't know all the details and the block is at home so no further work will done until I get some more information.

[lark55]

Thanks for the piston information Leonard. What do you think the approximate compression ratio will be if you are using a standard head (minimal milling,regular head gasket)

[StudeRich]

Thanks for the piston information Leonard. What do you think the approximate compression ratio will be if you are using a standard head (minimal milling,regular head gasket)

Everyone keep in mind that the "Regular" Head gasket, OEM, Stock for a '57 to '64 259 or 289 IS a Thin Shim beaded steel gasket for the advertised Compression Ratio.

So if you substitute the Three layer "Thick" Type '55-'56 gasket for the correct one or use the new "Best" Brand aftermarket perforated Black new car type material, your compression=HP will be Lower by .50 or .25 respectively.

[Skybolt]

Thanks for the piston information Leonard. What do you think the approximate compression ratio will be if you are using a standard head (minimal milling,regular head gasket)

http://forum.studebakerdriversclub.com/showthread.php?64877-Piston-interchange&highlight=holden+pistons

[Skybolt]