Partial - Full Flow engines ------------ Partial-flow" blocks refer to blocks not having an oil filter passage. Mid 1962 and all earlier engines. They either have NO filter, or have an add-on that filters by tapping into a cylinder head oil passage to filter PART of the oil flow. In spite of what some may say, a partial flow filter is much better than none. Chrysler engineers determined that even a partial flow system filters all the crankcase oil every 6 to 10 minutes. So if the engine has none, it is still very much worth installing a partial flow filter. Just make sure you have the right plumbing because there is a restrictor orifice that is needed to prevent dumping your oil pressure down the return line. If you suddenly get really low oil pressure after installation, the restrictor is missing. The older (partial flow) blocks were the most perfect and the strongest of the castings, tho that usually does not matter with Studes extra strong engines. Even the "weaker" Stude blocks are much stronger than the BrandX thinwall softblocks. The extra weight Stude carries is the actually it's greatest asset. The partial flow blocks could safely take a larger bore than the later blocks. But even the later blocks can easily take .125 safely. I've heard of over .150 being done safely on late full flow blocks. ----------- Refit to Full-Flow -the change took place on or about April 17th at engine number S-248301 for 6's and V-559387 for V8's. ---------------------- The later full-flow blocks were also extremely tough, but when Stude quickly reworked their sand molds in mid 62 to include the extra passages, they had a bit of core shift. That will not affect anything even on high powered engines EXCEPT when you get to the really too-large overbores. If you plan to build a 310 or larger like some have, then you want an early block with thick and even walls instead of the thick on one side and thin on the other late blocks. That will not matter to most hot rodders, but if you go extreme, do it with the thicker early blocks. The later blocks with full flow filters will take the same heads, bearings, oil pumps, manifolds etc as the others. You can put all the usual parts, crank, pistons etc on either style of block as long as you have the same cylinder bore.. 55 on up had the same bores. 51 to 54 have very small cylinders, very small valves and extra large valve lifters, so most people avoid them, but those are the same engines that Ted used to stay the NHRA National champ for several years and get into HotRod mag a few times, so they CAN be made to go fast. Another customer of ours set a Bonneville speed record just a few years ago with a sleeved down 232. Somewhere in mid 61 or 62 I believe, Stude changed the pushrod length slightly. When building an engine, be sure to line up all pushrods together to make sure you do not have a mixed set. I will go to PhotoPoint then post some urls to show the difference and how to tell late rocker arms from early rockers. I hope this makes putting together an engine easier... Now ask me how to make it really fly with some big valve cylinder heads. ( DJLevesque@webtv.net (David Levesque) Sep 2001) ----------------------------- I believe the Studebaker service engines had a stamped clover leaf vs. a serial number. oldcarfart@aol.com sep 2001 ---------------- ------------- -BLOCK DATA --------------- 259 Cubic inch engines 3.5625 Bore X 3.25 Stroke (3 9/16 X 3 1/4) --------------------- Standard and Avanti 289 Cubic inch R1 / R2 engines 289 Cubic inch engine - 3.5625 Bore X 3.625 Stroke (3 9/16 X 3 5/8) CID = Bore X bore X Stroke X # of cylinders X .7854 ------------------------------------- 304.5 cubic inch engines Avanti R3/R4 engines 289 cubic inch overbored 3/32" (.09375) same stroke 3.5625 + .09375 = 3.65626 ( 3 21/32") You must be very careful when overboring to this degree. The R3 blocks were specially selected by the factory to have almost perfectly centered bores so that the R3 304.5 cid bore would not excessively thin or penetrate the cylinder wall. ------------- Ford 312 CID Y-block standard pistons can be fitted to a Stude 289 with a .156 overbore which yields 314.93 Cubic inches. Ford 6 cylinder pistons can also be used and reversed in the cylinder for better torque ( more info when received) last Sept 2001 ------------ 305 Chevy pistons will only work if you bore out a stock 289 by 140 thousandths. I just did it. Scared the hell out of me boring the block that much but it looks to be OK or so I'm hoping when it all gets reassembled. The stock Chevy 305 piston is 3.700" and a stock 289 is 3.56 or thereabouts.