- Written by webmin
There has been quite a lot of progress on our Speedster project in the last few weeks. Despite a few setbacks, we expect the engine to go on the dyno shortly. These shots were taken at Allied Auto’s machine shop last week.
The engine was in pretty tired shape. When we pulled the heads, we found the right front cylinder wasn’t firing at all due to a bad valve and spring. When we ordered our replacement parts, we opted for the Lincoln Zephyr valve springs, which we purchased from Red’s Headers, and standard small-block Chevy exhaust valves, which fit perfectly for both intake and exhaust.
The crankshaft was pretty well used, the connecting rod journals cleaned up at .060 oversize. Normally on a later engine we would have opted to replace the crank altogether based on this finding, however, .060 over rod bearings were still available after some extensive searching, and some help from fellow H.A.M.B.ers, we found an NOS set at Antique Auto Supply in Texas. Once we found these we decided the crank will be OK despite using an oversize that large. Main journals were also smoothed, but we had more leeway with those because the mains are poured babbit and can be any size the clean up at. The babbiter just pours in enough new material to create a bearing that fits.
The block was also pretty tired, we could have probably gotten by with .060 over pistons, but it was safer to just bore the cylinders to .125 over. This gives us a 3-3/16-inch bore, the same as the later model 239 flathead and it made it easier for us with parts because we could use standard 239 four-ring piston rings on the .125 over three-ring pistons we bought from Egge. If anyone needs a set of lower rings for a 239, let us know, otherwise, they are going in the trash.
The engine has been re-assembled and some other parts had to be located in order to get to this point, I will add more updates later on those snafus. But the prospects of having the rebuilt flathead dyno’d and back into the speedster early next week are looking very good. Just barely in time for some break-in, then on to the first rally of the season in Oklahoma in two weeks.