Thanks for the feedback John! I like the idea of a tool steel cam as it could be conveniently thru heat treated and ground with no concern of exposing the soft inner core. I was hoping not to have to rough in the lobe profiles prior to heat treat and grinding… looks like I will need to reconsider that operation. Lucky for me, the T is not expected to perform anywhere near top fuel standards. Most T motors don’t need a stop watch to track performance, just a calendar
S7 is great because of its high strength and response to heat treat with very little post heat treat distortion. On the other hand, its machinability is terrible- much worse than 9310 in fact. If you're concerned about core strength, you can always double quench and temper 8620 to get the core tougher. Biggest problem is reliable heat treating shops. Most shops want to lay cams down rather than hang them in the furnace. All the salt bath heat treat shops in northern Ca are long gone, which was the ideal method for long skinney parts. Kevin- at some point you need to dump the T cam bearings and run the cam in the block-
Kevin You are right, performance in a T only requires a sun dial What I am referring to is the 8620 has an advantage by offering a better yield factor to absorb the torsional forces and unsupported flexing on the lobes Yes in theory using S7 could reduce the number of processes in finishing the cam, I am not sure this is completely true Some time ago there was the thought that stainless steel would be the material to use, it wasn’t Keep us updated on what you do J
Does anyone have the complete Milodon Banger article they can share? I have page 1 but nothing else. A search of HAMB has so far not been successful. Thanx
There's still a few heat treaters in Minnesota that still do it but lead time is very long. When i still had the mold shop we made many of the components for die cast molds that had to be tough but flexible because of the processing shock out of P-2O and salt bath nitride. For good surface hardness and lubricity but flexible enough to not fracture.
https://youtube.com/shorts/9T0LNSjB0_Q?feature=share It`s outside now .......getting close to a drive in it.
So, while I have been fapping off on the chassis, my compatriot and rust rescuer extraordinaire Commodore Swab has been piecing together hickory from 16' raw sheets to build the various wooden bits. We lifted it over for a look. Been a busy week, and a happy one.
It’s alive!!! The Akron-Hed fired right up with the base carb settings, and now must wait till the cooling system is assembled to tune better. Here is a link to a video of it running; https://share.icloud.com/photos/012feKncgXXDkL4_ISwAoXouQ
I ended up pulling the engine to finish porting the intakes. Then when that was complete I started cleaning up the exhaust valve seats, and found a crack... So I pulled down the engine the rest of the way, and took it to use a friend's mill to install a hardened seat. Got it back home and start to measure up for new rings, and it has over 0.020" of piston to bore clearance near the top of the bores, and negative at the bottom! The pistons are 0.005" over, and I suspect it's never been bored, just hacked with a hone in a drill to suit... So, new pistons on the way. Babbitt looks good and there was plenty of shims, so hopefully should be able to set decent clearances. I've also lightened the flywheel since it's out, and as I was ordering pistons I have ordered a pressure plate so that I can take some more off it. And my 3 phase power gets connected next week, so I can power up my newly acquired old milling machine (and my old lathe) - I think I'll bore and deck the block myself just for the sake of having done it. Should add hard seats for the other exhaust valves too I suppose. I think I'll add an oil filter too, and am wondering (and researching) about pressurized oiling. I've got a bunch of old (OT, but look period) superchargers here from an MG project too... I am trying (though probably failing!) not to get too carried away, I really want to it back on the road! Meant to be going to the Gresford Mud Run in July and the Gulgong Model A meet in September... Has anyone done pressurized oiling with babbit?
This is the engine I found for the speedster. Looks like a very nice 60's build? The distributor is a 35hp bug item. The intake and exhaust are like scaled down model A parts. No clue on the internals.
Put some 5.25's on the rear, I like the look. Plus, works out to same as 3.54 gears. I need to reverse the spring eyes. Every gasket on the 97 leaks but it starts and runs like a top so I just drive hell out of it.
Took her down the block a couple times this evening, totally different car! Down right snappy now and makes all the right noises! Still some adjustments to make as the low range is a bit temperamental and getting some off idle popping out the carbs, but gettin closer. The pump is keepin her kool, and only have a few drips to plug up
The Jalopy Journal
