What can you tell me about "factory relieved" 59 blocks. Were these truck engines, or replacement engines, or??? We recently tore down a 59 that was in my dad's '35 truck. He bought the truck from the original owner about 25 years ago. He was told that the local auto parts/machine shop put a new engine in the truck in 1956. My dad ***umed it was a rebuilt engine. When we pulled it apart, we found a standard bore, factory relieved engine with all factory Ford bearings, pistons, etc. So I guess it really was a "new" engine! The deck was not stamped with a serial number, only what looked like a CA license plate number and two small circles...one with an F and a 3 digit number and one with either 31A or 81A. If everything checks out OK, this engine will get rebuilt for my 32. Any info would be appreciated. Neal
I think the relieved blocks are like the Z blocks...you'll see lots of theories about truck, military, cracking, etc., but not a damn thing either listing them or explaining them from Ford! Here's a possibly irrelevant factoid: The only reference I've ever seen to relieving from Ford is on a different engine, the big Lincoln/truck flathead of '49-51. This was in a circa 1950 service bulletin, which said Ford (truck bulletin here) had started milling a relief in production engines in order to eliminate a cracking problem, and that it was recommended that existing engines be relieved. Dimensions were given. Time for a HAMB expedition to Ford archives.
Bruce - Kinda what I figured...I think the one I have came out of a 1948 Canadian Mercury military police car...yeah that's it. Any idea on the stampings on the deck...or lack there of? Thanks, Neal
I sold a 59AB motor to another Hamber awhile back that was also a factory relieved block, all standard. (should have kept it.) Maybe send a PM to orcas tow and see if he could pull the #'s off it.
I have a 59AB out in the garage. I was told it was a truck motor. Where do I find numbers? I don't see any on the deck (but it is a bit dirty).
I saw one many years ago that was pulled from a '39 Mercury, and the numbers matched the ownership papers (***le).
USA flatheads generally had no real info on the upper deck--I believe a couple of states required serial on motor and it was stamped there, but generally nada, serial was on trans. Variations were stamped up there, but I don't think I've ever seen anything I could ID as such on a 59. The prewar engines had a number of variation marks that went up there whenever two similar engines were in production, like babbitt vs loose bearing mains, sleeve vs cas iron bores, and piston/ring variants. Merc engines got a 99 up there for a couple of years, then the factory started painting them a different color from 221's. There is good info on this stuff in the '38-9 resto book from V8 club. Most factories produce occasional runs of engines with undersize bearings and such to use up mis-machined parts, and I wouldn't be surprised if Ford marked such up there... 59's in general are close to unmarked. I have one that I know left the factory as a new replacement engine, and its only marks were a letter or two in geometric boxes that I would guess are just an inspector's mark releasing the engine for use. My factory relieved block is a Z (another variant explained only by folklore), and it is a lump of rust still--can't tell if there are any marks.
I remember back in the 50s, they said the 42 Ford had a factory relieved block.At least thats what my buddy told me when we picked up a junk 42 Ford.
I've got 3 flathead engines that have the factory relief: A 59Z, a 99, and the third one is either a 59L or a 59X (I can't remember which at the moment). It's pretty easy to tell a factory relief job from one done by a backyard 'machinist' because the relief looks like it was gound out in about 5 seconds with some huge grinding wheel --- very uniform depth, but not polished looking.
Hi I´ve had two 59A engines with factory releaved blocks. The first had served in a fire truck (46-48 can´t remember exact year) and was still in standard dimensions. The other came to me through several owners but still I believe it too served in truck because there were hardly any nontruck Fords in Finland of yearmodels 46-48. Both had raised stamping 59L in bellhousing.
Check out the engine section in Rumbleseat's online flathead manual. It has some actual experienced info on "letter" blocks along with the usual speculation about military, export, etc.
Here's a link to Rumbleseat's online write-up. Select ENGINES at the bottom of the page and load 16 very usefull pages in PDF format. http://www.flatheadv8.org/rumblest/intro.htm Print them and save them
novice here...I have an 8BA motor and im curious about what relieving is and does it apply to my motor?
It could apply to any flathead. The area around the valves to the cylinders on the engine deck was cut down about the same shape as a head gasket or "relieved". Supposedly this allowed better "breathing".
According to Andy Granatelli in "They call me Mister 500" it was HE who taught Ford all they needed to know about relieving the stock blocks after they suffered cracking mainly in the truck blocks. Entertaining read, although I took most of it with a pinch of salt...
It helps increase air flow from the valve pocket to the bore. Wether an engine could benefit from relieving depends a lot on the head used. When the chamber size is reduced to increase compression, the flow path between the valves and bore may be reduced as well. Obviously some heads are better than others. Cutting a relief in the block between the valves and bore can regain the lost flow path. Most street engines built today don't bother with the relieving, but it was pretty common in the past. I added a quick paint drawing to help illustrate. The stock chamber in black with a high compression in purple.
Hey thanks for the Info and the awesome illistration..the drawing cleared up any missunderstanding too..i get it Now...Do relieveing not only allow more air and fuel into the cylinder but it minimizes block cracking?
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