Engine block I.D. pictures
- Thread starter 38 coupe
- Start date
Bored&Stroked
Well-known member
Rather than start a new thread, I figured this would be a better place.
Recently got this block and trying to ID it. From everything I can find it appears to be a 239 from a 39-41 (closer to 41?) truck based on the stamp on the left rear of the block 99T-638628 and the lower water passage.
From what I can gather this is a good block but one question is whether parts for a "59" block will fit properly.
That block is usually a 41-42 Merc type block - or a block that was used in WWII for a variety of uses. There is a bunch of flathead lore about this 'keystone' block being thicker and the cat's *** for a big bore stroker motor. Truth be told, they are not really any thicker or better than other years - just another perpetuated myth. I just built this same block/engine for my 32 Cabriolet - only because I wanted a pre-war block and this is the best one. Mine was essentially a NOS block - came in a create from WWII - STD bore, had just been broken (the engine) then not ran/used.
I have my own sonic tester and have tested a lot of different blocks - can find no consistent correlation between block year/type/nomenclature and being thicker than others.
As some noted, it should have the earlier valve angles (32-42) - but they are only slightly different from the 46-53 engines. There is some debate whether or not the 39-42 Mercuries used the LATE valve angle or the early one - I've never been able to confirm this. (To move the valves further away from the bigger 3 3/16 bore).
Valve angle: 32-42 = 101.45 degrees, 46-53 = 100.026 degrees
It is always wise to check for valve to head clearances - especially if you're running the early (small chamber) heads and/or an unknown cam. You can do this with a gasket and some modeling clay - you'll want .060+ minimum over the valves at the top of the pockets in the heads (which is where they would hit if they are too close).
rotorwrench
Well-known member
I haven't worked on any 41/42 Merc/truck blocks or wartime ones either but the 99 block that I have seen (1939) does have thicker walls. Maby not a lot thicker but noticably thicker through the water jacket ports than a 59 series. FoMoCo was changing the castings in the 41/42 time frame plus the wartime stuff may have been affected by shortages of materials. The most common wartime vehicles I've seen that had US built V8 engines were big COE transport trucks. I don't know how many were made for the war effort but I've seen pictures of them in Red Ball Express photos and others. These trucks were easy to maintain and the engines could be changed quickly if the maintenance facility had the cradle tools. Ford made a lot of G8T trucks but they were all 6-cylinder. Ford made other conventional cab big trucks for fire engines and they made the bomb loaders but I don't know if they had V8 engines or not. The bomb loaders resemble the CMP trucks made in Canada. My Pops outfit in Foggia, Italy had both the fire trucks and the bomb loaders. I just wish he were still around to answer questions about them. I'm sure all that stuff stayed in Europe & North Africa after the war.
v8fordman
Well-known member
I wrote that article years (decades) ago long, before digital cameras. If I recall, the pictures were in black and white....anyone remember them?
38 coupe
Well-known member
Well it has been a decade since I started this thread. Lots of good information and help was added during that decade. However, I hosted the pictures for the original postings of this thread on photobucket, and they changed their minds on how they operate (I never paid them money so I can't complain).
Since the early pictures are at best now only thumbnails, I have a question:
Should I attempt to update the original posts?
Should I attempt to duplicate the original posts here at the bottom of this old thread with attached pictures instead of linked pics?
Should I start a new thread instead of making new members scroll down through all of this one (I'm really conflicted on that idea since so many people contributed to this thread)?
At the minimum I can offer a chart with USA production line V8 engine identification as a sort of quick reference (see attached pdf).
Edit: I checked. I cannot edit any of my older posts in this thread.
Since the early pictures are at best now only thumbnails, I have a question:
Should I attempt to update the original posts?
Should I attempt to duplicate the original posts here at the bottom of this old thread with attached pictures instead of linked pics?
Should I start a new thread instead of making new members scroll down through all of this one (I'm really conflicted on that idea since so many people contributed to this thread)?
At the minimum I can offer a chart with USA production line V8 engine identification as a sort of quick reference (see attached pdf).
Edit: I checked. I cannot edit any of my older posts in this thread.
Last edited:
21stud
Member
38 coupe,
I think update original pics would be best? This is great thread, thanks! Deserves to be at top, sticky? is that possible here?
rotorwrench
Well-known member
I don't know if you can update the older posts. You might try it to see if it will work. If not, a person would have to repost these items with new entries.
This has been a problem with a lot of the older threads that predate the change from using links to photo sharing sites to posting directly to the threads.
This has been a problem with a lot of the older threads that predate the change from using links to photo sharing sites to posting directly to the threads.
RB
Senior Member
I have a relieved 59 block which has no 'L' designation immediately after the '59' but rather slightly off to the left top side of the bell housing near the 1/8"npt tapped oil gallery & the 'L' is read while facing the block from the right side. Just curious if it is a bonified 'L' code block ? anyone able to i.d. ? it has what looks to be factory intact paint but a much brighter green than I'm familiar with.
38 coupe
Well-known member
Allmost 59 marked blocks are equivalent. The exception is the over the counter replacement blocks cast with the smaller 221 motor size bore of 3 1/16 inches. All the speculation about different letter blocks being better has turned out to be just speculation. No metallurgical difference and no cylinder wall thickness has been found.
38 coupe
Well-known member
After thinking about it I decided to post pictures here at the bottom of this thread, and edit the old posts to reference the attached pictures. I'm planning on a post per engine group (1932 post, 33-34 post, etc).
Here is the post with 1932 engine block pictures. Many of the pictures were gathered from this thread, many thanks.
Here is the post with 1932 engine block pictures. Many of the pictures were gathered from this thread, many thanks.
Attachments
38 coupe
Well-known member
Here is the post with 33-34 engine block pictures. Again, many of these pictures were provided by gracious and helpful people earlier in this thread.
