Hi guys I have a question as to what flathead block to use. I have just strip down a 59ab that I purchase as a good running engine with a merc crank and 3 3/8 bores, I was going to just paint her up and drop her in to my coupe. I then desided to reseal & replace rings and maybe bearings quick hone and all will be good. Yes you guessed it I opened a can of worms! First piston out was broken between the comprestion rings,no drama I will put new pistons in. Not so easy bad went to worse cracks in the block between the head stud holes and cylinders,I noticed these after drilling out a few brocken bolts in pan rails and cleaning the whole block BIG waste of time and dollars that was. Spoke to machine shop guy who has told me to get myself another block. Question I have is I have been offered two blocks One is a 39 Merc the seller tells me it has factory sleeves and is factory relived?? The other is a 99 military engine that also is sleeved the guy selling this is very knowledgeable and tells me that will work with my crank shaft with minimal mods. Problem is the machine shop guy told me he has never seen factory sleeves??? Not sure which way to go ???? Which of the two is more desirable???
No difference between Merc and Ford blocks in general. Some engines were factory sleeved, not much help if worn beyond clean up. You can remove the sleeves and over bore or re-sleeve. Need to be sure the machine shop knows how to install the sleeves if it is required. I would guess that the Merc engine is a truck engine. I think the factory relief was only on the truck engines. And yes they put Merc engines in trucks, it is really the heads and crank that make them a Merc. Need to be sure the blocks you are looking at have been BOTH mag'ed and pressure tested. Don't even think about buying one that is not tested and they can prove they were tested. The way to go is with the block that can prove it has been tested and p***ed or your right back where you started.
The factory sleeves are thin, I think about .040 wall, and can simply be replaced if you don't need big displacement. Most old 239's down there will be Canadian military engines...they went from 99's to 29's, then added provisions for full-flow filtering and PCV about 1943. Also, some USA 29's went across the river for use in canadian bren carriers and trucks during the war. If you look around, you can get replacement NOS sleeves, slide them in, and transplant your 4" crank and build a 255 WITHOUT a machine shop...
Thanks Bruce so your saying I'm better of getting the 99 Military? Removing these sleeves?do they need to be pressed or weld so they srink the punched out? What are the best avenues to find the replacement sleeves or are they like rocking horse ****? Thanks for help Funk.
Thanks guys for your input. I sat down and watched "a sweet sickness" Again last night for the umteenth time Quote Mike Herman from H&H " if you want to build an early engine this is the block you need 59" Think I might just hang out until I find a good one and continue in the direction I started??? Any leads in Oz would be great.
Places like Joblot usually have them...they just get split and collapsed to come out, going in they need a mandrel so they don't collapse...fairly common, or find a friend with a lathe. Traditionally, racers preferred the prewar 239's, which reputedly were thicker than the more common 59. Nearly all racers were either 99 types or 59's. I don't see any issues for general use between 99, 29, or 59...go for the best block.
The angle between the valves on each side changed slightly when the 59 was introduced. Stock 99's will generally have slingers instead of rear seal, most 29's and all 59's had rope seals at rear. Everything interchanges and you might find either setup...to convert, you just swap the little castings that hold the seal or make the channel for slinger...with your 4" crank, you use the rope seal bits. There are several minor visual clues that distinguish the families externally...none matter for a hotrod.
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