In a recent post Donnie Brown wrote "I tore down 6 complete 26 27 engines to get one good block". I've been told before that good 26-27 blocks are hard to find. What's the issue with these 26-27 blocks? Were new blocks made after the end of Model T production in the 26-27 design?
One of the problems with the 26-27 engines is also a problem with any of the one piece valve cover engines. The two piece cover blocks have a reinforced area between #2 and #3 cylinders for the valve covers. The extra metal between the cylinders gives more strength and disapates the heat of the exhausts better. The 26 27 engines are prone to cracking in the #2 and #3 cylinders valve seat area. Not sure why they are worse than the 23 to 25 blocks.?? Another reason why 26 27 engines are hard to find is they are more popular. They have the hogs head support bolts at the rear of the block and also may have the desirable EE crankshafts in them. They also have 4 dip pans, They are unique because of the hogs head support bolts and can not be converted from earlier years by just changing the serial number. Since they were only made for 2 years (and the replacement engines) and are so sought after they are just all being used up.
For me, the late blocks don't have any flaw.
Most just get worn beyond reasonable expense to bring back to new.
If a rod let go, and the side of the engine is gone And if the original two-piece valve stuck open, the exhaust port can go away. Very hard to repair these things, without some $$$$.
Easier to find a block that is more easy to fix, like just valve seats, and re-Babbitt.
'26 block. Not only is the port missing iron, the valve seat is missing, but part of the rear of the block surface around both (difficult to see in this photo). Too many $$ for me to have fixed, as the block surface would need welding, and then machining. Found a replacement block that has serial # just 3 weeks apart from this original!
Dan: I do not see anything wrong with the block in your first photo that a little JB Weld will not fix. "Smile"
I 'fixed' that block alright, along with a busted hogshead.
Made it into my cutaway engine display
Dan, would you do a new thread on your cut-away please?
In keeping with just using older posts, here is the post back you started with lots of cutaway photos, and ones I shared of making my cutaway.
Fun with a SawsAll and some metal cutting blades!
i also have several 26-7 blocks here with cracks all over on the deck. cracks between valve seat and bore, and cracks between stud holes and water holes. they do seem more likely to crack than earlier blocks but i can not say why
The 25 block currently being torn down is one of the best I have seen. Its like a 26 but some things are different like a large Ford logo on the crank. Wondering if Ford got a little frugal with the later production. This crank if its not cracked should go 10 under and so far no cracks anywhere I can see. There is no shims left on the mains or rods.
All the improved car blocks were cast at the Rouge foundry which had much different tooling and processes than Highland Park. Perhaps the old slow way was better?
How hard is it to fix a crack in the #2 and #3 cylinders valve seat area? Is it worth fixing if it goes into the cylinder area?
Bob, the blocks need sleeved and hardened seats installed to repair them the right way, but look between 2&3 in the lifter galley up top for cracks there before spending any time or money in a 26&7 block, the crack will run all the way up to the freeze plug on some. I quit buying these blocks unless they are broken down to inspect, I have thrown to much money away on boat anchors!
Found that a junk 26 27 block is handy for other purposes then its normal use. Don't have a pan straightening set up? A 26 block with a hogs head carefully bolted to it will give you a way to check pan straightness and bolt hole alignment.
Want to find out if your crank is bent? stick two main caps up side down in mains one and three. lay your crank in with a dial in the middle of the block checking the center main run out and turn the crank over.
Straightening an exhaust manifold? cut four discs 1/8" or so thick that fit the exhaust ports stick them in the ports and tack weld a 1/2" pipe across them with an 8" handle out each end. Remove from block turn over and use to check port alignment with out a tape or a straight edge or burned fingers.
26 blocks are a handy shop tool.
Paul. Good idea,,, and Joe is right about the top of the lifter galley between #2 and #3. Three of my bad engines have hairline cracks in that location. I have a suspicion that those cracks may be a design problem from stress caused in casting. A lot of those cracks may have been there from day one. They just got worse thru the years. I have no proof of that but just my opinion.