Flathead Inspection Pics and Advice Needed

[brsturges]

I recently came across what I hope will turn out to be a good deal on a bunch of Flathead stuff including a complete 8ba motor (alleged to have been running but heads and intake were off) and a spare 8ba short block that is locked up. A quick visual on the “running” engine shows a pretty clean lifter valley area, adjustable lifters, and smooth rotation. Seller claimed it was recently rebuilt (the heads and intake were freshly machined). There is, however, one badly pitted piston with associated scoring on that cylinder wall. What causes this type of damage? Doesn’t seem like corosion to me but what do I know? Curious if anyone can help diagnose the cause.

I measure the cylinder bores to be about 3.243”, which I think means that the block has been already bored .06 over. How much more can these blocks handle? Any help would be greatly appreciated as always.

Brad

 

[alanwoodieman]

judging by the lifters going so low in their bores, I would think a reground cam, pretty clean, dents on the piston look like something got in there, maybe a broken ring which would also account for scoring in cylinder wall-do you have the head? any damage to it? 80 overbore is usually the limit but you can go 100 over-I personally think 100 overbore is stretching it!

 

[brsturges]

Thanks for the input, Alan. Broken ring is a good thought. I’ll have more info on that once I tear it down some more. The heads that came with it were not on the engine when it was running. As the story goes, my seller bought it in running condition but his seller wanted to keep the aftermarket heads.

 

[GordonC]

My block is bored out to 3.312". From everything I have read they can go to 3 3/8" and were quite often taken out to that. Check the underside of the head from that side of the motor to see if has the corresponding marks to that piston. Hard to tell how much damage is in the cylinder but something could have gotten down the intake or a ring could have come apart. The adjustable lifters could mean it has had a cam job at some point. Also the valves are tipped with the rotator retainer assemblies which were a 51 to 53 item I believe.

 

[Ol' Ron]

My present engine is out to .145 over. A few years back I built a 296 that was .187 over and was still running after 50k miles.. Raced a few teat were ,20 over. sonic testingg is a useful tool for saving hard to find blocks

 

[GB SISSON]

If that is the same piston, I don't see how a broken ring can come out of the land, leaving the piston whole, though dented. I thing something went down the intake. The cylinder scores don't look incredibly deep, but expect to see .080.

 

[tubman]

I have done 3 8BA series engines with .125 (1/8") overbores. The only problem I ran into is one had a casting flaw (pit) in the cylinder wall that was easily fixed with a sleeve. My machinist said it would probably have been a problem at .060 over.

 

[brsturges]

Thanks for the input guys. I think the block is relieved. Here’s a shot of the chamber area and it looks recessed. Don’t know if it is ported, but I took a shot down an intake runner so maybe someone can tell. Thanks again for all your help.

 

[Ol' Ron]

yes, that block has been relived, with a mild port job as well. should be a good runner. Check the cam as well.

 

[big job]

yes, that block has been relived, with a mild port job as well. should be a good runner. Check the cam as well.

you got better eyes than me I don't see no relief there should be right down to the valve seats ? or I am going blind or dense...
retraction; thought I see a head gasket your right Ron its my eyes sam

momma always said "least said easier mended" true

 

[48fordnut]

improper ring gap can cause scoring.
yes the block has been relived.

 

[brsturges]

I cleaned up part of one side of the block and there were no cracks visible in the critical areas, but there were a pair of common ones in between the water passage and where a head stud goes. I understand that those are not an issue. Clearly, I’ll need to clean the rest and have the block magnafluxed but this seems like a good start.

 

[cas3]

those bolt hole cracks are common, i wonder is it over torquing or just part of the game?

 

[brsturges]

I finally got into the engine a bit more. Got the crank and pistons out. The pan rail looked good with no cracks.

The rod bearings were down to the copper and the journals will need to be turned I think.

That one wrecked piston seemed intact, so it doesn’t look like a ring broke. Like many have said, something must have gotten in there. The previous owner had drained the oil and taken off the pan so I couldn’t find any evidence of broken metal bits in the engine.

Once the crank was out I could see the cam. Looks like an Isky Max-1. Seems like a decent cam and looks to be in good shape. Hopefully I can reuse it.

Take a look at the bottom of this cylinder. Is this evidence of a previous sleeve? Or is this some sort of crack? I really hope it’s no big deal since the block is looking good the more I get into it.

 

[RalphM]

Looks like cyl has been sleeved.

 

[brsturges]

Thanks Ralph. I guess a sleeve isn’t a big deal assuming it was done right. Is it normal for the sleeve to show a line like that?

I also was checking on the crankshaft and testing for the “ring” as discussed in Vern Tardel’s book. The crank rings great when the counterweight closest to the flywheel is struck. Not so much on the one closest to the front pulley. It gets progressively less ringy in the ones in between. I know this test is not 100% accurate, but I’m worried I may be looking for a new crank.

 

[brsturges]

I see “14-08” marked on the cam as well. Are there different Max-1 cams? Anyone know?

 

[flatheadmurre]

Datecode from the grinder ??

 

[brsturges]

I had that thought, but thought it would have been too European of them to put the year first.

 

[brsturges]

Just wanted to update this thread since I finally got the block to an experienced flathead builder who cleaned, magnafluxed, and pressure tested the block. It passed with flying colors! The one cylinder that is scored will need to be sleeved to get it back to .060 over. He also said one other cylinder will need to be sleeved as well, as it was a little out of round. The machinist didn't want to try to bore this block out further due to the previous sleeve. Ironically, I have found another good block while this one was at the shop and I think I may end up using the other block instead. It is bored .125 over. It's not ported or relieved like this one, but I think the extra cubes will make up for it. If anyone is interested in this block, let me know. I will be putting it up on the classifieds.