Technical Flathead Inspection Pics and Advice Needed

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

 

I believe they can be bored to .090 over. They walls will be pretty thin at that point. The worst case would be to sleeve the bad cyclinder. How long ago was the motor work performed? Adjustable lifters and clean valley make one believe it’s been apart and work performed.
The pict looks like a valvetrain or spring or something came apart in cylinder. Rest of block looks okay. Machine work wouldn’t be Terrible If rest of block checks out okay.

 

By the way, I’ve had worse lol

 

Looks more like a broken ring and upper land...Smartest fix may be to replace that piston (dependent on the other 7) and sleeve that cylinder.
Other variables will be pertinent.

 

My seller didn’t know how long ago the work had been done, since he didn’t have it done. But it has been sitting for a year or so. We’ll see how the rest looks when I can get into it more.

That block of yours was something else! Did it end up being rebuildable?

 

Vanness, early cobra engine?

 

Mike, that’s a good suggestion. It would be nice to not have to do too much machining if the rest of the block and cylinders are ok. Thanks for the idea.

 

Now that’s good stuff...until I met his family... that will make you jump.

 

Looks like your block has been relieved around the valves (compare it to the picture of the cobra motor). There is a lot of steel there, I'm not saying you shouldn't sleeve that bad hole but I took my 8BA to .125 over to fit some Ross pistons.

 

There is usually no problem going to a .125 overbore on these engines - that is what I normally do. The block has been relieved and I can't really tell, but may have been ported as well. Given these things, it might be a very good block/engine to use . . . might even have a 4.0" stroke Merc crank in it.

You should take a ruler and measure the stroke. If it ends up being a stroker - it is worth more $$$ to folks that like performance. The piston is like that because either a ring broke or some piece of crap got into the cylinder. It really doesn't matter if you are planning on rebuilding it anyway.

I'd take a wire brush and some lacquer thinner and clean the block as good as you can around the valves and through the transfer area toward the bores - looking to see if there are any cracks. Also, I'd pull the oil pan and see if there are any cracks on the pan rails. Lastly - it might have a performance cam in it - as usually folks who 'relieve' a block have also put other performance parts/modifications into the engine.

Good luck and if you need anything, just PM me.

Take care,
B&S

 

So it’s a stock 3.75” stroke crank unfortunately (I kind of got my hopes up ). It is definitely relieved though, as you guys thought. I took a closer pic that shows it well. I also tried to shoot a pic down an intake runner to see if anyone could tell if it’s ported. What do you think?

 

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.

 

Looks like someone has been in there cleaning up those runners. That is a pretty cool block your playing with. The relief job looks good and you said it had adjustable lifters. Hot rod flathead. You're a lot farther along than I was when I bought mine. Keep posting, I enjoy this stuff.

 

I give a Rats Ass if that block was solid Gold, I ain't touching anything that houses a "Python"!! To me, that snake is 15 ft. long and 10 in. in diameter! I don't do SNAKES!

 

That motor has had something in the cylinder when it was running. @Atwater Mike probably guessed it as close as any of us, he's been playing cars and motorcycles as long or longer than any of the rest of us. If I am not mistaken it'll go an eighth (.125) I believe or you can sleeve it, neither will be cheap, you just have to decide how much cool is worth to ya.

 

I’m all in on this motor. Always wanted a Flathead. The trick will be finding a good machine shop down here in South Florida that can work on these great old motors. Too bad I’m not closer to H & H Flatheads, as it looks like they will sleeve a cylinder for $90. Best case scenario I guess is that I only need to sleeve this one, and can simply hone the others and be good to go.

 

What you need to do is have the block cleaned, magged (if it passes that), then pressure tested . . . if it passes that, then sonic tested (if you're planning a large overbore). If you're going to not do a big overbore, then you need to have the bores accurately measured to see if they are round, not worn, not tapered, etc. This determines whether or not it really should be bored. I have YET to find one that didn't need to be bored - just sayin (folks ran the crap out of them back in the day). Do the best analysis work possible on the front end - then you can make good decisions based on accurate facts.

I'm sure it will need a valve job - they all do. You want to find a machine shop that really knows flatheads, has the correct flathead specific guide bore mandrels and truly understands the nuances of the flathead valve train. This is the area where I see the most heinous crimes! If you need any info, just PM me.

Those cracks are of no worry - we say that Ford has a "standard part number" for them - pretty much always see them. If you do the job right - then you'll have great results . . . if you're into cutting corners and slapping it back together . . . well, yah get what yah get! LOL

Good luck,
B&S

 

You are aware that a boring bar is a boring bar correct? It is not magic its just a motor and any machinist worth his salt can do the machine work.

Now repairing cracks and installing a sleeve is a whole nuther story. That does take some finesse but end of the day it is just a motor until you get into exotics like say an offy they all screw together pretty much the same.

 

B&S, I am not looking to shortcut things here. If need be, I’ll get all the machining I need. Just staying hopeful (or perhaps naive) that I can get away with just a sleeve and a hone if all else checks out.

Porknbeaner, i’m sure any competent machinist can perform certain tasks on these engines such as a bore, but in the event I’m looking at a sleeve, and perhaps more, I would like to find a shop who has been down this road before with these motors. If nothing else, it will give me some peace of mind, particularly if a fellow HAMBer can vouch for their work.

 

Like Ol' Ron said on your thread on the Barn, he's got one that's .145 over, and I've done 3 that went .125 over with no problem. Bore it out : "No replacement for displacement".

 

Not mentioned is that some flatties were factory relieved.

 

Very true, Tubman. So many great ideas and options here and on the Barn. I may end up going that route eventually. Time will tell.

 

Knead, that is true, but I understand that the factory relief looks much different. I think they are straight on the sides. I’m sure others with more experience and knowledge will chime in.

 

maybe look for a machine shop that does tractors? - the guy here in Oklahoma I used ( Pat's Machine) does more Ford tractors that have flatheads than cars exponentially... He def. knows his stuff and since farmers keep stuff forever - he fixes a bunch. maybe an avenue to snoop into.

 

Seems to me that 1/8x1/8 was a common motor at one time.

A flathead will sure take a serious hawging out and a sleeve only really becomes necessary when its time to repair a crack on a cylinder or huge bore becomes the name of the game. I don't recall the final bore size but when I was a kid Ol' man Dorman ( owned a race shop in the town I lived in) took one out so far that it ended up with wet sleeves. He said it was never gonna be a street motor and wet sleeves shouldn't be a problem.

 

3/8 X 3/8ths was the common flathead for eons. 296 cid. Meant the bore was 3 3/8ths. (.187 over bore) and the stroke was 4 1/8. 3/8ths over the standard 3 3/4 Ford stroke. 1/8th over Merc crank offset ground to use '48 rods and bearings for the extra 1/8 stroke. Yes Ford truck motors were factory relieved and yes the relief was straight sided. It was cut with a broach and could not do curves.

 

Like Beaner said, any competent machinist can do this, a motor is a motor. The same machinist that does the work on my other engines did my flatty. The only thing he didn't have was boring plates. I had the heads that came on the motor that I was not going to use, so we cut holes in them and made boring plates. I left them with him for future use when were finished with them. I gave him my copy of Joe Abbins book on making 335 HP out of a flatty and he followed the recipe.

He had built a couple mild motors years ago, he said he had fun building mine. You are going to love that motor!

 

Thanks for all the advice guys. I’m psyched for sure!

 

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.

 

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.