Projects Rebuilding a Flathead

Ok, so I was eyeing up parts for a Model A sedan build and I found a Flathead for sale on eBay. I favorited it for later since I was just searching for price checking. I was not planning to do any buying yet. However, the seller sent me a message that he would reduce the price by 10% if I took it now. I still wasn’t interested but thought if it was a real steal I’d get it. I sent back an offer of 40% off and he accepted. Now I’m the proud owner of a real crusty Flathead.

This thread will document my progress in bringing it back to life but first I’ve got some questions for the community. The seller said it came out of a ‘36 and it’s a 21 stud so I figure there’s not a big reason to doubt the year but is there any other identifying I could do? It has a large 5 near the integrated bell housing and an H by the passenger side front of the block. Images attached. Any help with identification?

Also, if anyone has any recommendations of a machine shop in Virginia that knows how to handle them I’d be grateful for a recommendation.

 

Ooof!....

Do you have all of it? Heads? Crank? Rods? Pumps? Pan? Hopefully you have all of it.
Early Flatheads can be really neat, but.....

What's done is done. I really wish you would have joined and asked here before purchase.

 

I just wish you would have conferred with us before buying.
Normally I’d advise to stay away from a 21 bolt pre 1937.
All that rust indicates it's been exposed to the elements for a long period. Odds are it’s cracked. I’d bet 80% chance.
21 bolts are low on power and worthless in a heavier vehicle. Speed equipment is expensive and hard to source.
How much did you pay for it.
I’d cut my losses quick on it and not invest another penny.
Sorry for the bad news.

 

@F-ONE Heads no, crank yes, pistons and rods yes, pumps no, pan no. I was afraid after I got an in-person look at it that it might be too far gone. I figured if there was any saving it then someone here would know how.

 

Don't Panic yet Motor City....
What looks to be rust in the photos may be dirt cobwebs and dust bunnies...Hopefully so.

This is country boy logic. You do not have enough there to build an engine. If you must build a 21 stud you at least need a another one with all the parts. One that is complete. Really this can be said about any of them. It takes 3 to make one.
I have seen complete and running 21 studs come up from time to time.
Really the best way into a flathead is to get a running example.

No harm no foul....Like I said to get one good flathead usually means getting 2....maybe three.
The best of the series were the 24 stud (59As) and the like. The later 8BAs, though more common can be a pain in the butt....
21 studs can be cool and to be honest I don't know much about them. The early ones had cast bearings like a Banger.
Bonnie, Clyde, Floyd, Nelson, and Dillinger loved them.

 

Fortunately I’ve only got a few hundred bucks in it. Do we think it’s worth hot tanking or some kind of rust removal process to see what we got? @Petejoe seems to think not. Any other opinions out there?

 

Magnaflux it to check for cracks.
Valve seat cracks and pan-rail cracks are the bad ones.
If you want to do a 21 stud...
magnaflux it first.
Checking for cracks is the first step...always.

 

You can do some of the cleaning yourself first. Wire brushes, degreaser, elbow grease and have at it. Look real close the areas around the valves. Most of the times you can see the cracks when cleaned with a wire brush and inspected carefully.

This is going to take multiple steps:
1) Clean as much as you can at home.
2) Get it magnifluxed. Some shops may want to hot tank it first, but don't pay for a shake & bake cleaning until mag'd.
3) If it passes mag testing, get it pressure checked.
4) If it passes pressure testing, get a quick reading of the bore size. If standard or .010 or .020 and no major pitting, then get it shaked and baked cleaned.
5) Even after that, you are going to need to poke and scrape to get all of the crap out of the water jackets.

 

Here is a page out of the early ford blue book to help you identify what year
I would check for Babbitt bearings or inserts first
If Babbitt most will tell you to run but I am currently putting together a ‘34 that the main bearing clearance is still with in spec
I’m also a fellow Virginian

 

If you've never done a flathead before and the block is good, it may be worthwhile to have the shop remove the studs. Breaking them off in the block can be a real challenge if you don't have the proper tools, etc.

 

Look on the left front where the intake sits to see (hopefully) an LB stamped in the deck. LB means "large bearing", which means not babit bearings. Valueable block, if it checks out ok. The little motors wind up faster, light crank an rods. Speed EQ is rare though, dont give up yet! Also, they are not all stamped, but most are. you can also check by the width of the main cap bolts, I forget the specs, but they can be found

 

If you can't build an engine out of it, strip it, clean it, paint it and make a glass top table out of it.

 

As banjorear said, clean the area between the valve pocket and cylinder bore (I use a wire wheel on my drill) look for cracks with a a magnifying glass. Look for cracks inside the bottom of the block along the inside walls. If you don’t see any cracks, move onto cleaning the cylinder walls and look for cracks and holes there. If all that checks good, I clean and disassemble the block and have it magnafluxed and pressure checked.

 

Common steps with an old, unknown engine are to disassemble, clean and inspect.
However, I'd strongly suggest first finding a rebuilder you have verified can handle the job.
Clean as mentioned to check the bearing type and for cracks around the valves, but hold off on disassembly until your builder has a chance to look it over and measure things. Is the bore at the limit already? Are deck heights okay? Have them mag test it assembled. You should be able to move it on as a lump fairly easy, but boxes of parts and an empty block are going to be harder to sell and takes up more space.

 

You need to see if its got poured bearings or if its a LB ( soppose to mean loose bearings ) meaning insert bearings for the mains . If its a poured main bearing it’s probably just best to give up and find another block . I dont know of anyone doing the bearings anymore, at least not reasonable.

 

When it comes to a flatheads, a proven good bare block is worth a nice sum. All the other parts are fairly easy to come by. Nice if you have them, but not a deal breaker. Good blocks are key.

OP, now I'm really curious. Is is a babbit block or does it have insert bearings?

 

@Motor City Mechanic
To get better idea of how to go about evaluating and disassembling your flathead, search and watch the @Mart videos. he takes it step by step, and although he's not a professional engine builder, he has good tips on what to look for and how to determine good vs. bad 'bones'. Take the time to watch and learn before you dump a lot of money and time into it. If this engine core doesn't pan out, look at it as an education going forward. Good luck!

 

I agree with 28phonebooth. A lot can be learned from Mart and his videos.
I wouldn't go as far to say he is not a "professional engine builder" though.
Even though he may not work in the engine building trade, he has more talent and ingenuity than most of the people, that are in the profession of rebuilding engines. At least most of the ones I know of anyway.

Bill

 

@‘28phonebooth Thanks for the lead on the videos. I’ll be sure to watch them.

@banjorear I took some of it apart and this leads me to believe it’s insert bearings, correct?


@rusty valley I haven’t been able to find LB anywhere but maybe it’s still hiding.

The valves are flat with no Ford script and the bearing nuts are wired. Is this an indication that it may have been rebuilt before? I’m going to take everyone’s advice and clean it and check for cracks. If I can’t spot any I’ll then take it to a machinist for hot tank and magniflux. I’ll definitely leave the studs for them to remove. Anyone have a lead of a shop they’d take it to in Virginia?

 

Yes, thats an insert bearing motor. Keep all the rod bearing in order until you confirm they and the crank are in need of rebuild, often times the floating bearings are reusable if the crank measures good

 

You cleared the first hurdle with the insert bearings
Your good deal is looking better hope your luck continues

 

He has been here since 2018 but not active. @Motor City Mechanic Yes Insert bearings and you have the crank and rods so another plus. As has been said check for any visible cracks before proceeding any further then get it magna fluxed for cracks. If there are none what are you going to do with it?

 

I would do some self cleaning for a look see. Then I would have it cleaned if it checks out by eye sight.
I hope that you got it for a decent price.
Good luck with it.

 

Rod bearings can be difficult to find for these. They are floating bearings. I don't know if anyone makes them any more. Macs auto parts often has some sizes. A machine shop can resize some of them, like honing a .030 under to a .020 under size. You can also run into these bearing in over size (OD) with rods honed to match. Finding these items would be very difficult if not impossible. However, these bearing clearances are pretty forgiving using .005" ( .0025 inside and the same in the rod) total clearance on the rod bearings. Mains are normal .001 to .002 clearance. If you decide you don't want to tackle this engine there are posts in the "Wanted" section here and on Ford barn. com looking for a good LB block.

 

A known good LB block should bring a grand. Restorers want them as they can be dressed up to look like a 32-36 but have real bearings.

 

I agree. I wasn't trying to disparage Mart in any way. His approach is methodical, logical, and informative. It's obvious he's got a lot of flathead knowledge to share.

 

@Motor City Mechanic

There are several threads on here about removing studs (as well as a few segments in @Mart ) that would be good to study before you have a shop remove them. They will just want to get them out, and out of their way...if a few break, that's just more work ($$) for them. You have the incentive to not only remove them, but salvage them and the block, so you might want to give it a try yourself (after researching methods and tools/equipment required). It's not rocket surgery but requires patience and tenacity.
Good luck!

 

Good news about the insert mains.

I recently removed studs from four blocks. The key is heat, stud removal tools, and patience.

I used an oxy acetylene torch and got them cherry red at the base. Let them cool for a day. Prior to heating, I sprayed them for days with Kroil.

While hot, I melted bees wax so it would wick into the threads in the block.

Heat expands the stud and the cooling shrinks it. The idea is this will break the bond of rust.

Some studs backed right out. Some needed to be reheated, some would not budge, some broke.

You may get lucky and they'll walk right out. Look up various post on here about how to do it. I think I have a pretty detailed post on it. I'll search for it and try to copy it on this thread.

 

@warhorseracing I’m at the very beginning of a Model A sedan project. Now that I know more about the various flatheads I’m not sure if this is going to be the engine for that or not. I’m going to get her cleaned up and checked. Then I’ll have to make a decision if this is the right match for that project or if it would be better off to go to someone else’s project.

 

@Motor City Mechanic If you don't decide to use it you could probably turn a profit to a restorer. Either way no cracks will bring a premium price. Less work to repair any that are not critical and a thorough check by you will insure a quality foundation.