Technical Flathead rotating assembly tight - pointers please

Looking for some guidance as this is my first flathead..

I ended up with an unfinished project that I've slowly been digging in to. A couple of weekends ago, I started digging into the engine and seeing if it rotated freely: it did not. The crank bolt would just tighten up, but the ***embly wouldn't move

I ended up taking off the distributor and valve covers, and everything was smooth and clean with a light coat of grease on the inside of the cylinders. No signs of damage.

I ended up putting a big *** pipe wrench on the crank pulley and finally got it to budge, but it was tight as hell. I did manage to get a full 360 on the crank, inspecting along the way and didn't see anything amiss. All the valves opened and closed, the cylinder walls all looked good. Pistons are stamped STD.

I'm looking for ideas on where to go from here. I figure that I need to pull the engine and start digging around, but I'm not positive of what I should be looking for.

 

It can be a few things . . . and you'll only know by taking it apart. The rope seals can be really dragging on the crank, but given how much effort it took to rotate it, my guess is that you may have an issue with the main or rod bearings being incorrectly sized or installed. You need to tell us what year engine you have . . . as the mains/rods can be very different from one year to the next.

Most importantly - DO NOT start it when it is this tight (even though the starter may not even turn it over).. Find the issue and fix it!

 

Since you said the pistons are marked "STD", I doubt they could be the problem, and since the cam and lifters seem to be moving, they are low on the list as well. You're on the right track pulling it apart; the first thing I'd check is the bearing clearances. Plasti-gage is your friend. You didn't say if it's an early or late ('49-'53) engine, and it does make a difference. The earlier engines have Full-Floating rod bearings and the earliest ones have poured Babbitt bearings. This complicates things beyond the capabilities of anyone who is not experienced with them. You may need the advice of a professional.

 

I'd like to see a photo of the "valve covers" you removed.

 

My first flathead, I had the same problem. It was a father/son project and I put the rod caps on the rods, torqued to specs and the crank refused to turn. I was 16 and when my dad came home from work he showed me the error of my ways. Every rod has a number stamped on it and every rod cap has a number stamped on it too. Put rod #1 with rod cap #1 .....same with the remaining rods/caps.

 

Also, the older cast iron rings were pretty tight in the bores and if the bores are dry and there is any rust at all, you'll have this issue. The cure -> take it all apart, check everything, check ring gaps, check bearing clearances and if things are right, the use high-quality ***embly lube in the bearings and bore lubrication in the ring packs and bores. Also, put some good moly break-in lube on the cam and lifters.

 

Thanks for the quick replies.
As best I can tell it's a 38-48 engine, but most likely post WWII.
- 24 bolts on the valve covers
- crab style, bolt on distributor
- no freeze plugs
- stamped "59"
I forgot to take pictures when I had the valve covers off, but here's some pictures of the engine.

I'll snap some more soon.

 

Just so you don't get slaughtered . . . this is a flathead engine, so those are not valve covers . . . they are the heads! The valves are in the block - so there are no valve covers. As I mentioned, you'll need to pull the engine and take it apart to figure out what is going on - do not attempt to start it!

 

BTW: That is a 24 stud flathead - manufactured after WWII (1946 - 1948) and prior to 1949.

 

Buy books.
You need to check the clearances on the bearings
You need to check ring gap
You need to check bore taper
You need to go through it and make sure it’s in specification.
It should not be that hard to turn
You need to find out why

 

every flathead gasket set i've bought listed a "valve cover gasket," AKA intake manifold...

 

While you have the engine apart, check to make certain that the builder removed all carbon from the pistons before installing the rings. I have found numerous "rebuilt" engines that had not had the ring grooves completely cleaned before re***embly.

 

technically, it does cover the valves. I mean, so does the hood, but the heads do cover the valves directly... just sayin' lol

-rick

 

Incorrect rope seal, or improperly installed can lock up an engine, rope supplied with the gasket package for my y block did that ( too thick)

 

Is there a transmission in it and is it a manual? If so, loosen the transmission up and shove it back. The input shaft may be pushing the crankshaft forward, causing it not to have any end clearance.

 

The pistons in my 8ba say STD on them and are actually .125 over! No idea what they were originally intended for.

Dave

 

37-41 engine. Likely 239ci. Good luck and let us know what you find

 

The “59” on the bell housing confirms that the block is the 1946-48 variety. From the Ford factory, these had the floating type rod bearings….not insert types. Many things could have been changed from the original stock configuration. You’ve been given mostly good advice….get the engine opened up to check things out. When the motor was rebuilt, they should have tested the rotation of the crankshaft in the new main bearings before they went any further. Properly fitted, the crankshaft should have rotated freely before they added the rods and pistons. Adding the camshaft and timing gears would be another step, followed by the valve train…….checking rotation at each step. It’s normal for things to start to tighten up a bit but it shouldn’t take a breaker bar and cheater pipe to turn the dang thing.

 

How long has the engine been sitting?? A few years back I picked up a vehicle with a sbc in it at a police auction, it had been sitting a while, and was VERY tight to turn over with a bar, I stripped it down, and found the wrist pins had siezed in the pistons (a combination of moisture, combustion **** and the varnish build up).
I had to take all the pistons off the rods, clean and re***emble to sort the problem.

 

It is too nice of an engine (from the looks of it) to "muscle" it with a breaker bar and attempt to start it. You're pretty much guaranteed to cause damage someplace . . .

 

Yep....
Be gentle. There’s no need to go “bull in a China shop”. This is not a 292 that’s been behind the barn fo 40 years.
As you go through it....
One of the first things to do is lossen/remove the rope seals.

 

I think the other guys have given all the good answers.

All I can say beyond that is that 50 something years ago I started the habit of turning the crank a couple of full revolutions after I installed each connected moving part. That means I put the crank in and rotated it a couple of full turns. Put the cam in or put the cam gear or timing chain on and rotated it a couple of full turns. Same with each piston and rod ***embly. Crank it over a couple of times by hand after each one. The thing with that is that is a "stop right here, something isn't right" deal and you back up one step and figure it out then and there.

 

I built a stock 8BA. It turned over really nicely-until I put the oil pan on. It would still turn with the crank bolt but was really tight. The guys at the Ford Barn said fire it up and that is what I did. 7 years later it's still running fine. That rope seal can be quite tight I guess. I have a rope seal on the rear and an Offenhauser 1 pc seal in the front.

 

I appreciate all of the replies... guess I'll be pulling it out of the car and going through it.

 

Years ago I learned about "breaka way torque" I think it was called. When the main and rod bearings are all torqued up and the pistons all installed it should only take 15 lbs of torque to turn the rotating ***embly. Any more, find the problem.

 

Good advice from @Mr48chev a couple posts back. Good looking flathead but if it were mine I'd lose that red fuel line.

 

You gotta love the HAMB.....
The guy has to turn his engine over with 10’ cheater bar.....
“You gotta change that red fuel line.”

 

Valve and piston cover's

 

Another question I didn’t see asked… have you ever witnessed it turn over freely? Nice looking flathead by the way!

 

Wanted to thank you all for the advise.

Yesterday I pulled the engine and started in on trying to find the problem. Where I ended up was finding over torqued main caps. Once I got those backed off and retorqued to spec the ***embly rotated freely.

Rotating_***embly by gerfunken posted Jul 5, 2024 at 11:21 AM

IMG_5350 by gerfunken posted Jul 5, 2024 at 10:06 AM

IMG_5363 by gerfunken posted Jul 5, 2024 at 10:08 AM

IMG_5362 by gerfunken posted Jul 5, 2024 at 10:08 AM

IMG_5361 by gerfunken posted Jul 5, 2024 at 10:08 AM

IMG_5358 by gerfunken posted Jul 5, 2024 at 10:06 AM

IMG_5359 by gerfunken posted Jul 5, 2024 at 10:06 AM