Calling on all Flathead Experts

I would like to ask for your thoughts. I'm new to engine rebuilding and flatheads and I'm learning a lot through the journey for rebuilding such a cool engine. The engine was taken out of a 51 Ford F1 and was told it was a 239 V8. Upon cleaning I noticed it had merc heads and thought that was a bit odd because the block is 1BA. I pulled the heads to try and measure the stroke but the engine was frozen. I spent weeks soaking it with different liquids that were suggested on here and tossed in the towel and knocked everything out. I'm glad I went this route because I'm learning a bunch more then doing a half ass job, I hope to be sending it out next week to be hot tanked and magnafluxed.

Here is my question to the experts. The engine is fifty years old and if it could talk it would have a bunch of stories. I know merc heads is not a indication of anything and since I could not measure the stroke could you look at the pictures I have of the crank and the measurements I took to help me figure out if I have a merc crank. It sure would explain the merc heads if I do. I did do a search to try and figure out on my own which crank I have, I only have a 5 and 6 marking on different parts of the crank. I also found in my search if I had a 5/8 clean out hole I could have a merc crank. What is throwing me is my clean out hole is really a hole in a hole. There is a 5/8 outer ring hole then a slightly smaller hole in it. Also near the crank gear is small shallow drill holes (what is that all about)

Please help a ignorant flathead guy be less ignorant....thanks for your help!!!!

 

looking at the cranks counter weights there is a straight edge along the widest points. measure this and if its 6" its the 4" stroke. i think if not it will measure 5.5 or so.

 

The 5/8 hole is the actual hole in question...your inner hole is the concave side of a cup plug, sort of like a Coca-Cola cap without the lumpy edge, driven in to keep the oil on the inside.
The cup plug is removed to clean out the crud in the trap back there when crank is turned and engine rebuilt, and then replaced with a new one when all is clean and going back together.
The big counterweight will measure as noted above a bit over 6" if Merc, somewhat under if Ford. Note to other people out there...said measurements do not apply to pre-1949 type cranks!

 

thanks I will check it out, could you give me a bit more about the proper way to measure from point to point and exactly where. "cranks counter weights there is a straight edge along the widest points" is a good starting point but looking at the crank i couldn't tell you from top to bottom if my life depended on it as this is the first crank I have ever touched.

 

You said it....

 

damit....i know I was going to be called out about that....dirty minds on here lol

 

Put the crank back in with a rod/piston. Spin it over and measure the stroke.

 

Beat me to it

 

heh heh heh heh uh huh uh huh uh huh

 

With the crank in the block, measure from the pan rail to the crank pin with the pin as close to the rail as it goes. Turn the crank a half a turn and measure from the same rail again. Done!

 

The latest issue (November) of Rod & Custom has a couple of pictures on identifying a Mercury crankshaft. It is in an article about H & H Flatheads.

 

Here is everything you wanted to know but were afraid to ask.

http://www.flatheadv8.org/boomer/crank.htm

Tig

 

thanks tig that is very descriptive and I feel I now have exactly what I need with everyones help to figure out what I have in my mystery flathead....thanks so much

 

You plannin' on puttin' that Flathead in your Avatar?

 

once its done it will be and I hope there will be a f100 truck attached to it

 

What about what Art said? Is common sense to rare a commodity today? Put the crank on v blocks and spin it. mark the outside of the throw at level one way and the inside the other. Measure between the marks. I know you can cut V blocks from 2X6s and scrounge up some paper faster than the HAMB. I am no "Flathead Expert' I'm not stupid either.

 

I like R Pope's method. So simple. Ive never heard of that before.

Thanks mate!!!

 

Is common class a rarity today? Get off the high horse.....thanks for everyone else's help and class

 

Being to lazy to think is not a mark of class. bring me a crank and with a 2 X 6 some nails and a 6 inch scale And I'll tell you if it's a 3 3/4 or 4 inch crank before you can ask the HAMB. And I don't even have to be smart.

 

didn't know building an engine for the heck of it or researching a possible alternative solution to answer my question a mark of laziness...I consider it the opposite...I think the majority of the HAMB community welcomes these types of questions as it is an open forum and not only do I learn from asking this question but others that read this thread...why would you want to decrease people coming to HAMB as a resource when they have a question? why would you want to restrict the flow of information? why do you feel the need to post and state "I am no "Flathead Expert' I'm not stupid either." on my thread, to me IMO it seems you wanted to make yourself look superior at my expense but in the process made yourself look arrogant, unhelpful and a HAMB member that is not an asset to this site but a problem....i hope you get better and join the community to help others

 

My Grandpa always told me the only dumb question is the 1 you didnt ask when you didnt know the answer. Don't be discuraged! The H.A.M.B. is here to help. Take it as a grain of salt.

 

drama...

 

5/8" Plug = 4" stroke.

 

amen..johnny

 

I will stand by my thoughts.The idea that there are no dumb questions I understand. But those questions that could and should be answered by the application of common sense come close. I'm sorry that I contradicted the OPs self esteem schooling. If he emails again I'll tell him he was right all along and send him a little trophy. Perhaps the foolish question not asked was "How can I determine the stroke of a crankshaft, quickly and easily?"

 

^(snicker, snicker)

 

I'll never look at a crank the same again!

 

Email: RickFox
Who would you want working for you? Someone who can and will reason through a simple problem. Or a dope who turns it over to the "Experts"? I see so much of this on the HAMB. And some of it in the shop. I get so tired of a machinist who can't do math or read a print. Hot Roders have always been do it yourself guys. That includes thinking. RF

 

Email Back: Flathead Johnny

Ever think there is a reason why I can not put the crank back in and turn it? If you read the post I have a frozen engine, I knocked out the pistons but am waiting for my flathead valve spring compressor that I ordered through ********* which is taking much longer than they said i just don't want to dig around in there with a screwdriver and do more harm, I can not turn the camshaft so something is bound, I have scheduled a time to drop off my engine to be hot tanked, bored...etc next week which I would like to keep and not rescheduled, if I got the tool monday I would just have enough time to disassemble the rest of the engine and I just don't have the time to mess around with anything else which is why I asked if there was a way to figure out a merc crank by looking at it and there is so I am glad I asked. You see what seems to be a simple problem is not always so simple as it appears, why don't you think and realize this and self reflect on who is really the dope

 

sad there are people on this site like this and no matter what is said they think they are gods gift to the world....even if I mentioned that I was waiting for the compressor and the whole back story in the OP I'm sure I would have got a similar comment for this guy. sorry this has turned to drama but if someone does not call this guy out he will keep up with his poor actions