Flathead 6 Rebuild Information

[Daniel L]

Hey guys!

 

I am just about to get my flathead 6 cyl. back from the machine shop and I was wondering if anyone has a pdf on how to rebuild the engine. Hopefully, it would have all the information to ensure the engine runs good.

 

My project is a 47' Plymouth Sedan! Still wondering if I am going to finish it after the engine is complete.

[Plymouthy Adams]

no pdf or other...follow your shop manual...it has all the info you  need.....as a caution....DO CLEAN the block....machine shops are notorious for charging cleaning fee before machine work just to keep the shop tools and themselves clean during machine process....they rarely clean the block after the machining process and there will be all kinds of debris in and about the block.....happy wrenching...fun time...just buttoning up a rebuild here....

[Mark D]

There are resources available.  This guy posted a short series on youtube which can ground you in the process of the rebuild;

 

 

And there is an four part Auto Restorers Magazine article that I posted which describes the Flathead 6 teardown and rebuild located here -> 

 

 

And there is also an illustrated 218 teardown page located on this site here -> https://p15-d24.com/page/p15d24/tech/218_teardown.html/

 

Good luck with your project!

 

[greg g]

Just think 6 Briggs and Stratton a in a row...

[Andydodge]

Plymouthy is right regarding cleaning the block........I got screwed by a so called expert when I got the original engine from my 1940 Dodge rebuilt by a jerk and after about 500 miles when the rear main started to leak I dropped the sump and found swarf and metal bits in the sump and scored crank journals..........he denied all responsibility...........and 49 years later I still badmouth the ******* and hope he had a painful death..........lol.........I don't forgive nor do I forget..........lol...........I then decided to hotrod the car, got a 318 poly, installed that, 18mths later pulled it and sent it off to be bored, machined & balanced etc......BUT I got it back in pieces, opened my shop manual, cleaned the engine enough so I could eat my breakfast off it and assembled it........and 49 years later its still going strong as ever...........moral to this story is its not in a fit enough state to reassemble unless you are prepared to eat something that touches the engine.........lol..........and trust nobody.............lol...............Andy Douglas    

Edited April 17, 2020 by Andydodge

[Sniper]

1 hour ago, Andydodge said:

moral to this story is its not in a fit enough state to reassemble unless you are prepared to eat something that touches the engine..

 

I've eaten my lunch at the junkyard with greasy hands, so that might be a pretty low bar to meet.

[Andydodge]

Sniper...........but was that unsaturated grease?......we have to look after our trim, taut & terrific figures...........lol............andyd 

[Sniper]

Don;t worry, my trim, taut and terrific body is well padded to prevent damage, lol

 

[keithb7]

I recently learned something interesting related to rebuilding our flathead motors. I've been itching to share it, might as well be here on a thread about tips on how to rebuild the old engines. Con-rods are off-set. I did not know this! Not until I laid them out, in order on the floor. See how they line up? They are grouped towards each other in pairs. Huh...Interesting. Why? I don't know. Perhaps someone else can tell us that. Are the position numbers stamped at the factory, as shown?

 

 

Edited April 17, 2020 by keithb7

[Sniper]

I bet the bores are offset the same direction?

[keithb7]

You're right @Sniper they are. The bores are off set in pairs, to allow for coolant passages into the head. I’m enlightened!

 

 

Edited April 18, 2020 by keithb7

[MarcDeSoto]

You should also know about the Master Tech series of booklets and filmstrips.  Check them out on MyMopar and the Imperial Club.  

 

http://www.mymopar.com/index.php?pid=400

[greg g]

Result is siamesed cylinder pairs.  This design is also why proper head torquing sequence is critical.  The gasket between cylinder pair is pretty thin so clamping force applied correctly makes for longer gasket sealing and life expectancy.

[tom'sB2B]

I encourage you to read this thread.