Engine questions

JHarley

JHarley

Junior Member
Hey guys, i bought this replacement engine about a month ago. It is a 239 bored .040 over and to my surprise it has a 4"crank. It isn't a fresh rebuild, but no ridge on cylinders and rotates seemingly fine. I dont want to tear it all apart but I want to remove all of the grime. Is it safe to steam clean the engine (crankcase and lifter gallery) without causing any damage? And also has anyone ever ran these main cap supports that Speedway sells?
Thanks, Julie
 

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Here is a pic of some of the crud in the lifter gallery. Should I just send it and change the oil several times?
 

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I think it would be fine, if you take precautions.

Make sure you use a steam cleaner and not just a high pressure washer and get it heat soaked, so it will dry fast.

Hand oil the internal areas and last, turn it over, with the pickup in oil, until you see oil flowing at the rods.
 
Those main cap reinforcements are unnecessary for most modifications, like hi boost blower ot nitro additive. Lucky find,steam clean should work just fine. good luck
Gramps
 
Thanks fellas. We have a Hotsy at work that I can use. I will get it good and hot and then oil it all right after. The seller hadn't said anything about it being a 4"crank, so I feel like I scored pretty well. The engine was supposedly some reputable local flathead guys spare a couple owners ago. Been sitting under a work bench for a few years. While it is tempting to do a full rebuild, I am so anxious to get it back in my pickup and get it running, so will run it as is. I could plasti-gauge it but think I will take my chances as is. Getting my radiator rebuilt at a local shop.
One more thing. Replacement 239 came with aluminum heads. The Offy paperwork says to torque them from one side to the other like you would if applying a decal. Seems so weird and against everything I have been taught about torque sequence, but I guess Offenhauser knows more about heads/engines than I do by a smidge��
 
My late friend who built my flatheads had seen those kind of main cap straps cause the cap to break right at the apex. Like Ron said, you don't need those.
 
I think a Hotsy is a pressure washer. If so, would not use it because it will drive grit in where you do not want it. Turn the engine on its tail and wash down in the valve valley then tip it over to drain.
 
Those main cap straps are not required unless you are seriously racing. They require special installation procedures to work right.

John Bradley one of the fastest flathead drag racers that ever lived used them.
 
jimTN said:
I think a Hotsy is a pressure washer. If so, would not use it because it will drive grit in where you do not want it. Turn the engine on its tail and wash down in the valve valley then tip it over to drain.
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I vote this way. I build engines for a living and washing a partially assembled engine with either water or steam is just not the best idea. Maybe get a siphon type blow gun and clean up that valley area and drain as jimTN suggests or use a good parts washer type brush with diesel fuel/kerosene/solvent and do it that way. Water has a way of getting where it's not wanted.


Terry
 
I have to agree with this ^^^ . If you have the motor mounted on an engine stand, you could wash it out with gravity to your advantage. Napa sells a 1 qt spray gun that clips on to a tire air chuck, so you can spray mineral spirits or diesel fuel and wash it out so the dirt falls into a pan instead of being pressure washed into areas you can not control. Napa also sells a large tin pan, about 3' x 5' that would hold the crud that washes out. Many of these old fords have that pan underneath where they sleep at night !
 
I like the ideas of diesel fuel or mineral oil to wash things down. If it was mine, I'd take it apart and clean the heck out of it - probably cost you a weekend of time and $250 in gaskets.

But, if you're going to do the "quick and dirty" method, then consider using a pressure tank to pump some oil through it while the pan is off and rotate the crank while doing so. This would re-lubricate the bearings - which isn't a bad idea before you start it. I'd also at least pull the oil pump, take it apart - check it out, etc.. If in doubt, put a new oil pump in it.
 
Also, on those main cap supports - you won't need them and if you were going to use them, the right way to install them is to align bore/hone the mains afterwards - to ensure that the center main bore isn't distorted from the torque the center support puts on the middle of the cap.
 
Also, I don't like what appears to be rust on the valve springs . . . do you see rust other places? Getting rust into the oil and running through the bearings isn't such a good thing.

I'd take it all apart, clean everything out, check the valve faces/seats, etc.. If the valves/seats look good, use some fine compound and lap them to check each one. Again - probably a weekend of time to know exactly what you have and the condition of everything in the engine.

Also, this makes it possible to put good assembly lube in all the right places - before you start the engine (which is also a very good thing). It has been sitting for a lot of years - things will be a bit "dry". ;)
 
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Bored&Stroked said:
Also, I don't like what appears to be rust on the valve springs . . . do you see rust other places? Getting rust into the oil and running through the bearings isn't such a good thing.

I'd take it all apart, clean everything out, check the valve faces/seats, etc.. If the valves/seats look good, use some fine compound and lap them to check each one. Again - probably a weekend of time to know exactly what you have and the condition of everything in the engine.
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^^^ This is also what I'd do if it were mine. It looks to quite possibly be a nice piece and would be a shame to damage it to save some time. I know it all adds up and delays the process but in the end it's always worth it in my experience. Congrats on getting a really nice combination though...it'll make you smile when you get it running and driving!


Terry
 
With the 4" crank, you have 255 ci. Now if it's bored oversize it will be more. Now this will increase your Cr as well. So consider milling the heads to add more. Unfortunately, adding a Cam will reduce the CR, depending on the duration. The L-100 will knock of more than a point. These things are important so the application of the engine is important, I doubt vey much you'll see the price of gas come down much in the future, so a well tuned Flathead can give you exelent fuel milages for a daily driver. Pulling this engine apart and going through it might be a good idea. Might consider a full flow oii filter as well. they don't cost much.
Gramps
 
All good points and I will contemplate all of it. The supports caps will be a no go for me. I appreciate the input.
 
Ol' Ron you are right as usual. As oil companies are making record profit ever quarter now, I wouldn't expect the price to go down anytime soon. Stock holders would not like that. I'm a stock holder. :) Geezzz if only I went all in with Tesla stock 10 yrs ago.



But a well tuned car runs better and also doesn't wash cylinders with excess gas. Efficiency and maintance is just smart.
 
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