Anybody have any experience with SEALS(rope type or others) on a double slinger crank on a flathead Ford v8. I know the engine was original 39 truck(never changed out) with 3 3/16 bore(39 cars had 3 1/16 bore). I ran the engine as a stocker then bored it .060 and ran it some more. Always leaked at the rear main(much more than just a drip or so,actually a small puddle) I tried several times to remedy the situation, but never had any real luck in making it much better no matter what I tried to change. Decided to try it again in a 36 Ford and the leak is still substantial. Having owned,sold,traded over 50 motors in a 60 year period I don’t know what else to do. Any chance with SILICON and letting it sit a day or so b4 adding oil after pan is put back on??? Engine has to be pulled as there is little clearance from pan to front crossmember.
Two avenues. 1. set up a very good PCV system to help keep stray oil away from the seal by creating negative pressure in the crankcase ( have never had great luck with this, I suspect you would have to use a vacuum pump to be truly effective ) 2. machine the fins off the crank, or swap to a postwar crank,fit later rope seal holders, upper and lower, (thee are available new) and run rope seals. I had this problem in a 39 Merc engine, I eventually gave up and fitted a 4 1/8 Scat crank and rope seal, cured the slow and the oil leak.
Just built engine found .002 mains and .010 rod bearings. Last tear down was because low oil pressure—the .002 mains brought oil press back up to 60 since down last year. Made drain back vent on pass frt of pan into a real outside vent that vents to outside. Since this crank is a full floater, it would be a shame to change over to later model inserts and 8BA style rods and discard these costly parts for a 8BA crank and rods. That would be the easy solution, but I am a stubborn 75 year old rodder who will go to moderate means to at least slow down puddle to a few drips. Any suggestions are considered. Thanks John in s.Texas.
Full floaters work fine on a late crank. its the other way that doesn't work. check that you have a tube screwed into the oil drain on the rear main. for some reason, pressure related, they leak more (a lot more ) if the little drain tube is missing. Also check that the tube that sits under the fuel pump and into the round casting at bottom of valley is in place. the internal engine airflow path relies on this entirely, lots of people leave them out. ruins the designed evacuation path for crankcase gases.
Is there a threaded portion from Henry to install a drain if one is not in place already on the rear main???The fuel pump arrangement already has a tube extending several inches covering the fuel pump pushrod. Appreciate your suggestions!!Flatheads Forever!!!
John , Isn’t that an 8CM Mercury pan and pickup ? Are you planning on using it,,,,,modified or something ? That’s just about the best pan you can get for these old engines . Tommy
Yes, that is a factory windage tray pan(49-51 Merc only—not Ford) Chevrolet did NOT have a windage pan(separate “tray” not attached) until the mid 60’s(I think,but could be wrong). Hot Rod Mag conducted a test on a strong “mule “ engine(Chevy) involving windage tray and same engine with no tray and found 8-12 hp(??) difference at nearly 6000 rpm. Yes, I know a Flathead doesn’t rev to 6 grand but just the fact that FOMOCO Corp was experimenting with oil control 10-12 years earlier than GM was is a surprise to many. The flathead pan with the tray only fits the 49-53 style of engine and will not bolt up to the earlier 32-48 style. Flatheads Forever.
I guess I'm not understanding. The engine is assembled, or disassembled? If disassembled, just have the extra slinger ground off and use a 40's seal back there. I thought they had changed to rope seals by '39.
nope, I'm pretty sure all prewar, (to 41) cars had the slinger type rear main. my 39 99A did, and a raised deck 42 221 block I did recently had a slinger too.
John , I think Ford was really working towards oil control,,and not so much windage. Trying to keep most of the oil in the sump and not rolling back and forth,,side to side . Imagine,,,,,some of the twister cambered road beds back then,,,,,and then imagine a sump already a quart or two low,,,,and that oil sloshing around ? It would be easy to starve an engine for oil,,,,and then after engine problems,,or short service life ,,,the public blames the manufacturer. Bad reputation,,,,and you didn’t necessarily do anything wrong . I could be wrong,,,,,,but like you said,,,,,those old mills didn’t turn that high yet . Just an observation on my part . Tommy
Good observation—-I never thought about any useage other than a windage tray—- now that I think about it more, you are probably right. Just goes to show even with 60 years flathead experience,you (me) are never too old to learn. The engine is not apart—-will try and do a more complete packing using pre—flattened rope seals to better fit the contour of the slingers(they are tapered)
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