21 stud flat head sump vent

[Road rat ricco]

High all, I have an old pal having problems with sump leaks on his old 21 stud flat head v8, any body got an easy fix? Thanx, road rat.

[The Yeti]

I think you'll find very few people here have even heard of a flat head much less have actually seen one.

Only suggestion is he hasn't replace the cap
With a plug or something like that, I haven't climbed under mine in 12 months (doing it this Saturday actually) but I think the only vent is the oil
Cap at the back

[Xauterus]

Ozrodders.com is a great source of info for early engines.

[mechanic]

The days before the PCV valve.
Some of the older motors had a catch can type of affair that was full of steel gauze halfway along the breather tube. This would carbon up and cause some pressure in the sump.
The breather caps also had steel gauze inside and had to be washed out at services.
Some of those oil leaks on older engines were difficult to stop.
Too much crankcase compression ??

[The Yeti]

your right Mechanic I had a brain fade moment on right hand side as you look at it at the rear towards the bell housing there is a breather tube.

check thats clear

[Road rat ricco]

Thanx for your replies guys, my old mate has a 32 ford ute self imported with a very old 21 stud engine, pre oil pump, probably a T model. he rushed ahead and had the motor worked on by unknowing engineers, high lift street cam, more carbies blah blah, now, when motor runs(sweetly) it looses so much oil that he has to turn it off, oil comes out of the vent at front of sump. Everything has been cleaned for the rebuild so blockage is not a problem. This engine is designed to splash oil and were renowned for oil loss, it has low oil pressure, some people say just weld the vent up, but I think that this will cause engine problems if no P C V. The fix by ford for the next engine was to put a internal overflow line in to the top of the valve gear and close the vent. Any one got a simple answer to fix this.

[aussiblue]

This shed any light on it: http://www.fordbarn.com/forum/showthread.php?t=3135 and http://www.fordbarn.com/forum/showthread.php?t=97564 noting the comment:

Here's a list that I was told to check and this was/is on a 24 stud but the principles should remain he same: the rear cam gear cover could be leaking, one of the plugs back behind the flywheel could be leaking (near the cam gear cover), the rear seal you put in for the pan may not have been installed just right and it's leaking, the oil filter line that comes out from the back of the block may be cracked down low or it's loose in the block, finally, once it's running and it leaks a lot after you shut it off, the crankshaft main and rod bearing surfaces may be out of spec.

and http://www.jalopyjournal.com/forum/t...athead.394976/ (note the comment about the oil pressure relief valve).

[The Yeti]

Sorry mate that ones beyond me even the 4 banger flattys I've played with are pump feed

What Aussie Blue has posted looks like a good place to start, Like wise as Xauterus has said Ozrodders is a good wealth of knowlege but it can take a little while for your membership to be activated to the forum worth the wait IMHO you DONT need to join OzErodders which is a hotrod club attached off the side

[aussiblue]

And note that unless significantly modified to specifically address oil leaks they will always be very generous in sharing their oil.

[Road rat ricco]

Thanx Bluey, the 21 stud is not the same as 24 stud, 24 stud had a oil pump, 21 had no pump, with oil spillage being a common problem to 21 stud, I think because of the vent in sump at front of motor, they are known to leak a lot if you take a corner too fast. There must have been a common fix by the early rodders, like blocking up vent hole or whatever. We just don't know what that fix is. Hellllpp.

[The Yeti]

actually thats not true, latter 21 studs had oil pumps (I have one)

I wouldn't recommend blocking the breather but perhaps baffling it or fitting a catch can

[Road rat ricco]

Thanx snowman, we will just have to assume that there has been something done wrong by the engineer, maybe a broken ring? Oil is pumping out. We will keep looking.

[aussiblue]

There must have been a common fix by the early rodders, like blocking up vent hole or whatever. We just don't know what that fix is. Hellllpp.

As suggested here http://www.jalopyjournal.com/forum/t...athead.394976/ you can use strips of scotch brite or a nerf ball but better there is actually a hard to get fibrous scotch brite like material designed to be used in PCV systems as a flame trap in the air cleaner that you can get from Repco etc. I use it in the air filter of my LC Lancer where the PCV hose connects; I also originally used a Scotch Brite pad folded over until I found the right fire trap stuff in Marlows. Curly Whirly stainless steel scourers can also be used provided they are suitably retained so they cant get in the engine.

[aussiblue]

This tacky pray booth arrestor pad material should be OK too http://www.bestbuyautoequipment.com/...trol-s/808.htm

[aussiblue]

This also http://www.ebay.com.au/itm/Fly-Racin...MAAOSwQItUIvSF or http://www.ebay.com.au/itm/FLY-RACIN...oAAOSwxYxU0mhi or http://www.ebay.com.au/itm/SMOWMOBIL...nocCrO6eM-lFVA etc Perhaps go talk to a Motorcycle parts place noting you need a fibrous fireproof material that will stop the oil but not the air. Ditto lawn mower / chainsaw parts places.

[aussiblue]

Some ideas here too: http://www.fordbarn.com/forum/showth...4276&showall=1

[Road rat ricco]

Thanx to all that replied with info, xauterus, yeti, mechanic, and Aussiblue. Great forum, big help, Aussiblue you are a bewdy mate. Thanx for all that work you did. Digest it all and let you know what's up. Ricco.

[The Yeti]

I'd actually like to retract my comment that no one here would have even heard of a flaty

Its been a good discussion

[The Yeti]

Some other places (On top of the ford barn) Ive found good advice

https://www.facebook.com/groups/284972548325168/

https://www.facebook.com/groups/FlatheadFord/