markanello Posted September 3, 2013 Share Posted September 3, 2013 (edited) I've got a 1958 707B that's pushing a bit of oil from the breathers that gets the valve covers moist after running it for a couple of miles. .The breathers have been cleaned and I don't believe I have an overfill scenario (oil on stick is below upper mark but stick is kind of bowed), The engine runs good and strong with and occasional backfire pop on decel. There is a small crack in the rear head casting on drivers side at the #4 just above and next to the capped spark plug hole. This is a single ignition and the crack is on the iron casting and shows a very light oil seep after running it. Any thoughts from those who have dealt with these types of issues on those old 707 gasoline engines? Edited September 3, 2013 by markanello Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/ Share on other sites More sharing options...
j hancock Posted September 3, 2013 Share Posted September 3, 2013 You may want to run a cylinder leak down test on the engine. If the engine has a lot of time on it, the rings are probably getting worn. Worn rings will pressurize the oil pan and the pressure along with some oil will come out the breathers.This test can also determine how well the valves are sealing to their seats.Jim Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203437 Share on other sites More sharing options...
1958 F.W.D. Posted September 3, 2013 Share Posted September 3, 2013 J hancock took the words right out of my mouth. Quote TWO STROKES ARE FOR GARDEN TOOLS Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203458 Share on other sites More sharing options...
MADDOG93 Posted September 3, 2013 Share Posted September 3, 2013 What was in your mouth ? Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203461 Share on other sites More sharing options...
markanello Posted September 3, 2013 Author Share Posted September 3, 2013 That was my thoughts exactly... Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203477 Share on other sites More sharing options...
Loadstar Posted September 3, 2013 Share Posted September 3, 2013 That was my thoughts exactly...The leak down test.....or What's in Randy's mouth????? Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203479 Share on other sites More sharing options...
1958 F.W.D. Posted September 3, 2013 Share Posted September 3, 2013 You guys are like school on Christmas Day......NO CLASS!!!!!! 1 Quote TWO STROKES ARE FOR GARDEN TOOLS Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203480 Share on other sites More sharing options...
markanello Posted September 5, 2013 Author Share Posted September 5, 2013 The leak down test.....or What's in Randy's mouth?????The leak down....lol. Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203869 Share on other sites More sharing options...
bullhusk Posted September 5, 2013 Share Posted September 5, 2013 An E/Z test, take the plug out of one cyl. At a time get a squirt oil can and a compression gauge, pull your coil wire out and take a comp. test on # 1 then squirt some oil into the cyl and take another comp. test if your comp. Goes up your rings are worn if not it's your valves do one at a time that's how my Pop would check the old gas jobs, also make sure your crank vent tube is not blockedBULLHUSK Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-203870 Share on other sites More sharing options...
markanello Posted September 6, 2013 Author Share Posted September 6, 2013 (edited) An E/Z test, take the plug out of one cyl. At a time get a squirt oil can and a compression gauge, pull your coil wire out and take a comp. test on # 1 then squirt some oil into the cyl and take another comp. test if your comp. Goes up your rings are worn if not it's your valves do one at a time that's how my Pop would check the old gas jobs, also make sure your crank vent tube is not blockedBULLHUSKWhere is the crank vent tube? Edited September 6, 2013 by markanello Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-204072 Share on other sites More sharing options...
markanello Posted September 8, 2013 Author Share Posted September 8, 2013 Where is the crank vent tube located? Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-204645 Share on other sites More sharing options...
Solution j hancock Posted September 9, 2013 Solution Share Posted September 9, 2013 Where is the crank vent tube located?If the truck is running breathers it may not have the tube. The vent tube would be connected to your valve cover and then run down along the side of the engine toward the ground. It was just a way to allow any pres. built up to vent to the atmosphere. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-204842 Share on other sites More sharing options...
markanello Posted September 9, 2013 Author Share Posted September 9, 2013 I have a breather on each valve cover... Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-204857 Share on other sites More sharing options...
bullhusk Posted September 13, 2013 Share Posted September 13, 2013 Where is the crank vent tube?Sorry! but I think you got your answer, It's just a way to vent the pressure in your crank case, in a case where your rings are worn the compression would by-pass your rings an and compress your crank case causing 'blow by' sometimes if the vent is not clear it will even blow your dip stick out! I don't know if that is the trouble with your engine, but it was just a thought, again I'm sorry I didn't get back to you!!BULLHUSK Quote Link to comment https://www.bigmacktrucks.com/topic/32593-707b-engin-e-pushing-oil-from-breathers/#findComment-205824 Share on other sites More sharing options...
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