Oil consumption through intake gaskets or intake

[junkyardjeff]

Ever since I installed the aluminum intake on my 302 it started using oil immediantly so I am thinking the oil is getting sucked up through the gaskets or the intake itself is porous. Its using about a quart every hundred miles on the highway (less around town) so I was thinking the intake ports should be soaked with oil and should be noticable if I used a scope and looked through every port with the carb removed. When I find a set of heads its going to get a cast iron intake in case it was not only the gaskets.

[enjenjo]

My guess is you used the rubber seals on the ends of the intake, is this correct?

[junkyardjeff]

I think I did.

[wayne petty]

did you use a new PCV valve when you swapped stuff around just before the oil consumption started..

let me take it back 2 decades... when i worked in the engine rebuilding shop..

a 390 FE  that had been rebuilt twice at another shop for excessive oil consumption and we had done it 4 times... same result.. 300 to 400 miles per quart...

i got in late on this... it was when the motor came back for the 4th time... i had no idea that on the third trip through the shop.. that it was the third trip through the shop..   after the 4th time with all new pistons rings.. bearings...   different sets of heads...  and it still burned oil.. i said i wanted to see the truck complete..

i looked.. it had a factory castiron intake.. chrome valve covers. red spark plug wires..  a well built carb...   i ask the owner.. what was done just before it started using oil...   he said.. it had a major tune up and all this chrome stuff was installed.. the carb rebuilt..  i ask if the PCV had been installed at that time...  his answer was yes...  i took a look... the opening in the bottom was HUGE..  i ask the owner to go to the ford dealer... buy the factory FORD.. in a ford box.. or in a Motorcraft box.. a new PCV valve..  the exact one for the application...  try it .. if it still burns oil . i will pay for it out of my pocket... a month later he returned.. it had Stopped burning oil...

the bubble packed PCV that was on the engine was sorted by shape... not calibration..

i don't have a PCV flow tester... there was one in the engine shop before the fire..     the 2 inch disc from RIMAC tools... PCV tester went over the breather opening. let you see how much flow there was so you could know if you needed more PCV flow.  or less...

if you have a conventional dip stick tube..    and one of the fuel pump vacuum tester gauges...   one that reads 15 pounds of pressure and 30 inches of vacuum on the same gauge.. pulling the dipstick.. hooking the gauge up to the dipstick tube..    stick the gauge under the wiper.. so you can see it while you drive.. do you build up vacuum.. or pressure???

you might want to see by blocking the breather for a few seconds.. see if you build a few inches of vacuum.. or a LOT of vacuum really quickly..

i don't have a CLUE what the flow rate should be..  i have searched and searched for that piece of info..  but i have not found it.. i am also NOT an SAE member..

i don't know if you have a flow meter on your MIG welder that you might want to use to see if you have TOO much PCV flow..

[enjenjo]

I think I did.

Several times I have seen the rubber seals on the end of the intake bend the ends up enough to cause vacuum leaks at the bottom of the end ports.  This can happen even with tunnel ram type manifolds, which you think would be pretty stiff.

When Ford went to factory aluminum intakes, they stopped using the rubber end seals, there must have been a reason.

A bead of silicone works fine.

[chimp koose]

check your plugs,if only a few are oily you have located the intake leak. Also aluminum intakes have a tendency to need retorquing after some use,could be the expansion rate as opposed to cast iron that squashes the gasket a little more. X2 on the end seals as well. I never use the rubber ones as there is always the possibility of pushing it out of place on installation.I had a friend whose 460 1/2 ton would burn oil when you turned left! Ends up the valley pan intake gasket was filling up and getting sucked out through the leaky gasket when it sloshed to one side on the turn.

[junkyardjeff]

I used the existing pcv when I switched the intake and have replaced it since and still the same,I wont use the end seals when it comes apart to repair the one head or change to newer heads. When I bought the intake from Jegs I also got their installation kit that had Mr gasket gaskets and bolts,one bolt broke while torquing it down the Edelbrocks specifications so i just put one original bolt back in. After I noticed the oil consumption I noticed all the bolts were loose so I put the rest of the original bolts back in and retorqued but no change in the rate of oil consumption.