For several years I've been trying to solve the mystery of my '64's oil loss; the car has always used around one quart every 500-700 miles. Like many other members who's posts I've read (like Joe Lucia), I suspected the intake manifold gaskets as I've noticed oil on the intake runners every time the intake was removed. I tried several different types of gaskets and sealers. I installed an NOS aluminum intake on newly rebuilt heads and the problem persisted. I tried different torque sequences, I even installed a valley lifter baffle, and different PVC arrangements, all to no avail. After 7 years, two engines and many late nights in the garage, I finally gave up and decided to live with the problem. That is until, I replaced my oil pan and in the process decided to put in a different oil pump. I've always run a Melling 55HV (high volume) and decided to put in a Melling 55 (standard volume) as I read so much about the HV pump being unnecessary and a HP drain. I also wondered if one other problem noted with the HV pump might be related to my oil loss--oil foaming. To my absolute amazement and delight, changing the oil pump stopped all oil loss!!! The car now uses very, very little oil, my plugs stay clean and my car has more HP as the oil is no longer diluting the octane rating of the gas. Case solved.
-
-
Re: C2 oil loss
Patrick -- interesting story -- thank you for sharing your findings with us. -
Re: C2 oil loss
Patrick -- interesting story -- thank you for sharing your findings with us.Comment
-
Re: C2 oil loss
I, too, have done the same thing with my 66 327/350. Upon the recommendation of my machinest, I used a Melling 55HV because of what he thought was exceessive side clearance of the rods. Oil pressure ended up being 90-100 lb on startup and 60-70 lb cruise, not to mention constant fouling of the plugs. Now that I have changed the pump to a standard volume, I expect to have resolved this problem.Comment
-
Re: C2 oil loss
I, too, have done the same thing with my 66 327/350. Upon the recommendation of my machinest, I used a Melling 55HV because of what he thought was exceessive side clearance of the rods. Oil pressure ended up being 90-100 lb on startup and 60-70 lb cruise, not to mention constant fouling of the plugs. Now that I have changed the pump to a standard volume, I expect to have resolved this problem.Comment
-
Re: C2 oil loss
Dan,
I have the standard melling M55 on my 327/300 and the oil pressure is about 15 PSI at hot idle and probably 40 at higher RPM. I too was concerned about rod side clearance when I rebuilt my 327/300 engine because I installed reconditioned rods. Memory tells me one set was about .020 but I am not sure how this would effect oil pressure and everything seems fine with the engine. I would definately go back the the standard volume pump. TimComment
-
Re: C2 oil loss
Dan,
I have the standard melling M55 on my 327/300 and the oil pressure is about 15 PSI at hot idle and probably 40 at higher RPM. I too was concerned about rod side clearance when I rebuilt my 327/300 engine because I installed reconditioned rods. Memory tells me one set was about .020 but I am not sure how this would effect oil pressure and everything seems fine with the engine. I would definately go back the the standard volume pump. TimComment
-
Re: C2 oil loss
I am using the Skat rods and the clearance is .019 to .020. As I said, I expect my problem to be resolved.Comment
-
Re: C2 oil loss
I am using the Skat rods and the clearance is .019 to .020. As I said, I expect my problem to be resolved.Comment
-
Re: C2 oil loss
What engine do you have in your '64? If it's the L76/L84, then it should have a high pressure pump, NOT a high volume pump. If the standard engine or L75, then it should have the standard pressure pump.
Did you find oil in your air cleaner housing? A thin misting is considered normal, but any visible droplets, and/or visible residue of oil beneath the bottom surface of the filter (providing you are using a modern replacement, and not the original foam type)is considered excessive.
Your valve seals/guides might be the culprit there. The high volume of oil to the valvetrain can cause excessive passage thru the valve guides. I also believe that the pre-PCV engines using .090" vacuum orifice at the carburetor would cause excessive scavenging of crankcase vapors under full vacuum (coasting, closed throttle). The PCV uses a spring loaded pintle to modulate the orifice size under these conditions.
I don't believe that the SBC has ever suffered from a lack of valvetrain oiling, but, rather, an abundance. The installation of a high volume pump would only exacerbate this. Better that you installed the proper pump.
Your engine could also have oil control ring problems, which would cause excessive oil consumption, while showing normal compression.
JoeComment
-
Re: C2 oil loss
What engine do you have in your '64? If it's the L76/L84, then it should have a high pressure pump, NOT a high volume pump. If the standard engine or L75, then it should have the standard pressure pump.
Did you find oil in your air cleaner housing? A thin misting is considered normal, but any visible droplets, and/or visible residue of oil beneath the bottom surface of the filter (providing you are using a modern replacement, and not the original foam type)is considered excessive.
Your valve seals/guides might be the culprit there. The high volume of oil to the valvetrain can cause excessive passage thru the valve guides. I also believe that the pre-PCV engines using .090" vacuum orifice at the carburetor would cause excessive scavenging of crankcase vapors under full vacuum (coasting, closed throttle). The PCV uses a spring loaded pintle to modulate the orifice size under these conditions.
I don't believe that the SBC has ever suffered from a lack of valvetrain oiling, but, rather, an abundance. The installation of a high volume pump would only exacerbate this. Better that you installed the proper pump.
Your engine could also have oil control ring problems, which would cause excessive oil consumption, while showing normal compression.
JoeComment
-
Re: C2 oil loss
Patrick, I really liked your story. Those hi presure or high volume oil pumps are one big waste for sure. I mean they cause boo coo problems. I always insist my FI customers use the Melling 55-stock version of the SB pump. If not I tell them they may experience FI distributor problems when the oil gets past the cheep seal and floods out the points. Not to meantion leaks. I mean if it doesn't leak its not a Chevy as Dick W says and for once he is right. And the fake pumps don't help. Go for the real deal.
Yes guys and girls forget the hi volume pumps. Duke and Joe L said this long ago I believe. John D.Comment
-
Re: C2 oil loss
Patrick, I really liked your story. Those hi presure or high volume oil pumps are one big waste for sure. I mean they cause boo coo problems. I always insist my FI customers use the Melling 55-stock version of the SB pump. If not I tell them they may experience FI distributor problems when the oil gets past the cheep seal and floods out the points. Not to meantion leaks. I mean if it doesn't leak its not a Chevy as Dick W says and for once he is right. And the fake pumps don't help. Go for the real deal.
Yes guys and girls forget the hi volume pumps. Duke and Joe L said this long ago I believe. John D.Comment
-
Re: C2 oil loss
Joe, The 63 to 65 hi HP Corvettes work fine with the Melling 55 pump. I mean they pass ops check and PV's with no problems. The hi-pressure pump on the FI cars causes a lot of oil leaks. See my other post. If my customer uses the hi-pressure pump and he or she has an FI distributor problem it is their baby. Been there. John D.Comment
-
Re: C2 oil loss
Joe, The 63 to 65 hi HP Corvettes work fine with the Melling 55 pump. I mean they pass ops check and PV's with no problems. The hi-pressure pump on the FI cars causes a lot of oil leaks. See my other post. If my customer uses the hi-pressure pump and he or she has an FI distributor problem it is their baby. Been there. John D.Comment
Comment