Oil consumption
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Oil consumption
Hello all
I dont know if I have a problem or not, but my motor is burning a bunch of oil. For every time I fill the gas tank on my '70 350, I need to add a quart of oil. My engine is still very new, so far I have put about 900 miles on it. My builder told me it would put out about 400-450hp, and I do believe him, this thing is fast. I still havent had it over 4000RPM, but I do drive like a maniac on occasion. I'm 21, what do you want me to do? From of stop, if I launch it I can look in the rearview and see a small cloud of smoke (no, its not from the tires), and I dont have any leaks under the car. What could be my problem? Is it because my engine is still breaking in? I am in the process of installing a new ignition system, It is kind of hard to work on when I live 2 hours from my baby most of the time, but next time I am back in the hometown I will finish it. As of now, it still has the original points type distributor in it, and the car is running a bit rich. Any insight would be greatly appreciated.
Joe
I dont know if I have a problem or not, but my motor is burning a bunch of oil. For every time I fill the gas tank on my '70 350, I need to add a quart of oil. My engine is still very new, so far I have put about 900 miles on it. My builder told me it would put out about 400-450hp, and I do believe him, this thing is fast. I still havent had it over 4000RPM, but I do drive like a maniac on occasion. I'm 21, what do you want me to do? From of stop, if I launch it I can look in the rearview and see a small cloud of smoke (no, its not from the tires), and I dont have any leaks under the car. What could be my problem? Is it because my engine is still breaking in? I am in the process of installing a new ignition system, It is kind of hard to work on when I live 2 hours from my baby most of the time, but next time I am back in the hometown I will finish it. As of now, it still has the original points type distributor in it, and the car is running a bit rich. Any insight would be greatly appreciated.
Joe
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: Oil consumption (JoeRags)
Yes, you have a problem. Did the builder sell you a complete engine? If so, bring it back ASAP and have them fix it. If not, eliminate anything you did as the problem (ie intake manifold gasket) and then bring it back.
Pro
Joined: May 2001
Posts: 608
Likes: 0
Re: Oil consumption (JoeRags)
I had some oil consumption issues with my rebuild at first also, but I was unable to spot a cloud behind my car. In my case, I had the shop build me a shortblock, and I assembled the rest.
The majority of my leakage was onto the ground, but I also was fouling the plugs. I personally can blame myself for 95% of the leak problems, with the exception of the shoddy umbrella seals that came with my heads.
I'd get in touch with your machine shop and insist that they look into the problem, and take your car to them and have them figure it out.
Just in case this is something serious, you should refrain from joyriding her until this gets fixed.
If you've got the time, remove a sparkplug, and see if it is wet with oil.
I'm no pro, but in my eyes, there are only 3 major ways to have oil in the combustion chamber - bad intake seal from either milling the heads or block and not machining the angle of the intake to match, leakage through the valve guides due to worn guides or bad valve seals, or finally, it might be an issue with the rings.
Good luck, and please, get this taken care of, this just might be the tip of the iceberg, and fixing it now can save you lots of headache in the future.
The majority of my leakage was onto the ground, but I also was fouling the plugs. I personally can blame myself for 95% of the leak problems, with the exception of the shoddy umbrella seals that came with my heads.
I'd get in touch with your machine shop and insist that they look into the problem, and take your car to them and have them figure it out.
Just in case this is something serious, you should refrain from joyriding her until this gets fixed.
If you've got the time, remove a sparkplug, and see if it is wet with oil.
I'm no pro, but in my eyes, there are only 3 major ways to have oil in the combustion chamber - bad intake seal from either milling the heads or block and not machining the angle of the intake to match, leakage through the valve guides due to worn guides or bad valve seals, or finally, it might be an issue with the rings.
Good luck, and please, get this taken care of, this just might be the tip of the iceberg, and fixing it now can save you lots of headache in the future.
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Re: Oil consumption ('75 383 ElkGrove)
Thanks for the input guys, I called my engine builder this morning about the problem. Im an idiot and have been putting synthetic oil in when its low. He says if I go back to petroleum based it should take care of the problem. I'll probly just drain it all and fill her up again with new oil.
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: Oil consumption (JoeRags)
Thanks for the input guys, I called my engine builder this morning about the problem. Im an idiot and have been putting synthetic oil in when its low. He says if I go back to petroleum based it should take care of the problem. I'll probly just drain it all and fill her up again with new oil.
Find a new builder.
My guess on your oil consumption is either a ring (or rings) were installed upside down, you have a big leak at your intake gasket, or the PCV is sucking a huge amout of oil into your carb.
I would still bring it back and have it made right. No properly put together engine burns 1 qt per 200 miles (about 1 tank, right?). Never, not with syn oil, not during break-in, not ever. Something is wrong.
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Oil consumption (JoeRags)
Here is a thought... I have a relatively high oil consumption on my engine.. Oil gets sucked through the intake gasket.. The reason is that I didn't use the intake that came with the engine.. I installed another intake.. The reason for the leak is simple.. My engine block was zero decked.. and the intake that I added was not cut to match the block.. Therefore - it's very difficult to make it seal good.. I didn't know about that when changing it.. I found it out later.. Cutting the intake isn't cheap but oil is...... It hasn't affected the performance of the engine.. so I didn't care...
Do you know if your engine block was decked?? If your block was zero decked and you didn't have the intake cut - you will very likely get some serious oil consumption...
[Modified by GrandSportC3, 4:41 PM 10/17/2003]
Do you know if your engine block was decked?? If your block was zero decked and you didn't have the intake cut - you will very likely get some serious oil consumption...
[Modified by GrandSportC3, 4:41 PM 10/17/2003]
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: Oil consumption (GrandSportC3)
Olivier, what makes me think it's not the intake is that he is seeing smoke at WOT. Under these conditions, there is no intake vacuum, so this is when the consumption would be the least. You would see the smoke under deceleration and cruising when the intake vacuum is the highest.
I have the same problem as you, but I fixed the intake leak by using a very small amound of Ultra Black RTV on both the head side and intake side of the gasket. I have pulled it after 5k miles and have verified that I'm no longer consuming oil there. I'd be really worried (and I am as I burn 1 qt per 600 miles) about burning any considerable amount of oil as it WILL gunk up the combustion chambers and backs of valves and that WILL lead to performance problems (and possibly detenation), not to mention that burning oil decreases the octane of your burned mixture in comparison of what it would be without any oil.
I have the same problem as you, but I fixed the intake leak by using a very small amound of Ultra Black RTV on both the head side and intake side of the gasket. I have pulled it after 5k miles and have verified that I'm no longer consuming oil there. I'd be really worried (and I am as I burn 1 qt per 600 miles) about burning any considerable amount of oil as it WILL gunk up the combustion chambers and backs of valves and that WILL lead to performance problems (and possibly detenation), not to mention that burning oil decreases the octane of your burned mixture in comparison of what it would be without any oil.
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Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Oil consumption (BeaterShark)
Olivier, what makes me think it's not the intake is that he is seeing smoke at WOT. Under these conditions, there is no intake vacuum, so this is when the consumption would be the least. You would see the smoke under deceleration and cruising when the intake vacuum is the highest.
I know for a fact that my problem is at the intake gasket.. It was just a guess that his problem was there too.. It also depends what color the smoke is.. If it's smoking black during acceleration - he might run too rich.. but if it is blue or grey - it's the rings... :(
[Modified by GrandSportC3, 4:59 PM 10/17/2003]