What makes a SBC consume oil?
Discussion
Rather than high jacking any other thread, here is another. I have been running an AS built 525 BHP motor for approaching 12000miles and have always consumed ‘vast quantities of oil’ for which I have generally come to accept as ‘normal’ after hearing and speaking to others.
But why is this the case?
I know, for me, a number of possible reasons:
1) I suffered a front oil seal failure early on which lead to oil being lost and distributed by the balancer around the engine bay. That was fixed but made very little difference to my oil losses.
2) Bore washing; My original carb based engine really did over fuel badly, now I have EFI that is sorted, yet I still use oil. Although I suspect that the damage has been done and the bores could benefit from re-honing.
3) Crankcase breathing; I have just purchased a PCV valve and am going to rework the breathing pipe work, up until now I have had an open system, with the usual ally catch tank.
So would anybody like to offer any other suggestions, why is a SBC more prone to oil loss compared to other LS engines, surely with the latest technology and materials a SBC can be made ‘as good’ as any other engine???
But why is this the case?
I know, for me, a number of possible reasons:
1) I suffered a front oil seal failure early on which lead to oil being lost and distributed by the balancer around the engine bay. That was fixed but made very little difference to my oil losses.
2) Bore washing; My original carb based engine really did over fuel badly, now I have EFI that is sorted, yet I still use oil. Although I suspect that the damage has been done and the bores could benefit from re-honing.
3) Crankcase breathing; I have just purchased a PCV valve and am going to rework the breathing pipe work, up until now I have had an open system, with the usual ally catch tank.
So would anybody like to offer any other suggestions, why is a SBC more prone to oil loss compared to other LS engines, surely with the latest technology and materials a SBC can be made ‘as good’ as any other engine???
Hello Phil, how are you doing?
You are indeed correct in your logic with regards to better modern materials etc. but I think that the route cause of this problem is that basically we are dealing with a motor that was designed over 50 years ago and although it has been constantly updated throughout it's long and illustrious life, the modern day SBC, in general, is asked to do more than it has ever done by way of being tuned and used for track work etc. and to that end I think that it is just too long in the tooth for what many latterday users are asking from it.
You are indeed correct in your logic with regards to better modern materials etc. but I think that the route cause of this problem is that basically we are dealing with a motor that was designed over 50 years ago and although it has been constantly updated throughout it's long and illustrious life, the modern day SBC, in general, is asked to do more than it has ever done by way of being tuned and used for track work etc. and to that end I think that it is just too long in the tooth for what many latterday users are asking from it.
Hi Steve,
I have only emptied the catch tank once and that was a waste of effort as it only had a very small amount of water with a dribble of oil in it. Some does make its way out of seals for sure but I can not believe very much. But how much oil do you need to burn before seeing blue smoke? I get through something like a litre every 150-200miles or so.
I have only emptied the catch tank once and that was a waste of effort as it only had a very small amount of water with a dribble of oil in it. Some does make its way out of seals for sure but I can not believe very much. But how much oil do you need to burn before seeing blue smoke? I get through something like a litre every 150-200miles or so.
I have been pondering the oil burning conundrum for a fair while now and the question I have is as long as your engine does not leave a slick beneath it every time it has stopped, is the fact that it consumes oil really that much of a problem? Sure, it is a pain to have to top up as regularly as some may find necessary but surely the burning issue other than the fact that modern day motors do not seem to consume oil at all, honestly, is it really a problem if yours does?
When I first started driving 26 years ago, it was a common sight to see folk at the road side checking their dipsticks and topping up the oil but these days, many do not even know where the bonnet pull is let alone how to check the oil level and indeed, even what to do or where the oil goes into the engine if needed.
This LS V SBC thing doesn't help matters either as all the + points of the modern engine that are constantly praised have all of us SBC owners willing our motors to behave in the same fashion, which of course, they can't.
Instead of trying to elevate our SBC's to LS status, how about trying to change our mental attitude towards them and try accepting their peculiarities and inherent down sides as quirks/characteristics of running the venerable SBC, what do you think?
If you are unable to alter your perceptions then maybe it is time to go LS?
When I first started driving 26 years ago, it was a common sight to see folk at the road side checking their dipsticks and topping up the oil but these days, many do not even know where the bonnet pull is let alone how to check the oil level and indeed, even what to do or where the oil goes into the engine if needed.
This LS V SBC thing doesn't help matters either as all the + points of the modern engine that are constantly praised have all of us SBC owners willing our motors to behave in the same fashion, which of course, they can't.
Instead of trying to elevate our SBC's to LS status, how about trying to change our mental attitude towards them and try accepting their peculiarities and inherent down sides as quirks/characteristics of running the venerable SBC, what do you think?
If you are unable to alter your perceptions then maybe it is time to go LS?
Lets not forget that the e39 M5 engine consuming 1 litre every 500-1000 miles is "in spec". My 540 (similar engine) uses NO oil.
The only record I have for my 350 shows I put 1L of oil in the course of one year - which sounds impressive, until I say that I only done 1000 miles in that year!
The only record I have for my 350 shows I put 1L of oil in the course of one year - which sounds impressive, until I say that I only done 1000 miles in that year!
GTWayne said:
^^^ Some left over Chinese food from the take away that we had last night, why?
you were sounding very "save the dolphins" and "world peace"......thought you must have chucked the leg over this morning. Over here in Hong Kong, "Chinese for breakfast" would mean exactly that..... I must say however that I usually prefer Thai.... and yes.... they are usually take aways.
This may sound off topic, but I can assure you that there's usually a fair amount of oil used.
Edited by crafty on Thursday 10th April 08:28
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