[Healeys] excess oil consumption

[Bob Spidell]

I've had a PCV valve installed--the 'Nock Kit'--on my BJ8 for years; 
maybe 40K miles or more.  It reduced oil consumption from 1qt/1,500 
miles to 1qt/3,500 miles or so (highway miles, consumption is a bit more 
for around-town miles).  There is no downside that I know of; others 
have reported gunk on the rear intake valves.  I'm contemplating an 
engine rebuild; will find out then.

I think 6qts/4,000 miles is way too much for a freshly rebuilt engine.  
Your friend could remove the vacuum dashpots--the big dome on the 
carbs--and check for oil residue.  If the rear is worse than the front 
carb it would confirm oil is getting sucked into the rear carb.  Does he 
have any leakage around the valve cover?  That would indicate the 
crankcase is getting pressurized.  Is he dripping a lot of oil?  Is it 
leaking from the timing cover seal?

Bob

On 7/9/2015 3:59 AM, Mitch Simmons wrote:
> If u have a pcv installed as per the Nock s version. What are the 
> negatives? will it suck oil into the intake? Could there be too much 
> vacuum and harm seals gaskets etc. ??     Mitch. 66 bj8
>
> Sent from my iPhone
>
> On Jul 8, 2015, at 2:36 AM, Oudesluys <coudesluijs at chello.nl 
> <mailto:coudesluijs at chello.nl>> wrote:
>
>> 6 quarts over 4000mls does not sound to bad for an old design British 
>> engine. It also depends how the rebuild was done.
>> The main reasons for oil consumption, apart from leaking, are wear of 
>> bores/pistons/rings, valve guide wear and blocked/dirty crank case 
>> breathing system.
>> Check and clean the crankcase ventilation system first. Check for 
>> wear in the valve guides. Check the compression with a hot engine.
>> That the engine was professionally rebuild does not mean anything, it 
>> depends who has done the job. It is also peculiar that after a 
>> rebuild a few years ago, a ring job was needed not so long ago!!!!!?????
>>
>> Kees Oudesluijs
>>
>> It is very unlikely that the air filters have something to do with 
>> the oil consumption. There is no vacuum to speak of created there, 
>> unless they are totally blocked or are absolutely tiny.
>>
>> ^qwarthodson at aol.com <mailto:qwarthodson at aol.com> schreef op 8-7-2015 
>> om 1:55:
>>> A friend ask me to post the following question about excess oil 
>>> consumption on this forum to see if anyone has any suggestions.
>>> I know the engine has been professionally rebuilt a few years ago & 
>>> the compression & leak down tests recently looked "normal". No oil 
>>> leaks.
>>> Thanks,
>>> Gary Hodson
>>> I had a brief conversation with my mechanic the other day and in the 
>>> next couple of weeks he will do a complete diagnosis on my Healey to 
>>> try to identify why I have had so much oil consumption.  FYI, I just 
>>> emptied the 6^th quart of oil into the engine yesterday – and that 
>>> is over 4,000 miles.  It is better than before the recent ring job, 
>>> but nonetheless, is not acceptable to me.
>>> Mechanic thinks the oil loss might be due to combustion of the oil 
>>> from the back air cleaner that is plumbed with the valve cover.  
>>> He thinks the air cleaner I have on it now is somehow creating a 
>>> vacuum pulling oil from the valve cover and injecting it back into 
>>> the piston and is actually burning the oil off very efficiently.  I 
>>> still don’t have any signs of leaks beneath the car nor any smoke 
>>> from the tailpipe.  Quite possibly the current Cooper air cleaners 
>>> are too small and are creating this vacuum.  The Cooper air cleaners 
>>> replaced some other chrome air cleaners the original owner had on 
>>> the car – I don’t know if it was original equipment.
>>> Will you do me a favor and see if anyone else had a similar issue 
>>> with oil consumption to identify a “solution” that worked for them?  
>>> Maybe there are other thoughts that we should ask my mechanic to 
>>> examine as well.

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