911t wet sumping
 

Hi,

I'm a 911 nubee...

I just bought a 1970 911t that wet sumps (5 quarts in 4 days)...
Does anyone now why.

Re: 911t wet sumping
 

Maybe it's me that doesn't understand but are you saying that you adder 5 quarts in 4 days???

You are aware that you check the oil with the engine runing, to temp (around 180deg) on a level surface?

Marc-André

Explain exactly what you mean Henry …

Explain exactly what the car is doing (how and when you are reading the oil level)

... and exactly how you respond (what the oil level is reading, and when you read it... and where and when you put the oil in) …

Beleive it or not, all these factors make a BIG difference...

May be with a little more information we can help …

Cheers,

1970 911t wet sumping
 

When I let it sit for 4-5 days there will be 5-6 quarts of oil in the sump if I drain it... The problem is that that much oil fouls the plugs before it can get pumped back to the tank...

911t wet sumping
 

If I drain all the oil (tank sump and filter), install a new filter and 8 or so quarts in the oil tank the car starts and runs OK (oil pressure and oil tank level on dash are fine). If I let it sit for 4 or 5 days 3/4 opf the oil drains into the sump and fouls the plugs on startup...

Re: Re: 911t wet sumping
 

If I drain all the oil (tank sump and filter), install a new filter and 8 or so quarts in the oil tank the car starts and runs OK (oil pressure and oil tank level on dash are fine). If I let it sit for 4 or 5 days 3/4 opf the oil drains into the sump and fouls the plugs on startup...

the draining of the oil into the sump is normal. The oil is pumped into the oil tank pretty quickly after you start it. When the plugs foul how far and what type of rev's are you running?

1/2 mile at 2500-3000 rpm

How do you know its the oil that's fouling plugs? ARe they oily? could also be incorrecly tuned carbs on idle circuit or very likely a weak ignition system caused by bad grounds to the contacts. Check these. The oil should not be getting into the chamber and fouling plugs. It could be that your rings are worn.

you're probably sooting the plugs from too much fuel. you didn't mention any white smoke, which would be billowing out the tailpipe if there was that much oil in there fouling the plugs, so it's probably not an oil issue.

What John said.

Also, your car should have Zenith carbs (not the best) i would start there by having a good Porsche mechanic check them out.

Paul

Thanks for all the help...
You are right, John Walker. There is not white or blue smoke coming out when it happens.

I took the Zeniths apart and cleaned them, checked the float level on both, set the mixture screws to the manual "start" settings and assumed it would run well enough to start tuning the carbs but it does not...

Does anyone know of any common problems that would cause both banks to be over rich???

too much fuel pressure blowing the float valves off their seats, 3# is normal, idle jets too big, .55 is normal, mixture screws turned out too far, turn them in until the idle starts to drop and then out until it just recovers and runs smoothest. poor ignition not firing the fuel, plugs too cold, try bosch platinum WR9DP. i'm not a big fan of these, but the tips generally stay clean enough to fire for a reasonable time in a rich running situation.

Just as a matter of interest...a 911 with a front oil cooler holds about 13 qts of oil....about 3 more than a car without a front cooler.

When you change the oil from a *warm* engine ( preferred) from a 13 qt car....about 6-7 qts will come from the tank and about 3 qts from the engine case. About 3 qts stays behind. If the car sits for a long time and you change the oil...the numbers almost reverse ( closer to 6 from the engine and 3 from the tank).

---Wil Ferch

Wil,
Thanks,
I'm used to 60's Triumph mototcycles where the total = 4 quarts and 1 quart might leak into the sump over the winter...

...because the other three are already on the floor.

Actually I have a '67 TR6C (so I'm authorized to jest), and just wondered the same thing for the same reason about my new '72 T; gotta love the intertubes.