Engine Woes

Most engine builders and mechanics familiar with VW aircooled engines regard the front of the engine as where the flywheel and clutch are, as that is toward the front of the car. The exhaust is at the back. Even when the relief valve has the cooler blocked off, I believe there is still a trickle of oil passing through it, so it shouldn't be empty. This leads me to believe you have the wrong oil cooler seals installed? And yes, the pump/filter combo should work; the small passages in the cover can't pass the volume of oil the gears can push above 6,000rpm and this can break/damage the drive tang, but below this rpm they're fine.

The chambers and piston tops will always have some carbon on them; are you sure the jetting is not rich? If you do new rings, are you going to rehone the barrels? I should have asked at the beginning- how old is this build? Sorry I don't have more definitive answers. Al

Just watched your video. Pretty good animation- as I said before, when the engine is cold, oil still trickles through the cooler; there's just not the pressure to force it through.

Alb, the original build was 20 years ago and then parked with 882 miles on it and last year before Carlisle I tore it apart honed the cylinders and installed new bearings. The cylinders did have some pitting but on the bottom side from sitting but I thought they would be OK, perhaps not.

I fought with some carb issues early on( Dell drip on the 3/4 side)( ended up float level)) but did have a nice burn on the spark plugs for awhile and throttle transitions were fine.

The carbon soot showing up on the crank in the balance holes led me to blow by but rich running could do it as well? As far as the cooler goes,I can  blow air through it while its mounted to the cooler stand and I was using the orange seals with kind of step in it. Wrong seal?

thanks

Pics

I agree it shouldn't be empty. Though the bypass valve never blocks the cooler passage, instead it blocks the main galley when the oil is hot. The path from the oil pump through the cooler is always wide open (both on dual-relief and single-relief cases), but when the bypass valve opens with cold oil or overpressure, most of the oil goes through the main galley. This make the pressure on the input and output of the cooler nearly the same so as you said there is little oil flow through the cooler.

I'd be concerned that there's something plugging an oil passage in the case if the cooler is dry after starting the engine. I suppose a missing bypass valve could potentially dump enough oil that it'd leave an air bubble in the cooler, but your oil pressure would be so low that the warning light would be on at least until the engine seized. From your pictures it doesn't look like the gaskets have been crushed so I'm not sure what else to point to that might cause that. Have any mods been done to the case?

Tapping the case and using a conventional full flow filter system is always a good idea; a 26mm pump takes less hp to turn, creates less heat (so I'm told), and will give more than enough pressure. Do you know about blueprinting the pump? What weight oil are you using? When the engine is warmed up, what's oil pressure at idle? 2,000rpm? 3,000rpm? 4,000? 5,000? I know these questions probably have nothing to do with the cooler being dry, but sometimes rambling on comes up with something...Al

PS- Here we go- You said you drilled and tapped the case to clean all the galleys; did you check that none of the plugs went in too far and blocked off an oil passage? Where are your temp and pressure sensors? Is it possible a fitting is seated to deep and blocking off the passage right before the cooler? 

Reading your first post again, have you measured the barrels (or had them measured) to confirm they're still round and in spec? If they're deformed, a light hone and new rings won't do it and the solution is a new p/c set.

ALB, I ordered new cylinders because of the pitting and pistons checked out OK.The whole motor in total has about 1200 miles on it with the first 882 being before the last tear down last April. The original chrome rings I think were a lot the problem and I just reused them the last time around. The old saying "Penny wise pond foolish" and 20 years ago they were the thing.

I'm using 10/30 dino oil and my pressures were running the 10 PSI per 1k RPM rule pretty much and even when it got hot 230 degrees the OP light stayed off at idle. My temp sensor is at the front of engine on the return side and runs true to the gauge as verified with the candy stick in the oil filler tube. The pressure is being read from the top just behind the distributor where the OP light switch is.

As you suggested I'm going to pull the plugs this weekend and clean and measure depths again. I'll be tapping the pump for full flow so I'll clean it up (ports) when I do.

Thanks for the input.

Update on oil issue/overheating.

Opened the case up and took out all the galley plugs and found one that sits in line with the relief piston perhaps a little close. I sanded the plug down a bit just to add more clearance.The relief piston was sliding up and down freely but when the case warmed up it could have been an issue.

My shop mate cleaned up the case once again as the aviation sealant emulsified when I had the initial carb drip and gas got into the the case.

I'm still waiting on jugs,rings and bearings, wish we had a parts house here in the east.

That's one clean garage! Garage envy...