Expanding Valley Pan

Philth · Post by **Philth** » Wed Aug 18, 04 1:00 pm

Hello all,

Amongst my other problems at this years Nats (ok, cut the violins) one of them was the fact that my valley pan expanded until it touched the intake manifold. It also looked like oil sprayed out of the dipstick hole. This was noticed after the one run on the Saturday and the one run on the Sunday (after attempting to flatten it - don't mention the screwdriver). This has never occured before, even during previous years racing and various amounts of 'safe' street testing, even up until the Nats. The only difference between this year and last years Nats is larger rear wheels/tyres, manual steering, battery in the boot, and a higher pressure fuel pump regulted to 7.5 psi. Also, I raced this year with the air filter on, if that makes any difference. What would cause this to happen now? Would this be the result of me unknowingly racing a whole quarter without a water pump and boiling over, after my drive belt flew off at the start line? For reference, the PCV valve is new, the breather can is clear from blockages, as are the hoses from both to the carb and air filter. The piston rings are also new - gapped and fitted to almost perfect bores 1 1/2 years ago. I have noticed that the distibutor only has one weight spring for the mechanical advance.

Any ideas?

Pete · Post by **Pete** » Wed Aug 18, 04 1:21 pm

Cooking it could not have helped.

Ivor · Post by **Ivor** » Wed Aug 18, 04 1:45 pm

With that sort of crankcase pressure Phil, it has to be a PCV problem...stupid suggestion number six hundred and ninety two...the PCV valve's in the right way round isn't it? 8)

Dave-R · Post by **Dave-R** » Wed Aug 18, 04 3:15 pm

Ivors right and I think I have mentioned it to you before Phil (you must listen to your Uncle Davey

) it has to be crankcase pressure and that means either the PCV system is at fault somehow or you have excessive pressure getting past your piston rings.

I think it is most likely the PCV system because if it was working even ring blow-by would not be a huge problem unless it was very bad indeed and it would be hoying oil oot the exhaust if the rings were shot anyway..

Philth · Post by **Philth** » Wed Aug 18, 04 4:17 pm

Well, the PCV is new and on the right way round (but worth mentioning anyway!). As said, it's not caused me any troubles up until now and I haven't altered anything in that area (just checks) since I rebuilt the engine 1 1/2 years ago. I don't think it's the rings as I'm not blowing blue smoke. As Pete said, cooking it at high RPMs probably didn't help at all and it was after that run that it happened. The engine still runs sweet, has a constant (but low) vacuum reading, good oil pressure throughout the range and doesn't overheat at all (when the belt is in place!).
Anyone else have/see this? I know Steve Case has written about it but I thought that was a backfire. I think as a matter of course I'll replace the PCV valve and breather can anyway, uncles Dave and Ivor!

Dave-R · Post by **Dave-R** » Wed Aug 18, 04 4:25 pm

Take the valve and breather off and blast the car up your local 'strip' and see if the problem is gone.

Kev · Post by **Kev** » Wed Aug 18, 04 6:04 pm

Then pop it back on for your return pass. If it pops, you hit the jackpot!

Kev · Post by **Kev** » Wed Aug 18, 04 6:05 pm

When I had a broken ring (top and bottom) there was considerable smoke from the breathers, but nothing major like blowing them out.

Matt · Post by **Matt** » Thu Aug 19, 04 2:48 pm

Happened to me - the flapper valve on the RH exhaust manifold stuck closed, diverting the entire exhaust from the RH bank through the heat riser passage in the intake . The intake gasket held for about 20 mins at 60mph, then a loud bang, & my oil breather was chasing me down the M20. Looking under the hood , the valley pan was right up there under the manifold.

Dave-R · Post by **Dave-R** » Thu Aug 19, 04 3:18 pm

First thing I did on my Challenger was cut that valve out and weld or braze the holes up. I was lucky in that on my previous car that valve had jammed in the full open position.

Phil has those nice TTI headers (flash git

) so that can't be his problem.