What a relief..!

Yes, it's been referenced before dear readers but it's time for some relief. The dreaded oil pressure relief valve thing. You may remember that I've already managed to clonk the current sump (hereby referred to as Oil Pan. It's an American thing) on a speed hump on our road (unadopted before anyone calls me out re road tax, IVA, legalities etc). Now this wasn't helped by the suspension naturally settling down a bit and me not noticing, but the original pan is very deep too.  

So the task is this. Remove the Camaro LS pan (known as muscle car pan) and replace it with the Corvette LS pan. Which oil half the depth (has a bit less oil capacity but the internal baffling is better to prevent oil starvation) and therefore is a much better option for speed bumps. The maximum allowable in the U.K is 4 inches.

 

However. Here's the big but.

 

Because I'm using the clever shut off 4 cylinders when cruising and variable valve timing engine with some more complicated and sensitive innards, the Camaro pan has an oil pressure relief valve embedded within it (in addition to the one be the oil pump) to help regular oil pressure. 

 

The Corvette one does not.

 

 So the first job is the drain the oil and remove the old oil pan... and then try and work out where the oil pressure valve feed point is in the oil circuit.

 For reference this above is the lovely (clean) new Corvette pan. Whilst below this is the lovely not so clean Camaro pan. Now even a 4 year old would be able to play spot the difference here. Yes, that cheeky upstanding cyclopsy cylinder is the oil pressure relief valve.... and it's mounted on a lot more aluminium than is available in the Corvette pan. A challenge.

And below, said relief valve as extracted from it's initial home. Of course, I could throw caution to the wind and say it won't be needed or I'll stick with the hump clumping old pan but neither option really in my nature... nor to I want to blow the internals the first time I press the loud pedal on the open road.

 

 

 Above you can see where the valve feed needs to come from, effectively the outer chamber - anywhere from within there as the oil filter seal seats against the wider flat ring, so anywhere inside that should do the job. The main thing is how to angle and position to get enough thread to seal and hold (and this is in soft aluminium remember) and also how NOT to get the top of the valve which protrudes into the crankcase, to get hit by the first turn of the crank! Much geometry and problem solving ahead I think.

 So, the good news is this; given that the oil pans are both designed to fit onto this engine block and that the bolt patterns and overall design where the pans meet the engine is identical, with a bit of triangulation I'm able to transfer the position of the valve from the old pan to where it would be in the new one.

 

Therefore as long as the seating of the valve is in that position window and preferably lower then I should be in with a shout of getting this right first time. 

 

Above I drilled and tapped a pilot hole to accept a bolt which I then used as a test to ensure that with the right height of the valve etc that all was positioned correctly. Below shows this clearly.

 

Then it was over to my friendly car enthusiast engineer neighbour's workshop to drill and tap to the right size and mill a flat shoulder for the valve to seat down on. No photo of that though, I forgot.

 

With a new oil pan there is a need to fit the corresponding accessories such as the oil pickup tube, dipstick and most importantly the windage tray which stops the oil pan turning into a giant food processing when all the rotating gear is whizzing round at 5500rpm. This helps the oil collect in the pan where the pickup grabs it for the next journey round the engine as opposed to it trying to suck up bubbles from a maelstrom... we all know that sound children make with straws at the bottom of a glass don't we?

 

The windage tray fitted the only way to test the valve position is with the oil pan fitted too. This of course presents a challenge around being able to actually observe what's going on. Here's where a smart phone comes in. Equipped with a handy video camera, light and being small I shut my phone (mostly in a bag to protect from dripping oil) in the bottom of the engine, bolted it up and turned the crank over by hand a few times to record the view... and from the above you can se a bit of interference of the valve (mid rhs) against the windage tray.  Thankfully there was plenty of clearance against the crank which was my main fear so it's all good.  

 Surgery time it is then...

 Avoiding getting any stray particles on the tray I opted for the operating theatre look for the windage tray (and as we know operating theatre staff have all sorts of footwear so my old trainers fit the part too :-) 

Shot of bottom end above before windage tray went back on. Lots of metal to spin round very fast. 

 Above, windage tray, oil pickup and new dipstick (lhs) fitted.

 Finally new oil pan on... and introducing the duct scoop... bottom of the bell housing now protrudes below the oil pan. I've made a small aluminium angle shim cover for that and it's all buttoned up.

 

Thankfully that's a big and potentially difficult job done - engine runs fine so on to the next thing.