Actually getting the OS2 rings from FCP Groton. They are .40mm or .015in. oversized. I'm not sure yet if they are regular steel or chrome. They are $95 for the set, which is what rings are worth. None of the auto parts stores even had a listing for them and the dealer was coocoo for coco puffs at $60 per cylinder.


http://www.fcpgroton.com/product-exe...es_for_fitment

 

get a compression gauge from a store. remove the spark plugs, and undo the coil plug. its a two person job with out remote start or a long tube.

screw the gauge where the plugs, and turn the ignition key to crank untill you see the gauge holding. move to the other plug hole..

push the throttle open for faster compression build.

 

Thanks. I guess I should check my compressions on all of my cars.

 

Well, I got all the parts in yesterday and the engine is built and ready to go back in tomorrow. The total bill comes in at less than $600 with parts and machine shop costs. The only machine shop work was milling the head and cleaning the block and head.

The crank journals were perfect as well as the rod and main bearings. The pistons showed no signs of wear and the bores had minimal wear. The ring gap of the stock rings measured .021 in. so I got new cast rings from Hasting in .010 in. oversize and cut them down to a gap of .016 in.

I replaced the one exhaust valve, which was the main culprit, and lapped them all.

Of course, new head and rod bolts, head gasket set and all lower end seals and gaskets.

I had already replaced the timing belt but I went ahead and replaced the t-belt tensioner pulley and idler pulley. The water pump feels as new so I re-used it.

I picked up a pair of NA cams but I put the turbo cams back in. Before, the engine only had 100psi of compression due to the carbon buildup on the exhaust valves and they all leaked when I poured water in the exhaust ports. This is why that exhaust valve burned a hole in the side of itself. I am curious to feel how the power feels stock. Also, there is a Porsche shop next door that has a dyno and I want to dyno with turbo cams and then with NA cams to see what the actual difference is.

 

Awesome! Congrates.

hope it goes smoothly for you

 

I stayed up till 3am finishing her up and she purrs like a kitten!

 

Cool

Looks good. I spent quite a bit more than that just doing a head gasket on mine a few years ago. I bought everything from the dealer and they don't even have a gasket kit, so I bought each one separate.

 

That's a clean looking engine for sure. Lucky it only destroyed one valve!

 

I have an 850 block I'm planning to rebuild, and it needs to be bored due to high mileage cylinders being out of round. I was searching for info on oversized pistons and found this thread, and I've got a couple questions.

First, you mentioned that your pistons and cylinders were both in spec, but you were getting oversized rings. I've never heard of oversized rings (except to fit an OS piston), and I can't imagine why you'd use them on a stock piston. I would guess you would need an OS ring in a cylinder that's been bored, but if that's the case wouldn't using a stock piston in a bored cylinder cause piston slap? I'm confused on several levels. Can you clarify what you ultimately ended up doing?

Second, did you get a chance to do the dyno run with the turbo cams and the N/A cams, and if so what were your results?

Thanks