Just pull the head... takes 30 minutes extra and you can clean all the carbon off the back side of the valves. I have never taken apart a 200/250 with bad valve seals that didn't have tons of carbon on the backsides of the valves, from the oil burning. Also, with cars of this age, it makes no diffrence how many miles are on the engine. The valve seals just dry out and crack from being old. The below pictures are what the valves and seals from my 30,000 original mile 200 looked like. The engine came out of a '71 Grabber that had been in storage since the late 70's, then pulled out of storage in 2003 and drove for about 2,500 miles before the owner decided to put a V8 in it. I personally pulled the engine from the car, and know the mileage to be correct. It still had the original PCV valve, radiator hoses and Autolite fan belt on it! After cleaning and relapping the valves in, and installing new valve seals, the engine runs great with no more smoke. So with cars of this age, I really wouldn't use the condition of the valve seals to determin what condition the rest of the engine is in.
great post, pretty much changed my whole perspective on this. thanx 4 the pics too, how would i go about cleaning the valves? dremel tool with a wire brush, or soaking them in some sort of solvent? thanx 4 the advice
I used a medium scotchbrite wheel in our 47 year old drill press. Worked good for me. A wire wheel would probably be faster.
you can change them if you want to while they are on the engine. you need to get a spreng compressor that only works from the top. not one of those ones that holds the valve in place and then compresses the spring. secondly you will ethier want to get an adaptor and use a compressor to compress your cylinder so the valve doesn't fall down into the cylinder. or you could just make sure that the piston is at the top of the cylinder then hopefully the valve wont drop too far into the cylinder champer. if the valve drops in you will then have to pull your head off.
Installing head Ive got a couple of questions dealing with the head of my 72 Mav. I have 2 different size of push rods , 6 of them being a bigger diameter of the others and when i pulled the head i never noticed untill now , can anyone of you help me? and tell me which size rods go into which place.
diameter of p-rods The diameter really won't/shouldn't make any difference, but the length sure will. Are any of them longer than the others? You may also want to post what engine you're working on with your questions.
Im sorry but I have to give props to (scooper77515) for that reply to cylinder flossing... that was great! haha
Then those six aren't original. All 12 should be identical. If they are all the same length, then it shouldn't matter where they go back in at. Personally, I would just put all the ones of same diameter on the exaust valves, and all the one so the other diameter on the intake valves, just evenly distribute them. If you have problems, you can still buy new push rods for these engines. Kind of pricey though from what I remember.
i think the O.D. of the rod doesn't matter (on a 6cyl.) the size of the ends of the rod are my concern. they should be the same. ... ...
speaking of rods, my dad says some of them are bent and some or looser than others...i plan to replace the asap, any long term effects on the engine from minor length variances...or power difference due to the length variances
