66 valve spring seals

[John F.]

Recently installed new valve stem seals to cure a small oil burning problem. Followed the service manual procedure including adjusting the pushrods afterwards, and installed new plugs. In trying to start the car, it sounds as though I'm getting no compression at all. Valve train is moving normally, and I'm getting spark, but engine just spools. Prior to doing this did not have any compression problems. Is it possible that the valves are not seating property or that the valve springs were not reinstalled correctly?

John Farren

[Thomas B.]

Re: 66 valve spring seals

John:
You say valve train moving normally - I'd guess not. Sounds like valves are not closing, or timing way off - open during compression cycle. I'd go back and recheck that the cam was off the lobe when you did your valve adjustment. Proceedure in service manual. If you are using the timing mark on the dampener and this is off then that could be your problem. You may want to check that the piston is at TDC when adjusting the valves for that cylinder. (Assuming you have not stuck a 30-30 in there)

[Duke W.]

Re: 66 valve spring seals

Maybe someone installed a mechanical lifter cam. Use of the hydraulic lifter adjusting procedure on a mechanical lifter cam will cause the valves to hang open and the symptoms you report.

Duke

[John F.]

Re: 66 valve spring seals

Tom - I think you were right. Went back and backed off the adjustment a few full turns and it cranked right up. Then went ahead and did the adjustment on the fly per the manual and everything seems to be fine. Although I followed the shop manual procedure, I must have just tightened them up too much. Thanks for the input.

John

[Thomas B.]

Re: 66 valve spring seals

John:
Great you got it running!- sounds like you do have hydraulic lifters but in your initial adjustment you got past the "range" of the lifter. Easy thing to do. For next time - if the manual you are using states that you tighten the rocker arm nut while turning the push-rod until it does not turn - that is where you can have problems. Especially if the lifters bleed down easily. You turn down on the nut and you think you feel resistance and then it goes away as the lifter bleeds down. "Weaker" lifters, that run okay, can do this rather quickly - enough that you may miss the beginning of the lifter range. You tighten down till you think you have it - and what you really have is all the slop out of the lifter. If you got a good hand, good feel (easier when the engine is out of the car) to see if you have pushed all the oil out of lifter you can try this, put the cylinder at TDC (using the service manual) and crank off the rocker arm nut until it is just loose. You should be able to press down on the push-rod side of the rocker arm and feel when you contact and then compress the spring in the lifter. The internal lifter spring may not provide enough force that it stops rotation of the push-rod but you can feel it with your hand. Tighten the nut just until it hits this first measure of resistance then another 3/4 of a turn should get the engine started.

Tom

[John F.]

Re: 66 valve spring seals

Tom - makes perfect sense. Thanks for taking the time to respond.

John