I finally got around to doing some diagnosis on my rough running 71. After checking the timing, I did a compression test. Compression was normal for cylinders 1 and 3, but 2 had 0 and 4 had about 30. I then did a wet test on number 2, and it remained at 0. As I understand it, this would make the valves the culprit. I was thinking if this was the case I could get away with just pulling the head. Any input? Also, I thought I read somewhere that once the head is off I could pull the pan from below and replace the rings and bearing in-frame. Anybody ever done this?
A mill designed for leaded gas commonly burns up (it's soft) valve seats when run w/unleaded. Unless you have an awesome set of tools you will probably need to send it off to a specialty shop and have new hardened valve seats put in, and have them rework the valves too. I've never tried your second question and have heard that you still have to undo the mounts and jack or lift the motor off a bit to get it done, but supposedly it can be done. Hopefully someone will chime in who has tried this.
Your second method isn't worth the trouble it would be a large hassle the transmission would also have to be backed of the block .much easier to pull the whole set or just the motor and clean up your block and get an idea of what u need
That's your best bet . If u have access to an engine stand that will help a lot on the rebuild there pretty cheap . Considering the relief it brings of being waste level with your motor
Harbor Freight, here we come. It's going to be interesting when it comes to parts. The Toyota Dealers no longer stock them, but I see a lot on Ebay. I'm hoping a machine shop will be able to source what they need.
