Timing


[Follow Ups] [Post Followup] [Dodge Power Wagon Forum]


Posted by Sherman in Idaho [72.47.9.37] on Friday, September 28, 2012 at 12:04:46 :

In Reply to: Re: Back to work posted by Kaegi [24.16.253.154] on Friday, September 28, 2012 at 11:20:48 :

I never had the timing cover off. The Plymouth engine had compression numbers written on the block next to each cylinder by the previous owner. I assumed the timing gears were on right and the compression numbers were valid. Two or three valves were rusty, so I de-rusted them and ground them in place using grinding compound and a drill. They may not be sealing as tight as they did back when whoever did the compression test. I could check the compression easy enough, but what would I do about it if it was low? Oil pressure is 40 psi cold at idle, which was very encouraging. Timing pulley and timing cover are civilian, but the pulley might be off of the old engine. I mixed parts as needed to make one good engine.

First I thought I had the oil pump in one tool off from where it should be, and that was why I couldn't get the points to be opening just as the timing pointer was pointed at the TDC mark. I was all set to take off the oil pump and move it one tooth over, but then "just to be sure" I stuck a wire in the test hole on the #6 cylinder and found that TDC according to piston position was not at the TDC mark on the crank pulley. So, I made a mark on the pulley to match the pointer, and timed it to that. The only logical explanation is the timing chain/gears are wrong, but would it really run that well with the gears ~20 degrees off from where they should be? I don't know why I didn't verify that the crank and cam had the right relationship while I had the engine mostly apart. It appears to fire on all cylinders, just not all that evenly. Once it's warmed up, I can idle it really slow. It does burn some oil (blue smoke), but timing wouldn't cause that. I didn't take any pistons out, because the cylinder walls had no rust or other damage, despite the rust on a couple of valves, so I don't suspect stuck or broken rings.

At this point, it probably is what it is. I'm not going to take all the front stuff off to get to the timing chain and verify it. Maybe there were different crank pulleys that were "clocked" differently depending on the application and I have the wrong timing cover for the pulley. I should compare all my old ones. My only concern is it has a bit of the lopey, wheezy sound that the old engine did, and that one ended up getting worse and worse until it threw that rod, so I wouldn't want to be ruining something. On the other hand, this one idles much slower, starts easier, and has more power. Could an engine really run pretty decently with the cam timing 20+ degrees off from where it should be, and with the spark timing set to the crank timing?

A funny thing I just noticed on the blown engine is on the head, the cavity in the head for the #1 cylinder only (the one that failed) is scalloped all around the edges, with the scalloping going in far enough to be well under the edge of the head gasket. I had saved the head, thinking it was good, but it obviously isn't. I can't imagine what would erode a head like that. The top face of the block and the cylinder liner were fine. I still have it in the scrap pile and double-checked.



Follow Ups:



Post a Followup

Name:
E-Mail:
Subject:
Message:
Optional Link
URL:
Title:
Optional Image Link
URL:


This board is powered by the Mr. Fong Device from Cyberarmy.com