My '72 250 is back on the road - Thanks for all the help!
 

I have had numerous setbacks along the way, but I am pretty impressed with myself (ha!) - I finally got the thing running. I have put over a 100 miles on the car and it runs great.

If you remember, all of this started because of a SERIOUS smoking problem that steadlily got much worse - over a period of years. Initially it smoked when I started it but then it smoked all the time and really heavy under acceleration. Did all the compression tests and leakdown tests and while things were not terrible there was always a problem with a cylinder or two. So I started by pulling the head and taking to a guy here in OKC. He pulled it apart and did the valves for me and put in new exhaust guides - intakes were fine - and said that while the head was contrbuting to my trouble he was convinced that I had a problem in the block as well. So I pulled the engine and replaced the following:

Main bearings
Connecting rod bearings
Piston rings (honed the cylinders lightly)
4 new gears (crankshaft, camshaft, intermediate, timing gear)
Timing chain (still had the original chain)
Rear crank seal
Front crank seal

Among various other parts.

Had some trouble getting the carbs adjusted and balanced but now it is running great - no smoke and plenty of horsepower.

Only 2 concerns, one of which is unavoidable. I still have initial acceleration hesitation, not too bad but noticeable. I have a Crane ignition and none of the speed relays and emission stuff work. I have (even prior to this rebuild) spent considerable time fine tuing the timing and playing around with using and not using the vacuum advance and retard. Currently, I am running the car at 8 degrees BTDC with no vacuum lines attached anywhere - both retard and advance are plugged and I am running NGK plugs - one plug hotter than normal since I have a hotter coil and the Crane - gapped at .040". I am thinking of widening that gap slightly to .045", which is what I was running prior to the rebuild.
The other concern is the running temp - my needle stays at the mark between the 175 and the 250 lines on my gauge. It is very hot here, over 100, and I am running the AC and while I am running at cruising speed the temp drops to halfway between the 175 and the line and at idle it can crawl above the line - but it never gets to the red.

I was having the same issues though prior to the rebuild - I put in an 87 Cel thermostat and I replaced the water pump and ever since then the car has run hotter.

Sorry this is so long, but I really appreciate all the help and suggestions along the way.

ryan

Ryan:

Normal temp will position the needle horizontal for most cars. If your engine is still tight from the rebuild it may run a bit hot until things loosen up. If you run AC the needle may run up to the line above 175, which by extrapolation is about 200 to 210 more or less. A 14# cap raises the boiling point to around 240 degrees, so you should be OK in OK with your temps.

230/8

How much did you wind up putting into this rebuild? I have a similar car which will require the same maintenance in the next few years...

If you're talking $$ - I'm not exactly sure. I have done this over several months and I have probably lost track of a few items along the way. I know that I spent $350 on the cylinder head/valve job. Everything else I did and I spent between $800 and $1000 on parts - which includes piston rings, main bearings, connecting rod bearings, engine block gasket set, cylinder head gasket set, all new gears, timing chain and guide rails, new hoses, coolant bypass tube, new plugs, and various and sundry bolts, nuts, sealant, etc.

Not bad overall, but my block/cylinders were in good shape - downside was the time it took as everything was pretty much a first-time experience for me, and I found myself 'backtracking' numerous times. Fortunately, I had some good local help and the advice on this board was very helpful.

ryan