06 March 2010
Getting started on rebuilding my 440 Six-Pack engine. This is an original MoPar 440 Six-Pack that was original equipment in my 1972 Jensen SP. Yes, Chrysler made 440 Six-Pack engines in 1972, they just couldn't sell them in the "Good Old USA" due to emissions legislation
I removed the engine from Pirate Jenny as part of the gearbox swap and it's been waiting patiently for that project to get finished. Well, the gearbox swap is all over but the prettying-up, so it's time to start on the engine rebuild.
I separated the engine and A-727 Torqueflite gearbox, and then raised the engine up and bolted it to an engine stand. First time I've ever had an engine stand to use!
The inlet manifold had been previously removed. I pulled the valve covers, rocker arm shafts, and pushrods. Everything was nice and clean. Pulled the heads off and found some carbon build-up, but not at all too bad. The cylinder bores look really nice! Nice and smooth with no perceptible ridge, and they are standard-sized (4.3125"). Looks like I won't have to bore it oversize with the extra cost that doing that brings. Yes, the pistons are high-compression ones with "eyebrow" cuts for valve clearance.
Removed all the valve lifters and then pulled the vibration damper (special part for 440 Six-Pack engines -- it is externally balanced), timing cover, and timing sprockets and chain. Then I carefully removed the camshaft. Cam and lifters show some wear, but really not too bad. It's scheduled for replacement anyway.
Time to turn the big beast over. This is where the engine stand paid for itself!
With the engine bottom-side up I removed the oil pan (or 'sump'), windage tray, and oil pump pickup tube. Things are still looking pretty clean! Crankshaft and connecting rods are now exposed. Took off a rod bearing cap -- the bearing shows wear. Removed the piston and rod after covering the rod bolts with rubber hose to protect the crank if it's good (don't know yet, so be careful!). Repeated the process with the other seven. All the rod bearings show scoring and wear.
Onward to the main bearings. Removed the rear main oil seal retainer (thank The Powers That Be for my dad's old 12-point 3/8" socket!) and put it in carburetor cleaner to soak overnight. Then removed all main cap bolts and removed the main bearing caps. Lifted the crankshaft (that bloody thing is HEAVY!) out of the block and set it gently on the garage floor. Bought a micrometer set and a dial indicator (on sale!) and proceeded to measure the crank journals. They all measure right on spec: 2.750" mains and 2.375" rods. Measured from two angles to detect any out-of-roundness and none was detected! Lifted the crank (that bloody thing is STILL heavy!) back into the block (with the upper main bearing shells in place) and checked each main journal for out-of-roundness with the dial indicator -- there is none! The journals could benefit from some polishing as there are marks on them, but that's all. All the bearings themselves do show scoring and wear, so that accounts for my low oil pressure.
It looks like I can use the original crank, rods, and pistons which will save me some serious money! I will, of course, check with my engine guy.
Looks like the next step is to get the block and crank down to the engine shop for some serious cleaning and inspection. After money gets popular again!
Sold my A-727 and Gear Vendors Overdrive. That makes the rebuild possible to continue. Tomorrow I plan to rent a small pickup and transport the engine parts to the shop to be cleaned, machined as needed, and assembled.
I am using the original Holley 2300 carburetors that were on the engine when Ma Mopar built it. They have just been rebuilt and are running well. They are mounted on a new Edelbrock aluminium version of the original intake manifold.
The camshaft I will be using is the Iskenderian 270-MEGA hydraulic, along with Isky's matching lifters. It has 270° advertised duration and 221° duration at .050" lift. Intake and exhaust are the same. Total lift is .465". Lobe separation is 108°. Pretty mild, but still should put out a bit more power than the original factory Six-Pack cam (which is pretty good, itself). Should maintain good low to mid range torque which will make driving with 3.07 gears more reasonable. She ought to be rather well civilised, but still be able to breathe a bit of fire now and then.
The Delta headers will remain unchanged, but the pipes will be enlarged to 2.5" diameter from the collectors back to the mufflers, and a 2" H-pipe will be added. I may add a pair of small glasspack mufflers behind the Flowmasters that I have installed now. From behind the mufflers to the resonator-tips will be 2.25" pipe -- that's the size of the resonators, and that far back the exhaust gases have cooled and contracted in volume quite a bit, so the 2.25" pipes behind the mufflers ought to flow as much as the 2.5" pipes right behind the collectors do. That's the theory anyway.
I bought a new Procomp 7000 distributor and the Procomp coil is on its way here as I type this. Should be plenty of fire for this engine and clean up the engine bay a bit as well.
I have decided to go with an external clutch slave cylinder operating a stock MoPar clutch fork. That will get the hydraulics out of the bellhousing and accessible if they need to be serviced. Not part of the engine rebuild, but it will be done at the same time.
Rented a pickup truck and took the engine to AIMS here in Sparks, NV. They said I'll know what needs to be done in about a week.
AIMS said engine ought to be ready tomorrow. There may be some more to do, though -- cleaning the valve covers and balancing the engine come to mind.
Engine condition was pretty good. Block, pistons, and rods were all in good shape. Crankshaft needed a minimum regrind as it was .003" out of round. Needed new valve springs and retainers as the ones in the heads didn't fit properly. I have no idea how that happened! She's getting new dual valve springs with PC type valve stem oil seals and retainers that fit!
The Procomp distributor had clearance problems on this engine and I couldn't use it. Went back to the stock MoPar distributor and added an MSD Street Fire CD ignition unit. Works well, but it burned out the Procomp coil in less than a day. Too much juice for a low-resistance coil. It works fine with a standard coil. The Street Fire unit has a built-in rev limiter and provides multi-sparking under 3000 rpm.
Picked up the engine parts yesterday. Spent today assembling the engine, and it's mostly done.
Here are some photos:
The bare block as I got it back form the shop.
After installing the crankshaft.
After installing the rods and pistons.
After adding the oil pick-up.
With heads, valve gear, and some flat black paint.
The engine is done and running well. Had a bit of a problem getting her to pass smog, but the folks at Deano's Automotive here in Reno persevered and found a bit of lint (probably from a shop rag) in one of the centre carburettor's jets; once the offending lint was removed, all was well. Jenny now runs strong and smooth.
The new clutch slave cylinder setup works quite well.
I had the exhaust system upgraded to 2.5" headpipes with a 2" H-pipe and two new stainless steel low-restriction mufflers by another local shop, Zamboni's Muffler Shop. Pirate Jenny now has a very nice rumbling sound to her, but not too much to live with on a long drive.
With the new exhaust system from ground level at rear.
View from the rear and underneath.
View from front and beneath.