Brian's 67 dart

Just where do you find a complete 340 engine? As I said in the last installment, I didn’t. I had to piece one together. This was not my preferred method and made the final cost of the engine higher than if I had been able find a complete core.

I had asked everybody I knew and everybody they knew – no dice. There had been some, “I will check with so-and-so, he may have one,” but none of these panned out. I began the search for enough pieces to make the whole with a little unease. This is not the way to build an engine – 40 year old parts from different motors.

I found a 340 block on Ebay two times, one within driving distance, but was out bid on both of them. Each morning at work, I log on to the iATN (International Automotive Technician’s Network), and read some of the latest forums. One morning, I browsed through the “for sale” forum to look for some equipment I was needing at the shop. Much to my surprise, I found this at the end of a post on some equipment for sale in Florida: “I also have a 340 Mopar block and heads.” A quick phone call discovered that he had the block, 8 rods, 2 new “J” heads, 8 assorted pistons and a crank believed to be out of a 318.

We agreed on a price and he said he would crate everything up and send it to me and drop me an email when the shipping cost was known. The email arrived a couple of days later and I sent a check off in the mail. He said it would be a few days before he could ship it. Good, things were looking up. A few days later, I was sitting at home watching the news when I see a report on a nasty hurricane that had just gone through the town where my 340 was. Oh no! I waited a few days to let them dig out from under this thing and then called. The hurricane had blown a few trees down at his house and had blown the doors off of his shop (a Chevy shop perhaps), but everybody and everything was ok. He said he would get the stuff shipped as soon as possible, but he had his hands full getting everything back together and repairing the backlog of cars that had created. I told him that was fine, I was in no real rush.

While I was waiting for the block to arrive, I began to remove the external pieces from my 273. My plan was to make the 340 to appear as close to a 273 as possible to retain the original look. The valve covers, timing cover, damper, and pulleys were cleaned & repainted and hanging on the wall awaiting their new gig by the end of the week. The oil pan was banged up and didn’t make the cut.

Now, where was I going to locate a forged crank? Hum…, I had one setting in the bottom of my 273 – but just how would that work? All of the throws and journals were the same as the 340, and it was forged. I sent up a post to the group here and asked about it. Got several good supplies with the information I needed – it would work just fine and was tough enough but would need to be rebalanced for the bigger rods and pistons of the 340. The cost of balancing the crank would be $300 to $350.

Much to my surprise, a few days later I located a stock ’70 340 crank during my nightly stroll through E-Bay. It had been taken out in favor of a stroker kit and was still standard. I bid on it and won it without much trouble. Sent off the money order and crossed that off my list – for now.

A couple of days later, the block, heads, and other parts arrived at the shop in a big wooden case. Took it home, along with my engine stand, and dragged off the pick-up and into the “Mopar Palace.” Broke open the crate and looked every thing over. Light rust had found its way onto every machined or unpainted surface but I could find no pitting. The block looked good and still had the crank nestled in its bore. There were eight rods with what appeared to be new bushings in the small ends. The “J” heads looked like they had been bolted on but had been run very little, there were noting residing on the backs of the valve faces and ports but a very light rust. There were eight pistons: 5 new .030 over of an unknown brand, 1 used .030 over and 2 stock 340 pistons. I ran the numbers on the parts: the rods were factory replacement and the block was indeed a ’70 340; the heads were the 360 “J” with the 2.2 intakes.

The crank was supposed to be out of a 318. It seems that the folks I had bought it from had originally planed to use the 340 in a drag racer. They had set the engine back but the time never came to complete it. During the time it set in the corner of their shop, they said someone had stolen the 340 crank and stuck a 318 in its place. They had not discovered this until they pulled the engine out to look at it before they ran the ad on the iATN. I pulled out the crank and stood up the supposed “318” crank. It was a forged crank and had some big holes in the counter weights. I ran the numbers and discovered it was not a 318 crank but was indeed the correct 340 crank for the engine! My Ebay crank showed up that week as well. (Both miked to be about .02 worn, picked the best looking one and had it turned 10-10).

Sent the block off to the machine shop a few days later to be cleaned and miked so I could tell what I had. No cracks with a standard bore. Looked good except for a deep scratch lengthwise down one of the cylinders. A .030 over bore, new cam bearings and freeze plugs soon had the block looking good. Gave it a through washing and put it on the engine stand.

Took the heads apart to take a look. When I pulled out the valves, I was greeted by a nice 3 angle valve job! Nothing showed any signs of wear at all, I could tell they had been bolted on but they showed no indication of use. I cleaned everything up. The ports were stock as well as the combustion chambers. Lapped the valves in, installed new seals with new springs for good measure. Stuck a set of NGK plugs in them, turned them upside down and filled each combustion chamber with mineral sprits to make sure the valves were sealing.

The next morning I began to assemble the block. The first thing was to install the dist. drive bushing. Drove it in place and honed it to fit the new MP (Mopar Performance) drive shaft. (My shop is located at 1733 Cleveland HWY in Gainesville, GA, “The Moparts Connection” is at 3363 Cleveland HWY – 2 miles away.) Flipped the block over and put the upper mains in, followed by the crank. Plastigauged the throws and found the oil clearance to be on the large side of normal (.003). Frowned a little and pulled the crank back out and coated the mains with Vaseline. Placed the crank back in the bore and tightened the mains to specs. The pistons, rods and windage tray soon followed.

The camshaft was a MP –4452759 (260/268 adv. dur – 430/450 lift) with the lifters and springs. The best buy I could find on the oil pan was from Mopar as well, even included the oil pump pick-up and dip stick & tube. The 273 pieces went on and I sat back and admired it for a while.

The intake and carb were another E-Bay find. The stock intake was off a ’68 340 and the carb was an “AVS” off a 383 HP from ’69. The intake came already glass beaded. I gave it a good cost of Chrysler Industrial Red to match the rest of the motor and installed it. Went through the AVS and reassembled it with a new kit. Put some gas in the carb and tried the accelerator pump – not too swift. The new pump piston was too small. I had an AFB setting on the shelf, swapped the pump out of it – perfect!

Covered the engine and pushed it out of the way. This took place from mid December to late January this year.