Small block 340 engine for sale and some questions...

-
Krooser said:
But do we buy a used car and disassemble the engine before we drive the car? No....

I'm not saying buy it sight unseen but a good inspection without disassmbling the engine is possible.

I bought my race car motor blown up... pulled one valve cover and the pan to inspect the carnage. While there was some unseen damage I bought the complete engine carb to pan for about what the crankshaft would have cost new from Mopar. Perfect heads. Block had two minor nicks at the bottom of the cylinders. Crank was easily repaired.

In the racing world engines are sold everyday racer to racer without a teardown. The sellers word often is good enough. Do some guys sell junk? Sure. Last summer I was looking for a SBC for an older dirt late model I have and want to sell. Found a long block for $800.00 from a local racer that had name brand parts and low laps. One call to another driver (his brother) made me back off on the purchase. The engine had good parts yes... but it was a mix and match conglomeration of parts from a few blown up/worn out motors.

A good DLM motor can be $30,000 used!

Do your homework but pulling a valve cover and an oil pan may be enough to tell you what you need to know.
Click to expand...

You are correct, but the point is that for most average project builders, throwing a rod or spinning a bearing because someone "cheaped out" could seriously derail or trash their budget altogether. Other than a gasket set, a teardown R&I costs little other than time, gives you the opportunity to satisfy that your own minimum requirements have been met, allows the time to verify what parts are actually in there and allows for the correction and/or replacement of items before a catastrophic failure forces you to do it.
 
2 grand and its all there? not seized? that's reasonable. If it is the earlier engine even better. i am putting one together (7/69 dated block) and need "missing parts" it adds up. Getting the steel crank turned was 250 for example. I will end up with a grand into it finding parts to "get it together". I did have most of it "laying around" though. so when I get it together I would want at least 2 grand maybe more and it would be ready to run.
 
In typical Chrysler fashion you can’t get a straight answer. I have never seen a MODEL YEAR 72 340 with a cast crank.

The text infers all 72 340’s has forged cranks, but the chart says a cast crank is possible in 72. Again, I’ve never seen an actual 1972 model year 340 with a cast crank.

Edit: I forgot to add the quotes out of the engine book.

93B37287-73AC-4ADF-B006-87EF168A8D91.jpeg
153D0634-7F26-43DD-B639-7FE274C8171B.jpeg
 
Last edited:
I bought the engine dis-assembled. When I found the pressed in pins, I thought they were from a different engine. I did some research (here probably) and was advised that they existed. I'll take a closer look tomorrow. I'm still learning too:rolleyes:
 
How bad do you want a 340? As mentioned it's always going to be a bit of a crap shoot if all things are in good working condition and complete 2000 maybe a fair price. I've seen fewf for less recently. And it was my understanding that in 72 forged cranks were used up in the 4-speed cars and cast cranks were installed in automatics
 
K.O. SWINGER said:
How bad do you want a 340? As mentioned it's always going to be a bit of a crap shoot if all things are in good working condition and complete 2000 maybe a fair price. I've seen fewf for less recently. And it was my understanding that in 72 forged cranks were used up in the 4-speed cars and cast cranks were installed in automatics
Click to expand...
My first '72 had a cast crank and a 3 speed manual.
 
I have always thought the 340 "turned into" the 360. Sort of, it definitely was transformed in the name of emissions. I am curious how well the later 340 performed compared to the early 340. I have had 70s era 318s that were stock except for a cam and header etc that ran really well. Fun on the street anyway. I would have to think the later 340 ran good for what it was. of course in terms of "sale value" the early one is the one to have. Just because it has all the "good " internals. Something as simple as the early high comp pistons vs the later flat tops makes a difference for example. I wonder how many guys back in the day took the later 340 made it into an early or at least switched heads etc.
 
Dartswinger70 said:
I have always thought the 340 "turned into" the 360. Sort of, it definitely was transformed in the name of emissions. I am curious how well the later 340 performed compared to the early 340. I have had 70s era 318s that were stock except for a cam and header etc that ran really well. Fun on the street anyway. I would have to think the later 340 ran good for what it was. of course in terms of "sale value" the early one is the one to have. Just because it has all the "good " internals. Something as simple as the early high comp pistons vs the later flat tops makes a difference for example.
Click to expand...
The early 340s definitely had a little more pep in their step due to the higher CR and the X-heads. The Hi-po exhaust manifolds helped a lot as well, for those that didn't have headers. My early ('69) 340 had the Carter AVS and performed really well despite being a high mileage motor. My '72 was no slouch either, despite being de-rated from 275 to 240 HP. I suspect the TQ helped a bit in that regard.
FWIW, I also had a pre-'70 318 topped with a Holley 2300 2bbl that ran like a scalded dog. The "good internals" are a fairly easy fix; just go back to 10:1 pistons and slap on a set of Eddy heads with 2.02s and there you are.
 
yellow rose said:
In typical Chrysler fashion you can’t get a straight answer. I have never seen a MODEL YEAR 72 340 with a cast crank.
The text infers all 72 340’s has forged cranks, but the chart says a cast crank is possible in 72. Again, I’ve never seen an actual 1972 model year 340 with a cast crank.
Click to expand...
@yellow rose , IIRC the transition took place mid-year 1972. My first '72 was built in October, which may explain why it left with the cast crank an 1.88 J-heads.
 
Captainkirk said:
@yellow rose , IIRC the transition took place mid-year 1972. My first '72 was built in October, which may explain why it left with the cast crank an 1.88 J-heads.
Click to expand...


From looking at the book (I need to dig out my older book because I trust it more) it seems that’s what Chrysler did. Someone else pointed out in 72 the sticks got the forged cranks and the automatics got cast cranks. All very plausible.

My 72 came through with the 10.5:1 pistons and 2.02 valves. I was the second owner so I know it wasn’t touched.

I kick myself every day for what I did to that car. Just stupid.
 
yellow rose said:
From looking at the book (I need to dig out my older book because I trust it more) it seems that’s what Chrysler did. Someone else pointed out in 72 the sticks got the forged cranks and the automatics got cast cranks. All very plausible.

My 72 came through with the 10.5:1 pistons and 2.02 valves. I was the second owner so I know it wasn’t touched.

I kick myself every day for what I did to that car. Just stupid.
Click to expand...
We had no way of knowing back then how rare, collectible and desirable these things would become. How many guys driving a new Chally think about what it will be worth 40 years from now?
 
My dart wasn't a rust bucket but it was ridden hard and put away wet. they were throw away cars and they got raced and beat smashed and dented etc. I can remember when Mopars got no love. If you drove one it had to run just to shut the Chevy guys up LOL!
 
Well ya figure between the late 340-360 the differences are the crank journals and the bore I think 360 had a dished piston but I am not 100% maybe some of them did? Things like the cam Im sure were different360 was a 70s smog motor. Alot of guys tout the 360. i would think with the right internals it builds up pretty well.
 
Last edited:
Here is more info... The date code on the engine is 9-27-71.
The number stamped on the front of the block. 39038100.
There is another number MH 340 P. I suspect someone stamped this one on.
The head casting #’s. 3418915H 0552 360
 
340 fan boys sure pony up money for unknown 340s! Build a 360 with $250 flat tops/pop ups and big valve heads and your roll'n a "stroked 340" for 1/3 the price. Just tell them that....
 
Google is a wonderful tool...

  • 1972 - The 340 four-barrel dropped to 240 horsepower:
    • Compression dropped to 8.5:1; the compression height of the piston via wrist pin location changed by 0.10"
    • The crankshaft was switched from forged to cast somewhere in the production cycle, believed to be in early April 1972, with engine 39118000 (thanks, Karl Thomas)
    • 340/360 were moved to "J" casting heads with 1.88" intake valves; exhaust valves remained the same
    • Paint went from orange to corporate blue
  • 1973 - The cast crank had a different number than the 1972 counterpart, because it was shot-peened for greater strength.
 
You must log in or register to reply here.
-

Back
Top