70 318 with 340 internals/Cyl Head

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So 318 external balance, 340 internal balance?
340sFastback said:
Is the balancer neutral balance? That is the only thing you are going to be able to see. Guy says this and that is inside the engine but no way to know other then if its neutral balance or not and head castings. Receipts for any parts or machine shop?

If you like the car and it runs good buy it. I would be far more concerned about hidden rust excessive bondo ect ect ect.
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toolmanmike said:
No Teens were internal as was 340's until about 72 when they started using cast cranks
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So Can I or can't I determine which crank is in the 70 318 block by checking the balancer, if they were both internally balanced? Am I tracking you? Someone is suggesting checking for a determination.
 
mario03srt said:
So Can I or can't I determine which crank is in the 70 318 block by checking the balancer, if they were both internally balanced? Am I tracking you? Someone is suggesting checking for a determination.
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I wouldn't trust the balancer myself. Who knows what combination of parts have been thrown together to make the engine work. And really, who cares. If it runs good and doesn't shake the car apart, run it till it blows or take it apart and check all the pieces.
 
mario03srt said:
So Can I or can't I determine which crank is in the 70 318 block by checking the balancer, if they were both internally balanced? Am I tracking you? Someone is suggesting checking for a determination.
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'68 - '71 340 were internal balance forged cranks and sometime in '72 340s went to cast crank external balance.
 
toolmanmike said:
I wouldn't trust the balancer myself. Who knows what combination of parts have been thrown together to make the engine work. And really, who cares. If it runs good and doesn't shake the car apart, run it till it blows or take it apart and check all the pieces.
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Yeah it could have a 340 crank in there and be externally balanced I think that is possible.
And yeah I would not sweat what is inside that engine cause you won't know unless you take it apart.

If engine runs good then look at other aspects of the car I would not focus too much on that engine that is easy to change later.
 
340sFastback said:
Yeah it could have a 340 crank in there and be externally balanced I think that is possible.
And yeah I would not sweat what is inside that engine cause you won't know unless you take it apart.

If engine runs good then look at other aspects of the car I would not focus too much on that engine that is easy to change later.
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Concur. Thats what I said , it is what it is. The guy who has it mentiond the 340 internals like it was a deal. I never heard of that in my time in SB Mopars, except for my 2000 4.0 Jeep which is easy to stroke with a 258 crank. He got this engine in an estate sale he claims and was given "anecdotal" info about the motor. He has ran it now for a while and says it runs out great and has some lope and will drive anywhere. Intake, 650 4 Barrel, Headers, 3800 stall, Accel Dizzy, 3.55 gears and 255 tires. This appears to be a professionally assembled engine. It should bring a nice smile. Ya, I'll be all over an AirGap Int.

If I get it I'll throw up some pics. It's a great deal as this guy has his eye on a 70 Chevelle SS and is ready to sell!
 
mario03srt said:
I'm awaiting some Skud Misslies any time....
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Cocked Locked and Ready to Rock! A little Big Daddy eye candy from the Nats a few moons ago!

Big Daddy.jpg
 
It sounds like whoever built that motor thought a lot about what they were doing. As for the 318 340 crank they are the same part number for the forge crank however they are balanced different because of 318 has lighter rods than a 340 and the Pistons are lighter. You can put 340 rods in that 318 it'll change the balance so I would think whoever did this had the rotating assembly balanced but I could be wrong. There's too much money in the add-ons for them to have not done it right. You can say a forged 318 crank is a 340 crank if you want to but they are not balanced the same. As for the valves a 70, 318 did not have 1.88 intakes. It had something like 1.78 intakes and 1.50 ehaust and the early 340s had 2.02 intakes and 1.6 exhaust valves not 1.65.
It's bored .030, so the guy put money into the block why wouldn't he have bought good pistons. Run a compression test on it. See what that tells you. As for the torker 340 that is the early version of that manifold I believe they had torquer 340, torquer 1 and torquer 2. Somebody correct me if I'm wrong.
 
1970 318 has forged crank and uses the same balancer as a 340 thru 1972
he is most likey bsing about the 340 crank getting those that no nothing to think its special
takes 5 min tops to get the block numbers
the people you are sorta calling out woudnt need to ask your questions as they know by a look whats what
I took me 2 words in search to find this
www.forabodiesonly.com

[SOLD] - 1970-72 340 ENGINE BALANCER

Hi, Very nice and clean 1970-72 340 engine harmonic balancer. New Chrysler Blue paint. Sheet metal ring on rear is mint! CT hi Asking $69.99 + actual shipping. I ship fast! Thank you.
www.forabodiesonly.com www.forabodiesonly.com
carry on
 
Jadaharabi said:
It sounds like whoever built that motor thought a lot about what they were doing. As for the 318 340 crank they are the same part number for the forge crank however they are balanced different because of 318 has lighter rods than a 340 and the Pistons are lighter. You can put 340 rods in that 318 it'll change the balance so I would think whoever did this had the rotating assembly balanced but I could be wrong. There's too much money in the add-ons for them to have not done it right. You can say a forged 318 crank is a 340 crank if you want to but they are not balanced the same. As for the valves a 70, 318 did not have 1.88 intakes. It had something like 1.78 intakes and 1.50 ehaust and the early 340s had 2.02 intakes and 1.6 exhaust valves not 1.65.
It's bored .030, so the guy put money into the block why wouldn't he have bought good pistons. Run a compression test on it. See what that tells you. As for the torker 340 that is the early version of that manifold I believe they had torquer 340, torquer 1 and torquer 2. Somebody correct me if I'm wrong.
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Thanks! I'll do some forensics here in a day or 2. I'll check block and cyl head casting numbers, balancer, mani ID, probably bore scope it also, pull the covers. Supposed to be "Built". The details are welcome to the discussion.
 
Do a cylinder pressure test while you're at it.
 
I have a teener with 340 heads, not enough compression. 4.56 gears with a spool. Hits 100 mph at the 1/8 mile mark and will not accelerate any more plenty of rpm left in 3rd gear of a 727 with a manual valve body. Motor was built with swap meet parts. Should have decked the block and milled the heads, but didn’t. Its alot of fun up to 100 mph though.
 
What would be neat is if it was bored to 4 inches and had a 360 crank in it. You'd have a 318 that was 360 cubes.
 
There are too many ways to swap parts around to boast on a 318 with 340 guts.
there are like;
5 of 3.315 stroke cranks
lightweight rods, heavy-weight rods, bushed or not,
piston weights are killer from the heavy forged 340 items to the lighter cast 318 items,
So when you go to assemble something like that, you gotta stir the pot just right.
If I had an abortion like that, I wouldn't mention it.
If it doesn't shake itself to bits, just drive it.
If it does shake, prepare to take it all apart and fix it.
Not a big deal. the proof is in the shakey-shakey.
 
mario03srt said:
Fish,

I'm comparing a stock 1.8x 318 valve to a 2.02 340 valve diameter. Cmon Man!

Do you work for MSNBC?
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I think your info is off. Not all 340 had 2.02 lots of later one's had smaller valves. On J Heads it is. Toss Up as to what they have.
 
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