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CluelessMopar

CluelessMopar

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I'm buying a 340 engine off a buddy that he's had sitting around for 10 years. The engine was fully rebuilt with less than 1000 miles on it before the car it was in was damaged in a fender-bender. I'm unsure of the cam, pistons, etc... All I know is that it has Edelbrock Performer RPM heads and supposed to have a rowdy cam. The guy who originally built the engine spent a pretty penny on it.

I'm going to need to get a different torque converter (maybe 2400 stall?) but first I need to know what my compression ratio is with this engine & cam specs. Any tips on what I should do? I plan on taking the timing cover/chain off to check out the cam and pull the intake & heads to look at the cylinders/pistons. Any other advice? I plan on replacing my stock 360 with this 340 in my 69 Dart. I already have rebuilt 727 & 8.75 rear with 3.55's.

Or do I just send it and start doing burnouts?
 
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Listen carefully. Do not get a 2400 stall. They are for trucks. A stock 340 came with a 3500 and brake stalled at 3000. I personally would buy a 4500 no less if the motor is cammed up. I run a 5500 tight on the street. If you put a 2500 behind any performance built engine you will destroy the back of the thrust bearing from converter push. If you are close to me in Pa. I can loan you a converter to try. I have many different stalls including Factory 340's. Try one then order what you want. I have 3500, 4500, 5500 to try Leave a deposit to ensure its return.
 
Oldmanmopar said:
Listen carefully. Do not get a 2400 stall. They are for trucks. A stock 340 came with a 3500 and brake stalled at 3000. I personally would buy a 4500 no less if the motor is cammed up. I run a 5500 tight on the street. If you put a 2500 behind any performance built engine you will destroy the back of the thrust bearing from converter push. If you are close to me in Pa. I can loan you a converter to try. I have many different stalls including Factory 340's. Try one then order what you want. I have 3500, 4500, 5500 to try Leave a deposit to ensure its return.
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Hey I'm actually in PA as well. I'm in Lansdale so that's about an hour and 30 min away. I might take you up on that. Send me a message and I'll give you a call. Hopefully I'll know more once I open the engine up a bit. I appreciate your help, I new to figuring out torque converters.
 
you cant see the pistons by taking off the intake and you cant see the cam by taking off the timing cover...get a converter and send it...
 
doug 371 said:
you cant see the pistons by taking off the intake and you cant see the cam by taking off the timing cover...get a converter and send it...
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Sorry when I said taking the timing cover off I really meant take the timing chain off and see if I can see any markings on the cam shaft. Was also planning on doing head gaskets. I should have said that in my initial post. I'll correct it now :)
 
Pull a valve cover and put a dial indicator on the push rod. That will tell you lift and duration.

Pull a spark plug out and get a scope from Harbor Freight to look at the pistons. While your at it pull all the plugs and put marvel mystery oil in the cylinders so you don't fire it dry.

Also turn the motor with no plugs with a starter to get oil on all the bearings. Or just prime the pump with a drill turning the motor by hand to oil both sides.
 
Oldmanmopar said:
Pull a valve cover and put a dial indicator on the push rod. That will tell you lift and duration.

Pull a spark plug out and get a scope from Harbor Freight to look at the pistons. While your at it pull all the plugs and put marvel mystery oil in the cylinders so you don't fire it dry.

Also turn the motor with no plugs with a starter to get oil on all the bearings. Or just prime the pump with a drill turning the motor by hand to oil both sides.
Click to expand...
How much Marvel Mystery oil would you recommend in each cylinder? Just a like a tablespoons worth?
 
Squirt some in so it gets on the piston all around the piston so the top ring is lubed first time up. So what I do is stand the left bank straight up put some in and then stand the right bank straight up and put some in. This insures the oil goes all the way around the rings.
 
Demonic said:
Just curious - what is the story on the car it used to be in?
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Was a 71 Demon that a guy spent close to $40k building. Car was in a accident where it was hit on the driver side fender. He got the insurance for the car and decided to sell the car to my buddy. My buddy has been parting it out for awhile.

I actually have the TTI exhaust (3 inch with X-pipe) & TTI headers from the Demon as well. Driver side header just had a small puncture mark on one of the tubes which I cut/welded back up. So the damage wasn't that significant to the speed parts.
 
The thing that really matters is the cranking cylinder pressure. You can tell an awful lot from the numbers. And the best thing is that the only thing that you need to put tools on, is the sparkplugs.
After 10 years I would do two Compression tests; First a normal dry one, then another one after oiling up the cylinders, just a lil.
BTW
just so you know,
my 1969 FSM lists the brake stall of the stock 340TC, as; 2350+/-100rpm.
IDK how that compares to real life, cuz I never had an auto-equipped 340; mine were all A833s
 
AJ/FormS said:
The thing that really matters is the cranking cylinder pressure. You can tell an awful lot from the numbers. And the best thing is that the only thing that you need to put tools on, is the sparkplugs.
After 10 years I would do two Compression tests; First a normal dry one, then another one after oiling up the cylinders, just a lil.
BTW
just so you know,
my 1969 FSM lists the brake stall of the stock 340TC, as; 2350+/-100rpm.
IDK how that compares to real life, cuz I never had an auto-equipped 340; mine were all A833s
Click to expand...

I owned many factory 340 auto cars in the 60's and 70's. They all foot braked in gear wide open throttle at 2800-3000 with a stout engine. I had some that I bought with rebuilds with replacement converters. They were real pigs to drive.

Just had a car here with a 2400 RV converter Todds Barracuda . You couldn't turn the tires at a dead stop . Todd and I had to start off in the cinders to get the tires turning. Were changing the car to 4 speed for him.

340's also came with a light governor weight to hold the shift to 6000 rpms. Adding a part throttle kick down servo from a taxi, police ,fleet car , or 71 up 904 really wakes them up in drive. They will down shift with partial throttle.

Adding these three things to any car will really change any car while driving the car in drive. You will love it. You will think you put another engine in.
 
Thank you for your real-world experience.
I'm not arguing.
Jus regurgitating what my FSM says.
I put a 2800 on my Low-compression 318 winter-motor, and ran it with various rear gears. She was a hoot..... and still is.
 
why would anyone buy a rebuilt anything with no idea whats inside?
 
340's are getting harder to find complete. Just sold a 50 year old original 1970 340 for $4000. Bought a 68 440 HP for $250 out of a storage place in Easton Pa. carb to pan. After tearing it down we found everything was new never run. So there are time you just have to Gamble. The older guy in the pictures and the younger mechanic swore it was a 340. So we took the loader and the trailer and picked it up.

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