my 340..3 cars, 34 years, 1 family. where to go from here

[challngd73]

Ok so here is my 340's story.. It was taken out of a 71 cuda my uncle had, and given to another uncle back around 1980. He went through the motor and ran it in his 65 barracuda. He rebuilt it a 2nd time back in the fall of 1987, but died a little over a year later. It sat in that 65 cuda for a few years until my father took it out and put it on an engine stand and manually turned the crank every so often. Back in 2006 my father took the motor to a machine shop and had them build it. The motor was bored .60 over, new crank, new pistons, the whole deal. My father let them choose the cam. He put the 340 back into his 66 barracuda, and it never ran right from the start. It didnt run bad mind you, but had no where near the power it had back in the 80's when my uncle had it. I was convinced a poor cam choice was the downfall, but no one knew what was in it. My father took the 340 out of the 66, and back on an engine stand it went. Fast forward 8 years....I bought my fathers 66 and the 340, which had only about 1000 miles or so on it since its rebuild, but hadnt been run for those same 8 years. I decided to tear into the motor last night and this is where i am at today...

[challngd73]

I discovered the cam is a crane cam, a 284 h12 that crane lists the "operating range" as 3,000-6,200 rpms. I dunno, I think that is a very poor operating range for a street car in my opinion this contributed to the poor performance. What do you guys think of this cam, as i am far from an expert. Also I found 2 cylinders with condensation in them, one not too bad, one not good. You can see from the cylinder head picture the price of condensation. Can anyone tell me what part number im looking for on the pistons to get more info from them? I assume the block and heads have to be gone through now? Opinions? thoughts?
cam specs: duration @ .050" int 228 exh. 228, advertised duration int 284 exh 284, lobe sep 112, valve lash int .000, exh .000, gross valve lift int .480 exh .480
pistons have "951 p" stamped in them.

[bandt]

You are right about the cam. It's bleeding off all the torque with the amount of duration in it. There are far better cam choices these days. The Lunati Voodoo series is popular with the guys here also Hughes engines has there own line of Mopar specific cams. Cams these days have more lift and less duration. For a street engine the operating range should be much lower. Need more info to give you a better idea. Auto or stick, if auto what rear gear and what stall on your converter? What compression are you running?

Sorry can't help with the pistons.

[challngd73]

You are right about the cam. It's bleeding off all the torque with the amount of duration in it. There are far better cam choices these days. The Lunati Voodoo series is popular with the guys here also Hughes engines has there own line of Mopar specific cams. Cams these days have more lift and less duration. For a street engine the operating range should be much lower. Need more info to give you a better idea. Auto or stick, if auto what rear gear and what stall on your converter? What compression are you running?

Sorry can't help with the pistons.

Well Im not sure what the compression ratio was before, but I would like to get 10.5 - 1 with the rebuild.  I have been checking out the voodoo hydraulic flat tappet 268/276 cam.  This motor will be put in my 66 Barracuda, running a 727 and 3.55 suregrip rear.   
currently has j heads on it and im not sure what one, but edelbrock intake.  TTI headers fpr exhaust.   I will pick the converter once i settle on a cam.
These cars are pretty light i believe so im hoping for some good performance out of it. 
the car...

[Haddixj]

just curious of the vin stamp on the block?

[challngd73]

just curious of the vin stamp on the block?

where is that located? under the timing cover?

[Chryco Psycho]

No pix of the top of the pistons , how high do they sit in the bore ? do they have 4 valve reliefs ?
 the cam specs seem mild to me , 228* duration with 112 CL & only .480 lift is not extreme but there are far better choices now .
 Piston may be cast or hyper , you really want forged , you could drop in a stroker kit for 412 CI .
 J heads are Ok but the 308 will make more power .
 Depends on the budget I guess .
 Cool car 

[Haddixj]

Pass side of the block above the oil pan rail should have a 1B followed by 6 numbers
Thanks

[RzeroB]

I believe the "951P" piston is a Sealed Power hypereutectic cast piston

[challngd73]

  top of piston

[challngd73]

I have to have a machine shop look at that once cylinder.  she is already .60 over so im a little concerned..   

[challngd73]

Pass side of the block above the oil pan rail should have a 1B followed by 6 numbers
Thanks

reads 2780930-340-8    date code       1-8-70

[RzeroB]

reads 2780930-340-8    date code       1-8-70

That's the part number and casting date that is cast into the side of the block ...

Look further "down" towards the oil pan rail (edge where the oil pan bolts up to the block) ... there should be a small smooth machined "pad" about 3/8" x 1.5" to 2.0" inches in length with eight character "stamped" into it ... that's the block's VIN pad ... sometimes it's hard to see the characters on it if it is covered with a lot of paint ... but it should look like this ...

[bandt]

No pix of the top of the pistons , how high do they sit in the bore ? do they have 4 valve reliefs ?
 the cam specs seem mild to me , 228* duration with 112 CL & only .480 lift is not extreme but there are far better choices now .
 Piston may be cast or hyper , you really want forged , you could drop in a stroker kit for 412 CI .
 J heads are Ok but the 308 will make more power .
 Depends on the budget I guess .
 Cool car 

I was looking at advertised duration of 284*. Those specs are very similar to the Mopar 484. The operating range looks high for the street.

[challngd73]

ok found it.  I think it is B425263.