Old Race 340 Teardown

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That was a dandy build, it would fun to hear it sing with a four speed and a set of 5.13's.
 
I looked up some info on X blocks and some of them were severely decked. That would explain the thin manifold flanges.
 
Super Sleeper said:
Cool! Do you remember if it was Jim Meyer or Bob Harris at that time? I know Bob raced at Las Vegas cause I have some of his timing slips but probably Jim Meyer did also before he sold the car to Bob. You are absolutely right about it being Super Gas class. That's what happens when I write things from memory!
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I have a picture of it went it ran Pro Stock with Jim Meyer from the world finals at Ontario Motor speed way. Bob Harris was driving at the Super Gas
 
Those BME rods can be run on the street just fine. I had a set from a 426 and read up on them. That W2 SD intake looks different from the one I had. My top was square, not clover shaped and the IIRC the bolt holes were double drilled on my example, just about 1/8 difference so they looked like 8's. Come to think of it, It must have been adapted to the LA when I got it as it bolted right up to my X heads with its port mismatch and all. Ran great! Traded it straight across for the proper LA SD intake at the Long Beach swap meet. That guy was selling a set of W2 heads for $300! That long ago.....
 
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pishta said:
got a pic of the front water neck?
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cool, I got to fashion one on my sheet metal intake. Thought about just running 2 Russel 45's out the flange, hosed to a remote stat housing.
 
70aarcuda said:
I have a picture of it went it ran Pro Stock with Jim Meyer from the world finals at Ontario Motor speed way. Bob Harris was driving at the Super Gas
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Cool, I'd love to see that picture if you care to post it. Here's one of the team. That's Bob, third from the left. I wish I knew more details.
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pishta said:
Those BME rods can be run on the street just fine. I had a set from a 426 and read up on them.
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Good to know, thanks. My knowledge of aluminum rods is very primitive. I assume they have a pretty limited life. If I decide to go with any replacement parts then these might be worth selling?

I really appreciate all of the help I'm getting on this thread. It will be another week before my friend can bring up his deck height micrometer. I'll have to try to cc a chamber also. All suggestions on how to assess this engine are certainly welcome.
 
As far as a “How to” refine it for the street, I would just simple order a set of custom thickness (& diameter) head gaskets from Cometic. Swap the cam to meet the need and run everything else it came with.
 
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The rods are eye candy for sure. If you can meet your compression requirements with that piston I’d not hesitate to use it. As well as the rods. The rods do have a life cycle in a drag race environment but in a de tuned street engine they’ll last a good long while. If you are going to road race it you should consider moving to a forged steel rod for constant high rpm durability.
 
Super Sleeper said:
Wow, thanks, I didn't know. Google told me the rest. But I was mistaken about his class, it was super gas. Don't know what those rules said in 1980. But it may also have been a left over piece from the Valiant, which he also ran as a 340 with a Paxton supercharger in the 11.80 bracket. The reason I think that might be the case is the doublers welded into the mounting flanges of this Strip Dominator. Would there be any other reason to do that?
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I knew the class wasn't right. Way too many pieces on that motor that are/were not Super Stock legal.
 
I would think this engine would be pretty valuable to the right person. You could sell this for quite a chunk and us the proceeds to build a proper street ripper. Replicating an engine like you have would be super expensive. Not to mention the development and tuning that would have gone into it. It's probably nicely sorted out as a race engine. You may find out the expensive way why that intake is so cut up. I bet you spend way more making that a street engine than you imagine.
 
70aarcuda said:
It is on another computer that has not run in a couple of years......give me a couple days to fire it back up.....
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I know the feeling with old PCs! I have several old hard drives spinning in newer PCs just to stay connected with older stuff. Thanks for taking the time!
 
Mean416 said:
I would think this engine would be pretty valuable to the right person. You could sell this for quite a chunk and us the proceeds to build a proper street ripper. Replicating an engine like you have would be super expensive. Not to mention the development and tuning that would have gone into it. It's probably nicely sorted out as a race engine. You may find out the expensive way why that intake is so cut up. I bet you spend way more making that a street engine than you imagine.
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Thanks! Certainly I understand that this purpose-built combo is worth keeping together. At this point I just wanted to assess its internal condition. Never really considered making it a street engine, just "de-tuned" as a possible road race engine. All the input I have got in this thread, including yours, goes a long way towards helping me understand what I have here.
 
Super Sleeper said:
Thanks! Certainly I understand that this purpose-built combo is worth keeping together. At this point I just wanted to assess its internal condition. Never really considered making it a street engine, just "de-tuned" as a possible road race engine. All the input I have got in this thread, including yours, goes a long way towards helping me understand what I have here.
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Not to mention the extreme sentimental value
 
Just a little update. I had a good look around the crankshaft, looks like a 2532457 forging with an 8-bolt flange. The piston travel I measured with my caliper was 3.454. So it's a stroker? The rod journal measured 2.1245, with a Clevite 0.001 undersize shell (in very good shape). So does that mean this crank was welded to build up the journal size? Or were there 2532457 forgings in 3.454 stroke?
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BTW, one bolt head broke off when I removed the flex plate. All 8 holes are threaded. - Jim
 
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I have the same crank, it’s 3.46 stroke. not welded up, the crank is a forged piece. I also have BME aluminum rods.
cubic inch is 362

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MoPar had a few (*3 I think*) small journal forged cranks in that stroke range to compete in the 355 cid rule. I also have one that makes 352 cubes with a 4.03 bore.
 
Here is a shot of a 1993 Mopar Performance catalogue showing the forged crankshafts available at the time. Yours should be the P4120312 or equivalent. The last 3 digits were often punched into the front counterweight face.

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Super Sleeper said:
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See how there's an extra thickness of plate welded on top of the original cast flange, under the bolts? It looks like it's meant to stiffen the whole flange. I thought the same thing about port matching the W2 ports but since the manifold was specific to the W2 (as shown in the original Holley box picture) I am not sure that would be necessary.

I think this manifold is a carry-over from his 340 that was in the Valiant, which had a Paxton supercharger. Maybe it was insurance that there was enough clamping pressure to keep from blowing out the gasket? I know he was developing enough pressure to crush brass floats. The carb was inside a pressure box (on the Valiant, not the Duster, which was always normally aspirated).
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Not sure, but food for thought. I have an old strip Dom on my 340. I friend of my ( ol.school Mopar drag racer) stopped by when I was buttoning up the top end. He said " lemme see that, before you put that on there" I handed it over, he flipped it over and closely inspected it. Said the areas around the bolt.holes were prone to hairline cracking on that intake, causing hard to find vacuum leaks....maybe they were preventive in your case?
 
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