Mystery block (to me at least)

Posted By: 67440dodge

Mystery block (to me at least) - 12/14/14 05:05 AM

Got a short deck big block on the stand. It came out of a 71 Challenger R/T, and according to the seller, it was original to the car. Build date on the block is June 7, 1971. Block has been decked so numbers on the pad are illegible. No VIN stamping is legible on the pad either.

Pistons are .060 over for a 383 (Speed Pro L2315F). Checked the bore, and it comes out to 4.310.

Stroke comes out to 3.38, so it appears to be a 383.

Here's where the fun comes in.

Casting number is 3614230-5. Block has the stiffening ribs for a 400, and the hump on the bellhousing mount for a 400. So for all intents and purposes, it's a 400 block. It even has the thick main webs of the early casting 400's. But the cylinders are bored for 383, and there is no sign of any sleeving being done to get .060 over 383 pistons in a 400 block.

Anyone ever see a block like this?

Posted By: WO23Coronet

Re: Mystery block (to me at least) - 12/14/14 05:25 AM

With that late of casting date it sounds like it's one of the last 383's made, OR it's a warranty block and they just used a 400 block and bored it to 383 specs, neat piece though

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/14/14 05:36 AM

Quote:

With that late of casting date it sounds like it's one of the last 383's made, OR it's a warranty block and they just used a 400 block and bored it to 383 specs, neat piece though

This is not the first time this has come up , the fact that it doesn't have a VIN points to a replacement block, without paperwork to back it up np saying what is going on in there .

OP , what is the SPD of the car ?

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/14/14 06:05 AM

Quote:

This is not the first time this has come up , the fact that it doesn't have a VIN points to a replacement block, without paperwork to back it up np saying what is going on in there .

OP , what is the SPD of the car ?

Don't know.. the guy sold the car the same time he sold me the motor and moved south. It's been sitting under my bench for 8 months and just started to check it out.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/14/14 06:36 AM

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Quote:

This is not the first time this has come up , the fact that it doesn't have a VIN points to a replacement block, without paperwork to back it up np saying what is going on in there .

OP , what is the SPD of the car ?

Don't know.. the guy sold the car the same time he sold me the motor and moved south. It's been sitting under my bench for 8 months and just started to check it out.

then it doesn't really matter I guess . It would have been a very late build car , like last week of production to get a 230 based 383 and only because there was no more 383 castings left to use. More than likely a warranty replacement block , couldn't have been the original or else the guy wouldn't have sold the car without it ???

Anyway at .060 it would need to be sonic checked before boring larger , at stock bore it would have been a nice block to build a 383 based race motor , assuming the bores were not core shifted bad , thick bores say rounder under power.

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/14/14 06:59 AM

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then it doesn't really matter I guess . It would have been a very late build car , like last week of production to get a 230 based 383 and only because there was no more 383 castings left to use. More than likely a warranty replacement block , couldn't have been the original or else the guy wouldn't have sold the car without it ???

Anyway at .060 it would need to be sonic checked before boring larger , at stock bore it would have been a nice block to build a 383 based race motor , assuming the bores were not core shifted bad , thick bores say rounder under power.

He put a 440/6 in the car, and intended on selling the 383 with the car to keep them together. But whoever purchased it didn't want the 383, so I bought it from him.

It's more a curiousity thing, had never heard of a block with a lower displacement than what the casting number said it was..

Posted By: dogdays

Re: Mystery block (to me at least) - 12/15/14 05:42 PM

Mopar, never say never!

Sonic check it. You may be pleasantly surprised. When you do, report back because this topic has come up again and again.

There are Industrial 413s that have the same casting number as Industrial 426s.

R.

Posted By: cudaman1969

Re: Mystery block (to me at least) - 12/16/14 12:31 AM

A 400 block is standard at 4.32. It is not a warrenty block, no way would they go to the trouble to sleave it back to 4.31. A sonic check would tell how thick the walls are. My guess is its a industrial block(they are the best blocks for strength) that started out at 4.25 bore and can go to 4.375 like the 400.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/16/14 01:29 AM

Quote:

A 400 block is standard at 4.32. It is not a warrenty block, no way would they go to the trouble to sleave it back to 4.31. A sonic check would tell how thick the walls are. My guess is its a industrial block(they are the best blocks for strength) that started out at 4.25 bore and can go to 4.375 like the 400.

A 400 block is standard at 4.342 , that's nice and thick where it is , but if he wants to bore it out it would be best to have it sonic checked , I had a 230 block that needs 2 sleeves because of core shift to go out to 4.375

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/16/14 05:56 AM

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

Attached picture 8363844-block.JPG

Posted By: StrkrDart69

Re: Mystery block (to me at least) - 12/16/14 06:12 AM

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

Dont ask questions until you have done your homework.

Posted By: dweller

Re: Mystery block (to me at least) - 12/16/14 04:41 PM

Quote:

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

Dont ask questions until you have done your homework.

Go back into your hole. Nothing wrong with the post or the discussion.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/16/14 09:40 PM

Quote:

Quote:

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

Dont ask questions until you have done your homework.

Go back into your hole. Nothing wrong with the post or the discussion.

Huh ??

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/16/14 09:43 PM

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

What are the pistons , 2315 ? they will be about .015 in the hole , but the block appears to have been decked already , which is why that ID pad is blank.

The only downside to those pistons are the lack of valve reliefs .

I would just run it as it until something causes you to have to take it apart.

Posted By: cudaman1969

Re: Mystery block (to me at least) - 12/17/14 02:12 AM

Quote:

Quote:

A 400 block is standard at 4.32. It is not a warrenty block, no way would they go to the trouble to sleave it back to 4.31. A sonic check would tell how thick the walls are. My guess is its a industrial block(they are the best blocks for strength) that started out at 4.25 bore and can go to 4.375 like the 400.

A 400 block is standard at 4.342 , that's nice and thick where it is , but if he wants to bore it out it would be best to have it sonic checked , I had a 230 block that needs 2 sleeves because of core shift to go out to 4.375

Sorry for the mistake on bore size,thinking one thing typed another.

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/17/14 06:10 AM

Quote:

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

What are the pistons , 2315 ? they will be about .015 in the hole , but the block appears to have been decked already , which is why that ID pad is blank.

The only downside to those pistons are the lack of valve reliefs .

I would just run it as it until something causes you to have to take it apart.

yea.. 2315's are in it. The cam that came with it isn't too crazy (Comp XE-274), so no valve reliefs shouldn't be a problem.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/17/14 06:33 AM

Quote:

Quote:

Quote:

The motor was freshly built when I bought it. Said he changed his mind after it as built and had a 440/6 done and put it in.

Wish I had a sonic tester, love to see how thick the walls really are.

What are the pistons , 2315 ? they will be about .015 in the hole , but the block appears to have been decked already , which is why that ID pad is blank.

The only downside to those pistons are the lack of valve reliefs .

I would just run it as it until something causes you to have to take it apart.

yea.. 2315's are in it. The cam that came with it isn't too crazy (Comp XE-274), so no valve reliefs shouldn't be a problem.

Should be a good base engine, and closer to 400 cubes vs. 383. What heads are you using ?

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/17/14 11:27 AM

Quote:

Should be a good base engine, and closer to 400 cubes vs. 383. What heads are you using ?

Plan right now is to go with 75CC Eddy's. The 452's that came with it are paperweights unfortunately.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/17/14 04:56 PM

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Quote:

Should be a good base engine, and closer to 400 cubes vs. 383. What heads are you using ?

Plan right now is to go with 75CC Eddy's. The 452's that came with it are paperweights unfortunately.

Good choice , so many people blindly go with open chamber heads because they think they were good because they came on 6 pk engines ...

Posted By: WO23Coronet

Re: Mystery block (to me at least) - 12/17/14 10:40 PM

Does it have the thick main webs like 230 blocks are supposed to have? Can you show a pic?

Posted By: dogdays

Re: Mystery block (to me at least) - 12/17/14 10:47 PM

Not all 230 blocks have these thick webs,, only the ones with the 1" high casting numbers.

R.

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/17/14 11:51 PM

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Does it have the thick main webs like 230 blocks are supposed to have? Can you show a pic?

If the pictures I've seen are of the thick main web blocks, then it looks like it does have them.

Attached picture 8365530-DSCF1175.JPG

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/17/14 11:52 PM

Here the side the throw was hiding

Attached picture 8365531-DSCF1179.JPG

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/17/14 11:55 PM

And no stampings on the oil pan rail.

Attached picture 8365535-DSCF1182.JPG

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/18/14 01:49 AM

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And no stampings on the oil pan rail.

the casting date tells you it's a thick web block , any 230 block before a certian date , I think it's 10/17/71 ??? is thick web.

There would be no stamps in that location, at least I have never seen it on anything built for the 69 and later model year on a Wedge block.

The VIN stamp you are looking for on the oil pan rail is on the SIDE of the block , pass side , just above the oil pan rail.

Posted By: 67440dodge

Re: Mystery block (to me at least) - 12/19/14 12:43 AM

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And no stampings on the oil pan rail.

the casting date tells you it's a thick web block , any 230 block before a certian date , I think it's 10/17/71 ??? is thick web.

There would be no stamps in that location, at least I have never seen it on anything built for the 69 and later model year on a Wedge block.

The VIN stamp you are looking for on the oil pan rail is on the SIDE of the block , pass side , just above the oil pan rail.

I've never actually looked for a stamping on the oil pan rail before either, I saw it mentioned in the tech archive here http://www.moparts.org/Tech/Archive/motor/36.html and figured I'd give it a look. The VIN pad is definetely bare, no signs of anything ever stamped there.

Posted By: B5 Bee

Re: Mystery block (to me at least) - 12/19/14 04:23 AM

There were some 440 cast blocks that only were bored to 4.25. They were over the counter, not production. I heard they were originally planned to go to NASCAR racers that ran a RB wedge in the early 70s. A few Stock Eliminator racers found out about them and used them for the thick walls.

Posted By: JohnRR

Re: Mystery block (to me at least) - 12/19/14 04:33 PM

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Quote:

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And no stampings on the oil pan rail.

the casting date tells you it's a thick web block , any 230 block before a certian date , I think it's 10/17/71 ??? is thick web.

There would be no stamps in that location, at least I have never seen it on anything built for the 69 and later model year on a Wedge block.

The VIN stamp you are looking for on the oil pan rail is on the SIDE of the block , pass side , just above the oil pan rail.

I've never actually looked for a stamping on the oil pan rail before either, I saw it mentioned in the tech archive here http://www.moparts.org/Tech/Archive/motor/36.html and figured I'd give it a look. The VIN pad is definetely bare, no signs of anything ever stamped there.

If there is no VIN there you can be 90% sure that was not the original block in the car it came from , that is why it didn't go with it .

I never saw that page , glancing over it quickly I saw one error , I'm sure there are more .