Author Topic: A scratch block  (Read 1117 times)

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Offline specialCJ

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A scratch block
« on: March 12, 2019, 06:39:46 pm »
Local guy has what he says is a CobraJet block for sale. C6ME-A casting and it clearly has a large A on the back and he says the date is 9A31. I don't believe it is a CJ block and he is reading the date wrong??
69 Mach 1 428 CJ-R

Offline sportyworty

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Re: A scratch block
« Reply #1 on: March 12, 2019, 06:58:45 pm »
The C6ME engineering combined with the A scratch sounds like 6A31
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Offline corbins

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Re: A scratch block
« Reply #2 on: March 12, 2019, 07:23:56 pm »
As noted in a recent post, there is really no such thing as a "cobra jet" block. And I don't believe that "A" block will have the 3 finger webbing commonly found in  the "C" scratch blocks , but I may be wrong.. others know much more :)
Steve Corbin

Offline specialCJ

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Re: A scratch block
« Reply #3 on: March 12, 2019, 07:25:33 pm »
I will try to get a picture of the date. Not looking for a CJ block, looking for a PI block but many who have 428's think they are all CJ blocks and want CJ money for them.
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Offline specialCJ

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Re: A scratch block
« Reply #4 on: March 12, 2019, 08:01:14 pm »
Picture he sent is of a hand stamped date I assume to be the assembly date.
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Offline sportyworty

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Re: A scratch block
« Reply #5 on: March 13, 2019, 08:12:54 am »
Assembly dates are typically 7-10 days after casting date. A C6ME block was not cast in 1969. The C7M variants were not even being used by Jan 1969.

"A" scratch on rear bulkhead with standard crank saddle webbing: August 1965 - October 1966
"A" scratch on rear bulkhead with reinforced crank saddle webbing: November 1966 - May 1967
"C" scratch on rear bulkhead with reinforced crank saddle webbing: June 1967 - March 1970
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Offline sportyworty

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Re: A scratch block
« Reply #6 on: March 13, 2019, 09:46:48 am »
I will try to get a picture of the date. Not looking for a CJ block, looking for a PI block but many who have 428's think they are all CJ blocks and want CJ money for them.

Pat the only unique 428 block is the 1966 Solid. 67-70 PI, CJ, and passenger car 428 utilized the same hydraulic cylinder block.
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Offline preaction

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Re: A scratch block
« Reply #7 on: March 13, 2019, 11:29:02 am »
Kerry, were the 66PI blocks similar to MR blocks in that they were drilled for solid lifters only ?
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Offline RoyceP

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Re: A scratch block
« Reply #8 on: March 13, 2019, 11:54:54 am »
More like 332 FE blocks with a bigger bore. They share none of the 427 block upgrades other than the lack of any provision for hydraulic lifters.

Those early 428 PI blocks are rare. The camshaft is a real snoozer, just like the early 427 cams. There was no real reason for them to have solid lifters. At least none that is logical to me.

Kerry, were the 66PI blocks similar to MR blocks in that they were drilled for solid lifters only ?
1910 Model T Ford Touring Red
1915 Model T Ford Touring Black
1914 Model T Ford Touring
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1968 Mercury Cougar XR-7 GT-E Green 427 W Code
1968 Mercury Cougar XR-7 428CJ R code 3.91 C6

Offline tbolt2

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Re: A scratch block
« Reply #9 on: March 13, 2019, 02:05:50 pm »
Kerry, were the 66PI blocks similar to MR blocks in that they were drilled for solid lifters only ?

The C6AE-6010-J Cyl Block Assy, which appears to be the PI.  Uses the 406 C2AE-6015-AJ Cyl Block design.  Tappet galleries are not drilled, a provision for oil pressure relief valve, .100" min wall thickness, and reinforced (three) webs.  Also twelve cyl bore (1-8,A-D) grade sizes for optimizing piston to wall clearance, the later larger thrust main bearing, and dye penetrant inspection for cracks or indications.  At least according to the engrg drawings.

The mechanical tappet camshaft was utilized as it was known that the hyd tappet cam was done at 4,500 rpm.

Regards,
Dennis 
Regards,
Dennis

Offline preaction

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Re: A scratch block
« Reply #10 on: March 13, 2019, 04:21:06 pm »
Dennis thanks for posting that info I figured these blocks were not too common today, info is the best ammo.
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Offline blackthunder70

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Re: A scratch block
« Reply #11 on: March 13, 2019, 05:36:28 pm »
Assembly dates are typically 7-10 days after casting date. A C6ME block was not cast in 1969. The C7M variants were not even being used by Jan 1969.

"A" scratch on rear bulkhead with standard crank saddle webbing: August 1965 - October 1966
"A" scratch on rear bulkhead with reinforced crank saddle webbing: November 1966 - May 1967
"C" scratch on rear bulkhead with reinforced crank saddle webbing: June 1967 - March 1970
Hi
Have two 70 DJ cars one with a may date and one with April dateboth have the c scratch and extra webbing
Cheers
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Offline x-70option

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Re: A scratch block
« Reply #12 on: March 13, 2019, 06:25:27 pm »
Oh boy
Mark Haas
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Offline wsu0702

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Re: A scratch block
« Reply #13 on: March 13, 2019, 06:48:36 pm »
Oh boy

That's an FT block that was cast with 428 water jacket cores.  Fairly rare but not the weird one-off that the OP claims.

Offline fecarman

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Re: A scratch block
« Reply #14 on: March 18, 2019, 12:14:06 pm »
And the saga continues. Something like the conspiracy theories. Maybe someone will make a movie about A and C scratch blocks and build dates. Yawn...……..

Offline redscj

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Re: A scratch block
« Reply #15 on: March 18, 2019, 01:28:03 pm »
     I thought that by 69 the casting number was meaningless.
« Last Edit: March 19, 2019, 02:59:55 pm by redscj »
Grant
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Offline sportyworty

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Re: A scratch block
« Reply #16 on: March 18, 2019, 08:40:37 pm »
And the saga continues. Something like the conspiracy theories. Maybe someone will make a movie about A and C scratch blocks and build dates. Yawn...……..

The fact is it's solved and quite simple to follow actually. The timeline is reliable and clearly illustrates the features.

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Offline sportyworty

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Re: A scratch block
« Reply #17 on: March 19, 2019, 03:59:34 pm »
     I thought that by 69 the casting number was meaningless.

The engineering number cast into the cylinder block is not a reliable indicator of original displacement. It was a common mold plate shared with other FE displacement apps. There are exceptions like the C8ME GTE 427 but for our 68-70 CJ cars they were using the C7M engineering number variants on 352/360/390/428 castings and the 428 blocks stop casting the number starting some time in October'ish 1968. Engineering numbers are not part numbers when it comes to application specifically
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Offline specialCJ

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Re: A scratch block
« Reply #18 on: March 24, 2019, 04:52:21 pm »
Wanted to share the answer to the mystery. Got a picture of the cast date on the block in question. It is 6A15 so obviously way too early to be a Cobra Jet block.

Pat
69 Mach 1 428 CJ-R