hemi? prototype? weird stuff here... need EXPERT HELP

Help with decoding your Hemi engine.

Moderators: scottm, TrWaters, 392heminut

60s70scollector352
Posts: 1
Joined: Mon Mar 23, 2009 8:56 am

hemi? prototype? weird stuff here... need EXPERT HELP

Postby 60s70scollector352 » Mon Mar 23, 2009 9:46 am

OK....here's what I have....I have a block that is a real mind twister....I was told it was a wedge block, but the casting numbers say different ( I think) The markings are as follows...(Side of block) 2468, then nothing...has a blank, oval shaped pad raised to the same height as the casting numbers and about 3" L x 1" HT....casting date 05/27/64.....(dist pad) "A 426 HP" The HP is Huge! it covers about 75% of pad and is behind the other stampings (have a few chrysler engines in my stable never saw that before) . So .....I know I'm missing a couple numbers here, what should be in that blank area?... my understanding was that the only wedge to have those first 4 numbers was a 413...this is a 426....the only 426 with that prefix...Hemi....soo, now I check rod and crank #s....all come up hemi, so why am I not a really happy guy??? because this block is not cross drilled for the main caps, and better yet, it's a 2 bolt main cap....??????? can anybody tell me what the hell this thing is for sure? Could this be a factory goof or prototype? This has so far stumped everyone who has seen it...even the guys at mymopar.com could not identify with any surety....I have a project this was supposed to power, but I can't use this with a clear conscience until I am sure. besides, it's a short block and I don't know what heads to get anyway!!!! be my hero and clear this up once and for all....lol...thanks

User avatar
scottm
Posts: 2776
Joined: Wed Aug 29, 2001 7:00 pm
Location: Texas
Contact:

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby scottm » Mon Mar 23, 2009 12:46 pm

Can you attach photos, or send them to me to attach them?

BlueDjinn
Posts: 44
Joined: Fri Aug 28, 2009 2:27 pm

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby BlueDjinn » Mon Mar 22, 2010 6:55 am

There is little doubt in my mind that the engine block in your possession is a Stage III 426 MAX
WEDGE and also one of the last, given the date; May 27, 1964. (5/27/64)
Late in 1962, early 63, Tom Hoover and the chief engineer of engine design, Bob Rarey were considering
a Hemi version of the B/RB engine. Up to that time the 426 wedge was the race engine and the decision
was made to put the Hemi head on that block to use the existing tooling.
Changes made to the block were made by lead designer Frank Bialk. One of those changes was new
number 2, 3 and 4 main bearing caps that would accept cross-bolts through the lower block skirt.
Half-inch bolts vertical through the main cap and three-eighths bolts through the block initially; later to
become nine-sixteenths bolts and seven-sixteenths bolts for even greater strength.
That these cross drillings are absent from your block would indicate that it is a dedicated wedge engine
and is not prepped to accomodate Hemi heads. It takes the wedge heads.
426 HP means that it was a first shift (morning) engine. An HP2 would be a second shift (afternoon) engine.
#2468330 is the Hemi block from 1964 to 1971 based upon the Max Wedge block; so not too surprisingly
the rods and crank come up Hemi as those dimensions and components were shared.
The numbers for the 413 MAX block were 2406730. That the HEMI is based on the Max Wedge block means
exactly that; based. The modifications made to the block to strengthen it and allow the mounting of the
hemispherical heads make it unique onto itself; but the 426 wedge is the foundation upon which the
426 HEMI was built.

DRHEMI
Posts: 15
Joined: Mon Jun 08, 2009 11:30 am

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby DRHEMI » Mon Mar 22, 2010 10:35 am

1963 426 blocks were "T" marked on the ID pad on the front valley cover rail. Max wedges would have an additional mark of "MP", and if a factory installed block in a lightweight car, the mark of "HC" would also be found. The only max wedges with an "HP" mark would be the 1962 413 MW. In 1964, the "T" was replaced with a "V". In 1964 there also were "426 HP" block IDs, indicating a non-max wedge block (in this case a "426 street wedge"-the 4 bbl 413 engine enlarged to a 426). 1965 saw the introduction of the year mark of "A" (followed by "B" in 1966, "C" in 1967 and so on for the next decade), and the last year for the 426 street wedge. I believe that your block is from a 1965 426 street wedge, 360 HP, single AFB, hyd lifters. This motor was found in B bodies, and some C bodies, such as police cars. Your block is useful for anyone who has a nice set of standard bore 440 forged pistons and can't find a tight std bore 440 block. A .062" overbore in your 426 and you have a nice 440 engine.
-Andy Carlson

crider
Posts: 3
Joined: Mon Jan 04, 2010 5:09 pm

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby crider » Mon Mar 22, 2010 5:20 pm

Wouldn't it be simple to just lay a wedge or hemi head gasket on the top of the block and see wich one matched up?

DHEMI
Posts: 100
Joined: Mon Mar 06, 2006 8:01 am

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby DHEMI » Mon Mar 22, 2010 8:57 pm

Gasket not required.Just look at the block.If it doesn't have the head bolt bosses
in the upper valley area next to the deck,it's a wedge.

BlueDjinn
Posts: 44
Joined: Fri Aug 28, 2009 2:27 pm

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby BlueDjinn » Sat Mar 27, 2010 3:07 pm

DRHEMI wrote:1963 426 blocks were "T" marked on the ID pad on the front valley cover rail. Max wedges would have an additional mark of "MP", and if a factory installed block in a lightweight car, the mark of "HC" would also be found. The only max wedges with an "HP" mark would be the 1962 413 MW. In 1964, the "T" was replaced with a "V". In 1964 there also were "426 HP" block IDs, indicating a non-max wedge block (in this case a "426 street wedge"-the 4 bbl 413 engine enlarged to a 426). 1965 saw the introduction of the year mark of "A" (followed by "B" in 1966, "C" in 1967 and so on for the next decade), and the last year for the 426 street wedge. I believe that your block is from a 1965 426 street wedge, 360 HP, single AFB, hyd lifters. This motor was found in B bodies, and some C bodies, such as police cars. Your block is useful for anyone who has a nice set of standard bore 440 forged pistons and can't find a tight std bore 440 block. A .062" overbore in your 426 and you have a nice 440 engine.
-Andy Carlson

0.062"...?! .062" is the difference between a standard bore 426 and a standard bore 413; which has
nothing at all to do with a 440. Sixty-two thousandths of an inch over standard bore on a 426 is .008"
(eight-thousandths) of an inch too small to accomodate a stock 440 piston.
That you have to go to seventy-thousandths (.070) of an inch over standard on the 426 to put the std
440 piston in that block would be a gamble with a 46 year old casting that you won't replace once its
gone. Don't do it! An old cherry block that might just need only a .010" (ten-thousandths) of an inch
cleanup is actually worth something and has the potential to last a long time.
If you want to maintain the integrity, longevity and value of your block, you are ill-advised to go anywhere
near the maximum allowable overbore.
Piston ring seal and cylinder wall flex are affected by cylinder wall thickness. The thicker the better.
The closer to standard the better. At just .010" over std, the 426's displacement is 428 (427.59).
At .020" over, the 426's displacement is 430 (429.60) and at .030" over it's a 432 (431.6)
Anyone with a "nice set of standard bore 440 forged pistons" should find a 440 block to put them in.
They are out there.

BlueDjinn
Posts: 44
Joined: Fri Aug 28, 2009 2:27 pm

Re: hemi? prototype? weird stuff here... need EXPERT HELP

Postby BlueDjinn » Fri May 21, 2010 2:10 pm

Depending on the sources of information there is a conflict leading to what I will call "cross nomenclature"
concerning the 413/426 wedges. If for no other reason other than my own edification I decided to do some
"digging"; and yeah, I know this thread is getting long in the tooth so it'll be my last post.

The markings are as follows...(Side of block) 2468, then nothing.....I know I'm missing a couple numbers
here, what should be in that blank area?...
The missing numbers from your block are 0,3,0 for a casting number 2468(030).

...my understanding was that the only wedge to have those first 4 numbers was a 413...
The 413 is not the only wedge with casting number 2468030.
That same block number was used for the 426 wedge. The 413 was block #2468030 from 1959 to 1965.
The 426 was block # 2468030 from 1962 to 1965.
...this is a 426....the only 426 with that prefix...Hemi....
426 HEMI is 2468330. 426 WEDGE is 2468030.
Other block numbers were used for the 426 wedge. Two of those casting numbers, 2406730 (1963-1965)and 2532230 (1964-1966) were used for either Wedge "or" MAX engines. The 413 MAX / Truck block, based on casting # 1852029 (1959-62) is the same casting number used for 426 wedge #1852029, (not a 426 Max). It would seem that the 413 and 426 share some block casting numbers; 2658836 is the Industrial / Truck 413. It's also the Industrial /Truck 426.
Block numbers 2205697 (1964) and 2440873 (1962-65) are 426 wedge.
...it's a short block and I don't know what heads to get anyway!!
Horsepower of your 426 #2468030 was 365@4800. Torque was 470 ft/lbs @3200. Compression ratio was 10.3:1. Uses a single 4 barrel on a cast iron intake. Cylinder heads would have been closed chamber with heat passage. To run that engine now on pump gas I'd run open chamber heads to drop the compression slightly; keeping in mind that it's a street application requiring heat passages for carburetor performance and hardened valve seats for unleaded gasoline.
If it were my block I'd locate a boneyard 1976, 77, or 78, 400 or 440 engine and take the cylinder heads complete with intake manifold. Exhaust manifolds too. Those cylinder heads are open chamber wedge, with hardened valve seats. The cylinder head number ends in 452. 452 heads are basically a factory upgrade on the 906 heads. They have the same valve size, flow the same and unlike the 906 they run unleaded gasoline. The intake manifold would port match the heads and the intake mounts a single Carter 4 barrel. That's where I'd start with it but then that's your business. It wouldn't hurt to get in touch with Direct Connection (yeah, I still call them that); I mean Mopar Performance, and they can open up your options.


Return to “Decode My Hemi”

Who is online

Users browsing this forum: No registered users and 1 guest