Re: [Chrysler300] HP block stamp on early 300s

Rich, Bob and All:

The 300D engine numbers are variable on the microfilm. They start out the year with just the last 4 digits only----no 583N or 3N58. I didn't look at all (I'm not that nutty), but by around 1078 they were using the 3N58 XXXX in the style of the C300, 300B and 300C---but without the "E". In less than 90 cars, they were writing the engine number on the IBM card as 583N XXXX. Not long thereafter, it settled in to mostly 3N58 XXXX. I have very few actual comparisons of Chrysler's written number vs what was actually stamped into the block, but do have that comparison for engine #1186. Yup, you guessed it! The number on the microfilm copy of the factory IBM card is 3N58 1186 and the actual block stamping is 58N3 1186!! The 1958 Service Manual states the 300D engine number to be 58N3 XXXX. Finally, nearer the end of the 300D production, many, if not most, IBM build cards had just the last four digits written in. Apparently the plant just gave up on the prefix order.

Anyway, that is all I know about the 300D engine numbers. Regardless of the order, a 1958 engine should have a "3" in its prefix somewhere to be a real "D" engine.

300ly, Gil Cunningham

In a message dated 1/13/2014 2:55:20 P.M. Eastern Standard Time, c300@xxxxxxx writes:

Bob:

1955-58 300’s had hemi’s which were individually serial numbered in the format shown below. The engine serial numbers had no fixed relationship with the chassis VIN’s but were recorded by hand on the IBM build card which enables documenting a block as “original”. XXXX’s are four-digit numbers with the first engine each year being # 1001.

1955: 3NE55XXXX

1956: 3NE56XXXX

1957: 3NE57XXXX

1958: I’m not sure. I’ve had both of these reported and would appreciate being advised which is correct (maybe both?): 58N3XXXX and/or 3N58XXXX

1959 engine serial numbers have been reported to me as MR413 XXXX or MR413 XXXXX . No HP’s reported in & #8217;59 or ‘60

C300K’ly,

Rich Barber

Brentwood CA

1955 C-300-- VIN: 3N551198, engine serial number: 3NE551098

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Bob Jasinski
Sent: Monday, January 13, 2014 11:05 AM
To: Chrysler300@xxxxxxxxxxxxxxx
Subject: [Chrysler300] HP block stamp on early 300s

Thanks for re-posting this Loren, I do remember reading it before, when George originally posted it way back when. Of course, George is gone now, so we can't ask him how he came by this information, but he was a very knowledgeable man and knew many people close to Chrysler corp.

Regarding the '55 to '59 300 letter cars, were any of those early 300 blocks stamped HP also? I've not owned an earlier car and am not as familiar with the block stampings. Was the '61 300G the first letter car to have the HP stamp?

Bob J

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Loren Nelson
Sent: Monday, January 13, 2014 9:23 AM
To: Chrysler300@xxxxxxxxxxxxxxx
Subject: [Chrysler300] Re: That's Racin' - Warren ave plant

Please excuse me if this has been sent before. I sent this with Outlook Express and did not see it in my mail, so will send it again. HP engines were discussed earlier in this thread. This was George Reihl's responce to a server question about 300 engines. I have no idea where he got this information or the accuracy of it.

Loren Nelson in sunny and finally warmer N. Georgia

Since you asked I went out to the garage and measured -- the HP stamp is
slightly larger than the S 41 stamp -- I'd guess one font size. The S 41
< span style='font-size:10.0pt'>stamp and the date code stamp are the same size.

By the way, HP blocks are a different casting blend than standard blocks --
higher nickel content. HP blocks also were heat treated for stress relief.
HP blocks were built in batches, separate from normal blocks, so they were
not pulled out of the production line for performance modifications. HP
blocks sat in a group in the warehouse until they were pulled for the
production line, which is why the date stamp on an engine can be much
earlier than the car's build date.

You are correct in the way the Chrysler blocks are cast. All 413 blocks, and
others, are cast out of the same material with high chrome and nickel
content. More than the other car manufacturers blocks & heads contain.

Blocks and heads co ming out of the foundry are cooled then reheated for
stress relief. Then sent for the initial machining. They are checked for
sand holes, discarded if any, then final machining and checked again. Any
blocks or heads not up to par are sent back to the foundry for remelt.

When blocks and heads are found to be perfect, after machining, some are
destined for the "premium" line. Generally for high performance, marine and
industrial use. From what I have been told by some of the "old timers", is
that on the premium engines, final machining is done with "new" tooling to
keep close tolerances. "Used" tooling is the used on non premium blocks.

After all machining is done, the blocks & heads are sent to the assembly
line. The 300 engines, Pistons, bearings, crank, etc. are carefully
assembled. All of the high perf. engines then get a precise balance job. I
have been t old, plus or minus 2 grams, other engines get as much as 20 gram
balance.

With the high performance engines, they get a flame hardened forged
crankshaft to .060. This is what makes a H.P. engine along with the
camshaft. N.Yers. and Imps do not get these engines and their cranks are not
hardened. After the precise machining, crank, camshaft, etc., then the "H P"
is stamped onto the block along with the date of engine assembly.

All 413 blocks have the same casting numbers along with the various shift
codes when they were cast. Exception to that rule is the "motor home"
blocks. They are cast special because of the extra cooling passages cast
into them and also the heads. Motor home blocks and heads should never be
mixed with regular engine components. But their cranks are hardened

Other non premium blocks will have the "diamond", "maltese cross" and other
stampings associated with "under sizes" incorporated into the blocks.

Re: undersize crank, oversize rod bearings, oversize lifter bores, and
sometimes oversized main bearing bores. On GM engines, one can find "shims"
under the main bearing caps because of oversize line boring. Never will one
find these marks on a premium "Chrysler" block.

All 413 blocks are not the same. That goes for all the other "H.P." engines that come out of the Chrysler foundry and machine shops, 318, 340, 360, etc. In all of my years, Chrysler builds the best engines. George Riehl>