block stamping

[68ys8030]

Guys,
I am working on a friends car and the block has a casting date of november and the stamped date on the front of the block is the 3rd week of march. the stamping looks factory.
can this be? over 3 months ? thanks ! steve

[rsatz28]

Not trying to hijack this thread, have there been any cases where the partial VIN has been restamped on the side of the block by the filter?

[Alss]

My 70 Chevelle was built the 3rd week of March..the motor..September!

ALbert

[nuch_ss396]

I have a February 69 assembled L/78 with an August 68 cast date
on the block. How's that for stretching it out?

Steve

[TimG]

I had a very late production 1968 435 Corvette with a nine month spread between the casting date and assembaly date. No question it was the original, unaltered block. It was a one owner, local car that terrorized the streets of Austin with a plate that said "NUKE" because it could blow away anything on the street. I first saw this block out of the car in 1985 in all its glory long before good stampings were being done. I owned the car for about three years and know where it is today.

[nuch_ss396]

Tim,

That has to be a record. My spread was about 6 months and
I always thought that was a real stretch. Nine months almost
defies our "knowledge" of production practices.

What, in your opinion, do you attribute the date spread to?

Steve

[mrrec]

Easy to believe. How about an August 67 cast and built L35 396 not installed until a 4B 68 Camaro??!! Untouched engine and original car with tons of docs and conversation with original owner so its right without a doubt....
Dave

[TimG]

That's interesting because I've heard that GM didn't let long blocks sit too long due to the cost of the completed motor. I would argue that this engine definitely had some problems as an assembaled long block and went to the repair area to be corrected. It could have waited for months to be repaired and finally installed in a a car. It was stamped and the problem could have been disocvered, something like a valve or cam could have failed and it may not have required a complete rebuild.

[nuch_ss396]

Tim,

As an NCRS member, you may have already seen this post I did there a few months ago.
I thought it fitting to post it here as well in light of the current topic.

************************************************** ************************************************** *
This article was in the: 1966 Corvette News magazine Volume 9 No. 5

I am not claiming any credit for this information. I just thought I would post it here
for all to see as I'm sure some have not seen this information before. Here is a basic
run-down of the assembly steps on BBC engines per this article:

- After rough machining operations, block surfaces are broached, cylinders honed,
main & camshaft bores are line-bored.

- High pressure water cleaning and hot air drying of the blocks.

- Install camshaft

- Main bearings & crankshaft installation along with rough cap bolt tightening.
All cap bolts are then hand torqued.

- Timing gears & chain installation followed by hand torquing.

- Piston are installed, bearings & caps added, rod nuts are hand torqued.

- Flywheel & clutch are installed. Now, based on some of the pictures in this
article, the bell housing is also installed and appears to be unpainted.
BTW, the oil pan is not yet installed.

- Oil pump installation

- Oil pan installation ( all 20 pan bolts tightened at one time ).

- Assembled short block turned over to assemble heads.

- Cylinder head water coolant passages were filled with shaving cream
( yes, that's what it mentions ). This was evidently done to keep stray
core sand particles from falling into the assembled engine. I'll have to
try this one - one day. And no, the brand of shaving cream wasn't mentioned.
Remember the old Noxema Shaving Cream commercials with the blonde? My money
goes with Noxema - HA HA.

- Cylinder head bolts are hand touqued.

- Initial valve clearance set with feeler gauges.

- Manifolds, water pump, and temperature sending unit installed.
High pressure testing of cooling system is then performed.

- Engines then go to the testing area ( less carburetor(s) and engine
accessories ). Water & oil are added. A temporary exhaust system is
attached. Liquid petroleum gas in pumped into the intake manifold. Also,
a temporary starter is used to crank the engine.

- Once the engine passes this inspection phase, it goes off to painting.

- Preformed masks are placed on the engine to shield all components that
shouldn't be painted. With a wall of water behind and beneath the engines,
they are sprayed with a quick-drying enamel paint.

Steve
************************************************** ************************************************** *

So Tim, at what point would you expect the engine to fail a
test and the assembly side-lined for repair? This is the
question I think most relavent to this topic.

Steve

[TimG]

I think an engine could encounter a problem at any number of stages. It could drop a valve during run-in, any number of threads could strip, a rocker arm could break. I was in Al Grennings two hour seminar in San Antonio on engine stampings and it was noted that engines with any number of problems sat in a holding area for repair. They lined up until workers could repair or salvage these blocks or components. I would imagine some were beyond repair if a rod let go, or something like that. If a thread stripped, they may set the engine aside until time permits and re-tap the threads. The engine assembly date and build durative are not placed on until well in the process and before the heads are installed. If a problem surfaced in the short block, the block could sit for weeks or months before being repaired with absolutely no stamp on the pad. If a problem surfaced after the stamp was applied, the long block could wait for repair and later be installed in a car with a long spread between assembly date and build date of the car.
Al Grennings class was amazing, he had dozens of idiosyncrasies in trim tags and stampings that would drive an NCRS judge crazy.