My 1968 C-20 Golden Anniversary Project

[GerhardH]

Disassembled.
Found some small metall particle below the camshaft. All others without issues.

[GerhardH]

Block cleaned with air gun and petroleum, this works realy good.

[GerhardH]

Found out that the cam is grind (casting number) 930. The GM # is 3896929.
Overlap 90°
Rocker ratio 1.5
Intake timing Opens BTC: 38° (BTC= Before top dead center)
Intake timing Closes ABC: 92° (ABC= After bottom dead center)
Lift .3900" (with 1.5 rockerarm, means lift on the cam is less)
Exhaust timing opens BBC 88°
Exhaust timing closes ATC 52°
Lift .4100" (with 1.5 rockerarm, means lift on the cam is less)
Duration 320°

In my service and overhaul books 1968 327 the lift for inlet and outlet are the same, strange.
camshaft journal ok (1.8682-18692"), surface ok

[GerhardH]

Cam bearings cleaned and checked, ok

[GerhardH]

Cam assembled, crankshaft bearings cleaned and inspected.
Marking on bearing:GMM420 57653 244J3
Marking on thrust bearing: 001 170d7 B GMMA 57871

[GerhardH]

More pictures

[GerhardH]

New rear main seals (FEL-PRO P2900) prepared and oil filter adapter installed.
Marking on old rear main seals: BRUMMER 474

[GerhardH]

Cover for the timing gear cleaned and prepared.
Marking on the old seal: 3980267 SDI

[GerhardH]

Some measures with the crank shaft:

4577 327 62-67 Truck small Journal 2.30“ main Journal x 2.00“ Rod Journal x 3.25“ stroke. Assuming the GM part number is # 3889304. The 4577 crankshafts were in my opinion over the counter production (my engine is a guarantee short block "CE".

[GerhardH]

Some piston measurements.

Piston 3796494 (GM 3816974)
They are 62-8 Chev. H.D. Truck, low compression, recessed head .085 x 3.125, 8.0:1 compression.
They have a steel insert cast into the top ring groove (armored groove) These pistons are a cast piston.

Piston Rings changed against Sealed Power Performance Ring Set E-251K: 5/64 x 5/64 x 3/16 (in.) groove widths. Steel top ring. Grey iron with phosphate coating 2nd ring. The top ring is a plain ring. Unlike Hastings and others. No markings. Installs either side up. Second ring has a dot on top side.

[GerhardH]

Oil pump pressure set to "stock"

[GerhardH]

Today tried to assemble. Got a reverse. In the overhaul book is written:
327 11/32-24 connecting rod cap 35 ft lbs
327 7/16-14 main bearing cap 80 ft lbs

Tried the main caps, after 70 ft lbs I got a bad feeling, stopped.
tried 35 ft lbs on the rod bolt , 30 ft lbs ok than the bolt would be longer and longer and longer


Now ordering new ARP bolts and try again

[GerhardH]

Finished timing gear cover,
chain play new timing gear from 1968: in: 3.868"; out: 3.541"

Lesson learned: It is not necessary to remove the "half moon" key in the crankshaft but was a good training.

[GerhardH]

some more:

[GerhardH]

After I got the right washers, finished the valve and spring assembly heads.

Installed height between 1.725" and 1.730" (origin is 1.750").
Valve pressure measured by 1.750" = 132 ft lbs. , second measurement after movement of the spring: 126 ft lbs. and third measurement after further movement of the spring 121 ft lbs.

Valve pressure measured by 1.730" = 130 ft. lbs. seat pressure
Valve pressure measured by 1.725" = 132 ft. lbs seat pressure

(The Summit 174000 valve spring kit has the following pressures.Seat Pressure at Installed Height 1.750" (lbs):125 lbs. Open Pressure (lbs):325 lbs.)

[GerhardH]

Some more:

[GerhardH]

I ordered the wrong set kit SUM-174001 get seals for 0.307 in. Valve Guide Diameter (in): 0.485 in.

Than I ordered the set for the right valve diameter SUM-174000 0.344 in. (11/32), but the Valve Guide Diameter (in): 0.530 in. instead of my 0.560"

Than I ordered additional seals by Alex parts: .520"- .565".

In my opinion all three different seals are the same.

Lesson learned, read exactly "before one click buy".

[GerhardH]

Suffered the next defeat. My block is Chevrolet small block 2-Bolt Main, small journal, therefore I ordered the ARP-134-5002 Kit.

To short- assuming that the CE (service replacement/warranty engine, casting # 3959512) was prepared as small and big journal to provide solutions for all guarantee cases?

[GerhardH]

Continue!

[GerhardH]

Some more

[GerhardH]

Fuel-,oil pump and cylinder heads

The small plastic bushing in my opinion don't needed if you have an oil pump shaft with a guide (both in picture 1).

Copper oil pump gasket SUM-111480, in my opinion normally not needed, but can't hurt.

[GerhardH]

Head bolts ARP #134-3701 (12-point)

16 pcs 1.750" UHL
04 pcs 3.060" UHL
14 pcs 4.180" UHL

Working perfect.

Torque: 70 ft lbs

[GerhardH]

Preparing rockers, pushrods etc.

Despite I ordered the same part number EPR 34B (8 pcs. each) twice I received two different lengths pushrods=== TIME DELAY!!! Lesson learned: Always order one complete set.

Right length 7.794“
Wrong lenght: 8.544“

Time for preparing accessoiries.

[GerhardH]

Preparing valve covers.

Grommets are perfect:
PCV Valve grommet 42052 Dorman and/or WVE 2P1006

[Ol Blue K20]

That's gonna be a nice engine!