My 1968 C-20 Golden Anniversary Project

[GerhardH]

Part4

[GerhardH]

Part5

[GerhardH]

Part6

[GerhardH]

Part7

[GerhardH]

Part8

[GerhardH]

Part9

[GerhardH]

Next part head dimension 3991492

[GerhardH]

Next cylinder head

[GerhardH]

next

[GerhardH]

some additional

[GerhardH]

#14

[GerhardH]

#15

[GerhardH]

end

[GerhardH]

Measurement of the hole for the temperature sending unit, guessing 1/2 NPT, will show evidence later.

[GerhardH]

Cylinder head hole indentification

[DeadheadNM]

Heads look great! Tell me about the beer in post #70 please

[GerhardH]

https://www.google.com/url?q=https:/...8FbdZmDlXE48RB
Augustiner Hell ( means not Hell means bright)
My favorite if I'm not in US and drinking IPA

[GerhardH]

Insvestigation where to measure the valve shaft ( Approx, 1.5" of the shaft is in the chamber and the valve guide is round about 2" long. Differences between several instruments. Use the micrometer therefore (3 Positions all 0.3414")

[GerhardH]

Valve head 2.02 " and 1.60"
Preparation for measurment chamber volume.

[GerhardH]

Forget to screw in the spark plug = Leak & again
Chamber volume 63 cc
Intake runner 164 cc
Exhaust runner 52 cc

Small block 64cc: Amount to reduce chamber volume by 1 cc (milling): 0.0055"
Remember: In the outer area cylinder heads up to 0.3 mm (0.011811") removed, means more or less matching.

[GerhardH]

So next steps:
1) Evidence for thread temperature sending unit in cylinder head driver side: NPTF 1/2 x 14. Remember NPTF is similiar to NPT but not identically.
2) Thinking on tomorrow: Piston stop tool already bought.

[GerhardH]

Load test on the rocker stud threads: 60 ft-lbs (without oil, sealer or antisizing)- ok and ready for go (production is 50 ft-lbs). Nut: deep-well wrench 11/16".
Rocker studs are 3/8 fine thread x 7/16" course thread, length overall 2.475".
Earlier pressure test done and investigation: no guide plates needed (as in the original engine in my car).

[GerhardH]

To measure the gap of the valve guides is not so easy for beginners. In my opinion you need a couple of hours to get a feeling what can be true and what not.
First cleaning of the guides. I used two measurement tools. First digital inside calipper. You have 5 digits thats could be a litte bit confusing because even if you make the identically measurement twice, you dont get the same last digit.
But on the end is easier than expected.
Let say a new valve has 0.341" shaft diameter (and this is over the complete shaft lenght. Than the maximum stem clearance can be inlet 0.0027" + 0.001" and exhaust 0.0027" +0.002". So that means the guide must be less than 0.3447" inlet and 0.3457" outlet. In practice I was measure all inlets and exhausts and was looking that I have no 0.35" at all. I get all guides below the limit. Than I asked an expert, he don't measured the system, only moved a new valve in the guides and told me: "Good for go"! Guide job will only burn additional money and is not necessary yet.

Second I used an inside feeler and micro, was also very suitable and delivered the same results.

Further I measured a brand new bronze insert: 0.342, ok bether than my existing with 0.344 but will do without guide job.

[GerhardH]

Last for today: Looking for warped heads, but the heads are already resurfaced:
By the way my orientation is a good book: "How to rebuild your Small-Block.CHEVY by David Vizard". Example given, there you will find that the limit of warpage schould be 0.003" (a compound gasket will take up far more warpage up to 0.005" according David.
Result: Less than 0.0025"

Monday shopping:
16 pcs Rocker stud (because I lend)
16 pcs Rocker arm
16 pcs Ball seat (Pivot ball)
16 pcs Rocker clearance adjusting nut
08 pcs Inlet Valves
08 pcs Outlet Valves
16 pcs Valve Springs (use always new one)
16 pcs Valve spring retainer (I got already with the heads)
32 pcs Keeper (use always new one)
16 pcs Oil seal

To fire on the 50 years old short block:
01 pc Oil pump
01 pc Oil pump securing bolt
01 pc Oil pump pickup pipe
01 pc Oil pump drive shaft
01 pc Oil pump drive shaft adapter
01 pc Oil pan
01 pc Oil pan gasket
14 pcs Oil pan bolts (small) (1/4"-20UNC x 1/2"long)
01 pc Oil pressure switch
10 ltr. Breake in oil
04 pcs oil pan bolts (large) (5/16"-18UNC x5/8" long)
14 pcs oil pan bolts star washer (1/4" diameter)
01 pc Oil filter pressure relief valve housing
02 pc oil filter pressure relief valve housing bolts
01 pc Oil filter spin on cartridge

01 scew set small block
01 gasket set small block

[GerhardH]

And preparation for the new valves:
looking for stock similiar but stainless steel.

At the moment I believe that the contact area (Seat width) shut be:

.060 to .080 inch for the exhaust and .040 inch for the inlet. (Exhaust must transpoprt more head)
.060 to .080 inch = 1.524-2.032 mm = 1.5-2 mm
.040 inch = 1.016 mm = 1 mm

Apply the paste to 3-4 points on the underside of the valve.
Rotate the valve in the seating with the valve grinding tool, lifting occasionally.
You can tread the paste with a litte bit oil.
Good cleaning after is mandatory.