My 1968 C-20 Golden Anniversary Project - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GerhardH · 08-31-2020, 06:56 AM

just middling

GerhardH · 09-06-2020, 07:36 AM

Compression test and leak test again with better equipment (to screw).
Comression (psi) /leak test (%) ok:

1: 180/17%
2: 190/42%
3: 190/42%
4: 180/28%
5: 180/25%
6; 190/25%
7: 180/22%
8: 180/22%

Found ot that the position of the piston is very important for leak test. Sometimes you could turn the pushrod with the fingers, the valves are still open a crack and you get more percentages, see cylinder 2 e.g.

GerhardH · 09-14-2020, 12:51 PM

Some interesting works on vacuum system:

1) A canadian friend gave me the advice that the spigot must be in the pipe- done. But than the porous hose became a leak. The switch point of the TH400 was rised dramatically, the switch over was very hard and the oil became foamy (Optimized for WOT (Wide Open Trottle)- Repaired and know now that hose, pipe and vacuum switch are working fantastic.

2) During the investigation found out that the vacuum advance in the distributor is dead too. Bought a new one AR23 (good advise from Gregski and Rich weyand here in the forum). START 5-7 inHg, Max. advance distributor degree 7.5° , Max inHg 11-12.5.

3) Some paint work for the new engine and changed the ugly blue distributor cap against a black one.

GerhardH · 09-14-2020, 01:09 PM

Preparing the new engine.

Attached the new tailgate letter decals - its great!!!

08-31-2020, 06:56 AM	#1
GerhardH Registered User Join Date: Aug 2017 Location: South Germany Posts: 527	Re: My 1968 C-20 Golden Anniversary Project just middling __________________ Best regards GerhardH! Members met: 68 short step, 68bowtie, 72c20customcamper, botmfedr1, C/10 King, Chevyland, cornerstore, dmjlambert, fun in dirt, GMan69, Ol Blue K20 1968 CHEVROLET C20 Custom Camper 50th Anniversary, Long bed (LB) 8', 327 V8, Air Condition (AC), Power Steering (PS), Power Brake (PB), Z62 Custom & Comfort Appearance, Turbo Hydramatic TH 400 http://67-72chevytrucks.com/vboard/s...d.php?t=760400

09-06-2020, 07:36 AM	#2
GerhardH Registered User Join Date: Aug 2017 Location: South Germany Posts: 527	Re: My 1968 C-20 Golden Anniversary Project Compression test and leak test again with better equipment (to screw). Comression (psi) /leak test (%) ok: 1: 180/17% 2: 190/42% 3: 190/42% 4: 180/28% 5: 180/25% 6; 190/25% 7: 180/22% 8: 180/22% Found ot that the position of the piston is very important for leak test. Sometimes you could turn the pushrod with the fingers, the valves are still open a crack and you get more percentages, see cylinder 2 e.g. Attached Images __________________ Best regards GerhardH! Members met: 68 short step, 68bowtie, 72c20customcamper, botmfedr1, C/10 King, Chevyland, cornerstore, dmjlambert, fun in dirt, GMan69, Ol Blue K20 1968 CHEVROLET C20 Custom Camper 50th Anniversary, Long bed (LB) 8', 327 V8, Air Condition (AC), Power Steering (PS), Power Brake (PB), Z62 Custom & Comfort Appearance, Turbo Hydramatic TH 400 http://67-72chevytrucks.com/vboard/s...d.php?t=760400 Last edited by GerhardH; 09-06-2020 at 09:38 AM.

09-14-2020, 12:51 PM	#3
GerhardH Registered User Join Date: Aug 2017 Location: South Germany Posts: 527	Re: My 1968 C-20 Golden Anniversary Project Some interesting works on vacuum system: 1) A canadian friend gave me the advice that the spigot must be in the pipe- done. But than the porous hose became a leak. The switch point of the TH400 was rised dramatically, the switch over was very hard and the oil became foamy (Optimized for WOT (Wide Open Trottle)- Repaired and know now that hose, pipe and vacuum switch are working fantastic. 2) During the investigation found out that the vacuum advance in the distributor is dead too. Bought a new one AR23 (good advise from Gregski and Rich weyand here in the forum). START 5-7 inHg, Max. advance distributor degree 7.5° , Max inHg 11-12.5. 3) Some paint work for the new engine and changed the ugly blue distributor cap against a black one. Attached Images __________________ Best regards GerhardH! Members met: 68 short step, 68bowtie, 72c20customcamper, botmfedr1, C/10 King, Chevyland, cornerstore, dmjlambert, fun in dirt, GMan69, Ol Blue K20 1968 CHEVROLET C20 Custom Camper 50th Anniversary, Long bed (LB) 8', 327 V8, Air Condition (AC), Power Steering (PS), Power Brake (PB), Z62 Custom & Comfort Appearance, Turbo Hydramatic TH 400 http://67-72chevytrucks.com/vboard/s...d.php?t=760400 Last edited by GerhardH; 09-22-2020 at 11:15 AM.

09-14-2020, 01:09 PM	#4
GerhardH Registered User Join Date: Aug 2017 Location: South Germany Posts: 527	Re: My 1968 C-20 Golden Anniversary Project Preparing the new engine. Attached the new tailgate letter decals - its great!!! Attached Images __________________ Best regards GerhardH! Members met: 68 short step, 68bowtie, 72c20customcamper, botmfedr1, C/10 King, Chevyland, cornerstore, dmjlambert, fun in dirt, GMan69, Ol Blue K20 1968 CHEVROLET C20 Custom Camper 50th Anniversary, Long bed (LB) 8', 327 V8, Air Condition (AC), Power Steering (PS), Power Brake (PB), Z62 Custom & Comfort Appearance, Turbo Hydramatic TH 400 http://67-72chevytrucks.com/vboard/s...d.php?t=760400 Last edited by GerhardH; 09-16-2020 at 07:51 AM.



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