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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: braxton.hartshorn.7 on August 05, 2014, 01:50:22 pm
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I am wondering if its a hydraulic roller, flat tappet or what without taking the engine apart right now
Any answers are appreciated.
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All factory first generation truck small blocks were flat tappet. Only the car lines migrated to roller cams.
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Thank you. And always replace lifters as well if flat tappet right?
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A new flat tappet cam requires new lifters. The cam lobes and lifter feet (not the cam bearing journals) must be liberally coated with the cam grinder's recommended break-in lubricant (typically a proprietary high pressure molybdenum sulfide grease that is generally supplied with the new cam). The cam bearing journals should be coated with light engine assembly lube or motor oil. In addition, a high quality ZZDP enriched mineral break-in oil should be used during the break in period. Drain and replace the break-in oil and oil filter after ~100 miles, using fresh ZZDP enriched oil, or a ZZDP additive like GM EOS, for the subsequent service interval. I cannot stress enough the recommendation to initially start and immediately bring the engine to ~2,500+ RPM for 30 continuous minutes to ensure adequate lobe lubrication from internal oil splash. DO NOT let the engine idle for the first 30 minutes. This is especially important when installing aftermarket cams.
When replacing a camshaft don't overlook the timing chain and gear set - a double roller set will provide better service life.
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Thanks again I will definitely take all that into consideration