Unknown sound

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1974Blueflame

Junior Member
Joined
Oct 10, 2024
Posts
13
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2
Location
east bay
First Name
cole
Truck Year
1974
Truck Model
K1500
Engine Size
350 V8
Ok I was driving down the road then a knock possible misfire started happening I got it home found it was coming from the #7 cylinder I pulled the valve cover for that side and the rocker arm on the exhaust port of #7 cylinder does not sit on the push rod like all of the others the push rod does move when I wrench over the engine but there is still a knock any help would be super nice if I gotta take this thing a part possibly a lifter is ****** any body else dealt with this
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
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Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Vortec heads? If so, self-aligning rockers? If yes to vortec, and no to self-aligning rockers, that's what you need.

At the very least say what engine it is, any modifications, enhancements, or lack thereof. We need more info, and pics dang it, post up pics of the offending problem
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
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24,250
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Test

Sticky

NOPE, not "STICKY", op probably wrote "effed"
 

1974Blueflame

Junior Member
Joined
Oct 10, 2024
Posts
13
Reaction score
2
Location
east bay
First Name
cole
Truck Year
1974
Truck Model
K1500
Engine Size
350 V8
Vortec heads? If so, self-aligning rockers? If yes to vortec, and no to self-aligning rockers, that's what you need.

At the very least say what engine it is, any modifications, enhancements, or lack thereof. We need more info, and pics dang it, post up pics of the offending problem
These are the exact engine specs for this
Engine Specifications:
• HP: 330
• TQ: 380
• Block: OE block 4 bolt main 1pc seal 1987-2000
• Bore/Stroke: 4.040 x 3.480
• Displacement: 350
• Crankshaft: OE Reground external balance rear of crank/internal balance front of the crank
• Rods: OE powder metal 5.7”
• Pistons: Hypereutectic 9.1:1 compression
• Rings: Moly
• Camshaft: Hyd. flat tappet
• Cam Specs: 224/234 @50 .465in/.488ex 112LSA
• Timing Chain: Double roller
• Cylinder Heads: ATK cast iron 76cc/165cc 1.94/1.50
• Rocker Arms: Stamped steel 1.5 ratio
• Oil Pan: Rear sump 5qt (not for Chevelles with steering behind crossmember, some corvettes and 62-67 chevy II’s)
• Oil Pump: Melling high volume
• Balancer: Internal balance 8”
• Flexplate/Flywheel: Pioneer #FRA-159 external balance 168 tooth
• Intake Manifold: ATK dual plane intake
• Distributor: HEI (Iron gear)
• Water Pump: OE long pump
• Carburetor: Quick Fuel 670CFM vacuum secondaries with electric choke
• Fuel Pump: Mechanical
• Spark Plugs: Champion #RV12C
• Spark Plug Wires: 8mm

Engine Info:
• Oil: Conventional / Non Synthetic 10W30 with Comp Cam zinc additive #159 for first 3000 miles
• Oil Filter: Wix or K&N per application
• Timing: 34-36 Degrees
• Spark Plug Gap: .035”
• Firing Order: 18436572
• Octane: 91+
• Stall Converter: 2200-2500
• Exhaust: 1 5/8 Headers
 

Radiohead

That guy on the Columbia
Joined
Mar 17, 2022
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Low Earth Orbit where it's safer
First Name
Eric
Truck Year
MCMLXXIX
Truck Model
C-20 Silverado Camper Special
Engine Size
454 crazy cubes, or 7.4 luscious litres
I would suspect a wiped cam lobe knowing nothing else about it.
 

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