Cylinder 7 Dead

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Mar 4, 2025 | 10:39 PM

#16

mattqwert

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8th Gear

Joined: Feb 2025

Posts: 8

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From: North Carolina

Leakdown Test

Did the leak down test tonight, leaking like a sieve. Put a vacuum gauge on the carb and it was oscillating quickly between 27-53 so I'm pretty confident its a bad intake valve. I will throw another set of heads on this weekend and go from there.

Attached Files

carb vacuum test.mp4 (7.54 MB, 10 views)

Mar 4, 2025 | 11:38 PM

#17

tbear853

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Joined: Feb 2004

Posts: 10,796

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From: The Shenandoah Valley

I forget that scale, but is from like 7 to 22 inches vacuum. Ain't good by either scale.

Mar 5, 2025 | 12:20 AM

#18

Rubiranch

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Joined: Jun 2004

Posts: 4,760

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From: South Central Utah

edit, I missed post 16

Mar 6, 2025 | 07:54 PM

#19

Viper Pilot

Fleet Mechanic

Joined: Feb 2022

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Quote:

Originally Posted by mattqwert

Dang, sorry to hear that but at least you know now and have a plan. Not knowing is the worst.

Mar 14, 2025 | 03:11 PM

#20

mattqwert

Thread Starter

8th Gear

Joined: Feb 2025

Posts: 8

Likes: 2

From: North Carolina

New (used) heads fixed it, still not running as hot as the other 7, about 100 degrees cooler. Vacuum test and leakdown tests passed.

Mar 15, 2025 | 11:57 AM

#21

Rubiranch

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From: South Central Utah

Quote:

Originally Posted by mattqwert

New (used) heads fixed it, still not running as hot as the other 7, about 100 degrees cooler. Vacuum test and leakdown tests passed.

Sorry to hear its not up to snuff with the other cylinders.
If you don't mind, how much were the reman heads and do they have hardened seats and valves??

Apr 9, 2025 | 08:57 AM

#22

mattqwert

Thread Starter

8th Gear

Joined: Feb 2025

Posts: 8

Likes: 2

From: North Carolina

They came off another 302 motor I had. I think I picked that engine up for ~450 but I mainly bought it for the 4 barrel Holley and PS pump it had on it, so by my math the heads were free! Not sure on the seats/valves