Choose your color scheme:
The Vette Barn  
 
Go Back   The Vette Barn > C1 & C2 Corvette > C1 & C2 Corvette Open Discussion

C1 & C2 Corvette Open Discussion General and technical C1 & C2 Corvette discussion - ownership, maintenance, repairs, modifications, restoration

User Tag List

Reply
 
Share Thread Tools Search this Thread
Old 01-17-2024, 7:20pm   #1
AUTOHOLIC
Vette Barn Crew
Points: 1,831, Level: 26
Activity: 12.7%
 
AUTOHOLIC's Avatar
 
Join Date: Mar 2023
Location: Cottonwood, AZ.
Posts: 268
Thanks: 20
Thanked 182 Times in 92 Posts
Gameroom Barn Bucks: $500
Default 383 vibration issue

I bought a stroked 350 to a 383 from a guy that raced the new engine twice and then switched to an LS engine. The engine was built with good quality parts by a well respected shop.
The engine was installed and is still with my mechanic. It was running smooth but has suddenly developed a vibration that starts about 1250 rpms and gets worse and stays the same at about 2500 rpms. The engine is externally balanced and has a fluid balancer. My mechanic has removed the belts and run it to eliminate anything like pulleys and accessories causing the problem. He spoke with the shop that built the engine and has a complete file on his it and checked the position of the flywheel weight which is all correct. He plans to pull the trans and clutch tomorrow to see it it eliminates the vibration. Neither of us understand as it suddenly just started this.
Has anyone encountered this?
__________________
Previous screen name on Corvette Forum was 68hemi
See my albums by clicking on my screen name for info and pictures of my cars.
My vehicles are driven DAILY
1965 Rally red/black leather coupe with stealth 383 appears like a factory 365 h.p. engine
1966 Nassau blue/blue L72 convertible
1972 El Camino SS Silver/black
2011 Polaris RZR 900
AUTOHOLIC is offline   Reply With Quote
Old 01-18-2024, 8:52am   #2
roadpilot
Barn Stall Owner #121
Points: 2,082, Level: 28
Activity: 18.8%
 
roadpilot's Avatar
 
Join Date: Jul 2023
Location: Oviedo Florida
Posts: 710
Thanks: 158
Thanked 368 Times in 197 Posts
Gameroom Barn Bucks: $500
Default

Well here goes the guess's.............
How bout the engine mount pad?
What kind of fuel pump are you running?
Fuel filter restricted?

More guess's later
roadpilot is offline   Reply With Quote
Old 01-18-2024, 3:52pm   #3
AUTOHOLIC
Vette Barn Crew
Points: 1,831, Level: 26
Activity: 12.7%
 
AUTOHOLIC's Avatar
 
Join Date: Mar 2023
Location: Cottonwood, AZ.
Posts: 268
Thanks: 20
Thanked 182 Times in 92 Posts
Gameroom Barn Bucks: $500
Default

It has new motor and trans mounts.
It has an electric fuel pump.
No fuel restrictions
__________________
Previous screen name on Corvette Forum was 68hemi
See my albums by clicking on my screen name for info and pictures of my cars.
My vehicles are driven DAILY
1965 Rally red/black leather coupe with stealth 383 appears like a factory 365 h.p. engine
1966 Nassau blue/blue L72 convertible
1972 El Camino SS Silver/black
2011 Polaris RZR 900
AUTOHOLIC is offline   Reply With Quote
Old 01-18-2024, 5:00pm   #4
roadpilot
Barn Stall Owner #121
Points: 2,082, Level: 28
Activity: 18.8%
 
roadpilot's Avatar
 
Join Date: Jul 2023
Location: Oviedo Florida
Posts: 710
Thanks: 158
Thanked 368 Times in 197 Posts
Gameroom Barn Bucks: $500
Default

Quote:
Originally Posted by AUTOHOLIC View Post
It has new motor and trans mounts.
It has an electric fuel pump.
No fuel restrictions
Do you still run the factory fuel filter? I just changed mine and
it was almost closed off. I run a electric pump too and never thought
about the Orginal fuel filter.
roadpilot is offline   Reply With Quote
Old 01-18-2024, 5:04pm   #5
roadpilot
Barn Stall Owner #121
Points: 2,082, Level: 28
Activity: 18.8%
 
roadpilot's Avatar
 
Join Date: Jul 2023
Location: Oviedo Florida
Posts: 710
Thanks: 158
Thanked 368 Times in 197 Posts
Gameroom Barn Bucks: $500
Default

Quote:
Originally Posted by roadpilot View Post
Well here goes the guess's.............
How bout the engine mount pad?
What kind of fuel pump are you running?
Fuel filter restricted?

More guess's later
The flywheel is balanced? Installed correctly?
roadpilot is offline   Reply With Quote
Old 01-18-2024, 5:11pm   #6
GTOguy
Barn Stall Owner #421
Points: 34,960, Level: 100
Activity: 99.2%
 
GTOguy's Avatar
 
Join Date: Sep 2021
Location: Those satisfactions are permanent
Posts: 13,249
Thanks: 5,557
Thanked 6,942 Times in 3,393 Posts
Gameroom Barn Bucks: $500
Default

Since it was running smoothly and suddenly developed a problem, something changed. Not likely an engine internal issue if it still runs fine with no noises. Possible clutch/pressure plate issue or defective or shifted motor or trans mounts. Also, verify the exhaust is not contacting the frame.
GTOguy is offline   Reply With Quote
The Following User Says Thank You to GTOguy For This Useful Post:
Old 01-19-2024, 11:32am   #7
AUTOHOLIC
Vette Barn Crew
Points: 1,831, Level: 26
Activity: 12.7%
 
AUTOHOLIC's Avatar
 
Join Date: Mar 2023
Location: Cottonwood, AZ.
Posts: 268
Thanks: 20
Thanked 182 Times in 92 Posts
Gameroom Barn Bucks: $500
Default

We found the problem.
The new clutch has a loose finger on it and have a replacement coming.
Thanks to all for your help.
__________________
Previous screen name on Corvette Forum was 68hemi
See my albums by clicking on my screen name for info and pictures of my cars.
My vehicles are driven DAILY
1965 Rally red/black leather coupe with stealth 383 appears like a factory 365 h.p. engine
1966 Nassau blue/blue L72 convertible
1972 El Camino SS Silver/black
2011 Polaris RZR 900
AUTOHOLIC is offline   Reply With Quote
The Following User Says Thank You to AUTOHOLIC For This Useful Post:
Old 01-29-2024, 6:48am   #8
SJW
Vette Barn Crew
Points: 1,756, Level: 25
Activity: 0%
 
SJW's Avatar
 
Join Date: Jul 2022
Location: Maryland
Posts: 127
Thanks: 9
Thanked 41 Times in 25 Posts
Gameroom Barn Bucks: $500
Default

Good of you to post a follow-up with the culprit identified.

Live well,

SJW
SJW is offline   Reply With Quote
The Following User Says Thank You to SJW For This Useful Post:
Old 01-29-2024, 10:45am   #9
AUTOHOLIC
Vette Barn Crew
Points: 1,831, Level: 26
Activity: 12.7%
 
AUTOHOLIC's Avatar
 
Join Date: Mar 2023
Location: Cottonwood, AZ.
Posts: 268
Thanks: 20
Thanked 182 Times in 92 Posts
Gameroom Barn Bucks: $500
Default

Quote:
Originally Posted by SJW View Post
Good of you to post a follow-up with the culprit identified.

Live well,

SJW
It is oh so important for people to post follow-ups as that is what really makes these forums so helpful to others later on that are searching for potential help with a like type problem.
__________________
Previous screen name on Corvette Forum was 68hemi
See my albums by clicking on my screen name for info and pictures of my cars.
My vehicles are driven DAILY
1965 Rally red/black leather coupe with stealth 383 appears like a factory 365 h.p. engine
1966 Nassau blue/blue L72 convertible
1972 El Camino SS Silver/black
2011 Polaris RZR 900
AUTOHOLIC is offline   Reply With Quote
The Following User Says Thank You to AUTOHOLIC For This Useful Post:
Old 02-02-2024, 7:46am   #10
SJW
Vette Barn Crew
Points: 1,756, Level: 25
Activity: 0%
 
SJW's Avatar
 
Join Date: Jul 2022
Location: Maryland
Posts: 127
Thanks: 9
Thanked 41 Times in 25 Posts
Gameroom Barn Bucks: $500
Default

Did you happen to take photos of that defective PP? I'm curious as to what it might look like.

Live well,

SJW
SJW is offline   Reply With Quote
Old 02-02-2024, 3:57pm   #11
AUTOHOLIC
Vette Barn Crew
Points: 1,831, Level: 26
Activity: 12.7%
 
AUTOHOLIC's Avatar
 
Join Date: Mar 2023
Location: Cottonwood, AZ.
Posts: 268
Thanks: 20
Thanked 182 Times in 92 Posts
Gameroom Barn Bucks: $500
Default

Quote:
Originally Posted by SJW View Post
Did you happen to take photos of that defective PP? I'm curious as to what it might look like.

Live well,

SJW
No, sorry I did not.

On another note, it still had a slight vibration that we just discovered the trans that was just rebuilt and has a new internal shaft that was bought from Tremac is out of spec. They said it was US made but my mechanic questions that and is so sick of getting junk NEW parts is looking for a quality USED part to replace it with. I too am sick of this and am dying to get my car back out of the shop.
__________________
Previous screen name on Corvette Forum was 68hemi
See my albums by clicking on my screen name for info and pictures of my cars.
My vehicles are driven DAILY
1965 Rally red/black leather coupe with stealth 383 appears like a factory 365 h.p. engine
1966 Nassau blue/blue L72 convertible
1972 El Camino SS Silver/black
2011 Polaris RZR 900
AUTOHOLIC is offline   Reply With Quote
Reply

The Vette Barn > C1 & C2 Corvette > C1 & C2 Corvette Open Discussion


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 11:06am.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
Copyright 2009 - 2024 The Vette Barn


Support the Barn:
 
Download the Mobile App;
 
Follow us on Facebook:

Become a Stall Owner

 

Apple iOS App        Google Android App

 

Visit our Facebook page