C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Engine issue with my '68 :(

Thread Tools
 
Search this Thread
 
Old Nov 7, 2017 | 01:38 PM
  #21  
GrandSportC3's Avatar
GrandSportC3
Thread Starter
Team Owner
 
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Default

Originally Posted by Chapter2
A blown power valve will usually exhibit black smoke out the exhaust from the mega-rich mixture. I'm still betting on an ignition issue.
You may be right but I personally suspect a valve train issue (spring/valve seat/pushrod/rocker arm or lifter) but I may be wrong.. 2nd place in my opinion could be head gasket issue.. I highly doubt that it's a bottom end issue as there was no smoke at all and no issue with oil pressure..

If it's the bottom end and I have to pull the engine, I'll likely drop in the 406/600 HP engine that I've sitting in my garage.. I would have to change pistons on it to drop compression to allow pump gas in it... Right now, that engine has 13.5:1 compression..

see pic below..
Attached Images  

Last edited by GrandSportC3; Nov 7, 2017 at 01:52 PM.
Reply
Old Nov 7, 2017 | 04:13 PM
  #22  
stingraymaniac's Avatar
stingraymaniac
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2003
Posts: 5,135
Likes: 71
From: Umeå Sweden
Default

That's a really nice garage
Reply
Old Nov 7, 2017 | 05:10 PM
  #23  
ronarndt's Avatar
ronarndt
Drifting
 
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
Default

Start with the easy to check stuff first before you do major surgery. The problem started abruptly, so something broke, wore out or fell out of place. If you are lucky it will be an inexpensive part and easy to fix. Good luck.
Reply
Old Nov 7, 2017 | 07:31 PM
  #24  
GrandSportC3's Avatar
GrandSportC3
Thread Starter
Team Owner
 
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Default

Originally Posted by stingraymaniac
That's a really nice garage
Thanks.. That's that it looked like when I finished it.. Now it's full of stuff..
Reply
Old Nov 7, 2017 | 07:36 PM
  #25  
GrandSportC3's Avatar
GrandSportC3
Thread Starter
Team Owner
 
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Default

Originally Posted by ronarndt
Start with the easy to check stuff first before you do major surgery. The problem started abruptly, so something broke, wore out or fell out of place. If you are lucky it will be an inexpensive part and easy to fix. Good luck.
Pulled off the valve covers and checked the lash on the valves.. No obvious valve train issues.. everything is tight with no signs of any issues.. Had a hard time getting off the valve covers.. They were stuck pretty good to the cork gasket and the cork gasket is stuck pretty good onto the heads..

Will pull the plugs tomorrow.. Couldn't find the proper 13/16 wrench for the spark plugs right now, so I will have to do it on another day..

Last edited by GrandSportC3; Nov 7, 2017 at 07:37 PM.
Reply
Old Feb 16, 2018 | 03:38 PM
  #26  
GrandSportC3's Avatar
GrandSportC3
Thread Starter
Team Owner
 
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Default

Finally, I had time to do some more research on my issue.. Turned out to be a carb issue.. The carb had so many issues that I had to have it rebuilt.. Car runs better than ever before now.. Haven't driven the '68 since November.. Glad to finally got her back running..

Last edited by GrandSportC3; Feb 16, 2018 at 03:39 PM.
Reply




All times are GMT -4. The time now is 12:01 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE