The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-28-2007, 09:47 PM   #1
68dontneedanewone
Registered User
 
Join Date: Nov 2001
Location: Covington, GA USA
Posts: 67
Overheating Intake Manifold - Help !!

Here's the deal......... 72 V8, either 350 or 400 small block ('new' truck, haven't checked casting numbers).

Son took a rock in the radiator and severely overheated it.
Got it home and had water droplets out of both (duals) tailpipes, but with 150lbs +/- compression in all cylinders, so figured it blew the intake manifold gasket.

Replaced the manifold gasket and sandblasted/painted the manifold while I had it off. Should have taped off all the openings, but didn't. Used 100lb air nozzle to blow out all passages afterward.

Now the truck is 1) hard to start when hot, 2) diesels after shutting off, 3) expels gas/air mixture or other smoke-like substance through carb/air filter housing, and 4) manifold has turned black over both sides of center water channels (between #2-4 and #3-5 intake channels).
Timing and dwell are spot on the specs.

Any ideas on what I've done, or what might be the problem/fix?

Thanks for any ideas,
Earle
__________________
Earle - Covington GA

68 Chev SS/SWB: 350-Edelbrock intake/carb, 'built'700R4(kevlar bands etc), front disc, A/C

2002 Silverado CrewCab LongBed
8.1 Vortec
Allison Tranny

Last edited by 68dontneedanewone; 03-28-2007 at 09:49 PM. Reason: Additional info.
68dontneedanewone is offline   Reply With Quote
Old 03-28-2007, 09:52 PM   #2
GREASEMONKEY72
Registered User
 
GREASEMONKEY72's Avatar
 
Join Date: Aug 2006
Location: Bakersfield,CA
Posts: 7,893
Re: Overheating Intake Manifold - Help !!

check the timing it could be the deiseling problem and also the carb could need a rebuild and also sounds like its got to much fuel going into the carb, that would be the white smoke coming out of the carb and i dont know about it turning black on the sides but it could be that it wasnt cleaned and preped good enough before you painted it and now the paints coming off, i hope any of that helped and goodluck
__________________
-steven
Alte Seele S.S.

"Allison" '72 C/10 LWB 350SB/TH350 - DD

PITBULL IS NOT A CRIME
GREASEMONKEY72 is offline   Reply With Quote
Old 03-28-2007, 10:12 PM   #3
Sammy
Registered User
 
Join Date: Apr 2000
Location: Bonne Terre, Mo
Posts: 3,005
Re: Overheating Intake Manifold - Help !!

If you were puting on aftermarket intake, with older engines you have to cut the intake gasket or you will block a water passage. Thats a warning with the gasket set. ???
__________________
'69 Chevy Long Fleet & '71 GMC Short Step & Project "ODD BALL"


"You can wash a pig, soak it in most expensive perfume. In the end it is still just a pig."

ODD BALL build thread http://67-72chevytrucks.com/vboard/s...d.php?t=478629"
Sammy is offline   Reply With Quote
Old 03-28-2007, 11:42 PM   #4
68dontneedanewone
Registered User
 
Join Date: Nov 2001
Location: Covington, GA USA
Posts: 67
Re: Overheating Intake Manifold - Help !!

No, it's the original manifold. I'm sure there aren't any passages blocked by the gasket - double checked one last time before setting the manifold back in place.
__________________
Earle - Covington GA

68 Chev SS/SWB: 350-Edelbrock intake/carb, 'built'700R4(kevlar bands etc), front disc, A/C

2002 Silverado CrewCab LongBed
8.1 Vortec
Allison Tranny
68dontneedanewone is offline   Reply With Quote
Old 03-29-2007, 12:23 AM   #5
CrashEd
72 chevy
 
CrashEd's Avatar
 
Join Date: Jan 2007
Location: Central Il
Posts: 725
Re: Overheating Intake Manifold - Help !!

If it wasn't a high heat paint then it would burn on the air passages that heats the carb up. The passage between 3-5 and 2-4 is exhusat.
Ed
CrashEd is offline   Reply With Quote
Old 03-29-2007, 03:45 AM   #6
cameeks
Long Fleet Club
 
cameeks's Avatar
 
Join Date: Aug 2006
Location: Deer Park, TX
Posts: 5,666
Re: Overheating Intake Manifold - Help !!

Quote:
Originally Posted by CrashEd View Post
If it wasn't a high heat paint then it would burn on the air passages that heats the carb up. The passage between 3-5 and 2-4 is exhusat.
Ed
Also try to do the compression test with the radiator cap off could have blown the head gasket and the closed coolant system could be keeping the pressure up.

The last Idea was me thinking too much. Might not affect anything.
__________________
Chris Meeks

'69 Chevy Custom/10 Long Bed <-- Thread of the work I did before selling.
Truck is now finished to the new owners design and running around.
I was shown some pictures of the finished product. At least it survived the junk yard.

FAQ Index by Krue Site Vendors Subscribe Here Forum Rules
cameeks is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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 -4. The time now is 08:53 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com