SBC TPI question - Why is there a small heater hose going into my TPI manifold?
10-19-2010, 11:40 AM
#1
Pro
Thread Starter
SBC TPI question - Why is there a small heater hose going into my TPI manifold?
Hello Folks,
On my 1986 Corvette TPI engine, I have a small hose (3/8" maybe) that comes off of one of my regular heater hoses through a T-fitting and feeds into the rear of the TPI manifold, near the distributor.
The other typical SBC heater hoses are present and accounted for (i.e. one to the water pump and one to the front of the intake manifold).
What is the purpose of this small heater hose?
Thanks in advance!
On my 1986 Corvette TPI engine, I have a small hose (3/8" maybe) that comes off of one of my regular heater hoses through a T-fitting and feeds into the rear of the TPI manifold, near the distributor.
The other typical SBC heater hoses are present and accounted for (i.e. one to the water pump and one to the front of the intake manifold).
What is the purpose of this small heater hose?
Thanks in advance!
Last edited by kbuhagiar; 10-19-2010 at 11:58 AM.
10-19-2010, 01:23 PM
#3
Race Director
Between that small water feed and special gaskets that have a pin-hole in the rear water ports (vs completely open), it was a measure GM took to try and address uneven cooling leading to intake gasket leaks -- which SBC are known for.
For whatever reason, they thought holding fresh (radiator-cooled) water in the rear of the manifold would help. Obviously, the small feed tube would be slow -- as are the restricted water ports on the intake gaskets -- to let the water back out.
For whatever reason, they thought holding fresh (radiator-cooled) water in the rear of the manifold would help. Obviously, the small feed tube would be slow -- as are the restricted water ports on the intake gaskets -- to let the water back out.
Last edited by GREGGPENN; 10-19-2010 at 01:26 PM.
10-19-2010, 01:40 PM
#4
Pro
Thread Starter
Between that small water feed and special gaskets that have a pin-hole in the rear water ports (vs completely open), it was a measure GM took to try and address uneven cooling leading to intake gasket leaks -- which SBC are known for.
For whatever reason, they thought holding fresh (radiator-cooled) water in the rear of the manifold would help. Obviously, the small feed tube would be slow -- as are the restricted water ports on the intake gaskets -- to let the water back out.
For whatever reason, they thought holding fresh (radiator-cooled) water in the rear of the manifold would help. Obviously, the small feed tube would be slow -- as are the restricted water ports on the intake gaskets -- to let the water back out.
I'm trying to clean up the engine compartment on my 47 Plymouth, and I'd like to get rid of it, but I'd like to be sure that it wont affect engine performance or dependability.
Thanks again.
10-19-2010, 01:47 PM
#5
Race Director
Don't place too much emphasis on it.
P.S. If you want to read more, do a search on SunCr with the keywords "galvanic, corrosion, and/or gaskets". With one or more of those keywords, you should be able to find his complete/knowledgeable posts on the subject. He is a retired GM service technician IIRC.
Last edited by GREGGPENN; 10-19-2010 at 01:59 PM.
10-19-2010, 06:28 PM
#8
Le Mans Master
10-20-2010, 12:26 PM
#9
Le Mans Master
I've never worked for GM.
The Vette L98 restricts coolant flow at the rear of the intake to keep coolant at the rear of the heads longer. F-Body L98's don't. If you want to get rid of the hose - which is there to provide sufficient coolant - swap in the F-Body intake gaskets without the Restrictors. Read all about the differences in TPI's here: http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf or watch the videos here: http://www.hotrodlane.cc/Video/TPI%20VIDEO%20PAGE.html
PS - there's nothing "steam" in a cooling system and excess air is expelled through the Coolant Reservoir. If you have steam, it's boiling over.
The Vette L98 restricts coolant flow at the rear of the intake to keep coolant at the rear of the heads longer. F-Body L98's don't. If you want to get rid of the hose - which is there to provide sufficient coolant - swap in the F-Body intake gaskets without the Restrictors. Read all about the differences in TPI's here: http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf or watch the videos here: http://www.hotrodlane.cc/Video/TPI%20VIDEO%20PAGE.html
PS - there's nothing "steam" in a cooling system and excess air is expelled through the Coolant Reservoir. If you have steam, it's boiling over.
10-20-2010, 12:49 PM
#10
Le Mans Master
I've never worked for GM.
The Vette L98 restricts coolant flow at the rear of the intake to keep coolant at the rear of the heads longer. F-Body L98's don't. If you want to get rid of the hose - which is there to provide sufficient coolant - swap in the F-Body intake gaskets without the Restrictors. Read all about the differences in TPI's here: http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf or watch the videos here: http://www.hotrodlane.cc/Video/TPI%20VIDEO%20PAGE.html
PS - there's nothing "steam" in a cooling system and excess air is expelled through the Coolant Reservoir. If you have steam, it's boiling over.
The Vette L98 restricts coolant flow at the rear of the intake to keep coolant at the rear of the heads longer. F-Body L98's don't. If you want to get rid of the hose - which is there to provide sufficient coolant - swap in the F-Body intake gaskets without the Restrictors. Read all about the differences in TPI's here: http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf or watch the videos here: http://www.hotrodlane.cc/Video/TPI%20VIDEO%20PAGE.html
PS - there's nothing "steam" in a cooling system and excess air is expelled through the Coolant Reservoir. If you have steam, it's boiling over.
