Replace SSI with Headers for 83 sc

[RSTarga]

Originally Posted by 7783911

Thats easy enough but still leaves the SSI outlet open to water/debris which would eventual gunk up the ssi or cause internal damage?

They are Stainless Steel so what could possibly happen to them? The heater box surround are not completely sealed up so they still get water and dirt in the surrounds.

[Walt Fricke]

Think about it this way:
a) with the heat off, water and stuff could get into the system through the flappers (which are closed to the cabin, but open to the heat exchangers and the atmosphere. And the SSIs are stainless, and water is going to boil off pronto anyway. This isn't an issue.
b) As to blocking off the exit from the heat exchangers causing the exhaust manifold to overheat, 1) don't block it off there. 2) Without the heater fan, very little air is blown through the heat exchangers, although some from the engine cooling fan does get through, and it will continue to do so - it will just exit at a different place. And 3) technically, headers work best when hottest (which is why you often see racing headers with an insulating wrap) because that raises the speed of sound in them, which changes their acoustic properties in a good way, promoting scavenging and cylinder filling. So being hot isn't necessarily a bad thing. There can be issues with wraps and localized overheating and weld cracking, but those supposedly are due to header construction issues.

This doesn't seem to be a common issue. I suggest you simply remove the flexible hoses, disable the power to the footwell blowers, and see if you still have hot air (hotter than ambient, anyway) blowing into the cockpit. If it is, remove the flapper boxes and plate over the opening. Or replace the flapper boxes. The air surrounding the transmission is apt to be hotter than ambient in any event.

[Flojo]

Originally Posted by Walt Fricke

Think about it this way:...

when deleting the heat system anyway e.g. by closing the flappers and disconnecting the heat tubing from SSI, you can cut open the SSI-collector and take it off... tadaaa headers.

when you cut in such a way that you can weld the collector shut again, your good

[7783911]

Flo

I dont think marring these pieces of art is the best way to fix this...my goal if I want to remove heat) is to block at outlet of flapper instead and have flapper wide open (maybe remove the open/close wheel which is only a 1 minute job...well after removing the damned flappers which is more like 1 hour each side on your back looking up into pieces of dirt that tend to fall right onto face every time)

IIts getting colder up here inn Canada so maybe in a couple of weeks I will start at the frunk vent system and so what a poor engineering marvel can be corrected for air flow direction..ie flappers in main boxes and checking cables for correct run

I wish there were a simple diagram showing which cable goes where and flapper position for each...that could be part of the issue but not all since flapper should be blocking heat 100% from getting to cabin and it isnt

lord ..should have left old flappers alone and lived with it as it was..then i wouldnt have buggered up the frunk vent system

[Walt Fricke]

I did wonder why a denizen of the frozen north would want to disable completely the cabin heat system.

My only experience is with the manual cable/lever system. That is relatively easy to adjust so that lever all the way down means valve closed.

Does yours involve the automatic/thermostatic system? That might have more ways of not working just right?

[7783911]

Manual

replaced cables/guides
pulled flappers , cleaned and rebuilt

had front vent system apart to fix air controls and i am sure something isnt correct..so that what i will tackle next along with pulling flappers again to confirm 100% closure

i ll just plug away til its right