b18a1 to b18b1 swap... question about thermostat housing

sportsma1539

New Member
I noticed the thermostat housing is a little different between the b18a1 and b18b1 engines. The b18a1 has an extra spot for a smaller hose that connects.(I dont know where it connects in the engine bay) The b18b1 does not have this hose and is just blocked off. Should I switch over my thermostat housing to the b18b1 or will it be ok??? Also I have an extra plug on my b18a1 harness that is not on the b18b1 engine. Just leave it unplugged?? Thanks
 

tilegend

New Member
so you should use the thermostat housing that comes off your A1 b/c that last hose goes to the FITV located on the manifold
 

sportsma1539

New Member
are you sure?? everything is attached to the intake manifold. there is no extra hose. ill try to get a pic of it sometime soon
 

tilegend

New Member
are you sure?? everything is attached to the intake manifold. there is no extra hose. ill try to get a pic of it sometime soon
the FITV should be under the throttle body attached to the intake manifold
 


sportsma1539

New Member
the FITV should be under the throttle body attached to the intake manifold
I'll have to get a pic of where I'm talking about. Its not a really small hose, just small compared to the radiator hoses next to it. I dont remember taking any large hoses off the intake manifold. But I could be wrong. Ill get a pic tomorrow.
 

tilegend

New Member
its not a large hose at all, i forgot the diameter of it when i replaced it but. we'll wait for pics.
 

sportsma1539

New Member
its not a large hose at all, i forgot the diameter of it when i replaced it but. we'll wait for pics.

right! i initially said it was a small hose. But its actually somewhat large compared to most hoses but smaller than the large radiator hose.
 

sportsma1539

New Member
ok i have pics. the first one is the original thermostat housing from the b18a1 with the extra place for a hose all the way to the left. The second pic is one of the open lines that i have on the intake manifold. What i was wondering is that the line that goes to the extra hose on the thermostat housing. Can that open line on the intake manifold be plugged without any trouble if that is indeed the hose that goes to the therostat housing.



 

tilegend

New Member
the second pic you posted is the FITV (thingy with the brass plate on it)

you said you're going to use the B18A1 intake manifold so you must use that and to use it properly (FITV) there has to be coolant flow THROUGH it, so coolant must flow in and out for it to work properly.
 

sportsma1539

New Member
ok gotcha thanks for the help. The only thing that is bugging me is that I dont remember taking a hose off. Usually, Ill take one end off and leave the end of the hose on to whatever its connected to. But neither end had a hose on it. Maybe I took the hose off when i took the throttle body off. I had another piece off hose that i tried to use to connect the two but it wanted to kink up on me. Any suggestion on the type of hose to get.
 
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