bmw e9 or in this case e12 m30b35 swap coolant routing

bavarian

bavarian

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ok engine is in i have some questions about the cooling system .

the b35 as you know has no coolant port in the back of the head , it has a block plate , the old e12 engine had a coolant port in back of head.
now my question is how do i go about routing the system From the smallest port of the: thermostat housing > heater core in >heater core out > coolant reservoir

i do have a new two port coolant reservoir , this would make things easier , do i have to T between thermostat housing and heater core in? i wouldn't have a problem with my original order of : thermostat housing > heater core in >heater core out > coolant reservoir but im worried that tiny little hose that goes from the coolant reservoir back to the radiator wouldn't be able to keep up with the flow , if anyone has a b35 e9 coolant hose diagram that would be a huge help
 
use the coolant port of the E12 head or E9 which ever car your putting the engine in
 
Throw the blocking plate away and use the original e9 pipe.

Done

if you are going FI- Use the e28 533i coolant hose setup from thermostat housing to
tank and heater core return.

That little hose is there to keep the water pump working and to get rid of air bubbles.
 
Don, what's unique about the 533i setup? Curious since I have a B35 swap (out of an '89 635CSi) in my E12 and for instance when I had to replace the lower rad hose it took a while to figure out what would work since I had no idea what part was in there. My upper rad hose setup is different from most B35s I've seen photos of.
 
thanks for the suggestions but engine is installed with blocking plate already and it would be a pain in the ass to change it now
 
i wonder if one hose feed into heater core then one hose out to reservoir would work the problem would be there only one way out of the reservoir and that is the small overflow hose to the radiator but idk if that would allow enough flow
the e34s have a T joined into the upper radiator hose so this should allow more flow , worst case i can throw a T on the upper radiator hose but deff pretty annoying , i see no other option to keep flow
 
A good wrench can pull that blocking plate and replace with pipe in less than an hour.
Disconnect your tranny mounts and tilt the engine forward.

Only one hose I know of for lower radiator hose.

The 633i one year only “750” hose.

Thank Carl Nelson for that info.

Occams razor says:

Best answer is simplest.

We use the e28 hoses because they fit, they are available and they are priced right!
 
hey thanks for the help done , wondering do you have a picture or part number of that hose i tried to look it up , my e12 stock hose almost fits but there a b35 m6 stud that sticks out pretty far out of the lower timing cover and is in the way
 
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