but i need some help. 85 12a blew up and seized. 81 is junk but motor good... see where im going? so we pulled the motors and went to swap. so many things different. even the harness is on different sides. oil coolers are different, throttle cables and so on. so putting 85 top end on 81 keg. we want to get rid of all the vacuum lines and rats nest. easy on fc but i dont know a lick about carbs or what they need. too young i guess. anyone want to help?

 

I do believe there is a link to rat's nest removal in the sticky at the top of the 1st gen section.

And yes there are a lot of differences, however the oil cooler - well I say upgrade to a front mount intercooler. Search to find out how to do that. The beehive oil cooler sucks.

Other than that everything should swap over.

 

Oil cooler is not a problem. Remove the beehive and it's mounting pedistal, replace it with the pedistal from the 81. While you have if off, replace the o-rings too.

 

yeah i found the removal on the 79' model but i didnt know if they are the same. and i was thinking of going overkill and running both the beehive and an fc cooler since it is an autox car. too cold is never bad

 

Can't run both and yes too cold of oil is bad, parts wear more just like when the oil is too hot. Install the fmoc and you'll be good. You will have to do some serious hardcore racing before more oil cooling is needed.

 

Part of the reason to change to the FMOC is to lower underhood temps, so leaving it there eliminates this as well as as Trochoid says, too cold is bad, if oil is cold it remains thick and does its job less efficiently causing wear and power loss from friction.

Do not reuse the old O rings, check the heater hose beneath the beehive, they often fail from oil leaking onto the hose and can quickly cause a blown engine from rapid heat increase.

 

Link to a recent save for this very reason

https://www.rx7club.com/showthread.p...=1#post6198637

 

ok. it is an autox car and people always worry about racing in 100* temps but the fm should be fine. any help with the rats nest on the carb?

 

you are going to have to check the fb rats nest removal to get the exact hose sizes, but this thread contains a drawing that simplifies the hose routing down into a very easy to understand drawing


https://www.rx7club.com/1st-generation-specific-1979-1985-18/rats-nest-guestions-539993/

 

awesome! nick this is for you buddy!