clayne

I know some of you read RX7C so this may be a repost - but it seems there aren't a lot of engine builders reading that board regularly (I wonder why)... anyways:



I'm about to pull this coolant line completely and wanted to get a quick sanity check before doing it. It's the original line that is routed to the throttle body for TB heating when cold. It then exits the top of the TB and passes behind it and back down into the rear housing.



I've done the TB coolant bypass/FIC adjustment a while ago and have no issues with that - I just wanted to check with other knowledgable folks as to if removing that coolant path would be an issue. My thinking is that it will not be an issue as it appears to be for TB pre-heating only and does not represent the core of coolant flow within the engine based on the hose-sizing and exit/re-entry points. If you look at the flow-path it should be exiting the cooling system mid coolant-flow and then re-entering near the t-stat exit where heated coolant exits anyways.



I've heard from an Australian guy that he has had it blocked for 2 years without any problems, then I've heard from another guy who's mechanic told him to not cap it as it may prevent coolant flow out of the rear housing (this seems hard to believe).

j9fd3s

its fine that you blocked it off, they added that coolant path for the efi in 83. those caps will fail eventually, it might be better to run a loop hose or something

pengaru

I grab the nipples with locking pliers, twist, and pull em out. then tap the holes NPT and install hex socket NPT plugs.

93BlackFD

i ran a loop line...better cooling

clayne

Thanks for the info guys.



I'd drill and tap if I didn't have a swarf into housing issue with the engine still mounted and together in the car.



Next time it's torn down I'll do that though, it's a good idea.



j9fd, any better substitute for the caps, short of NPT hex caps?



93blackfd, well the coolant path there is from the rear housing STRAIGHT to the t-stat exit. If the coolant exiting there still has room for heat-transfer, then it's technically worse cooling.

Jeff20B

I'd say it's worse cooling too. I blocked mine off with broken exhaust studs (they're stainless steel so it's ok ). You can see them in the pics of my engine.

GMON

Cooling will be fine. Ive done it on 4 cars and all are good. You can do it in the car no problem if you use a vac-cleaner while you drill and tap.



GregW

suganuma

anything special on the plugs pengaru? Should we worry about expansion for the materials? i.e. aluminum plug on pump and steel on the housing?...I don't THINK it would crack, but I figure better safe than sorry....



TIA,



-Nic

j9fd3s

it doesnt get that hot there

pengaru

I used just regular hardware store npt plugs on those, steel.





the rotor housings on the other hand, if you have to plug the coolant ports that the turbo ones have for NA use... aluminum hex socket NPT plugs are the way to go.