bleung

Isn't it easier to just screw in the screw on the cam? Maybe not as clean as removing unwanted components though.

gcthree

Being that you're removing the coolant to simplify, it seems logical to remove these components- and the notion of a cam safety-wired seems half-baked.

quicksilver_rx7

Just take the spring out and re-install the screw and run it all the way down

Sesshoumaru

iTrader: (1)

I've removed the thermal wax in both FC's and FD's too.

On the FC's you have to worry about pinching the hose. If done properly though it won't pinch.

On the FD it's not even close due to the manifold design.

I try to keep the rear iron as cool as possible so I run a line.

GARCO MOTORWORKS

I remove the thermowax parts and the cams and levers .I also cut off the shaft that sticks out of the casting and smooth it all out before polishing .No screws no wires no ugly . The good looking work and performance is in the details .

tcb100

How about a more fundamental question: why disable it the TB coolant line at all?

The mechanism serves a purpose. Fast idle at startup is real useful. Using a wax rod/coolant solution to get the car off fast idle works just fine too.

What's the point? Is this simply for "cleaning up the engine bay"? If so, it seems like a pretty marginal contribution to that vast undertaking while removing some functionality.

Sesshoumaru

iTrader: (1)

They have a thing in the FC's called AWS (advanced warm up system) it also has another name. That's Advanced Wear-Out System.

Just like the thermal pellet in the e-shaft.

Most ppl don't drive in the winter. Even during winter (yes I drove my FD in snow). It would still idle and start up fine (about 1.2k till warm) with out thermal wax. The ISC and the BAC on the vehicles can support the car's idle when cold if everything is adjust right.

bleung

IMO it doesn't clean up the engine bay much unless you remove all the cam stuff with it since the hose is only visible where it connects behind the throttle body. It makes removing and re-installing the throttle body easier though as the lower throttle body hose is very short and bent.

Jesuscookies

iTrader: (1)

You need fuel, spark, engine, and a big *** turbo. That about covers it. All those extraneous systems, add complexity, and are one more thing that can break, leak, or otherwise, destroy your engine when they go out.

Now, as I understand it, this system is used to keep the butterflies from freezing shut under very cold start conditons. Guess what? I live in So. Cal, and my car will never see anything below 40.F

Couples these 2 factors together, and you have the reason I chose to eliminate it.

Sesshoumaru

iTrader: (1)

it doesn't keep the butterflies from freezing shut.

It's just used to allow more air to the engine when cold so the idle is higher (taking the place of your foot).

FYI on older cars they had a "sub-zero" starting assit. Rad fluid would be injected in the LIM. It was later recalled but I've seen alot of FC's with it. That system is not needed.

FDNewbie

iTrader: (10)

I didn't do it to clean up the engine bay...I did it because the end of the TB (where the FIC is) was actually cracked, and I had to drive home that night, so I couldn't even give it enough time and see if I could seal the crack w/ gasketmaker. That's for starters.

Another thing is, I don't think it's necessary to have, given that I never push her when she's cold. I wait until the water temp gauge reads about 180.

Lastly, this is just my logic, so it may be flawed, but the purpose of the coolant running to the TB is to warm it up quickly. What about once it's warmed up? You have super hot coolant running through the TB, which is a place where you want the coolest air possible. So I was thinking getting rid of the coolant hose to the TB would help reduce temps there a bit.

Yep, my FB (84 GSL) has a small secondary coolant tank, right up against the firewall for the sub-zero starting assist. Antique stuff baby!

mad_7tist

the coolant line delete does not realy help keep the tb any cooler. it will reach an operarting temp without the coolant just the same. the coolant just makes it faster. it does make the uim r&r easier

FDNewbie

iTrader: (10)

Maybe I'm wrong, but I wasn't talking about reaching operating temp. I'd think the coolant is REAL hot, and would keep the TB hotter than it normally would be, if there was no super hot coolant flowing through it.

tcb100

The only thing the coolant line does is heat up the wax rod so that the car comes off fast idle after a start-up. It's just a simple method of idle control, sort of like the wax in a thermostat, opening it up when it gets hot.

Like the post says above, if you disable it, the coolant will not flow, the wax rod will never get hot, the car will never come off fast idle - unless you do something about the fast idle cam, like wire it in a position. I don't really see why we would want to disable the feature, but what the hey.

I think that's the end of it though. I don't think there are channels running through the throttle body like there used to be with carburators, to combat icing problems. I suppose there might be some small effect on TB temperature but I would not imagine it's a major deal.

GARCO MOTORWORKS

I disable the hat wax rod because it gets rid of 3 rubber hoses and 6 clamps that can cause a water leak . The throttle body is now easy to remove .The throttle body has fewer adjustments to keep . With the rod cut off and the other parts removed ,a cover plate where the hot wax rod was , it all looks much cleaner . Someone show me the hot water jacket around the throttle body that heats it .

FDNewbie

iTrader: (10)

Gotcha. My fault. Thanks for the clarification

Mahjik

iTrader: (1)

That was my main (only) reason for doing it. While I do live in an area where it does get cold, my car doesn't usually see the road during winter.

quicksilver_rx7

The TB coolant works in conjunction with the AWS for "Start-up emissions" purposes only. Other than that, it's crap. Fast Idle heats up the catylist system, blah, blah, crap. It's also one of the many weak links of the RX-7. Removing it is, in my opinion, a reliability mod as that hose (made of rubber) is known to split due to the HIGH underhood temps, and drain your coolant supply, thus resulting in overheating, which results in a new engine. Plus removing it also allows for easier removal of the UIM next time

(there will always be a next time)

b0ng

One question guys (by the way, this thread rocks!):

If we disable the TB coolant line (drill and tap the rear nipple on the block ), when flushing the coolant system, I can't release the the TB coolant line (because it's now non-existant) to reduce air pockets when re-filling coolant. Will this be a problem when flushing the coolant system?

FDNewbie

iTrader: (10)

You mean for burping the coolant, right? The way I do it, and the way PFS taught me to do it, was to open the cap on the coolant filler neck, rev the engine, then let it idle...the bubbles will work their way to the top, and the coolant level will drop. Add coolant, repeat, etc. It's always worked for me. If this isn't a good method, plz someone jump in and clarify why (not).

b0ng

FDNewbie, yes, burping the coolant is what I was refering to. Thanks for sharing.

One point to note is that when I was reading on this Forum about using the Radiator Funnel to burp the coolant system, one of the user was having a problem refiling the system WITHOUT removing the TB coolant hose. So one of the steps did clearly say to remove the TB coolant hose. The user almost had over-heating problem..scary. Should I dig up and post the link to that posts?

Comments please..thanks again.

Mahjik

iTrader: (1)

b0ng,

What you do when you fill the system without the TB Coolant line is:

1. Fill the filler neck
2. Squeeze the lower radiator hose a few times to push air out
3. Repeat 1 & 2 in sequence until full

Then just do the normal stuff (i.e. running the car with the heater on etc).

rx7tt95

Someone made a very important point I'd like to reiterate...connect the rear plate to the front with a coolant line to keep the rear plate cool. The coolant coming off the rear plate at that point is extremely hot. You will aid in your motor's longevity by running a line to the front instead of just plugging it.

quicksilver_rx7

There is also a device on the market that is basically a funnel with a radiator cap on the small end that is used to burp coolant with. We use them at the dealership I work for

b0ng

Ah, quicksilver_rx7, yes, that's the device I was talking about. However, this is the post that raised my question earlier:

<hxxp://www.rx7club.com/showthread.php?t=342309&page=2&pp=15>
A word of caution: Remove the throttle body coolant line when filling up!! I have this funnel thing and it's great but it still couldn't get all the air out of the system when I flushed it. I was really close to overheating while using it, then I removed the TB coolant line and everything worked out great.

However, Mahjik did point out above on how to burp the coolant system without the TB Coolant Hose.

Thanks for all the infos man.