interested to see how this goes. lmk temps, etc. and i assume you do more than average spirited driving. if all goes well ill be doing this to my track car. very very interested, and keep up the good work

 

Sorry guys for the delay, have a family member in the hospital. I got the car bleed, and initial results seem promising. The lower hose is hot, the fans kick on at the appropriate temp, this is all while idling in the garage. The car does seem to run a tad bit hotter than I remember, but last time I drove the car was about a year ago so I am having some hard time remembering what kind of coolant temps I would see under normal driving conditions.

I work another full week, but I am going to try to take it out one night, for some highway pulls to see what happens.

I think that the slightly higher temps that I remember could be due to removing the heater core as it does act as small radiator.

 

Great job

 

that would be a good explanation along with the loss of coolant volume from removing those lines and the core.

 

Took it out on the highway today and did a few moderate pulls and it did not over heat, but it got hotter than I would like. So I am going to look at a few other things to fix this. Temps got up to 230's.

 

simple fix, get rid of that intercooler thats blocking airflow and sending pre-heated air into the radiator

 

If you are attempting to get the thermostat to open sooner, shouldn't you have ran the line from your radiator on the inlet side and not the outlet? IE bring in warm coolant instead of cool?

I am having some issues of overheating with my VQ 240sx that I just finished as well and I too removed all of the heater/bypass/oil cooler lines. I had assumed that it was because I had tried my luck with the stock 240sx rad but I am wondering if the issues you are having may be plaguing me as well. I just put in a new griffin rad and efan and once I finish some wiring, I will have the car up and running again and let you know how my cooling system is performing.

Here is the only thing I can think of as far as removing the heater core goes...
Maybe the heater core acted as a reservoir and held coolant in your lines so when you started the car, heat would transfer faster than it does now since you only have air to transfer heat to the thermostat (water transfers heat faster than air)... Just a thought...

 

i just gutted my nismo stat for now. the new line is doing its job i have measured temps of 180 plus going thru the line.

 

Ya, and I made a fundemental mistake in my previous post but not realizing there is always going to be coolant in the lines, no air. So, my only guess would be thermo or air in the lines. Like I said, I will let you know how mine does in a week or two.

 

hmm, strange that you're getting 230* temps. that's a little warm for just street pulls.

are you pushing this engine super hard? i'm not sure of your build/hp.

 

not pushing the car very hard.not sure on the power, I am getting a retune soon. still stock block for now.

 

so stock block so you're under 500hp then. That's odd to have a cooling issue like that with all your mods. I could see 230's on a track but just doing pulls on a highway i wouldn't think it should get that high.

 

I totally agree, i am going to see what temps the car runs with the stat removed.

 

even with a stat it shouldn't get that hot. After 180* (or 160* for nismo) open is open so the temp will only increase with a lack of cooling power. Stock block with your mods shouldn't have that much of a lack of cooling.

 

Any updates? I just cranked my car tonight for the first time with new cooling system and temps got up to 240deg F before I shut her off. The inlet of the radiator is scorching and the outlet is cool to the touch. It has to be some issue with the thermo not opening. I just don't understand how heat is not generated around the thermo? It is looking like I'll be making some sort of radiator bypass like yourself...

edit* Maybe removing all of this stuff is just making filling the cooling system impossible? Theoretically, a full cooling system should be pressurized at both sides of the thermo but since our water pumps can't pull water through a closed thermo, the engine isn't filling with coolant??

 

^^ Probably there is air around the stat keeping the hot water for getting to the stat to let it open.

 

this is the reason



The thermostat is closed so the coolant coming from the radiator will NEVER reach the spring on the backside of the thermostat in order to open it unless there is coolant coming in from the backside. The backside gets coolant from the bypass and from the heater. if both of these are removed then hot coolant is never reaching the spring on the backside of the thermostat. if you have one of these and it's still not opening then there is probably an air bubble stuck on the backside of the thermostat right where the spring is causing the hot coolant to not fully heat the spring. I had that issue with mine. It was a huge pocket of air and the coolant wasn't reaching the spring which would open the thermostat. A proper bleed removed that bubble and it was working fine.

 

Right now, I just have a cap on the nipple on the back water pipe that went to the intake manifold. I'm going to try and add coolant there. I'll let you guys know how that goes.

 

the coolant will still run down behind the tstat housing and trap an air pocket in there. Just get a spill free funnel and do it the right way and that air bubble disappears and no problems.

You'll also need to find a way to route coolant around to the backside of the tstat. it will never open if you have taken all the pipes off from the backside of the tstat by the head. Hot coolant will never hit the spring on the thermostat therefore never opening it.

 

Yes I am thinking that I am going to weld a 6 and fitting to the rear crossover pipe and route that to the side of the head (top port) where the heater flowed into. Due to the design of the head, I am pretty sure that is the reason my t-stat still did not open correctly even with the bypass.

I tried the spill free funnel, pressurized bleed and anything I could think of. For now I just removed the stat.