Cooling system help, expansion tank

[gsracer]

Well ever since the i changed the intake manifold, and had to throw out the stock thermostat housing in favor of the one that i had to fabricate the car ran a lot hotter.

I originally attributed this to the fact that there was no thermostat any more, however this past week i took it apart and welded a restrictor in there to simulate the thermostat and still have the same thing.

Just recently i notice that the radiator after a while will develop an air pocket despite not having this problem before, My expansion / bleeder tank has alway just had two lines one on the upper and one on the lower hose. I never ran the line to the radiator water neck, it is currently capped with a plug, and i am wondering if this could be the problem. The radiator is the lower than the engine but it bleeds fine. Its just after running it for a while that the air pocket starts to develop

here is some pics of the setup..

you can see the expansion tank in on the right side where the wiper motor used to be. It is literally the highest point in the engine bay.


http://img.photobucket.com/albums/v344/gsracer/intake%20manifold/e8c3fdf2.jpg


Here you can see the two lines from the expansion tank one goes to the inlet and one on the outlet. towards the back of the highest point of the water neck, and on the highest point on the water outlet.

http://img.photobucket.com/albums/v344/gsracer/intake%20manifold/d0a8ce4c.jpg?t=1325911057





I guess the question is would running a third line to the plugged vent in the radiator remedy the air pocket?

[zerodameaon]

Give it a shot with some calmpon lines. On the stock KA etc. the little tank on the passenger strut tower acts as the expansion tank so that should work about the same to your aftermarket one. Even though there is a higher spot air can sometimes be trapped in awkward places like a radiator cap.

[rb25_s13*CHUKI]

Is that damn thing even enjoyable? what kind of power are you putting down?

[jr_ss]

Is that damn thing even enjoyable? what kind of power are you putting down?

Read his build thread and you'd see. It's also his track car.

You could try adding the line, however, I think there may be going on here. Have you checked for a headgasket issue yet? You could possibly be forcing combustion air into the cooling system when it's running super hot. Do a leak down and hydrocarbon test.

[gsracer]

Yea. I really don't think the head gaskets are blown. When I say hot it is relative. Before the car would run at 185-195 cruising. Now it cruised 200-210. I can't cruise at say 80 mph for extended times with out it climbing up past 210. On the track it does get hot as High as 230 but it's a drift car and they all run hot so that's to be expected after two or three hot laps. It's the street cruising that's bothering me.

If I where to put a line going to thr radiator neck. Do I need to replace thr sprig loaded radiator car with just a blank cap. I just don't see how water will get past the spring cap otherwise.

[jr_ss]

Yes, you would need the pressure rated radiator cap on your expansion tank and a blank on the radiator itself.

Edit- read this thread in the link I am providing. This gentleman is/was having a similar issue. Both V8 related however different manufacturers.

http://nissanroadracing.com/showthread.php?t=4039

[Def]

Do a hydrocarbon test. Usual "bad" behavior of a gasket failure into a coolant passage.


If you kept filling the radiator and still get "air" - that's a dead giveaway. There's no magic place where you could have gallons of "air" hiding in your cooling system if you keep topping it off over and over.


Are you ever popping the cap on your expansion tank with all this air volume in the system?

[gsracer]

Do a hydrocarbon test. Usual "bad" behavior of a gasket failure into a coolant passage.


If you kept filling the radiator and still get "air" - that's a dead giveaway. There's no magic place where you could have gallons of "air" hiding in your cooling system if you keep topping it off over and over.


Are you ever popping the cap on your expansion tank with all this air volume in the system?


how does one administer said hydrocarbon test?

and when i pop open the expansion tank a lot of water gets pushed out. as for the air pocket I'm finding its only maybe a pint or a little more to top it off till its filled again.

Its not that I'm not doubting you guys, i think theres just a little more too it. Being that it didn't do it before i had to chuck the thermostat and redesign the cooling system, i think there more going on here.

Since there is no thermostat i restricted the Oulet not the inlet as normally with a 7/8 restrictor. And the neck is plugged, i think that it just accumulates air there for some reason. Looking at it again it seems the radiator is tilted up at the neck, i just don't know how efficient my bleeder tank setup is.


http://img.photobucket.com/albums/v344/gsracer/5D653CA2-F9A7-4CD9-840A-D67589D6409B-14669-00001366433873EC.jpg

[zerodameaon]

I just had a thought, maybe a swirl tank will alleviate some of your problems. For the HC test there is a kit you can buy or hopefully borrow from someone called a Block Test Kit. Head Gasket or Combustion Leak Test Procedure (Gasoline Engines Only) (http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm)

[gsracer]

well i just picked up a hydrocarbon tester from napa, ill test when i get home and report back...

[rb25_s13*CHUKI]

Your a sick man! 391 ft lbs! Sorry i know this isn't your build thread but I like your car! Hope you figure out your heat problem!

[gsracer]

thanks man...

i take it this is bad news.



http://img.photobucket.com/albums/v344/gsracer/intake%20manifold/40740BFB-1096-436A-8A9F-F1117C8416B2-14956-0000138EA504D215.jpg

[jr_ss]

Looks like someone has a bad headgasket...

[future]

Should have been checked first? Lol

[gsracer]

well most likely, I'm gonna try to plumb in the water neck to the expansion tank as a bandaid till i can get the other motor together, see how long i can make it last, next month will be 4 years till the day that this car is running so lets see what happens.

[zerodameaon]

That motor is a troll dude, its awesome. Is that adapter one off? Whats going in next?

[gsracer]

for the intake mani yes, the rest can be gotten at mazworx. I contemplated selling it all and going with an ls7 or something but my wife told me to stop being a bitch and fix it, so thats what I'm gonna do, except I'm gonna put some cams in to.

[jr_ss]

If I'm not mistaken the vk56 intake manifold is a direct bolt on no?

However, I know that you are running a Porsche IM.

[gsracer]

the vk doesn't bolt on unfortunately..

[jr_ss]

the vk doesn't bolt on unfortunately..

Well that sucks... That would be an easy upgrade from the OG VH.

[zerodameaon]

Yeah The manifold adapter is pretty cool. LS intakes are a lot better then even the aftermarket VH manifolds. That whole sideways crap is annoying.

[gsracer]

yea... i hated the stock one, plus picking up that much power is cool.

Im dropping off my sore block at the machine shop friday to get machined. The heads are done with some nice cams, titanium retainers and dual valve springs. The bottom end is getting loosened up for what hopes to be 8-8500 rpms.

Im gonna continue to race the motor in the car in the mean time till the new one gets done, then after its ready I'm going to the dyno and gonna put 16-20 psi thru this one and either completely lift the head or make some sick power, or catastrophically disassemble it.

[jr_ss]

yea... i hated the stock one, plus picking up that much power is cool.

Im dropping off my sore block at the machine shop friday to get machined. The heads are done with some nice cams, titanium retainers and dual valve springs. The bottom end is getting loosened up for what hopes to be 8-8500 rpms.

Im gonna continue to race the motor in the car in the mean time till the new one gets done, then after its ready I'm going to the dyno and gonna put 16-20 psi thru this one and either completely lift the head or make some sick power, or catastrophically disassemble it.

In for pictures, videos and your thread updates...

[gsracer]

<<<<UPDATE>>>>

I got bored today and figured what the hell i took out the 1 inch restrictor in the outlet of the engine, then i added a 1/2 inch restrictor BEFORE the water pump where the factory thermostat would be. Thinking it really couldn't get much worse.

What do you know it got id say 75 percent better. Took the car out for about 2.5 hours.

Cruising 45 mph wouldn't got over 180 degrees
Cruising 85mph wouldn't go over 200 degrees.

I had to beat on it and i mean beat on it and the highest temp recorded by the defy was 210.

Im still gonna add the bleed line to the radiator neck tomorrow. Do you guys think the 1/2 restrictor is a little to small maybe step it to 5/8

Thoughts.

***EDIT

Im still gonna build the motor either way...