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JoshS
02-08-2007, 02:59 PM
My car has a plastic radiator, and an external, pressurized, plastic expansion tank.

Some of the replacement radiators on the market replace the external plastic expansion tank with an aluminum one integrated with the radiator. Legal? I'd be nice to get rid of the plastic stuff that doesn't last very long.

Z3_GoCar
02-08-2007, 04:22 PM
Hey Josh,

3a Any Radiator may be used provided.....

Basically if it's a stock replacement and it requires no modifications to mount (aka Zionville) your golden. That being said I just ran four weekends with the stock plastic and it worked just fine. If you're looking to economize and get out on the track you could just run what you've got.

James

JoshS
02-08-2007, 06:26 PM
Hey Josh,

3a Any Radiator may be used provided.....

Basically if it's a stock replacement and it requires no modifications to mount (aka Zionville) your golden. That being said I just ran four weekends with the stock plastic and it worked just fine. If you're looking to economize and get out on the track you could just run what you've got.

James
[/b]
At 100K street miles I don't feel comfortable running what I've got! I already snapped the plastic hose running to the expansion tank just by looking at it funny (when installing the CAI). I'd like to run the Zionsville one with the integrated expansion tank instead of the regular aluminum replacement, just for peace of mind, but only if it's legal.

Andy Bettencourt
02-08-2007, 06:37 PM
I am thinking it's a no-go. It's not a radiator and the rule doesn't say anything like 'cooling system' in the allowance, does it? If it does, then you could be ok but I think this is one of those bottles that has to stay in...

dj10
02-08-2007, 07:04 PM
Hey Josh,

3a Any Radiator may be used provided.....

Basically if it's a stock replacement and it requires no modifications to mount (aka Zionville) your golden. That being said I just ran four weekends with the stock plastic and it worked just fine. If you're looking to economize and get out on the track you could just run what you've got.

James
[/b]



I recommend the Zionville, plug n play. I use to run the stock but the plastic necks break.

JoshS
02-08-2007, 07:45 PM
I recommend the Zionville, plug n play. I use to run the stock but the plastic necks break.
[/b]
Thanks, it'll definitely be a Zionsville, the question is, which one? Because it's not just the radiator necks that break, it's also the expansion tanks. But I guess I'll just use the stock replacement and get a new factory expansion tank.

splats
02-08-2007, 08:02 PM
Where does it say that the expansion tank "MUST" be hooked-up (ie. rubber hose)???? The tank is not a TRIM piece, so I too think that it is one of those silly things that must stay.

dj10
02-08-2007, 08:10 PM
Thanks, it'll definitely be a Zionsville, the question is, which one? Because it's not just the radiator necks that break, it's also the expansion tanks. But I guess I'll just use the stock replacement and get a new factory expansion tank. [/b]



The stock repalcement is the one you have to use to stay legal. I used my old expansion tank on the new radiator. Knock on wood nothing has failed me after 1 1/2 seasons with it and the cooling with the right thermostat is very good.

Z3_GoCar
02-08-2007, 08:18 PM
I am thinking it's a no-go. It's not a radiator and the rule doesn't say anything like 'cooling system' in the allowance, does it? If it does, then you could be ok but I think this is one of those bottles that has to stay in...
[/b]

But the tank is an integral part of the radiator, as in remove the radiator and the tank is removed without doing anything else. I'd like to see someone remove the radiator with out removing the tank :lol:

I understand I had the tank leak on my street car at ~92k and it's a 1.9liter which isn't known for radiator issues. Turned out to be a set of bad o-rings. I had to use a block of wood and a dead blow to get it off the radiator after I'd pulled it from the car, and a piece of all-thread to reassemble it. I'd think that you could also mount an external catch tank too while you're at it, that's one thing I wish I had on the race car but don't know how to with the stock tank.

James

mlytle
02-08-2007, 08:59 PM
But the tank is an integral part of the radiator, as in remove the radiator and the tank is removed without doing anything else. I'd like to see someone remove the radiator with out removing the tank :lol:



James
[/b]

you talking about the 6 cyl? nice try, but the tank ain't part of the radiator...it is easy to pull the radiator without the expansion tank. :P

instead of a zionsville, try a pwr. zionsville is basically a stock rad core with alum endtanks. nice unit, i used one on my race car for 3 years. the pwr uses a thicker core (actually two different capacities are available). i have one of those on my race car now. works great. ditch the stock aux fan and put a spal pusher fan on the front of the radiator and connect it to the stock aux fan wiring harness. bimmerworld carries both items.

in my experience the only problem with the stock expansion tank on these cars is that it does not hold up well in a major frontal collision. for some reason my 12 year old expansion tank with 175k miles got a little leak in it when it got sandwiched between the flying engine and the radiator in a 90mph impact with a camaro. :mad1:

Z3_GoCar
02-08-2007, 09:04 PM
I just had a look at the radiator on my racer. It's definetly a Six-cylinder radiator. But the tank would interfere with the second vanos, as it's just ahead of the exhaust cam. Maybe worth a look on real-oem to see if you could back-date to an earlier integrated tank, then you could just sell your external tank on e-bay.

James

Edit: I just saw your post Dan, both my four and six have integrated plastic tanks. The four's on the right and the six is on the left.

JoshS
02-08-2007, 10:28 PM
On my car, the expansion tank is on the left side towards the rear of the engine compartment, between the strut tower and the fuse box.

Z3_GoCar
02-09-2007, 12:08 PM
Josh,

You might want to search Real-oem to confirm this but I'm sure my radiator is a stock unit, aluminum core with plastic side tanks, with an integrated tank. Use an early production date, mine's 10/1996. I suspect that they added the finder tank with the switch to double vanos as it sits right where the exhaust vanos would go. Since they're on the same spec line, I don't see an issue with back-dating to an integrated tank and removing the finder tank if it fits in your car without modification. The change should be covered as a back-date. Good luck,

James

JoshS
02-09-2007, 03:26 PM
Interesting thought, but A) I have double-vanos, and B) I have a Coupe, and you can't update/backdate between body types. I'll just replace the stock expansion tank and all of the other cooling system plastic parts (but I'll use an aluminum radiator.)

JoshS
03-07-2007, 06:56 PM
Not to dredge up an old issue, but I thought I'd share today's experience. I put a new radiator in the car but left the other parts intact for the moment. Then warmed the car up and bled the system. Shut it off, and heard a really quit hiss ... from a teeny tiny crack in the expansion tank!

New stock replacement on the way, along with everything else that's plastic in the cooling system!

mlytle
03-07-2007, 07:12 PM
which radiator did you go with?

planet6racing
03-08-2007, 08:36 AM
Where does it say that the expansion tank "MUST" be hooked-up (ie. rubber hose)???? The tank is not a TRIM piece, so I too think that it is one of those silly things that must stay.
[/b]

More importantly, where does it say that it doesn't? If it doesn't say you can, then you can't.

JoshS
03-08-2007, 10:52 AM
which radiator did you go with?
[/b]

Went with the Zionsville. Turns out that the Z3 radiator is shaped slightly differently than the normal E36 radiator, to allow air to reach the normal air intake behind the left headlight. It would seem that the PWR radiators aren't available for the Z3, unless you want to lose that air intake source.

mlytle
03-08-2007, 12:25 PM
Went with the Zionsville. Turns out that the Z3 radiator is shaped slightly differently than the normal E36 radiator, to allow air to reach the normal air intake behind the left headlight. It would seem that the PWR radiators aren't available for the Z3, unless you want to lose that air intake source.
[/b]

good choice, zionsville works well...and more intake air is good! :)