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leaky bbsc coolant resovoir

8 July 2003
not really specifically FI, but since it does come with the bbsc, i thought more bbsc'ers might find it here.

My polished aluminum coolant resovoir, the one mark supplies with the bbsc, has leaked from the cap for a while. I bought a new cap to no avail. Mark then suggested I buy a cap with 2 psi more pressure (18lb i think?) and stick it on.

I replaced it about 2000 miles ago and not a drop since. This is pretty basic i suppose, but heard a couple other people complaining about it, so thought the uninformed might be happy to hear there is a super easy fix.
Speaking of the reservoir which came with the bbsc kits-- has anyone actually measured it's capacity versus the OEM/stock unit?

When I first installed my setup I began thinking of a way to increase the coolant capacity because it looked *much* smaller than stock... and the nsx's already run pretty god damn hot at the track. I've been debating getting another tube type reservoir and running it inline with the bbsc tank... or maybe just getting a custom one made, but there really isn't much room in there. And, since the tank/cap has to stay the highest point in the system for proper burping/bleeding.. it makes it even more difficult.

Has anyone else thought of a clever way to increase the coolant capacity?

peiserg said:
..... a cap with 2 psi more pressure (18lb i think?) .....

Except the additional internal pressure is subjecting the tank to the possibility of rupturing a weld.
mikeh said:
.....and the nsx's already run pretty god damn hot at the track.

No they don't, unless there is a problem. Several years ago I was attending a track event in July when the ambient air temperature was 103 °F. The needle on the temperature gauge stayed just under the half-way mark all weekend long.

The coolant reservoir volume is a fraction of the total coolant volume that is in the radiator and engine. You will not substantial increase the system's overall capacity by installing a larger reservoir.
Oh Yes We Were

Andrie Hartanto said:
Sorry to say, but probably you don't drive it hard enough. I managed to overheat 3 different NSX that I drove, while the owners didn't have the problem.

That particular weekend, I shared my car with another driver. It was not like we were in the novice green group, either. I was solo yellow and he is an instructor. The car ran double duty for the entire weekend. He boiled the brake fluid.....I'd say we were driving the car pretty hard, and still no overheating issues. At the time it had the CTSC - thus even more heat into the engine.