mark kibort

Qualifying went well, 1:49.0 and 1:48.6 in practice, the wing is working great. what a difference down all the moderate to high speed turns!! carocel i can get on the gas mid point and floor it out the exit. pretty interesting. But, the only drawback, is i have a high speed push that i can drive around now, but we will see how that plays out at the track. certainly dont need any more downforce and the GT3 wing is set at about 8 degrees . Im on the front row with the EVO, behind is the BMW, S2000, Speedvision vet, a couple of cameros, with scot too. He did a 1:53.xx. not bad for a PR and only one hot lap, (literally).

scot has overheating issues. the expansion tank is new, but after a session , it looses about a gallon or more of water. bad bad bad!!!!!! now what. compression check is fine . 155 to 165psi per cylinder plugs are black and heathly looking. AHHHHHHHH!!! its got to be a small leak in the headgasket that when you are racing, the big cylinder pressures push through the leak and pressureize the water system and it blows out the cap. (set at factory 1bar)

we are taking drastic measures not. barrs stop leak!! and maybe even the real deal, Nanotechnology, K&W Perminant headgasket repair. but that takes some time to do. drain, flush, treat, run, drain again, run, and leaks are perminantly sealed. (even block cracks)

any other ideas.

Poor scot. the guy deserves a full race day! (without overheating)

mk

mark kibort

The more i think about scot's problem, the more i think its a cracked HEAD!!

anyone with me? he did loose coolant at laguna but we think due to the cracked water bottle. now with all fixed, it seems to be pushing exhaust into the water jacket and pressurzing the system. the headgaskets are new, i wouldnt think they would go, especially since we are getting good compression. (however, that is a momentary hit)

makes sense though, around town, no problem. a hair line crack in the heads, feeding to the water jacket in the heads could leak out compressed expanding gases from ignition under 1000psi+ and pressurize the water system. then, it just hits the 15psi pressure cap on the reservoir and pumps the water out over a 20min racing session. he is down 1-2 gallons every session . and its not being burned , due to the plugs being black and dirty still. warped heads??? i wonder.

anyone experience warped or cracked heads before???

Mk (for scot)

mspiegle

Well, it IS an aluminum engine. Its pretty easy to warp when you overheat. My friend's sister recently overheated her brand new trailblazer (aluminum), and the car shut itself off to protect the engine. When they started the car up again (with coolant system checked and full of coolant), they began having all kinds of problems. Her head was warped just enough to not function properly when the engine is turned on and you're seeing lots of PSI in the combustion chamber.

I forget from your previous work on the car.... have you pulled the heads and had a peek inside? Did you ever try the leakdown test to see if pressure was escaping into the coolant system?

dr bob

Mark--

Better POLAPS (like NAPA) have an indicator solution you can add to coolant to detect combustion components. It will instantly identify if you have a head or head gasket leak. From there the fix isn't too different-- zyglow the heads and see if there's a crack. Gotta take 'em off anyway for the gaskets.

HTH!

sublimate

You said in the 1st post that he's overheating.
Have you actually measured the coolant temps?
Perhaps he's just simply overheating (which would, of course, force the water out too).

FlyingDog

Mark, I'm all for DIY car work, but maybe it's time to take it to a professional. How far is Scot from the shop that builds Mark A's engines (Precision Motorworks is it?)?

heinrich

check the coolant pressure sensor.

Normy

What's a "POLAPS"? I guess you mean auto parts store, since you mention NAPA.

-What is this product called? I haven't heard of it before, and do you know if it is compatible with propylene glycol coolant?

Thanx!

N!

John Veninger

Mark,

Is he loosing the coolant out the overflow due to the over heating? I had an overheating issues in the past. Only happened when the temperature was real hot, upper 90's. No problem in the 80's.
Replaced the 20 year old radiator, problem gone.

dr bob

Plain Old Local Auto Parts Store .... Like NAPA (whatever that stands for... )

I don't remember the name of the product. It used to come in a fancy kit, but the indicator changes color without the benefit of anything els in the kit. Pour some in, run the engine a bit to circulate, and look again for the new color.

littleball_s4

I saw it a couple of times, not in sharks. Simptoms are exactly those. Required new heads.

mark kibort

actually, the car starts to loose coolant before it get way hot. before the second white line. at that point, the temps start occilating due to the G forces and water level going up and down feeding the pump. then after 2 gallons are gone, the temps start to head too high. usually after 7 laps of racing, and then if he pulls back on the rpms and WOT, the temps get in the near normal range . In the pits, the same thing. He is dry 1-2 gallons. plugs are black, (not water washed) pipe is black (soot), no steam out of the engine at any time.
We think its cracked block or head gasket that allows the 2000 psi to pressurize the water jacket. leak down may tell, but thats only up to 200ps or so.
i think the chemical kit is the best way, but we already put the new water in the radiator. Maybe some flogs later, he can get some kind of sample to test with.

dont think a pressure test would do the trick, as thats only to operating pressure, maybe double (15psi to 30psi) and nothing is going in the cylinders. we think its coming out of the cylinders.

Scot ran great, right up to the point where he finished lap 7 and went hot.

water is gone out the overflow tube

thanks for the replies. any other ideas??

MK

SharkSkin

The overflow tube should only flow water out of it if there is too much water. IIRC, it sits near the top of the tank. You might consider verifying that coolant is escaping there. For that to happen, you would have to be getting so much high pressure gas in there that it doesn't get a chance to make it to the top of the reservoir so it pushes water out. You say that water is gone out the overflow tube. Is this established fact or conjecture? If conjecture, cut the toe off a sock and tape it to the end of the overflow tube. If it's wet with coolant when this problem appears, then you've proven it.

Have you verified that the cap holds pressure and releases above the set pressure? Pressure testing with the cap in place will tell you this. If it doesn't hold enough pressure, the water could be boiling out as steam.

heinrich

Dave, Mark lives on the breadline, his socks have no toes anymore. Mark, I wonder about the black plugs. Is the engine overheating for other reasons? A cracked head should give you SOME oil in the coolant IMHO. And it sounds as if he's driving a LOT before issues arise. Have you checked simple things like the thermostat and its seals?

SharkSkin

Maybe he should look for some next time he dumpster dives for tires.