kris

That is in fact pretty accurate stuff right there.

BB, let us know when you take the beast out to Zolder.

belgiumbarry

first sound with the ITG air filters and exhaust ... seems very OK , even for circuit Zolder. ( 95 dbA)

second reving you see a backfire on the left bank... must install a A/F meter to see where i am , think very,very rich as i see the black exhaust...

www.vette.be/vroem.mpg

belgiumbarry

got a test run with the AFR gauge ... AF was 10 ... playing a bit with the mixing screws ( got it up to 11 ) suddenly .. PPPPSSSTTT the overflow on the watertank was squirting like a maniac , think a gallon was pushed out of it ... damned. What could that been now ?? perhaps i didn't deaerated it good ?

i checked meanwhile the thermostat and that one was opening ( on the coocking stove ) only past 90°C ... so i orderd a new one to replace it before another try... got it today.... price : 60 euros ! isn't that very expensive for a thermostat ????

SharkSkin

Leaking head gasket?

belgiumbarry

indeed afraid of... but still hope the thermostat , circulationproblem.. as the heater circuit was still cold ( so no real circulation ? ) and the lower rad hose was just became " warm" at the moment there was water/steam out the overflow ???

the car was running fine when i started the build last year and i didn't touch the heads...

there's no sight of water in the oil as no oil in the water ... so i still have good hope

SharkSkin

The coolant circulates out through the bleed hose on top of the radiator(Cannot enter through the closed thermostat on the lower hose) and goes to the coolant reservoir. It's also coming out of the bypass below the AAV(which you don't have anymore) to a tee in the line between the bleed hose and the reservoir. The larger "heater line" which I see you still have installed allows water to return to the block from the tank.

The water circulates around mostly inside the engine with the thermostat closed, with no particular restriction.

The head gasket can leak from the combustion chamber straight to the water jacket without involving any oil passages. There are test kits available to check for combustion gasses entering the coolant.

I'm really sorry if that's the case... I have been following your project with great interest and have been looking forward to your first test run and/or track vids.

belgiumbarry

THANKS Dave for the help.
But i'm i correct that i have still all hoses as needed ? i have the bleeding hose from the radiator , the hose from the water bridge to a T in that bleeding line up to the reservoir. And the bigger hose, reservoir to waterbridge.
Sorry if i misunderstood , but i was doubting as i was missing a hose ? no ?

SharkSkin

Yes, it sounds like you have all of the hoses needed to allow proper circulation when cold or hot. I was pointing out that from what I can see of your coolant setup, there is nothing to point to a circulation problem causing the coolant overflow.

belgiumbarry

put in new thermostat and let it idle for 1/2 hour during which i worked on the carbs ... temperature stayed 86 ° ! and no signs of anything wrong ... now also the heater hoses got warm and the little return lines to the reservoir ... possible the old thermostat kept sticking ?

got the 2 electric fans on and was amazed how "cold" the return hose is in comparison with the 86° rad in hose . Ok, ambient temp is only 2°C ... bloody cold dammit

not to mention i'm happy again

www.vette.be/thermostat.MPG

Marcquito

Norbert,

First, I must say what a beautiful car you have. Looks like tons of fun - I hope to see some pics and possibly videos of your beast on the track! I'm also interested in you rear hatch-mod. My father had the same idea from looking at the 'Vette as well. He has already begun the cutting process and has his own design in mind which looks nearly identical to this one. He's going ALL metal and no fiberglass. I wonder if you have any tips or any sort of advice with this type of custom modification? I personally like the look of the rear hatch glass from the factory, but this look can be beautifully done as well (yours, for example). Our 928 S is all black, so I think this look would look very very good.

Any help? Thanks!

Oh- and Welcome!

belgiumbarry

thanks Marc

we made it from aluminium, completely welded and bolted to the hatch . The 2 louvers in it are 928M . We laser cut the hatch contour "flange", bolted it fix and welded the side plates to it with the ground plate. The window is a Lexan sandwiched with a laser cut flange , rivetted all together. Got the rivets in diameter and lenght so that they stuck fix in the inside holes without those nasty deformed endings protruding the cabin

Marcquito

Thanks for the reply. Nice work! I'll send my father the link to this thread so he can view your masterpiece.

belgiumbarry

don't exagerate Marc, its a piece , not a "master" one...

mark kibort

I was fighting this for over 4 years. engine would occasionally overheat, (gauge temp) yet radiator was cool. turning the car off and restarting, sometimes even coasting on a warm up lap before a race if you can believe it, would heat soak the t-stat and it would then function normally. when i pulled the engine, i found the seating seal in the t-stat housing was destroyed and old.

now, with a new seal, that problem went away. You also might have had air in the system. squeezing the hoses and forcing the water back into the reservior can bleet the system and get the air out.

mk

belgiumbarry

yes , having the problem i did a search on thermostat and amongst them read your posts about it... very strange ... my seal was 1 piece but as hard as stone.... on the other hand i cannot see what the seal can do on the thermostat , my seal was sure still "closing" and even a small leak would act as the little hole we used to drill in the thermstat disque to have instant a bit circulation ...?? i think , if thermostat is sticking , there's very quick a point were steam is generated in the engine , making a enormous volume and pushing all the water up to the overflow.....Must also mention i have the low pressure cap from 928M....which indeed allows steam sooner as it holds the system on a lower max pressure.

I hope for sure that was it and no head gasket problems are on my way...