project89

iTrader: (1)

since my new motor went together ive always suspected that i was lifting a head or had a gasket that wasnt sealing.

at idle i get no pressure in the cooling system,

i have one of those vent lever caps, since ive always been suspiscious of it ive always poped the vent lever on the rad cap before every run so the system couldnt build presure, car never went over 170* on the top end of the track this way

well long story short was i was able to finnaly get a presure gauge taped into the cooling system and sure enough under boost im presurizing the cooling system

i have one finaly race left for the season
i do not have time to put new head gaskets on

how bad is this to actually run the car like this?
u guys think maybe trying to retightenning the heads might help

this last race will be the final runs before this motor comes out of the car for good. though i dont want to destroy the motor cause i am getting something else to put the motor and turbo system into either a 1st gen rx-7 or a mid 80's s-10 pickup
and a twin turbo 4.3 motor will be replacing the 3.1 turbo motor in the camro

Sonix

iTrader: (1)

Can you explain the vent lever on the rad cap? If the rad cap isn't allowing you to build pressure, it would be venting off into the overflow... If you have no thermostat, you wouldn't build pressure... Could that have failed open?

I think you're building boost in your cooling system, not because your intake manifold is becoming boosted, but because you are loading the engine. You put load on it, (ie. spin it higher) and it can't circulate the coolant fast enough, it backs up, and "pressure" is measured. Seems pretty normal to me and unrelated to your turbocharger.

Are you getting chocolate milk oil? Oily coolant? losing coolant into the engine? (ie, not on the ground by the overflow tank?)

project89

iTrader: (1)

i dont run a thermostat,just a restrictor,

the radiator cap has lever on it that releases the pressure in the cooling system.basically ur right it jest vents to the over flow

if i leave the vent closed and take the car for a drive and go into boost it presureizes the cooling system instantly.

the motor canbe cold if i go into boost then pull over and pull the lever u can hear all the air escaping out the cooling system,it also swells up the radiator hoses.

with a pressure gauge taped into the upper rad hose im seeing just as much presure as i am running boost except if i go over 16 psi then the rad cap opens anyway since imusing a 16 psi cap

no oil in the coolant, and no water in the oilpan. but it will fill the overflow up, this entire season i would have to drian my over flow and top off the radiator after ever pass

also if u take the rad cap off while the motor is cold and put ur hand over the top of the rad and hit the motor against the 2 step and build boost u can feel air comming out of the radiator

Sonix

iTrader: (1)

Hmm... You have a very convoluted system compared to other 'normal' turbo cars... I would want to keep it simple, where I didn't have to mess with the cooling system after ever run (if I could avoid it...)

Try closing your vent, (such that it would build boost in the cooling system), then lock open your waste gate or something. Whatever method is easiest to completely "turn off" intake manifold boost. Take it for a spin. It'll be LAZY, but load up the engine and check. I imagine the rad builds pressure as normal.

If it doesn't (which is strange), but would confirm your suspicions that the cooling system pressure is related to the intake pressure, then i'd be trying to find out where/how. Intake manifold to water jacket leak might be a source, but that should blow coolant into the intake when you hit your BOV, and other times....

project89

iTrader: (1)

ill give that a shot i can just unblot my wastgate and stick a dump tube on it to test.

im pretty sure its doing something it isnt supposed to be doing earlier this year i had my daughters mom in the car driving it down the track and we pushed a freeze plug out of the block right before the traps.when i left the rad cap unvented
^^^ talk about scary thank god the car was on street tires and not slicks

i dont htink its a manifold gasket issues even though these motors do have intake gasket sealing issues but like u said when they go out they fill the motor with coolant.

im leaning more twards im leaking compression threw a headgasket into the waterjacket under high boost

Sonix

iTrader: (1)

Nah, I wouldn't lean towards your last thought. Boost is negligable in the cylinders. 15psi is nothing compared to 800psi of cylinder pressure. Boost or no boost, if it was leaking in the head gasket it'd just dump all kinds of pressure into the water jackets... But more importantly, it'd be sucking coolant into the cylinders as well. Losing coolant, blowing white smoke, or hydrolocking...

drknow90rs_ss@y

iTrader: (3)

One thing nobody has mentioned; You could pressurize your cooling system with a pressure tester (Available at autozone, checker, pep boys) to see if it loses pressure...

Shagwell

Comon cranking cylinder pressure is closer to the 150-200 range(not 800), and 15psi of boost doesn't mean you're only adding 15psi of cylinder pressure. Pressure is only a measure of restriction. The pressure measured in the intake is relative to the volume of air being produced by the turbo's that is not making it into the cyllinders. - All of that said, 15psi of boost could easily double or triple your cylinder pressure at rpm.

As the last guy posted, go pick up a pressure tester at your local parts store(many have them as a "lone-a-tool"). If it leaks down you have a problem. If it's a head gasket, then the motor is getting water back into it when you shut it off, not to mention the combustion cycle is creating the "plasma cutter effect" on your engine and heads' deck surface.

Sonix

iTrader: (1)

Cranking pressure is lower yes, I meant combustion pressure. You don't have a spark lighting a flame front when you're doing a compression test. 200psi of cylinder pressure doesn't get your car doing 13.0's in the quarter, 800psi does (or much more...)

but yes, try a cooling system pressure test, that's a good surefire
way to check it.

project89

iTrader: (1)

yup its bleeding down on me, im not gonan do a thing but put an additional 15ftlb's ont he head bolts and run it for my final race.

chances are i will just run without coolant in the motor anyway,since its cool enough outside to do so.

push the car to the lanes and upto the line and then fire it up make the run and shut it down when rentering the pits. and run some water threw it inbetween rounds


i have one goal for my final outing 11 second time slip or break the motor trying, either way after this next race the motor is comming out and being replaced by a twin turbo 4.3L vortec motor

Shagwell

Sonix - you're correct, I miss read what you were saying. Again, boost can easily double or triple combustion pressure.

project 89 - you're kidding right? No coolant on a gas motor and you think you'll be able to drive it back to the pit area after a run? You'll be lucky if the pistons haven't started molding into the cylinder walls before you even get onto the return road. - You're taking a huge risk with yourself, none-the-less an unknowing opponent. What happens if it lets go and kicks the pan out? Oil in front of your rear tires at who knows what speed. That kind of crap can get you permanently banned from a track for good reason. It's hurt/broke man. It's your choice to risk yourself, you don't have the right to make the choice for others.

lt1z350

iTrader: (2)

my buddy was doing just that with his 5.0 and a masterpower turbo. fords only having 4 bolts per cyl are terrible for gasket problems. Retorque to spec of your bolts and see what happens. are you running mls gaskets? aftermarket bolts like arps? I pulled my arps to 80 lbs with molly on them with a mls gasket then re checked after heat cycleing and all of them pulled more than I liked to reach 80 again. so go through the paces again as if you just built it and make sure you are at the right torque. too much is as bad as not enough.

project89

iTrader: (1)

same 4 bolts per cyl,i never did run the car again the track never opened back up due to cold weather.

motors coming apart over the winter,for new head gaskets,bearings,cam and a partial block fill