overheating under boost only ?
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Launching!
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From: Jacksonville, Florida
overheating under boost only ? Do LS engines "push" coolant? Ive had turbo cars before that when the HG starts to fail under boost only, they would push coolant out and not recover/cool back down.
this is my first boosted LS application- I just got the car together and dynoed etc. Ive been driving it around and it will stay at 190 with a 185 stat in it so its ok in traffic and normal driving.
When I start hammering on it the temp will start creeping after a 2-3 WOT pulls up to 205- then a few more pulls will get met 215 and so on- if I make another pull or two the aftermarket autometer gauge which is tapped into the flat spot on top of the pump will start climbing faster and ill shut it down. ( I assume at this point its seeing steam and pegs 240-250 on the gauge since its mounted in the highest part of the water pump and there is a void where water used to be.
I don't want to spend fruitless hours chasing problems and throwing parts at it if its the head gaskets leaking under boost only.
this is the 2nd motor that did this- the first 4.8 only lived about an hour and died on the dyno (rod bearing/craigs list rip off motor) but they are both overheating about the same way.
any thing I can check for ?
as far as air pockets I took the steam tube hose(4 corner steam tubes) off when I was filling the radiator and I have let it run in the driveway for 30 minutes with the cap off to burp any air.
its got a nice new Griffin LS swap radiator in and a nice fan set up that kept my stroker Ford 408 engine at 185 consistently.
it does have a 4" thick intercooler and a tranny cooler in front of it now but no ac condenser.
this is my first boosted LS application- I just got the car together and dynoed etc. Ive been driving it around and it will stay at 190 with a 185 stat in it so its ok in traffic and normal driving.
When I start hammering on it the temp will start creeping after a 2-3 WOT pulls up to 205- then a few more pulls will get met 215 and so on- if I make another pull or two the aftermarket autometer gauge which is tapped into the flat spot on top of the pump will start climbing faster and ill shut it down. ( I assume at this point its seeing steam and pegs 240-250 on the gauge since its mounted in the highest part of the water pump and there is a void where water used to be.
I don't want to spend fruitless hours chasing problems and throwing parts at it if its the head gaskets leaking under boost only.
this is the 2nd motor that did this- the first 4.8 only lived about an hour and died on the dyno (rod bearing/craigs list rip off motor) but they are both overheating about the same way.
any thing I can check for ?
as far as air pockets I took the steam tube hose(4 corner steam tubes) off when I was filling the radiator and I have let it run in the driveway for 30 minutes with the cap off to burp any air.
its got a nice new Griffin LS swap radiator in and a nice fan set up that kept my stroker Ford 408 engine at 185 consistently.
it does have a 4" thick intercooler and a tranny cooler in front of it now but no ac condenser.
Thread Starter
Launching!
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From: Jacksonville, Florida
You will need some head studs and possibly may need reduce your boost / timing a couple of degrees. Assuming that you are running pump gas, sounds like you are right on the edge of detonation.
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Thread Starter
Launching!
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E85 for fuel- tuner told me my timing was conservative.
I have a friend who is coming by today who has HPT so we can log it- ill see what the timing is and if there is any knock and also cyl head temp.
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I'd put good gaskets/studs in it, then again we build them to drive and be reliable. With ls9 gaskets/arp studs we haven't pushed coolant with A LOT of boost.
Also have any holes drilled in the thermotat? If not you can do that, fix to help from getting air trapped behind the thermostat.
Had this exact thing happen to me. put 10-11lbs to the stock headgaskets/stock head bolts and they lifted as soon as i got off the dyno. Im on E85 at 19* timing. it would blow coolant out of the resevoir and start getting pretty hot after a few pulls. Threw in ls9 headgaskets/arp head studs and everything is perfect. didnt change the boost or timing at all.
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Launching!
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From: Jacksonville, Florida
I guess denial isnt a river in Egypt. I ordered the $69 KMJ studs and the $35 GMPP LS1 MLS gaskets- Well see how/if they work-
I just couldn't swallow $253 for head studs-
If the Chinese junk fails it will be one on many lessons learned the hard way.
I just couldn't swallow $253 for head studs-
If the Chinese junk fails it will be one on many lessons learned the hard way.
There's quite a few people running a lot higher horsepower on the Chinese studs, surprisingly. I bet they'll work out great for you, and for $69, they're hard to beat!
i run the kmj studs and they work great, we also have them in the sunbird, and my friend jace is using them in a 6.0 with 23lbs of boost on a 6.0 so lots of surface area there...
do the ebay studs come with a manual? or specs?
i have tightened ARP and KMJ's to 80 and never had a issue.
i would bet it was too much timing causing too much cyl pressure people who tune on e85 are like, ill just throw 8deg at this motor it wont detonate lol.
i ran 21lbs of boost in my friends pickup truck on 16deg of timing for a lonngggggggg time over 650rwhp in the truck, ran 10s, 4700lbs and it never pushed water or got hot.
so i think it might be the tune, or possibly super weak hg or bolt or something that is letting it in....
is it a stock steel gasket or paper gasket motor?
do the ebay studs come with a manual? or specs?
i have tightened ARP and KMJ's to 80 and never had a issue.
i would bet it was too much timing causing too much cyl pressure people who tune on e85 are like, ill just throw 8deg at this motor it wont detonate lol.
i ran 21lbs of boost in my friends pickup truck on 16deg of timing for a lonngggggggg time over 650rwhp in the truck, ran 10s, 4700lbs and it never pushed water or got hot.
so i think it might be the tune, or possibly super weak hg or bolt or something that is letting it in....
is it a stock steel gasket or paper gasket motor?
I have had the eBay studs to 80lbs 5 times on 1 set of studs and still fine. Had a 4.8 with stock gaskets and eBay studs and 22lbs of boost and was fine. Running a 370 and gonna see how it does with eBay studs and 18-20psi with a pt91.5
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Launching!
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From: Jacksonville, Florida
yep- i hope that its it- i remember bending the corner of it with my thumbnail to see if it was MLS
I ordsered the Pro Comp studs from KMJ on ebay and the ls1 gaskets from summit earlier.
I ordsered the Pro Comp studs from KMJ on ebay and the ls1 gaskets from summit earlier.
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