How much power should I be making with this setup? Cammed LS3 4th Gen
sounds familiar 
Coolant actually flowed pretty well per the shop.. It did bubble for a second at start but afterward it stopped...they're going to try to remove the baffles behind the bumper to try to get it some more air flow. Hopefully that will help.
So the thermostat was replaced again (I believe with a Delco unit, my previous 2 units were Duralast units)
Also replaced the Airdam
Its now running at 220 / 225 and it doesn't seem to go higher - but its also been cooler outside, been in the low 90's most of the week..Although I think I do remember it overheating even in the low 90's in the past.. ..they're going to reconnect the heater core and rebleed it Monday and try again ..
If it doesn't go over 225 / 230 - do you think there is still cause for concern?
What Im thinking of doing is picking it up next week, testing it for a bit, see if it holds out, if it does then I leave it at that. If it doesn't then replace the head gaskets.
Also replaced the Airdam
Its now running at 220 / 225 and it doesn't seem to go higher - but its also been cooler outside, been in the low 90's most of the week..Although I think I do remember it overheating even in the low 90's in the past.. ..they're going to reconnect the heater core and rebleed it Monday and try again ..
If it doesn't go over 225 / 230 - do you think there is still cause for concern?
What Im thinking of doing is picking it up next week, testing it for a bit, see if it holds out, if it does then I leave it at that. If it doesn't then replace the head gaskets.
I'm really believing it has something to do with the headgaskets at this point.
TECH Resident
Joined: Sep 2019
Posts: 818
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From: Melbourne, Australia
I'd say just drive it. When my car was stock coolant temps sat at 230-235 with oil temps the same
more important is what your oil temps are. Try log oil temps , if there under 230 you hv no problems
so unless your losing coolant somewhere and coolant temps stay under 240 , drive it.
more important is what your oil temps are. Try log oil temps , if there under 230 you hv no problems
so unless your losing coolant somewhere and coolant temps stay under 240 , drive it.
11 Second Club
Joined: Jul 2010
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I only managed to put down right at 400 HP to the wheels during a dyno tune. This was a LS1 to LS3 motor swap into a 1999 4th Gen F-Body.
Choke Points:
The shop felt my stock fuel pump (aprox 4 years old as is not the original factory pump but a replacement) was good enough to handle 500 whp so they recommended against installing my Racetronix unit. The shop was also unable to use the 100mm MAF I provided them because they needed a conversion harness and of course without the MAF, my 98 MM lid was also not installed.
During the tune we monitored fuel pressure, it remained between 61 and 62 PSI. The injector duty cycle was 'okay' per the tuner. He stated that it was running too lean at the top end and he was afraid of pushing it further.
It drives decent but my 6th Gen still feels faster and that kind of disappoints me given how much I invested in the swap. I was certain a cammed LS3 would put me close to the 500 WHP range
- Freshly rebuilt LS3
- BTR Stage 2 Cam & supporting valvetrain (Specs: 225/238 .612"/.585" 113+3)
- Yank 3600 Stall
- Built 4L60E
- Stock LS3 Heads
- Stock LS3 Injectors
- Speed Engineering Headers, Hi Flo Cats, Speed Engineering True Duals
Choke Points:
- Stock F-Body Fuel Pump
- Stock F-Body MAF
- 76mm FTP LID
The shop felt my stock fuel pump (aprox 4 years old as is not the original factory pump but a replacement) was good enough to handle 500 whp so they recommended against installing my Racetronix unit. The shop was also unable to use the 100mm MAF I provided them because they needed a conversion harness and of course without the MAF, my 98 MM lid was also not installed.
During the tune we monitored fuel pressure, it remained between 61 and 62 PSI. The injector duty cycle was 'okay' per the tuner. He stated that it was running too lean at the top end and he was afraid of pushing it further.
It drives decent but my 6th Gen still feels faster and that kind of disappoints me given how much I invested in the swap. I was certain a cammed LS3 would put me close to the 500 WHP range
I guess the LSx gods hate me or something. Even with the right fuel pump, no more running lean, 100mm MAF and LID I'm only putting down 413 at the wheels. Did you have head work?
I'm really beginning to wonder if I do have a bad head gasket hence my overheating issues. I'm not sure what to attack next. Is there any other way the AC can cause it to overheat besides being overcharged?
I'm really beginning to wonder if I do have a bad head gasket hence my overheating issues. I'm not sure what to attack next. Is there any other way the AC can cause it to overheat besides being overcharged?
I guess the LSx gods hate me or something. Even with the right fuel pump, no more running lean, 100mm MAF and LID I'm only putting down 413 at the wheels. Did you have head work?
I'm really beginning to wonder if I do have a bad head gasket hence my overheating issues. I'm not sure what to attack next. Is there any other way the AC can cause it to overheat besides being overcharged?
I'm really beginning to wonder if I do have a bad head gasket hence my overheating issues. I'm not sure what to attack next. Is there any other way the AC can cause it to overheat besides being overcharged?
im swapping my ls3 ported heads for ls7 heads . Will have for sale soon set up with springs for llsr and with yella terra adjustable rocker arms. And a set of lifters for a solid roller. Just add the right cam and you will be making power and fresh head gaskets to go with it 😁
To add insult to injury now both of my Camaro’s are down and I’m driving a loaner Trax. My 17 SS fell prey to the infamous TC shudder and they want to replace the torque converter and I am literally 1k miles outside of warranty. FML.
TECH Fanatic
Joined: Jan 2017
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My new build has an lt1 rad, ls2 pump and stock 98 fans and here it is 110 degrees. Seems to run fine on the freeway with ac on but climbs to 230 on the street, at which point I shut the ac off. Might only need to upgrade the fans but I'm not sure yet, It's hot outside. And humid which is worse.
And you have to monitor with an obd scanner. The gauges are wrong. My 98 gauge reads 20 degrees low.
And you have to monitor with an obd scanner. The gauges are wrong. My 98 gauge reads 20 degrees low.
Last edited by Bspeck82; Jul 28, 2020 at 01:44 AM.
My new build has an lt1 rad, ls2 pump and stock 98 fans and here it is 110 degrees. Seems to run fine on the freeway with ac on but climbs to 230 on the street, at which point I shut the ac off. Might only need to upgrade the fans but I'm not sure yet, It's hot outside. And humid which is worse.
And you have to monitor with an obd scanner. The gauges are wrong. My 98 gauge reads 20 degrees low.
And you have to monitor with an obd scanner. The gauges are wrong. My 98 gauge reads 20 degrees low.
Just wondering, does anyone think this could be being caused by bad catalytic converters? They're pretty much new, less than 2k miles, but if they just so happened to have clogged, could this explain why its overheating and only on the highway? Is there any way to test to see if the catalytic converter is bad? Will a heat gun give you any indication if its overheating? If so, how hot?
Last edited by Need4Camaro; Aug 8, 2020 at 01:04 AM.
Yes plugged cats will cause temp issues. Usually an exhaust shop can pressure test them. But if after a drive it is a furnace under the car that is usually an indicator
