Ls9 HeadGasket / ARP Studs w/4.8L
01-03-2011, 06:23 PM
#12
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i came across the rx7 dude on ls1tech. very impressive on a stock bottom end. ive thought of studding my motor before i run into any problems. is it alright to intall studs one by one without removing the heads?
01-04-2011, 01:55 PM
#13
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Nice truck! That thing rips!
Starting a single turbo 4.8/4l80 build on a Chevelle soon myself. There is not really much info on 4.8 builds over there so I thought I would try here. Seems that I came to the right place.
What's the plan for the MP70 you took off? That is what I was going to run on the Chevelle.
Starting a single turbo 4.8/4l80 build on a Chevelle soon myself. There is not really much info on 4.8 builds over there so I thought I would try here. Seems that I came to the right place.
What's the plan for the MP70 you took off? That is what I was going to run on the Chevelle.
01-04-2011, 10:25 PM
#14
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The day has come, work a little to play a little. During the install of the PTE76GTS, I noticed some coolant around the heads/block, both sides, like a tear drop from a 4.8L who's been gettin beat on 
. A few nights priors to the swap, I was really cranking the MP70 for her last days. I included a HPtuners log showing one of the many 1st-4th gear pull with boost mostly 17-18psi area and on the 3/4 shift it spiked 19.9PSI. This was on Stock Gaskets/Head studs, so I figure they put a hell of a fight for nearly 90k miles of many many many pulls being at or above 15psi.
I drained the oil and seemed normal and the over flow was only slightly low.
. A few nights priors to the swap, I was really cranking the MP70 for her last days. I included a HPtuners log showing one of the many 1st-4th gear pull with boost mostly 17-18psi area and on the 3/4 shift it spiked 19.9PSI. This was on Stock Gaskets/Head studs, so I figure they put a hell of a fight for nearly 90k miles of many many many pulls being at or above 15psi.I drained the oil and seemed normal and the over flow was only slightly low.
01-07-2011, 03:43 PM
#15
Well I just got back in town last night from work. Came home to a UPS box from Texas Speed.. Hope to have it running by sunday for sure. Also my heads are Cast # 862's. Can any one tell me if these have any "Known" problems?" Any key areas to inspect?
Head: 1999+ 4.8L / 5.3 Liter Truck
Material: Aluminimum
Quick search : Combustion Chamber Volume: 61.15cc
Compression Ratio: 9.5:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 1.89 inches
Exhaust Valve Diameter: 1.55 inches
Head: 1999+ 4.8L / 5.3 Liter Truck
Material: Aluminimum
Quick search : Combustion Chamber Volume: 61.15cc
Compression Ratio: 9.5:1
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 1.89 inches
Exhaust Valve Diameter: 1.55 inches
01-07-2011, 04:07 PM
#16
After doing a little more research, I do NOT have Castech heads, so I should be good to go, also didn't notice any hairline cracks around the stud mounting surface.
I've read around the GM forums the answer is no. I will say however I've done this on many 4g63T engines (turbo eclipse/talon) and ran over 35PSI with no problems. I really don't understand why there would be a difference. If I would have know more about LS engines having a 3 MLS head gasket stock I would have tried to do the 1-1 swap from day one. The stock bolts look very weak and i'm surprised they held as long as they did, i'm sure the MLS gasket had a LOT to do with it.
I've read around the GM forums the answer is no. I will say however I've done this on many 4g63T engines (turbo eclipse/talon) and ran over 35PSI with no problems. I really don't understand why there would be a difference. If I would have know more about LS engines having a 3 MLS head gasket stock I would have tried to do the 1-1 swap from day one. The stock bolts look very weak and i'm surprised they held as long as they did, i'm sure the MLS gasket had a LOT to do with it.
Last edited by foose04; 01-07-2011 at 04:41 PM.
01-11-2011, 07:58 PM
#20
Update... she lives once again! I will say this is a pretty damn good job for a one man operation! So far it seems to have sealed up great. Drove it for a couple days then today started doing some tuning pulls for this weekend trip to the track.
Some info on my night of tuning, I took 1 degree timing away from the MP70 tune at 15psi that went 7.00@98. I started doing second gear tuning pulls at 10psi,then 11, 12, 13,14,15. 15PSi on the PTE 76GTS is...well..best way to describe it....Violent!!
l. I turned it back down to 13.5/14psi and made a 1st-3rd gear pull, feels very strong, running around 15.5 degree's timing and 11.5 air fuels. After all the tuning, coolant was on the same line I left the house at. (score!)
I'll see how she does Saturday, hope to get a NPB. Worked hard on those damn studs and gaskets, time to play!!
Couple shots of going back together.
Some info on my night of tuning, I took 1 degree timing away from the MP70 tune at 15psi that went 7.00@98. I started doing second gear tuning pulls at 10psi,then 11, 12, 13,14,15. 15PSi on the PTE 76GTS is...well..best way to describe it....Violent!!
l. I turned it back down to 13.5/14psi and made a 1st-3rd gear pull, feels very strong, running around 15.5 degree's timing and 11.5 air fuels. After all the tuning, coolant was on the same line I left the house at. (score!)I'll see how she does Saturday, hope to get a NPB. Worked hard on those damn studs and gaskets, time to play!!
Couple shots of going back together.