08-28-2016, 05:21 AM | #1 |
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LSX questions
Need to be educated on LS motors...lol
Bought a 6.0 that is totally disassembled. Everything looks to be in very nice condition. Was told it only had 66k miles on it, and came out of an '10 Express Van. The tranny came with it (6L80) and all of the wiring. So what motor is this? LS2,3,4,5??? Is there anything special about this motor that I need to check into? I do need a complete bolt kit for it. The guy had planned on replacing them, so he thru them away Gaskets??? Any special head or intake gaskets needed? Thanks! I am sure I will have a ton more questions putting this back together.
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08-28-2016, 10:08 AM | #2 |
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Re: LSX questions
"So what motor is this? LS2,3,4,5???": Should be a L96. You can find a general description here............http://gmauthority.com/blog/gm/gm-engines/l96/
"Is there anything special about this motor that I need to check into?": Should be Flex Fuel and Variable Valve Timing. I've not dealt with either in any of my conversions, but you'll need to research how you want to deal with these in your project. It is also 'drive by wire' on the throttle - make sure you have the gas pedal out of the van "I do need a complete bolt kit for it. The guy had planned on replacing them, so he thru them away": I'm assuming your'e speaking of the head bolts - these are 'torque to yield' and once stretched are not intended to be used again. If you think you might have the heads on an off a few times, it might be worthwhile to put a stud kit in it to replace the bolts. The mains are not torque to yield, but you'll get more consistent clamping with a stud kit there too. "Gaskets??? Any special head or intake gaskets needed?"; I've had good luck with the GM head gaskets for stock or near stock builds. If you're going to push up compression or use boost, you might think about a Cometic head gasket. Intake: My experience with these engines is that the 0-ring type seals in the intake take a 'set' after many heat cycles, and eventually start causing an intake leak. Replace them with NAPA, Felpro or GM seals. A few other things when you're putting the motor back together- -Be very careful getting the correct o-ring installed on the oil pickup tube. You don't want the oil pump sucking any air. -Pay careful attention to your rods and mains clearances. I might think about replacing the oil pump while the motor was apart. It pays to have it checked by a machine shop with LS motor experience (my opinion) -The rod caps are 'cracked' not machined. Keep them together and in the right orientation. Some builders think the rod bolts should be upgraded to ARP. Do some research and come to your own conclusion -I like the NAPA rear main seal with the centering ring -These motors respond very well to even a mild cam upgrade, and now would be the time to do it. Replace the springs with the cam. Make sure your pushrod lengths are spot-on with the correct 'wipe' of the valve stem. Check all your pushrods and make sure none are bent. Consider upgrading the trunions on the rockers, especially if you put a cam with more lift or move the rev limiter up (after new springs) |
08-28-2016, 11:09 AM | #3 | |
meowMEOWmeowMEOW
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Re: LSX questions
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'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD
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08-28-2016, 05:56 PM | #4 |
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Re: LSX questions
I have no idea how to add pics to a reply.
But the block has 6.0 IV on the front of it and is cast. And the heads have 823 stamped on them. The heads have been ported and polished, and looks to be decked. They are rather large rectangular ports. Hope this is what info you needed. Thanks! |
08-28-2016, 09:35 PM | #5 |
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Re: LSX questions
Should be a L96, IIRC.....Just a Flex Fuel version of the LY6.
The "823" are good heads, They do not normally need Intake Runner Porting, It does more harm than good from a velocity standpoint, But I don't know how they were ported, Who Ported them, Or why someone would do that for a 4" bore engine. Stock (as cast) 5364 L92 Heads (Same a 823's) Flow 309 CFM at .500" lift on a 4.030" Bore, While it Flows 313 CFM at .500" lift on a 4.155" Bore. While I'm not an expert by any means (I build Transmissions), This proves a couple points....... 1. 300+ CFM at .500" is VERY good flow. Rivaling a 230cc AFR Cathedral Head! 2. A 4" Bore shrouds the large Intake Valve. Because of the large intake valve, Piston-to-Valve clearance (depending on the Cam used) can get VERY close, Decking/Milling the heads only aggravates the issue. Your engine's static compression ratio (9.5:1) is kind of low, So the heads were probably Milled to raise it, But a better approach would have been Flat Top Pistons with Intake & Exhaust Valve Reliefs. You can have your pistons "Fly Cut" if the PTV is too close. Do Not install ARP Rod Bolts without having the Rod "Honed" back too size. |
08-28-2016, 09:49 PM | #6 | |
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Re: LSX questions
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08-28-2016, 10:04 PM | #7 |
meowMEOWmeowMEOW
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Re: LSX questions
Does the L96 run the dished pistons like the Lq4 would? I'd have to double check. You technically gain the extra .3-ish to work with in terms of PTV. I have milled heads (decking is for the block, milling is for the heads) on my 6.0, and can cram somewhat of a donkey d!ck cam in there before getting SCARY with PTV.
IF you buy good head gaskets (LS9, not up for discussion) with a known squish, and torque a high quality fastner properly (ARP, no discussion), and run a MEASURED grind (huge discussion here), you can get away with evil things in the way of PTV. Here's my warning tho, you're playing with blood magic if you don't have measured verification of any claims on those heads. If they've been worked, I wouldn't touch them unless I could see a flowbench result. Same goes for the milling; wouldn't touch it without verifying deck surface heights. If you start doing parts ordering or assembly without knowing those things, you can end up in a hole that can't be dug out of. A heavily worked head on a peaky cam can result in damn near undriveable street miles. If you were to lose a large amount of port velocity from overporting, and then be running that with a short duration high lift cam, you'll end up running out of air, right when your powerband should be coming on. I'm not sure about the GenIV truck intakes compared to the GenIII truck intakes, but if the heads do flow anywhere near 300cfm, you'll be bottlenecked at the intake manifold.
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'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD
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08-28-2016, 11:16 PM | #8 | |
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Re: LSX questions
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08-29-2016, 01:42 AM | #9 |
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Re: LSX questions
Here is a pic of ports... And maybe this are not milled??? They sure look clean to be take offs. I will get more pics tomorrow of the block, pistons, and rods.
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