LS2 Build Questions ???
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LS2 Build Questions ??? This is going to be my first LS build thats getting setup for drifting purposes. Its power goal is gonna be around 400hp at the wheels so like 475ish at the crank? The power isnt all that special but its going to ALWAYS be high in the RPMs and the goal is to make it last as long as possible. (<-- just as all people say that about their builds lol)
I have an LS2 out of an 08 Trailblazer SS. It got tore down and stripped with 100k on the clock. The block did not have a failure AT ALL. Everything looked fantastic so as long as the crank and cam spec out the goal is to reuse the cam and crank. With that being said here's the hopeful parts list...
Questions for the build are
1.With the stock crank being reused and no engine failure, the heads and block shouldnt need to be decked all that much, im wondering what Piston and Rod choices are going to last(for as long as possible realistically) under High RPM use?
2. How will decking resurfacing the heads determine my pushrod choice?
Bottom End
-Used Stock LS2 crank
-Used Stock Camshaft
-Looking at TSP Conn Rod and Piston Packages?
-Looking at Cam, Crank and Rod Bearings through TSP along with ALL ARP hardware
Cylinder Head/Top End
-TSP Chromemoly Push Rods
-Cloyes Timing Chain
-PRC Spring Kit (Comes with Springs, Guides, Retainers, Keepers, and Seals
-Havent looked at Valves yet
I would also like to add that Im new here so Hi Everyone!
I have an LS2 out of an 08 Trailblazer SS. It got tore down and stripped with 100k on the clock. The block did not have a failure AT ALL. Everything looked fantastic so as long as the crank and cam spec out the goal is to reuse the cam and crank. With that being said here's the hopeful parts list...
Questions for the build are
1.With the stock crank being reused and no engine failure, the heads and block shouldnt need to be decked all that much, im wondering what Piston and Rod choices are going to last(for as long as possible realistically) under High RPM use?
2. How will decking resurfacing the heads determine my pushrod choice?
Bottom End
-Used Stock LS2 crank
-Used Stock Camshaft
-Looking at TSP Conn Rod and Piston Packages?
-Looking at Cam, Crank and Rod Bearings through TSP along with ALL ARP hardware
Cylinder Head/Top End
-TSP Chromemoly Push Rods
-Cloyes Timing Chain
-PRC Spring Kit (Comes with Springs, Guides, Retainers, Keepers, and Seals
-Havent looked at Valves yet
I would also like to add that Im new here so Hi Everyone!
Last edited by LSmitty2; Jun 13, 2015 at 08:52 PM.
It's fine it's in the right spot. Keep in mind it's the weekend, but if you don't get the response you want, we try to encourage you use the search function since questions like this are asked all the time.
1) For something that will live at higher RPM, a lightweight rotating assembly is a good idea. Manley has some really lightweight I beam rods in the 580-590g range. Probe makes a nice budget piston that is pretty light and has a 1.5/1.5/3.0mm ring pack. Our sponsors should be able to get you set up some nice components and maybe even make a few suggestions based on their experiences.
2) Decking the block and heads could change your pushrod length, depending on how much preload you need. There are several variables that come into play, so it's usually easier just to get the engine together and then use an adjustable pushrod to see what length works.
1) For something that will live at higher RPM, a lightweight rotating assembly is a good idea. Manley has some really lightweight I beam rods in the 580-590g range. Probe makes a nice budget piston that is pretty light and has a 1.5/1.5/3.0mm ring pack. Our sponsors should be able to get you set up some nice components and maybe even make a few suggestions based on their experiences.
2) Decking the block and heads could change your pushrod length, depending on how much preload you need. There are several variables that come into play, so it's usually easier just to get the engine together and then use an adjustable pushrod to see what length works.
Crank rods pistons are good to reuse the cam has to go if you want 400 to the wheels unless you improve the heads intake and exhaust then is possible but maan the cam adds lots of power and beautiful lyrics.
Here's what I would do;
Replace the rod and crank bearings leave the cam bearings along new Melling high pressure and high volume oil pump brand new single row timing chain set, get a set of ls3 intake and heads preferably the 821 castings mill heads .040 get a cam and matching set of valve spring kit slap that together and head for the dyno, you'll be glad you did.
Here is why I would do this, the bottom end is plenty strong for what you want to do so instead a spending the money there put the money in the top half and just refresh the bottom.
Will cost you about the same and will end up with an easy 450 to the wheels and sounds like an orchestra.
Here's what I would do;
Replace the rod and crank bearings leave the cam bearings along new Melling high pressure and high volume oil pump brand new single row timing chain set, get a set of ls3 intake and heads preferably the 821 castings mill heads .040 get a cam and matching set of valve spring kit slap that together and head for the dyno, you'll be glad you did.
Here is why I would do this, the bottom end is plenty strong for what you want to do so instead a spending the money there put the money in the top half and just refresh the bottom.
Will cost you about the same and will end up with an easy 450 to the wheels and sounds like an orchestra.
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Deck the block, deck the heads, if its all apart. That way you have the best gasket seal. Hone the bores, install new rings. I would have the skirts coated to build up the piston to wall clearance.
Decking the block/Heads It most likely won't change pushrod length, in theory if you take .010 off the heads .010 off the block it would shorten the effective pushrod length by .020". However it would just add .020" extra preload on the lifter which should be fine. The base circle on a comp cam is typically .025 less than stock, if you upgraded the cam most likely the pushrod length would stay the same because of the decked/block heads. Sorry for rambling but that's how it works out.
Camshaft, upgrade the cam, even an LS7 cam would be decent upgrade, or a comp 220 somthing cam, there's plenty used cams available. Install PAC 1218 beehive springs (or new yellow GM springs) and new LS7 lifters, install new valve seals. Grind the valve seats... Or just lap them atleast.
Anyway point is there's no reason cost wise to not upgrade the camshaft or do some minor upgrades while its apart.
If you change the pistons/rods you will need to balance the crankshaft.
Bearings:
main 2199P
rod 663P
Cam bearings leave them alone unless they're bad. I generally like coated bearings, you can get the above from Calico coated.
Decking the block/Heads It most likely won't change pushrod length, in theory if you take .010 off the heads .010 off the block it would shorten the effective pushrod length by .020". However it would just add .020" extra preload on the lifter which should be fine. The base circle on a comp cam is typically .025 less than stock, if you upgraded the cam most likely the pushrod length would stay the same because of the decked/block heads. Sorry for rambling but that's how it works out.
Camshaft, upgrade the cam, even an LS7 cam would be decent upgrade, or a comp 220 somthing cam, there's plenty used cams available. Install PAC 1218 beehive springs (or new yellow GM springs) and new LS7 lifters, install new valve seals. Grind the valve seats... Or just lap them atleast.
Anyway point is there's no reason cost wise to not upgrade the camshaft or do some minor upgrades while its apart.
If you change the pistons/rods you will need to balance the crankshaft.
Bearings:
main 2199P
rod 663P
Cam bearings leave them alone unless they're bad. I generally like coated bearings, you can get the above from Calico coated.
Last edited by Fraser588; Jun 17, 2015 at 03:08 PM.
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With the engine having a high RPM life, I would put the money into the bottom end. These engines can hit 400 at wheels with the right intake and exhaust and everything else being left stock.
I would deck the block and heads and look at a .040" head gasket for some added compression. Since it is going to be living in the upper RPMs, perhaps look at ditching the stock intake for Vic Jr. single plane.
I would deck the block and heads and look at a .040" head gasket for some added compression. Since it is going to be living in the upper RPMs, perhaps look at ditching the stock intake for Vic Jr. single plane.
On The Tree
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When you deck the block you need to take off enough material you don't chatter the cutting head. Typically .005-.007 each pass, just to skim a block you typically take off .010" each side. The pistons are already above the deck .006". Unless you cut the piston tops down (which is very easy to do) , you end up with the piston out .016" +/- ; the factory .052" gasket would be best option, .040" gasket is tight then take off the .016" you're at .024" quench , with a forged piston rocking seen them touch the heads with that tight of quench (not bad but too tight.)
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That is true, but it all depends on how much is actually taken off and how far out of the deck the pistons go. If the quench is still fine, then a .040" head gasket is still feasible.
That isn't to say that a .052" GM gasket is a bad choice, either. It all boils down to the math.
That isn't to say that a .052" GM gasket is a bad choice, either. It all boils down to the math.
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Alright cool, i appreciate the resonses guys. What im gathering from this is, i got someone telling me to do the bottom end but not the top and i got someone telling me to do the top end but not the bottom lol.
Im confuzzled here gentlemen
What i gather from this is both the top and bottom end are able to handle the power and last in the high RPMs. So bolt ons and a tune and im there?
Im confuzzled here gentlemen
What i gather from this is both the top and bottom end are able to handle the power and last in the high RPMs. So bolt ons and a tune and im there?
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Its seems more cost affective to upgrade the cam vs the bottom end especially if the bottom can handle 475-500 at the crank.
Drifting is a whole different ballgame for the shortblock versus 1/4 or 1/8 mile racing, as I'm sure you're aware.
Before I go spending a couple grand in the top end, I would want a nice bottom end that I know isn't going to puke its guts out after a couple laps and potentially ruin the entire engine.
You're right that a new rotating assembly would require rebalancing the crank, but with the right components, the machinist will be taking weight out of the crank. The bobweights will be reduced and lessen the loads the critical components, like the rod bolts and wrist pins, will have to endure constantly.
As the saying goes, there's more than one way to skin a cat. I'm not saying the stock components won't work, but I would be uncomfortable using them and the risk is not worth the reward.
While some SBEs have done the former, I would not for a second trust them to do the latter. Doing it right the first time will cost less in the long run with that kind of power.
On The Tree
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Ok well this leads me to ask another question then... If i go with a 220 cam am i gonna have to worry about PTV clearances? Prefrence on LSA#s? How do they effect power band?
Its seems more cost affective to upgrade the cam vs the bottom end especially if the bottom can handle 475-500 at the crank.
Its seems more cost affective to upgrade the cam vs the bottom end especially if the bottom can handle 475-500 at the crank.
Camshaft wise a better cam for drifting would be 224/230 XER lobes 112+2 (based on minimal info)
Far as the bottom end, adding ARP rod bolts would be a good idea, have the rods honed.
Oiling is an issue for drifing and TBSS pan is bad, I would change to a better oil pan. RMR GTO did well in drifting they used Accusump.
See article:
http://www.caranddriver.com/features...rifter-feature
Last edited by Fraser588; Jun 24, 2015 at 11:45 AM.
On The Tree
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Point is, if 800rwhp is ok, less than 500 should be fine. LS2's are sometimes daily driven with 500rwhp.
I talked to Rhys Millen long time ago, if I recall they had SBE with 243 heads.
Article on the GTO Drift car can be seen above.
LS2 factory rods are stout, and LS2 factory pistons generally don't break unless its lean or detonated.
Drag raced.
Point is, if 800rwhp is ok, less than 500 should be fine. LS2's are sometimes daily driven with 500rwhp.
I talked to Rhys Millen long time ago, if I recall they had SBE with 243 heads.
Article on the GTO Drift car can be seen above.
LS2 factory rods are stout, and LS2 factory pistons generally don't break unless its lean or detonated.
Point is, if 800rwhp is ok, less than 500 should be fine. LS2's are sometimes daily driven with 500rwhp.
I talked to Rhys Millen long time ago, if I recall they had SBE with 243 heads.
Article on the GTO Drift car can be seen above.
LS2 factory rods are stout, and LS2 factory pistons generally don't break unless its lean or detonated.
On The Tree
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Had nothing to do with the rods or pistons... I'm done here.
The most important modification, however, was increasing the oil supply to the engine. Forcing the GTO into high-rpm sustained drifts starves the engine of oil and can easily fry it. "We blew our first motor," says Millen. Apparently, other magazines doing stories on drifting—also using Pontiac-supplied cars—blew engines as well. So a Pontiac PR guy, fearing we might want to treat a standard GTO press car to a drifting regimen, treated us to a five-minute tongue lashing about how those cars are not set up to drift.
We doubt any production car was developed with drifting in mind, and it's likely that many would meet the same ruination eventually. So don't try this at home with Dad's new GTO. With that in mind, Millen increased the volume of the oil pan and added an Accusump pressure accumulator. The oil capacity was increased by three quarts to about eight, and the Accusump maintains oil pressure during the slides.
We doubt any production car was developed with drifting in mind, and it's likely that many would meet the same ruination eventually. So don't try this at home with Dad's new GTO. With that in mind, Millen increased the volume of the oil pan and added an Accusump pressure accumulator. The oil capacity was increased by three quarts to about eight, and the Accusump maintains oil pressure during the slides.
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A lot of interesting stuff here guys. The motor is being swapped into a 1990 nissan s13 thats why power wasnt a huge concern. They make kits that a come with custom oil pans and pickup tubes so that shouldnt be an issue 
I've looked into an accusump oil pump which is probably what im going with. Ive read great things about their pumps.
Im not taking what you guys say as biblical truth but being as this is my first LS build your responses to weigh kinda heavy on my descions. Thats why im coming here lol.
The back and forth is a little confusing but thats why i thought bottom end now since the cam was easier to swap after the motor had been put back together. The sustained high RPM use was why i thought of going that route now and cam later. But anyone that has used stock bits for long periods of time can chime in. Im listening haha
I've looked into an accusump oil pump which is probably what im going with. Ive read great things about their pumps.
Im not taking what you guys say as biblical truth but being as this is my first LS build your responses to weigh kinda heavy on my descions. Thats why im coming here lol.
The back and forth is a little confusing but thats why i thought bottom end now since the cam was easier to swap after the motor had been put back together. The sustained high RPM use was why i thought of going that route now and cam later. But anyone that has used stock bits for long periods of time can chime in. Im listening
haha 
change the pistons and go 5 over. Hone with deck plate to get a better than factory bore. JE or Mahle pistons should work well in this application. Put ARP bolts in the stock rods. Most aftermarket drop in pistons require you to pin fit the small end of the rod. This will keep the short block solid enough for your goals and abuse. You can run GM blue LS3 springs and GM .550 lift LS6 hot cam and get around 500HP or go to comp and get a little more cam to get more. Stay under .610 lift and use double springs as they are very reliable without spending a boat load of money.