When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi, I have a LS2 out of a 2007 Trailblazer SS that has blown up. I am currently in the disassembly process of the motor, it is out of the vehicle. I have a lot of general LS based knowledge, and would like opinions on what I should do to this LS2 motor. I do not have a target horsepower. Just want some decent numbers above stock. It has 243 heads on it and I will forsure be putting aftermarket shorty headers and cutouts on it. I prefer to keep the stock TBSS intake, upgrade injectors, maybe do work to the 243 heads and put a large cam in it for more power. I will be getting it Dyno tuned at a shop in the end. The old block I assume spun a bearing so if that’s the case I will be taking it to a shop and have them rebuild it. What should I upgrade? Probably will need new crank brlearing etc etc. thanks for any pointers and help in advance I’ll post some pictures and keep up to date with comments! I will have about $4000-5000 to work with.
If you take it to a good builder most of your budget will be eaten up in the repair of the motor. Then do cam, pushrods, trunion upgrade and by the time you're done with that and get it tuned and buy headers that'll be about all your money. Do long tubes instead of shorty headers, you shouldn't need injectors for minor mods either..
What is the trunion upgrade? Isn’t there also a oil pickup upgrade? This motor failed due to oil starvation the dealership said. What brand of long tubes will fit in a trailblazer ss?? And aren’t these injectors only rated for stock horsepower? Thanks.
A lot of companies make long tune headers for LS Trailblazers. I think JBA, Pacesetter, Stainless Steel Works, Kook's & American Racing Headers all do. Probably some others as well. I'd want 1 3/4 primary and 3 inch collector long tubes.
Since the LS2 injectors are 34# pounds @58 psi, they should be good for at at least ~500 fly wheel hp with a good fuel pump with an 80% duty cycle. The injectors are probably good for ~420 wheel hp at 80% duty cycle.
The 99 LS1 injectors are 26# pound @58 psi and with a fresh fuel pump are good for 420+ wheel hp. The #28.8 pound LS1 injectors could support ~450 wheel hp. Probably not idea, since duty cycle is well over 80%l but definitely workable.
Last quote on labor & machine work that I had from a shop with an excellent reputation to rebuild an engine was $2,000 to $2,500 plus parts.
What is the trunion upgrade? Isn’t there also a oil pickup upgrade? This motor failed due to oil starvation the dealership said. What brand of long tubes will fit in a trailblazer ss?? And aren’t these injectors only rated for stock horsepower? Thanks.
Trunion upgrade.. that's replacing the bearings in the rocker arm. The stock rocker arms are excellent but over time the needle bearings may come out and go into the engine, it's happened to many people. So people replace/upgrade them. The problem is that the original replacements were needle bearing style just like the OEM setup but the aftermarket ones wear out very quickly, lot's of posts on this happening below 10k miles. Google it and you'll see what I'm talking about.
Oil starvation is very rare and usually only happens in road race applications or someone running it low on oil. If you aren't going to road race it or seriously drag race it and go so fast and lift the front end so high that oil runs away from the pickup don't worry about that part. There's many thousands of high power setups on stock oiling systems going for years no problem.
I believe your stock injectors are 32 lb/hr which should be fine for cam only, and would be close to or actually be maxed if you did intake, heads, and cam. Stock injectors are for factory power but there's usually quite a bit of head room there.
Last edited by 00pooterSS; Jul 16, 2018 at 04:23 PM.
Yes, I actually am familiar with the trunion upgrade, will definitely do it! Some 1.8 roller rockers I think would be good for it?
whar cam would you guys recommend me going with? This will be a kind of driver daily/ but I don’t mind it having some stuff in it like big cam and stall converter. I’ll also do valve springs and chromoly push rods right away
Yes, I actually am familiar with the trunion upgrade, will definitely do it! Some 1.8 roller rockers I think would be good for it?
whar cam would you guys recommend me going with? This will be a kind of driver daily/ but I don’t mind it having some stuff in it like big cam and stall converter. I’ll also do valve springs and chromoly push rods right away
You can't really beat stock rockers for light weight and strength, they also have a great wipe pattern on the valve in stock setups under around .630 lift so if you go to another rocker plan accordingly, they're almost all heavier and will require more attention paid to either valve spring strength or weight of the valves. I would use the stock rockers and cam it accordingly rather than buy bigger rockers and work the cam around that, that's backwards.
Not being a dick but at least once a day someone asks what the best cam is and there is usually 50 different answers, and they're almost always right, all of them.. Point is it's really hard to answer that question.
How rowdy do you want it to be? What size stall are you willing to go up to? What vehicle will it be going into? Will you be towing? Do you want to spray it or boost it in the near future? etc etc. Honestly the best cam recommendation will come from one of the sponsors like BTR, Cam motion or TSP. They cut cams and can make a cam that fits your specific needs. And since we know none of those can't really answer your question.
Oil starvation is very rare and usually only happens in road race applications or someone running it low on oil. If you aren't going to road race it or seriously drag race it and go so fast and lift the front end so high that oil runs away from the pickup don't worry about that part. There's many thousands of high power setups on stock oiling systems going for years no problem.
.
Not rare in that platform.
There a well known issue with the sump/oil pans of the V8 gmt360.
You can't really beat stock rockers for light weight and strength, they also have a great wipe pattern on the valve in stock setups under around .630 lift so if you go to another rocker plan accordingly, they're almost all heavier and will require more attention paid to either valve spring strength or weight of the valves. I would use the stock rockers and cam it accordingly rather than buy bigger rockers and work the cam around that, that's backwards.
Not being a dick but at least once a day someone asks what the best cam is and there is usually 50 different answers, and they're almost always right, all of them.. Point is it's really hard to answer that question.
How rowdy do you want it to be? What size stall are you willing to go up to? What vehicle will it be going into? Will you be towing? Do you want to spray it or boost it in the near future? etc etc. Honestly the best cam recommendation will come from one of the sponsors like BTR, Cam motion or TSP. They cut cams and can make a cam that fits your specific needs. And since we know none of those can't really answer your question.
i want it rowdy! A stall? Maybe3200- 3500, it’s going on a trailblazer ss, no towing, no boost or spray,
i want it rowdy! A stall? Maybe3200- 3500, it’s going on a trailblazer ss, no towing, no boost or spray,
Okay then a cam around this size with a 3600 or so converter. And don't cheap out on the converter, you'll regret it. A good converter will be about $800. I personally like Yank and Circle D for converters.
Okay then a cam around this size with a 3600 or so converter. And don't cheap out on the converter, you'll regret it. A good converter will be about $800. I personally like Yank and Circle D for converters.
ill probably get 10 wide Toyo proxes or nitto 420. Yeah I’ll get a yanks converter. I’ll show you the motor just opened her up today cyl 1 piston toast and rod not existent.
Upgrade to the pcm of nc pickup tube relocation kit. The tbss are bad about spun bearings. When i got mine it had a spun bearing. I rebuilt it and added the pickup tube kit. Well worth the money! It moves it from the front toward the rear of the oil pan. It will fix the oil starvation problem.
Is block rebuildable?? Usually not a good sign with a broke piston or bad rod.
pulling the pan and the rest off today or tomorrow I’ll keep the posted updated and get some pictures hoping to see little to no damage to the block, but I may not get lucky.
Damn that's pretty bad. Hard to say what happened to the piston there. At first it looked like damage from the ring lands butting together but looking closer it looks like the piston is broke in half?
And I don't know what nitto 420 tires are but you'll need drag radials not street tires. Unless you're used to a car spinning a lot and getting buck wild lol. It's fun but spinnin ain't winnin!
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.
7 Most Reliable High-Performance Engines GM Has Ever Built
Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
LS2 engine help: what should I do? 
