Hey guys, need some help with my upcoming build. My LS3 decided to not LS3 anymore... we're pretty sure it dropped a lifter but not sure on the extent of the damage yet, oil pressure fell to 7lbs but got it shut down pretty quick. Either way motor is getting pulled and gone through. Hoping the bottom end is ok but plan to pull and re-ring the pistons. My current setup is stock bottom end, stock heads with a TSP LS3 Stage 1 N/A cam (225/236 .629"/615" 114 LSA, 109 ICL as Standard). I'd like to squeeze a little more out of it N/A without having to do a convertor. A little more low end torque wouldn't hurt but mainly I want good power through the curve. I do alot of backroad spirited driving and plan to get into doing some track days soon. I occasionally take the car to the drag strip but not chasing a number so peak hp isnt really a concern. Just want a good well rounded setup with maximum drivability (although a little extra chop never hurt lol). Curious to see if anyone has any recommendations. Obviously this plan may change a bit depending on if anything else is majorly hurt but we're hoping as of now were going to be replacing lifters and cleaning everything up. Should have a better idea of what all needs fixed next week and can go from there. Thinking about maybe doing an aftermarket head while I have them off as well. Also should note, I'd like to stick with stock fuel system and intake.

 

You didn't say if you had headers and if you've done an exhaust swap....

A good set of long tube headers and high flow catted x-pipe will give you 20 to 25 RWHP and a healthy torque increase across the full RPM range; also if you have the standard exhaust (NOT NPP) then upgrading that to a good aftermarket system (Corsa Sport or Extreme, for example) will get you another 5HP or so. I'd also consider a TRUE Cold Air Intake system (Callaway, for example) that derives intake air from outside, NOT the engine compartment (like the stock system or most other aftermarket intakes). Afterwards, a dyno tune to optimizing ECU parameters after all the add-ons.

I wouldn't go too much further (especially cam-wise) if you want good driveability, unless you're up for a head swap and/or a supercharger! $$$$

I currently have an '08 C6M, which dyno'd at 400 RWHP (stock LS3) with a Corsa Sport exhaust and Callaway CAI. I then put a GM "hot cam" crate engine in there (don't ask why) with American Racing Headers, high flow catted x-pipe, and tune. Ended up at 452 RWHP, and completely streetable. Pulls really well and sounds incredible... I'm very happy with the results and still get 26+ MPG on long trips at 80 - 90 MPH. Ultimately it's an individual decision as to how streetable we want our cars; I'm happy where I'm at since I l drive mine all over and want something that I can live with and not worry about bucking and surging, etc. but still have that extra 50 -65 HP over stock for the fun factor!

Good luck on your build and let us know what you decide to do and how it turns out !!!

 

guess I should have mentioned the car is already had some bolt ons. (haltec intake, speed engineering headers, offroad x through a stock npp). Current plan is to switch to a GPI SS1 Cam, gonna leave the heads alone as long as their not hurt. We suspect we're gonna find a chewed up cam bearing but haven't gotten that far yet. Also looking into maybe doing a FAST102 and a little bigger throttle body. Checking into a few things now. As long as the bottom end didnt take a hit we're just going to check the bearings, clean it all up, and send it. May throw a set of rings in it while were there and upgrade some hardware. In a perfect world I'd like to see 500wheel on the stock convertor but i know thats probably unrealistic. I'd be happy with high 400s, the car made 476 on the previous setup. My main thing is I want a good power curve through the range.

 

I'd skip the FAST 102 and have GPI rod-mod and your intake manifold. Cost less and will probably make more power

 

ive looked into the rod mod thing a little as well, heard good things. May go that route.

 

Sorry my bad.... I should have figured that ! Sounds like a fun project!

 

mill the heads 25 thou

 

I'd sure rethink your camshaft choice. .646 lift? No way I'd run that much lift on a street car. I don't think even trunion upgraded stock rocker arms would live a long life. Then you have potentially more valve guide wear. If the heads are off, I'd run them through Tx Speed or GPI's CNC porting program. I'd use a .040 head gasket along with a .010 mill also. GPI's rod modded and ported intake manifold mentioned earlier would be a good upgrade too. Did all of this to my LS3 3+ years ago. Still running strong.

 

Well... bad news... looks like the short block may be toast. Got the heads off last night, cam lobe for cyl 1 completely gone, metal everywhere, one lifter snapped, lots of metal in the oil and laying around on everything. Hopefully we'll have the shortblock out tomorrow and we'll have a better idea but I cant imagine the bearings are gonna look that great.

 

Hopefully it's salvageable. A kick to the nuts for sure though.

 

My main hope right now is that the block isnt hurt. As long as the block itself looks ok I guess the next step will be off to the machine shop for a full assessment/rebuild.

 

If you're going to install new rings, you should always install new rod bearings, even if they aren't severely worn. There's a good reason older guys have a phrase we call 'rings and bearings.' I'd do them, but that's just me........

 

with where we're at now its gonna need a full rebuild at minimum if I'm lucky and the block isn't hurt. Keeping my eyes peeled for a good shortblock now.

 

I've done the above and would do it all over again given the chance. I also had Gwatney port my throttle body.

 

Agreed

 

So as it stands right now it looks rebuildable. Just trying to decide what the most cost effective option would be. I found a good low mile short block local I'm going to look at Monday, My thoughts were buy that one, sell my factory short block to recoup some of that hit, take the rest of my budget towards having the heads ported, GPI rod mod intake, and a new cam/lifters. Seems to be the most cost effective route and probably the fastest rather than waiting on a machine shop. As for the Cam probably going to give Cam Motion a call today and see what they recommend (also considering BTR's stage 2 n/a cam). Still thinking I want to stay with the stock convertor. I eventually plan to 6 speed swap this car so I cant see putting money into a custom convertor to do what I want the car to do. Not to mention the increased odds the trans will be the next thing to go if I upset its high mileage with a new, looser convertor. I'd like atleast a few months to let my wallet recover lol. What do you guys recommend for lifters? I'd like to stay far away from the LS7 lifters as they've cost me more than one Motor in the last few years. That's one area I dont mind spending good money for the extra insurance. I've heard the Johnsons are a good bet but curious to hear peoples thoughts. I had a set of Comp 850s I ran in a 5.3 build a few years ago and they seemed to be pretty good (or atleast they wern't the reason I blew that one up). Let me know what you guys think! I'd like to try to keep myself under the $4000 mark but I know thats not gonna be easy.

 

When you call Cam Motion make sure you talk to Bobby. He is the smartest cam guy I've ever talked to. It's likely you will be directed to him, but i would ask.

If you are thinking about milling the heads (more compression), make sure you till him. He will do PTV calculations out loud as you listen.

Tell him your plans and goals. I've got a LS2 with a complete LS3 topend. TSP ported and milled the heads. Gwatney ported the throttle body and ported/rod modded my intake. He worked with me and provided several cam options. As I had a LS2 short-block PTV calculations were critical.

Maybe also think about a Spin Monster style cam from Cam Motion. See: https://www.corvetteforum.com/forums...n-and-now.html

If I had the PTV to use that cam I would have. But I didn't want to flycut the pistons with the engine in the car.

Good luck.