Full LS7 build after rod and valve failure
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From: Riga, Latvia
Full LS7 build after rod and valve failure Hi all.
This is my first US made car (except my first car, which I imported from west coast - an Acura CL 3.0 Premium, there are like 5 in Europe
)
An 2006 Z06 Corvette for fun spirited drives, maybe casual track day - not a daily, hence some more fun cam is ok.
Bought it from auction and it came as "engine rebuilt" and just after a couple hundred km it broke an intake valve.
After disecting it, I noticed that it's all stock, except for the CHE Precision rockers.
Dug deeper, noticed that there is major wear on the connecting rods, and here started my rabithole down the LS7 titanium rod issues + stock head issues.
As replacing rods to steel H beams is not an option with stock crank (impossible to find rotary assembly balancing places that know US V8's) I am basically replacing everything except the block.
Block will be machined and honed (using the plate) to the next size pistons.
Here is the list of things I am about to order, just need some input.
This gives the basic setup of:
Basically I would love any and all input to see how far from an optimal setup I am now. I would like to pick up extra 100hp or so, but still keep the engine reliable in broad terms.
Do I need to use some fancy zinc infused motor oil to ensure lifespan?
Here are my main questions:
Thank you so much everybody for your time!
This is my first US made car (except my first car, which I imported from west coast - an Acura CL 3.0 Premium, there are like 5 in Europe
)An 2006 Z06 Corvette for fun spirited drives, maybe casual track day - not a daily, hence some more fun cam is ok.
Bought it from auction and it came as "engine rebuilt" and just after a couple hundred km it broke an intake valve.
After disecting it, I noticed that it's all stock, except for the CHE Precision rockers.
Dug deeper, noticed that there is major wear on the connecting rods, and here started my rabithole down the LS7 titanium rod issues + stock head issues.
As replacing rods to steel H beams is not an option with stock crank (impossible to find rotary assembly balancing places that know US V8's) I am basically replacing everything except the block.
Block will be machined and honed (using the plate) to the next size pistons.
Here is the list of things I am about to order, just need some input.
- HEADS - 1171000 Brodix BR7 262 LS7 Aluminum Cylinder Heads Package Assembled (2 Heads) - https://cnc-motorsports.com/1171000-...d-2-heads.html
- CAM - Comp Cams 54-471-11 LS Rectangular Port Hydraulic Roller Camshaft - .624 Int .624 Ex Lift, 114 -LS - https://cnc-motorsports.com/catalog/.../category/923/
- PRE-BALANCED ROTARY ASSEMBLY - CP 11.1:1 Pistons GM LSX LS7 7.0L 427 Balanced Rotating Assembly Kit, Compstar Crank - https://cnc-motorsports.com/catalog/...ompstar-crank/
- TIMING CHAIN KIT - Cloyes 9-3167AZ Hex-A-Just True Roller Timing Chain Kit - upgrade to dual roller - https://cnc-motorsports.com/cloyes-9...chain-kit.html
- HYDRAULIC ROLLERS - Comp Cams 15956-16 Short Travel Hydraulic Roller Lifters - link bar - https://cnc-motorsports.com/catalog/...oller-lifters/
- All the gaskets
- Maybe upgrade intake, ignition if needed.
This gives the basic setup of:
- 71 cc CNC Ported Combustion Chambers
- 2.204 / 1.614 Valve Size
- 1.350 Hydraulic Roller Spring, 180 lb Closed, 430 lb Open,1.885 Installed Height, .700 Maximum Lift
- .624 Int .624 Ex Lift
- 114 lobe seperation
- Cam asks for #26926-16 springs with 505 lbs./in. spring pressure, I have no idea how to calculate if the ones with the Brodix head are good enough?
- 15956-16 Short Travel lifters should be able to handle those springs up to like 7000-7200RPM? Redline will depend on the power curve from dyno runs, no idea where it will end up in.
- The rotating assembly has some little "stroker" kit with stock stroke crank, but 6.125" rods instead of stock 6.067 in., but as compression with 70cc head is same as stock, I assume the CP pistons have altered compression height. So I guess this combo gives me the benefits of less side loading and bit more time at TDC?
- Stock CR is 11.1:1, with 70cc head the rotary assembly kit is same, as I want to use the 71cc brodix head, it will drop a bit to 10.9:1 ish. Car will run on 93 Oct so, I assume a little drop in CR will allow more aggresive timing....?
- My CHE Precision rockers are still in good condition, so I hope to reuse them, but read about increase in MOI compared to stock rockers, so maybe go back to stock?
Basically I would love any and all input to see how far from an optimal setup I am now. I would like to pick up extra 100hp or so, but still keep the engine reliable in broad terms.
Do I need to use some fancy zinc infused motor oil to ensure lifespan?
Here are my main questions:
- What thickness head gasket to use?
- What lenght pushrods to order? Or do I order the measuring tool and then re-order pushrods later?
- What ECU flasher do you use on these ECU's? I have a ton of tools, but never had remaped US made car, so I am thinking stuff like HP Tuners? Looking for a professional, easy to use tool, preferably with easy to get definition files + live tuning capabilities.
Thank you so much everybody for your time!
