[Trochoidal]

Originally Posted by Katech_Zach

Mistype, good catch! I edited it, It is only ARP connecting rod bolts

It’s all good sir!

Your engine is gonna sing at 8k! I hope to see a video after your project is complete.

[AZIROC]

Tagging for interest.

[Katech_Zach]

Originally Posted by Trochoidal

It’s all good sir!

Your engine is gonna sing at 8k! I hope to see a video after your project is complete.

I sure hope so, or I want my money back!

So part of this forum post is to help out others who want to achieve similar goals. I want to explain the thought process and logic between the changes i've made to our standard package in order to meet my goals.

Getting the supercharger to want to go up that high is going to be a challenge, especially because the runner length on the blower is fixed. The best thing you can do for a positive displacement blower is to remove any restriction in front of the rotor pack (inlet), and keeping the rotors in their efficiency range. In this case, I want to be efficient at a much higher RPM, so I will be spinning this blower slower than your traditional customer.

You might ask, "Zach, if you spin the blower slower, won't you make less power?". This is not necessarily true, you are just going to make less boost. You can optimize an engine to make more power with less boost, so that is the route I will be going. Everything will jive together and produce the results I am looking for.

On this car, I will be running a prototype Katech 120mm throttlebody. On dyno, we tested a 103mm to a 112mm on a common 2650 package making 1000HP at the crankshaft. The results showed this jump was good for about 2% (20hp) at peak power. We did not test this 120mm on engine dyno nor do I expect the gains to be as good, but I can predict that we may gain another 1% efficiency up top. Another note, this testing was done at 7000 RPM. At 8000 RPM, the efficiency gains may be more. We will see when it is all together.

To help this supercharger breathe, I am also using a TooHighPSI billet supercharger lid with an air divider machined into the middle, as well as some prototype C&R racing supercharger intercooler bricks. My goal is to improve the air charge conditions over the standard 2650 configuration, and these items should help me do so.

Maggy 2650

Katech 120mm Snout

Katech 120mm Throttlebody

TooHighPSI Lid, Bottom with Air Divider

TooHighPSI Lid, Top

[Camden45]

This is one of the most insane motor builds I've seen. Definitely refreshing aside from all the normal high hp builds.

[sr71bb]

Originally Posted by Katech_Zach

It will rip, thats for sure



AC belt breaking is no fun! by any chance was the AC accidentally engaged while racing? or was it turned off the entire time? Very cool build. I will eventually build a Z/28 spec build when the time is right

YEAH, it was turned off the entire time. That I THINK was the original AC belt and I should have already changed it out and will do that now on a yearly basis.

WTF GM would put an exposed wiring harness around the cam cover is beyond me but they did.

[That1guy_tim]

In for 8k RPM!

[That1guy_tim]

Also please use conicals. Very interested to see how they perform.

[ZL1 1LE]

Subscribed!

[Katech_Zach]

Originally Posted by That1guy_tim

Also please use conicals. Very interested to see how they perform.

No conicals on this build unfortunately! I am using a really cool PAC spring that I will talk about once I get to the valvetrain portion.

Current update: I mentioned in one of the responses above about the LT4 bottom end being left relatively stock. I am sticking true to this, the only thing I will be doing is ARP rod bolts. After taking the rod/piston assemblies out of the block and inspecting the bearings, wear looked great so I will be reusing stock bearings. When installing ARP rod bolts, it is important to check the housing bores to make sure they do not deform with the higher clamp load. Sure enough, the housing bore went from a perfect circle to more of an oval shape due to bore distortion (not visibly, you have to measure this). I had our engine builders touch hone the rods with our rod hone, and they are now perfectly round and within spec for the factory bearings once again.

I also chose to modify the factory valve covers to retain factory PCV functionality. We are currently in the works of producing a billet motorsport grade Gen V LT valve cover with metered PCV baffling built into them, so for now I will stick with modified OEM valve covers. I chose to powdercoat these close to my factory nightfall grey metallic.

Lastly, to aid with oil control and feeding the pickup tube at full tilt, I cut a small slot in the front of the oil control plate that is bolted above the pickup tube. The purpose of this plate is to keep oil around the pickup tube under high braking conditions. The downside to this plate, is on high speed uphill acceleration, you run the risk of oil flying over the top of the pickup tube if you are also running low on oil by the end of your track day (why some of these cars scatter at various tracks on long uphill straights). I did this modification based on an "engineered guess" after discussing with improved racing (who is working on a proper pan baffle), so this is a modification that is done at your own risk.

Modified OEM Valvecover

Modified OEM Valvecover

Finished OEM Valvecover

OEM Connecting Rod / Piston Assemblies

ARP Rod Bolts Installed

Shortblock Reassembly

Oil Pan Mod, Before

Oil Pan Mod, After

[That1guy_tim]

Originally Posted by Katech_Zach

No conicals on this build unfortunately! I am using a really cool PAC spring that I will talk about once I get to the valvetrain portion.

Current update: I mentioned in one of the responses above about the LT4 bottom end being left relatively stock. I am sticking true to this, the only thing I will be doing is ARP rod bolts. After taking the rod/piston assemblies out of the block and inspecting the bearings, wear looked great so I will be reusing stock bearings. When installing ARP rod bolts, it is important to check the housing bores to make sure they do not deform with the higher clamp load. Sure enough, the housing bore went from a perfect circle to more of an oval shape due to bore distortion (not visibly, you have to measure this). I had our engine builders touch hone the rods with our rod hone, and they are now perfectly round and within spec for the factory bearings once again.

I also chose to modify the factory valve covers to retain factory PCV functionality. We are currently in the works of producing a billet motorsport grade Gen V LT valve cover with metered PCV baffling built into them, so for now I will stick with modified OEM valve covers. I chose to powdercoat these close to my factory nightfall grey metallic.

Lastly, to aid with oil control and feeding the pickup tube at full tilt, I cut a small slot in the front of the oil control plate that is bolted above the pickup tube. The purpose of this plate is to keep oil around the pickup tube under high braking conditions. The downside to this plate, is on high speed uphill acceleration, you run the risk of oil flying over the top of the pickup tube if you are also running low on oil by the end of your track day (why some of these cars scatter at various tracks on long uphill straights). I did this modification based on an "engineered guess" after discussing with improved racing (who is working on a proper pan baffle), so this is a modification that is done at your own risk.

This shit is cool! I swear in another life I'm an engineer lol

[Katech_Zach]

Good morning guys, happy Thursday!

One of the most important parts of this build, the valvetrain and cylinder heads. For this build, I will be using our tride-and-true Katech CNC ported LT4 cylinder heads. We maintain port velocity by balancing material removal in specific areas with keeping the rest of the port relatively untouched. A lot of the time, people will often criticize a cylinder head by how much CNC cleanup a port has (full shiny machined surfaces vs a head that looks blotchy). I want to squash this internet science, because just because all the material is CNC'd, doesn't mean it flows ideal for your application. A good port will remove/rework areas that need to be touched, and often times will leave some areas untouched. In our port, it is a toss up from core shift, sometimes a majority of the port cleans up (fully CNC machined), other times only the critical areas get removed. In my case, I know our cylinder heads will move the air that i need, and if I ever needed more I would switch to our LTK cylinder head. We have another high output factory casting option in the works, I will reveal this at a later date.

For valvetrain, I will post a more detailed writeup at a later date. Getting this thing to live at those RPM's, you need stability and increased rigidity. As hard as it is to visualize, every component with load on it will be deflecting in some way, shape, or form. I will be adding stiffness to a lot of components to survive at these RPM's as well as decreasing harshness to minimize deflection.

Note: Some of these components will not work with other generic components, so be careful when installing. For example, typically the 7/16 pushrods do not fit, so you have to clearance the pushrod channels in the head. In my case, the style of lifter I used gave me additional side clearance and allowed me to run these pushrods without additional modifications.

To get this done, I chose to use the following components:

Comp Cams BSR Shaft Rocker Gen V LT System 1987-16
Trend 7/16-.165 Wall Double Taper Pushrods
Custom Camshaft
PAC 1222x Spring
PAC R455 Retainer
PAC S121 Seat
PAC +0.050 Lock, Pac -0.050 Lock
Katech Ti/Mo Intake Valve KAT-7486
GM Sodium Filled Exhaust Valve
CHE Bronze Guides
Johnson ST2126LSR Lifters

Ti/Mo Valve

Ti/Mo Valve Face

CHE Guides

PAC Offset Locks

Comp Rocker Arms + Pushrods

Valvetrain Misc

Head Breakaway

Assembled Heads

[2010REDSS]

Awesome build Zach!
50% tried and true Katech + 50% R&D = 100% Badass!
Keep up the pics and posts, fun to watch! Any chance you'll have this on the track yet this season??

[Katech_Zach]

Originally Posted by 2010REDSS

Awesome build Zach!
50% tried and true Katech + 50% R&D = 100% Badass!
Keep up the pics and posts, fun to watch! Any chance you'll have this on the track yet this season??

I am hoping to hit up Pitt Race and Grattan this year. I do not know if I will be able to make it to the Ozark's with my current schedule.

I also plan on going to LS Fest East and potentially another event or two that are similar to this before the end of the year.

Pictures will keep coming!

[6spdhyperblue]