RichieRichZ06

Well for those that don't know our LS7 blew up on the track last November. After a short debate over what to do, we decided to bite the bullet and have Katch build us a forged 427. After a little wait, it is finally back and on the road again.

Specs are: Katech Street Attack 427 with 11.5:1 cr. Callies Dragon Slayer crank, Callies rods, Diamond pistons, WCCH ported, milled LS7 heads, ported Fast 102, NW 102 TB, ARH long tubes, ARE 3 Stage dry sump, LS9R Clutch etc.

We took it over to the dyno yesterday and it made 582/555 SAE on a conservative (12.0:1 afr) tune and mild timing. The torque of this thing is nice. It makes over 400 rwtq from 2,000 up and 500 rwtq from 3,750 and up, peaking at ~4,800 rpm. I picked up between 50-70 rwtq over the old setup across the powerband, while also picking up 30 rwhp at less rpm then before.

I could not be happier with the results.

Special Thanks to :

Jason and Katech Perfromance for building a great engine.
Richard at West Coast Cyl Heads for the LS7 heads
Shawn at Ragin Racing for the ported Fast/tb
Gary Amrstrong at ARE for the Dry Sump System
Rick at Synergy Motorsports for the tune and use of the dyno all day.
Steve at RSD for the new Alum Radiator, Pfadt parts etc

Here are a couple pics of the finished product.

FNBADAZ06

Very cool !!!!
I may have missed the original thread, but what happened on the track that blew the original motor ?
With the new pistons and milled heads, what's your new compression numbers, and are you still on pump gas or E85 now ?

Lawdogg

Now that is what an LS7 should look like. Sounds like a great build. Congrats!

Z06Ronald

I couldn't have said it any better!

1.8t

Very nice results! Stock valves in the heads or did you switch the exhaust valves for 1 piece stainless?

RichieRichZ06

I did not make a thread about it because of all the Chicken Littles on here that will tell us the LS7 sky is falling.

It was either a valve failure or a piston failure, too hard to tell by the pile of scrap metal it made. With 24k on the car, over 2 years of track days, 60+ Auto X events and over 150 passes at the strip, it was on borrowed time. We did not lose too much sleep over it when it popped because I knew it was coming eventually.

It is 11.5:1 with the milled heads, pump gas only.

Thanks, I am very happy with it!

1.8t

Excellent. Are these numbers produced with the Torquer cam shaft? If so, did you use the Katech supplied valve springs or go with a dual spring? Only reason I ask is the heavier weight of the exhaust valves, I always wondered if the Katech beehive would be able to control it.

1.8t

So those are the beehives that Katech specs for their torquer camshaft. Thanks for the info . It is crazy to see so much power come from that Torquer camshaft!

Katech_Zach

Highest Torquer 110 cam results ever recorded

Translator

Congrats Richie. Those are Awesome NA numbers, and great TQ to boot as well, no meth, and runs on good old regular 91 octane CA gas.

Kurac

awesome build and great numbers.

Stage7

Engine looks great, and aweseme #'s, especially the torque for a 427 on real deal everyday pump gas. Enjoy it! Nice work Katech and WCCH.

RichieRichZ06

Yep.

Rick was suprised to see the numbers too. He was hoping for ~560. The previous setup made 555 rwhp and there is a noticable difference in power from that one to this, especially in the mid-range.

FWIW, 2 stock ZR1's did 525-530 on his dyno the other day, which seems to be the norm for most dynos.

I was hoping for 550 tq and it did it.

04_Z06_CE

Very nice! So did you send your blown motor to them ?

Les

Nice! Congrats Rich. I hadn't seen this thread and just a few minutes ago I was wondering if you'd gotten the car back together yet. It's gonna be wicked fast and very enjoyable on the street with all that torque!

Translator

Richie, please post the dyno graphs when you get a chance.

LEAVINU

That is such a clean build with top notch products!

I'm interested in hearing more about the external oil pump system as to the benefits/reasons for going that route.

RichieRichZ06

Nope, the old engine was a paper weight. I sent them a brand new bare LS7 block and they assembled the engine.

RichieRichZ06

It is another stage of scavenging, besides what the stock pump does. The issue with the stock system is that it can't keep the tank full under high G corners and it allows too much oil to stay in the pan. With this pump, it will always keep the tank full and the pan empty.

We use the car a lot for auto x and a few tack days so I did not want to leave the stock system responsible for oiling. The ARE kit is a work of art and really makes the system a true dry sump with multiple points of scavenging.

DJ'sZ

Congrats Richie...great build...!!