After having a bunch of fun with a cam-only LS3 in my 300ZX drag car and getting it running down to 10.5@128MPH, I decided to build a new motor.

Originally I got a great deal on a set of lightly used Wiseco 12:1 pistons designed for a stock rod/stroke. So I ended up buying a set of Scat rods with ARP 2000 bolts and a stock LSA crank. After tearing down a donor L92 block I had and taking it to my local machine shop (IDM Speed and Machine) it turns out the block was worn enough that a clean-up hone would put it to 0.008" PTW on those Wisecos. Sooo.... I ended up buying a set of 4.07" 12.2:1 Mahle's with Lunati rods from TSP. The final build on the engine is as follows:

2008 L92 Block 0.007" Over
12.2:1 Mahle Pistons
6.125" Lunati Rods w/ ARP2000 Bolts
LSA Crank
ARP Main Studs
Melling HV/HP Oil Pump
King Bearings with 0.0025" on the mains and rods

LOJ Private-Label CNC Ported 823 Cylinder Heads, Stock L92 Valves, Stock Guildes
PAC Dual Springs with Ti Retainers
ARP Head Bolts
Stock 0.051" Head Gaskets
LS3 Valley Tray

LOJ Spec LLSR Cam by Bob at Cam Motion
5/16" 0.120" Wall 8.100" Manley Rods
Jesel Roller Rockers
Morel Link-Bar Solid Lifters

LOJ Oil Pan
LOJ 1-7/8" to 3" long tubes by Kooks
Fast 102 w/ Mid-Length Runners, Fast 102 Throttle Body
LOJ Cold Air Intake

The trans is an ATI Competition TH400 w/ a Brake and a Reverse Manual Body
The converter is a 4500RPM Stall 9" unit from ATI
The car is on 26x11.5" Hoosier Slicks
3.69:1 Stock Rear Diff/Axles/Suspension/etc.


The whole idea was to build a motor that would RPM. This was for a couple reasons:

1. I like high reving motors
2. The car is still on stock rear suspension, and I plan on leaving it that way. This presents a problem because there are not many gear options for the 300ZX TT R230 differential. I'm already running out of revs at 128MPH and a 7000RPM limit. If I want to go quicker and faster, I can put a 27" tire on it, but that's not enough. The 27" tire combined with a 7500RPM limit and 15% converter slip will get me to 141MPH at the limiter in direct. More on that later...

So I assembled the motor on Friday, installed it on Saturday, Started it up on sunday, let it idle and rev for a bit, drained the oil and put in dominator 15W-50, and trailered it out to Gettysburg on Monday for Jeremy Formato to tune. The results were surprising to both of us...





That's 545WHP@7400RPM through a high stall, auto, and slicks.




545 WHP is 641 Crank at 15% Drivetrain Loss, 681 @ 20% and 727 @ 25%. Jeremy seemed to think this setup is likely in the 25% loss area.

Using a 1/4 Mile ET/MPH to HP calculator for the old setup, a 10.5@128 would be 545 crank horsepower, which is exactly what TSP said their cam setup would make, so I believe that calculator to be accurate.

If the new setup is making 641, the car would go 9.9@135
If the new setup is making 681, the car would go 9.7@138
If the new setup is making 727, the car would go 9.5@141

FWIW the car's race weight is 3282lbs. So by the above numbers, you can see why I would need the Rev's to keep the stock diff ratio and still not run out of gear.

Anyway, just thought I would share, can't wait to get to the track and actually see what the car does.

 

That thing makes awesome power! But I find it hard to believe a stoke stroke is making 727 crank hp lol.

 

I completely agree... I'm in the 680ish camp. But we'll find out when I go to the track and get kicked out.

 

Excellent Results!
I am more in the fixed drivetrain results camp, I would estimate
Your crankshaft HP between 645-675, (100-120 HP drivetrain loss).
Who is LOJ, and are you able to share Head flow #s and Cam
Specs? The peak is similar to my 396", 7100-7300 RPM with a
FAST Mid Length Runner as well. Should really rip, in for track
Results.

 

LOJ Conversions, it's a small business I own doing LS swaps in Nissans and really anything you bring me.

I've got to dig up head flow numbers, but I'm happy to share the cam specs.

238/248 112+2 0.697/0.671

 

You've got a LOT left on the table with that thing my man. You can use a MUCH bigger cam and you need to get a 6000-ish stall converter in that thing ASAP. You could drop your 60' by a tenth I bet and recovery off the shifts would be much better. I'd send it back to ATI and ask them for the most torque multiplication in stall with the tightest finish line performance they can muster.

We run a hydraulic 239/251 on 110+2 in a SBE 10.4:1 LS3 and have gone 10.13@131 at 3200 pound race weight w/ a powerglide in a less aerodynamic wagon.

Also if your converter is slipping 15% at 7500 there's a problem. Slip should decrease with RPM and at 7500 should be no more than 8% and 6-7% should be achievable.

Cool car and congrats on the results!

 

Looks like it's going to carry really well

 

FWIW, I'd seriously look at bigger pushrods like 11/32 and then shift around 8000 RPM. That power curve is so sweet, and it peaks so high, you'd really gain alot of power under the curve by stretching your RPM, which will also stretch your gears a bit too.

Very nice motor. We continue to see these shorter length runners and LLSR combined with good heads really just getting it done. A very impressive motor that likely would have dyno'd 570 at the wheels through a T56

 

Awesome results. This is what happens when you have a very well thought out plan that you actually execute. Make sure to keep us updated with track results. A track video wouldn't hurt either.

 

Ls3's deserve that RPM

 

Thanks for the advice, I'll look into it.

Agreed!

Thanks! I plan on switching out the pushrods, but I was on a super tight time crunch getting it together for the dyno. I essentially ordered about 8 different sets of pushrods to make sure I'd have a set the right length when putting the motor together, and there weren't too many in-stock options in 11/32" when I was ordering. Now that I've got the right length, I sent back all the other sets and can order a 11/32" set in the right length.

I'd love to extend the RPM more, but those truck intake valves have me worried a little bit. I'm going to get kicked out of the track no matter what I do, so we'll just play it by ear.

Thanks, will do!

 

LOL been there!

Work the eighth until you feel good, then do your hero run. if you're lucky, byt hte time you dialed int he eighth, they won't be watching you any more...

 

Great results! I do love that power curve.

 

SuperHatch,
Beautiful car you have there. 9s will be easy.
Long time AMSOIL User/Dealer here , I am using
Dominator 10W-30 with 30 PSI+ @ Hot Idle & 73 PSI @
7600 RPM, with similar clearances. Curious as to
your oil temps and pressures, and decision on 15W-50?
I think your cam specs/size for your valve weight &
RPM is spot on FWIW.

 

That's pretty much exactly what I plan on doing...

Thanks!

Thanks! My oil weight choice was based on the machine shops recommendation. I have 40psi hit @ idle and 85-90psi hot at 7500. I don't have an oil temp gauge so I can't comment there.

 

Do you have any pictures off the cylinder heads after porting? Those have to be some damn efficient heads to hit that number. You, or whoever ported them, must know what they're doing.

 

There are pics on my Instagram feed.... @lojconversions

 

 

Those look really good.

 

Yeah, I second that.