I've been scouring these forums for months now and I'm looking for some advice on my build....

Block
Line Bored after ARP main studs
Decked (less than .005 for flatness only)
Cylinders bored .030 over

Pistons
Speed pro Hyper flats
Hasting rings

Crank
.010/.020

Cam
TSP Torquer V4

Heads
799 castings
Fresh valve lap
Mild hand port and polish

Intake
Planning on running a truck intake unless my hood will not close... Then I will run a LS6 most likely

This is all on an iron block LQ4, going in a G35 coupe mated to a 6-spd. Weight is around 3400lb

The crank I'm using is out of a LS6 vette. I can't for the life of me make a decision on my rods. All I need is to deliver the rods and have the bottom end balanced before I can start building.


Dilemma...
Stock Rods, Scat I-beam (bushed), H-beam

The reason why I'm stuck here is because I don't know what I can realistically expect. I come from the drag bike world where we turn crazy rpms and spray out the hole. I'm not planning on doing either of these with this car. Initially I said I was going to plan for a 250 shot of gas but maturity beat the ego mindset here. I made the decision to go hyper pistons to steer me away from later slapping a the nitrous on in a knee jerk decision.

I know hypers sit a little more snug in the hole so piston slap is less of an issue. Are floating rods really going to provide any benefit here? I like the scat rods, and what I've read about them but they are press fit. No big deal, hone the small end and slap some bushings in them and make them floating. I'm now looking at machine time and bushing cost. Doing this and I'm close to the cost or at the cost of H-beams. If I go H-beams I'm pretty sure, as well as my machinist, that weight will need to be added to my crank. So Here I'm adding more money.

The jest of it... Money... It's not spending the money, but what will I gain with that money? Are H-beams needed? Are floating rods much better than press-fit? Are the stock rods with some arp bolts more than I'll ever need?

I'm trying to prevent frivolous spending. If I decide to that I want more power and want to add nitrous in excess of 75hp then I will buy pistons. If I buy pistons I will need balance the bottom end again and then I can upgrade the rods. I don't foresee this happening any time soon though. The car is staying in stockish form and mostly see highway driving and weekend fun with the wife.

I was planning for 430-450 whp, but the more people I talk to say I could be closer to the 500 mark with the setup I'm running. 500hp in a G35 coupe will be quite the fun little car to drive.

I'll close with I appreciate any remarks given. "Spend it once" is advice, but I ask for consideration with what I've said before falling onto that true but overrated response. This is by no means a shop dream, I've owned the car for many years now and as I said all machine work is done at this time minus balancing of bottom end which will be +/- 0.5 gm btw.

Thanks much,
Thomas

 

You can do 500HP with a STOCK short block with no problem. Stick a good cam in it, get the 799 heads CNC ported, run either manifold you mentioned, and run, Forrest, run!

 

Since you have a decked block, pistons and a crank already, your rod length is determined for you.

Depending on what the compression height/distance is will determine the rod length you need. Are your pistons 1.340" or 1.314". That will tell you if you're buying stock length 6.098" rods or aftermarket 6.125" rods.

For your application, I wouldn't hesitate to use a stock GEN IV (floating) rod. If you require a 6.125" rod, then take your pick of aftermarket floating rods, I-beam or H-beam. At your power and RPM level, it won't really matter.

I will say to try and stick as close to stock weight as you can so you don't have to add a bunch of mallory to balance the stock crank.

I just finished balancing my stock LS3 crank using stock rods and JE/SRP pistons. It was 40 grams heavy and I ended up drilling a couple holes in the front and rear counterweights to get it within 4 grams at each end and 1 gram total.



Cole

 

The pistons are 1.325 compression height.

I have to buy rods regardless... If I go stock rods, are the stock rod bolts strong enough to provide reliability without being abused?

If I go Scat, will I miss anything from being on a pressed pin?


If I need stronger bolts then I will be in them for the cost of the Scat with ARP bolts already, if the floating pins is that beneficial then I will be in the scats honed for the cost of some H-beams.

 

For your purposes, stock rods will be fine. Use ARP rod bolts if you feel the need for more strength.

 

I'm finishing up my 6.2 LS3/LS7 heads with a stock crank, stock rods, stock rod bolts. The motor will probably spin to 7000 if the valve train stays happy and should make around 550-575HP at the crank. I'm not worried about the stock rods or stock bolts.

 

Scat 26100944P rods arenr bushed so you would have to bush them.
66100945 are the hbeam bushed
I would use a gen4 rod if the pistons are floating style.

We have both floating and pressed pin hyper e pistons so there are plenty of options there also

We have honed out the small end of the scat rods to floating pin size and ran them as a floating pin rod. Youll also have to drill oil hole in top. Local machine shop does it quite a bit!