LSPATROL

Hey all!
I know "cam selection" posts are everywhereeee you look, but my circumstances are rather unique and after weeks of searching around im just as baffeled by the range avalible and different opinions that im no better off then when i began!
The car its going in is a 2002 Nissan Patrol wagon 4x4, 4 speed auto (RE4R03A)
(I live in australia)
Its a heavy vehicle at 2550Kg or (5600 LBS)
I broke a ring due to over rev 4 weeks ago out bush so i tore the engine out and stripped it, and off it went to the machine shop to get oversized to 3.905 for the new pistons, new cam bearings and decking etc etc.
Now iv got the bottom end re-assembled and im stuck at which cam to use!
Ill write up whats in the engine and what heads below for info.
What im looking for is Torque, and lots of it!! It needs all it can get trust me as the stated weight is unloaded.. Also i tow the boat with it and use it offroad alot.
But at the same time i still want a fairly impressive amount of power output as well. The engine is high compression so im hoping that will contribute all around. A angry idle would be nice to but i cant have the best of everything!..
Overall im hoping to increase my torque substancially, still have a fair bit of mid range to early top but not much as iv rev limitied it to 6000 rpm.
Street manners i couldnt care less, its auto! A lope would be good if anything! Economy isnt to be expected when building things like this though..

Engine specs:
LS1 alloy block bored to 3.905, Deck standard height
Manley platnuim series -4cc pistons, total seal gapless rings
Manley conrods 6.125" (longer)
ACL race series bearings
ARP head and main stud kits, balancer bolt, cam bolts
Full fel-pro gaskets, New GM oil restrictor
LS2 heads, Minor porting, Milled down 30 thou
Comp dual valve springs, titanium retainers etc
Come Ultra gold series 1.72 ratio roller rockers
Pushed length to be measured
L98 lifters (aussy version updated LS2 with way better heads and manifold)
LS6 intake manifold
Undecided on throttle body size?? Any ideas??
Compression ratio comes to 11.7 which is fine as our premium unleaded over here is 98 octane at the pump. Standard unleaded is 92 and midrange premium is 95.
Exhaust primarys are 1 3/4 merges to a single 4", then down to single 3"

Diff ratio is 4.11
Automatic is a RE4R03A 4 speed with a 2000RPM stall
Vehicles tyres are 315/75-16 Mickey Thompson BAJA CLAWS's (35")
Used mainly for daily driving, bush, towing boat etc. But i still want it to go as hard as possible! Spending this much i want some decent results.

Thank you in advance to anyone who has any recommendations, because i cant go any further until i make a decision unfortunetly.

99Bluz28

iTrader: (35)

With a 214/222 115lsa+0, lift .602"/.572" with 1.72 rockers, IVC is 42 and it has -12* overlap.
The cam lobes are Comp Cam LXL lobe #13155, and Xtreme RPM high-lift #3714.

With your 11.7:1 SCR you'll see roughly a DCR of 9.07

LSPATROL

Thanks bud that sounds good.
not too aggressive.
How do you think the dynamic comp will go that high even on 98 pump? I'm at sea level in the tropics so our air density is huge!

LSPATROL

Oh and my head CC is 60-61
head gasket is 3.910 @ 0.030 thou.
cometic

garygnu

also look at comp cams 54-455-11.

99 2500

I would go with the crane 1449041 210/218 114+4 .551 lift . I had a comp 212/218 114 .522 lift cam and swapped over to the crane above and couldn't believe the difference in torque in the 2000 rpm range. This is in a 4x4 2500 pickup and now holds overdrive gear where it would always downshift with the comp cam.

99Bluz28

iTrader: (35)

99 2500,
That Crane cam would be fine if his engine can safely handle a 9.5 DCR with 98 octane. IMO, I think he probably would be fine with a DCR of 9 with 98 octane, but I really don't know about a 9.5 DCR .
IMO, it would actually be a lot easier to spec a cam for his engine if the SCR was at least a full point lower, but with his engine having 11.7:1 SCR and with him wanting a lot of torque its just not that simple.
Most small shelf grinds that are good tow cams will need the cam retarded at least to the where the ICL equal or greater than the cams LSA just to keep the DCR down.

99 2500

Good point, forgot about his high compression

RezinTexas

I'm running a 224/228 .566/.571 115+1 in my heavy 4x4. Still plenty of low end, and it really sings up top. I do a fair bit of trail off-roading, and its never let me down. However I have a stroker crank, so this likely makes a difference.

LSPATROL

So lets say i used the standard GM 0.051 head gasket from the cometic 0.030, (i actually have some at home) that will drop .7 ish off my static, would that bring my dynamic back to more practical levels with a cam like that?
98 octane all day is nice, but when you travel it can sometimes become scarse. 95 is readily avalible at every serivce station. But my tuner can account for that i guess regardless.
And whats with all the compression calculators saying different things! Its annoying and inconsistant!
If someone knows of a *correct* one, can you share please..
in theory, i calculated 11.7 at one calculator, 12.3 at another, not good...
So can someone tell me what it will REALLY BE

3.905 bore
3.910 @ 0.030 or 0.051 head gasket (depending on static comp numbers)\
3.622 stroke
-4 cc dished pistons, 150 thou inlet valve reliefs, 170 thou exhaust reliefs
0 deck height
60-61 cc combustion chambers (un-measured, only calculated)

LSPATROL

Ok so after much searching I think iv found an accurate compression calculator, Its actually a really good program, calculates everything, dynamic, static, litres, stroke, boring the whole lot!
I downloaded it and it gave me these figures

It says with my setup and the 0.030 head gasket i should get a more "realistic" 11.03 static compression.
Anyone think otherwise?

Performancetrends.com
Thats where i found it.

99 2500

I get 11.1 with the .030 and 10.5 with the .051. Just to compare I'm running 10.35 compression with 91 octane and 28 degrees of timing with the crane cam and no problems.

99Bluz28

iTrader: (35)

Here's what I cam up with, 11.2:1 SCR with the calculator I'm using.

This is with:

3.910" bore

3.622" stroke

4cc dished

0 deck height

60cc chambers

.030" gasket

With a .051" gasket it comes out to 10.62 SCR, which sounds like to big of a drop to me, but I could be wrong.
If this is indeed correct then I'd go with the .051" gasket.

99Bluz28

iTrader: (35)

For the 10.62 SCR. I'd try a 213/220 113lsa+2, lift .609"/.572", IVC is 37.5 and overlap is -9.5, and the DCR is 8.61.

FYI, this is with Comp Cam LSL #13093 lobes, and Xtreme RPM high lift#3713 lobes.

This is of course assuming the VE calculator I'm using is correct.

JakeFusion

iTrader: (7)

Don't forget that the 98 Octane rating there is different than the octane rating here. Australia uses RON and the US uses AKI, which is an average of RON+MON/2. Therefore, 98 octane is roughly equivalent to 93 used here.

I would still aim for 8.5-8.7:1 DCR.

99Bluz28

iTrader: (35)

Wow, didn't know that!

Thanks for the input Jake.

LSPATROL

Yeh I didn't either! Thanks for that bud good insite and defiantly something I needed to know!thanks!
Also I spoke with a top engine builder and he clarified a few points that I was off track on.
one straight away been too much compression, it made sense too. He said with how the ls heads flow now days and running that much comp id have to pull that much timing out that id bite my nose to spite my face as such. And that it would if anything end up a pig. Basically put he said on the older chevs running high comp had its main upsides based on the **** head designs, and their lack of flow, unlike the new LS styles today.
he uses a program based on what my heads cnc and flow to to calculate the optimum static and dynamic compression required for this engine, and thus assisting in the cam decision overall in the end.
so, my heads are packed up to go get the once over and see what he comes back with. He told me to list a few of the cams I'm looking at so he can enter them into the scenario and see what the outcome of those spec's will be so iv listed the ones here. Thanks everyone I appreciate the input and ill let yas know how it goes!

LilJayV10

iTrader: (39)

If it hasn't been said the tighter quench you run the more compression you can get away with because it controls flame travel better and resists detonation.

Wouldn't increasing quench to lower compression be counter productive?