Guys,

After building a new 408cid iron engine for my truck from the ground up, I'm curious as to what everone suggests to increase the hp and tq numbers. I got approx 365 rwhp@5800rpm and 345ft lbs @ 5200 on a Mustang-Dyno. Here's what I have:

6.0L iron block bored .030 over
4" Eagle crank
Diamond pistons -15cc (dish)
243 LS6 heads, milled to 62cc, CNC'd by Patriot (300cfm@.600)
Torquer 2 Cam, 232/234 duration @ .500 lift
.040 cometic gaskets (10.6:1 SCR, 8:1 DCR)
patriot gold dual springs
Comp cams moly rods (7.35)
stock intake manifold
stock 85mm TB
K&N air intake filter
42lb lucas injectors
ported oil pump
stock coils
1.7 roller rockers

The obvious upgrade is the manifold and TB....but how much will this really help ?.....The other obvious is the cam...if I go to something like the TSP Giant or MS4 will I lose torque?...Basically, I'd like to know what will improve my numbers (500hp+ ) without losing the low end torque...

Stroker2112

 

Your truck is an automatic, I'm sure, so don't expect dyno hero numbers. Are those locked or unlocked? An 8.00:1 DCR is just ok, but in a truck you have to leave a little wiggle room if you plan to tow or haul heavy loads. What kind of truck is it and what converter?

I wouldn't focus on dyno numbers out of a truck. See if you can hook it up and look for good numbers at the track.

 

You have probably already seen this thread but here goes anyways.
https://ls1tech.com/forums/generation-iii-internal-engine/649674-line-some-recent-threads-discussing-smaller-cams-milder-combinations.html

 

that is a very strong motor but as said there was an awful lot of attention to detail put into that motor so the typical results from your run of the mill build will probably be lower than his results.

 

Well, I dunno but I have a 370 with that cam TV2 on a 113+0 (degreed) and the numbers are in my sig.
11.88 SCR though and 8.65 DCR

 

heads, cam, intake/t/b, and raise scr is what i would improve on.

 

ummmm... ditch the pistons, go with some -8cc's, up your compression and youll gain a good 20-30 RWHP just from that..

 

Your numbers are actually pretty respectable for a truck running through an automatic (either a 4L60E/4L65E/4L80E). What have you done in the way of tuning? What AFR are you running at WOT? Has your timing been optimized for the fuel you're running? Are you getting knock retard? These are the kinds of questions you need to be thinking about. 500 RWHP without loosing low end torque is not obtainable without a power adder. What are your goals for this truck?

Steve

 

Thanks, I think I have a better perspective now. My numbers, once corrected, are similiar to Predator's 370...and the piston swap advice really makes sense although I'm a little concerned with using the 91 octane here in Omaha. My trans is a lvl 5 4l65E from Chuck at FLT(love it)...the tune was custom (completely impressed with the work done here given the amount of problems we endured) using HP tuner software...I believe my AFR is in the neighborhood of approx 11:1-13:1 at WOT..no retard...truck (2000 silverado) is running really good. I think I'll wait until the weather gets better, then go to the track and get some times to see where I'm at. My next question is probably better suited for the FI thread, but would nitrous be an easy add on to my h/c & compression setup?...

Stroker2112

 

Forgot to say that I have a VIG 3000 converter.......rear end is unlocked.

Stroker2112

 

your setup would be good with nitrous, the big bottom end tq it would give you will help considerably in getting that heavy truck moving.

 

The 402 in my car has same -15cc Diamond 11520 pistons, they are a stinkstar combination for high power NA. Even with 62cc Darts honestly it was a shocker on the dyno.

However I found my 402 to be incredibly tight, within a week it picked up 15rwhp, only from break in style driving and changing the oil few times. FAST 90/90 picked up 15rwhp peak. The turbo mufflers I had on the car I found were too restrictive, picked up 30rwhp by dropping them ended up at 451/455.

What i'm doing now? Diamond -15 pistons are good for something, Boost! swap the heads and cam put a 76GTS on it, making power no prob.