5.3 to Forged 347ci
 

Well, I have my engine out and had some ideas lol.

So I am currently setting at 411 Crank HP and 407 Crank Tq with my Gen 4 Iron block 5.3 LMG. I want more lol. I am looking at getting Wiseco Pro Forged Pistons 3.905" bore -3.2 CC Flat top, K1 Technologies H-Beam Billet Rods 6.098" length with ARP 2000 Bolts, K1 Technologies Forged Crank 3.622" stroke 58 Tooth reluctor wheel. Durabond BI-Metal Chill Casted Micro Babbit Teflon Coated Cam bearings, Clevite H-Series Tri-Metal Performance Rod Bearings, Clevite Coated H-Series Tri-Metal performance Main bearings. Total cost with machine work needed $2500. Brian Tooley has a kit with the Crank, Rods and Pistons for $2100. It will also put me at 10.5:1 Compression Ratio and 7.1:1 Dynamic Compression Ratio with my existing cam. Exact Cubic inch of this setup would be 347.03

I currently have ARP main studs, ARP Balancer Bolt, ARP Head Studs, ARP Flexplate Bolts, Crane 210/218 .551/.551 116+2 LSA 110ICL Cam, Comp Trunion Kit, Comp 5/16 .105 Wall 7.350 Pushrods, Pac 1218 Valvesprings, Pac Ti-17 Retainers, Pac Machined Valve Locks, Texas speed AFM/DOD delete kit, LS6 oil pump, ARH 1-3/4"x3" Longtubes, Corsa Sport 3" Catback, Airaid Jr kit, running a Blackbear tune.

I have been looking for a L76 6.0 or a 6.2 for my truck but will cost more than this setup when I find one. Average price is around $4000. So i thought this will be a better setup being forged and will great with Nitrous or Boost. This setup should net me upwards of 500+ Crank HP by my estimations. Which is 90 more RWHP than I currently have.

Just wanted everyones thoughts and opinions on this setup and anything you may recommend or change.
phump

Im just curious on how you estimated your flywheel hp? Did you convert your whp or did you use an engine dyno?

i was under the impression the Gen 3 iron 4.8 and 5.3's could take a good beating as is. Is that not the case with the Gen 4s. Increasing displacement by .4 liters and reusing all your exisitng parts will net you 100 fwhp?

i'm no expert...

I have 411 crank Hp because I had it engine dynoed. I have yet to get a wheel dyno but it should be around 325-335.

A stock LS6 is making 405 crank Hp. My old C5 z06 had a TSP 224 cam, headers, ported throttle body and what not and it dyned at 420 WHP from a baseline of 358WHP, so 420WHP is roughly 485-490 at the crank. I am going with a slightly larger bore and lighter roating assembly. Who knows if thats accurate. But i figured 500 crank Hp is not out of line.

And what do you mean by take a beating? I could get alot more out of my engine by going with ported heads and a larger cam but I am building the motor for torque and not max Hp, hence larger CI makes more torque at a better RPM. My engine right now makes peak Hp at 5800 RPM and peak torque at 4900RPM. So stepping up to a 5.7ci will allow me to tow better I hope lol. I wanted to go with CNC heads but was told by TEA that it will not help with building more torque or Hp at lower RPMs but add Peak numbers. They also recommended my to try a larger CI motor like the "347" to help with that, and their heads cost almost as much as the Forged rotating assembly.

I am no expert either but have built 4 bigger power engines.

I've run lots of boost through iron 5.7's (5.3 with ls bore size) with no issue. .

I've done this to mine. It ran fantastic for about 2 years (until now) when it suddenly seized two sets of rings (which means the block is toast). The cylinder sleeves get thinner when you go this route and any mistakes are a lot less forgiving.

I think it may actually be too wide of a piston for the stroke, causing the piston to rock in the bore and be prone to dragging the rings.

I have also looked at doing a 383, 3.903" bore with 4" stroke. I want reliability as well. I don't want anything to crazy because it will get to a point where I can buy a L76 6.0 or even a L92 6.2. But the Forged 383 will be roughly the same price as the 347. But I notice a 6.125" rod is very popular and more available.

Can I do a 6.125" Rod, 4.000" stroke with a 3.903" bore. Can a .027" longer rod cause issues. I can go either route with rods.

Very much later down the line when I have the money I will be doing a TVS1900 and want a stout assembly for that. I am not looking for 1000HP but just something that can surprise these new mustangs even now and then and tow well. I was told the 347 would be better for boost than the 383.

I am no expert in LS engines by any means and that is why I ask for advice in this situation.

Not sure you should be posting advise like this as it isn't really clear (to put it a nice way).

If your theory of the "piston being too wide" for the 3.622 stroke motors, why is it that a 6.0 with a piston that is nearly +.100" "wider" with the same stroke works fine.

Your issues are coming either from the machine work, or faulty assembly.