i have a gen 4 and put DSS forged flat tops and compstar rods in it. stock crank but i did have it all balanced

 

I run an L33 aluminum gen 3.5. I ran stock crank, +.020 wiseco pistons and K1 rods. Had probably 150 passes on in (all mid 9 second to 8.70 passes) without an engine issue. I will say this is due to a good engine guy, but even more important, good fuel, and a very smart tuner.

 

Youll need to have it balanced but rod an pistoning them or pistons on gen 4 rods is very common

 

gen 4 rods seem pretty strong and the turbo engines are a bit easier on them. I've got an iron block stock 4.8 crank (std), with gen4 rods and wiseco .020 over pistons.
I'm gonna boost it up and see how strong the gen 4 rods really are!! the short stroke long rod motors seem to live well at high rpm and the iron block is an anvil

 

That is the trick........do not try to make big power at lower rpms, on a small ci motor.........thats when you will really find out how strong they are.

 

99% of the time going to forged rod/piston is lighter than stock parts and while it will need to be re-balanced it usually doesn't require any tungsten on the crank so pretty economical. As I have said many times on here, RPM is your friend on these builds. You will bend/break way more parts at 5000rpm than at 7000rpm making same power.

 

Why is that?

 

Peak torque always occurs at the highest cylinder pressure. This is also the most likely place in the power curve to experience detonation. This is the area most likely to bend/buckle rods. Broken cranks and cracked/shattered stock pistons generally happen in this region due to detonation. Higher RPM with appropriate AFR and timing simply minimize the chances of having damage from the combustion event and rely on mechanical integrity which the LS platform as plenty of. How many times have you even heard of breaking a cap, crank, rod or piston due to excessive rpm?? Its very rare. So if you take it a little easy on timing and be sure shift extension doesn't drop back into this area RPM is still your friend. Torque tows the car to the track, HP and RPM wins races.

 

on another forum they talk about setting the timing to where it keeps the engine out of the torque range and then ramp it in towards the higher rpm.I think they said 28 degrees on the trans brake and then once its released take i down to 14 degrees till like 5k then ramp timing in for the higher rpm horsepower.Is this seem right and what kind of ramp are you using

 

Piston speed is also part of the equation, shorter stroke, slower piston speed.Slower speed, less force I have been Watching you tube videos during covid and Engineering explains piston speed, bore and stroke. Some do not apply, but some real interesting stuff

Also Competition plus just put up a video by John Kaase about tools he has in his shop, and brings some interesting points up about rod bolts and lifters

 

TDC Dwell is a big factor as well, which can become a serious problem when fast shallow chambers are involved. This can also lead to ignition issues as this pushes dielectric strength of the charge so high even what is considered very powerful ignition systems not be able to jump the plug gap without experiencing misfire issues. TDC Dwell can also be a big contributing factor causing detonation.

 

I generally have parts in my own engines that I don't have to tiptoe thru any region of the tune-up. I'm not about how much I can get away with on how little. If anything I try to encourage my customers to over build the engine because at some point in the not too distant future they will want to turn it up higher than their original goal. It is human nature. I understand the kick a lot of guys get trying to beat physics but physics is immortal and will win sooner or later. I'm attaching a example of physics winning on an engine I did not build. This engine was being tuned by a very experienced tuner and had given zero signs of being at its limits, AFR good, timing good, plugs good, rpm good, etc. BOOM!!! 80% of the engine destroyed and no budget to build another anytime soon. It had some of the very best import parts on the market but ultimately they came up short. For another 5% - 10% of the short block cost I would not have a picture to post and the owner would have more than a pile of destruction. Sorry to go off on a tangent.

 

I generally have parts in my own engines that I don't have to tiptoe thru any region of the tune-up. I'm not about how much I can get away with on how little. If anything I try to encourage my customers to over build the engine because at some point in the not too distant future they will want to turn it up higher than their original goal. It is human nature. I understand the kick a lot of guys get trying to beat physics but physics is immortal and will win sooner or later. I'm attaching a example of physics winning on an engine I did not build. This engine was being tuned by a very experienced tuner and had given zero signs of being at its limits, AFR good, timing good, plugs good, rpm good, etc. BOOM!!! 80% of the engine destroyed and no budget to build another anytime soon. It had some of the very best import parts on the market but ultimately they came up short. For another 5% - 10% of the short block cost I would not have a picture to post and the owner would have more than a pile of destruction. Sorry to go off on a tangent.
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Who's H-beams are those?