Well evoM community, I need your help here. I purchased a nice evo8 with around 35k miles under two years ago. It needed a little TLC in the cooling department, but that has since been resolved.

When I purchased the car I saw that it had forged pistons (unknown make), BUT stock rods. I can not figure out for the life of me why someone would do this, or what benefit it can possibly have?

Currently running a garrett 3582r with supporting mods.
Sitting at 370whp/311tq on a mustang dyno on 28psi.

My dilemma is this...do i upgrade to some GSC S2 cams + valvesprings/retainers next? Or... pull this frankenmotor and do new 10:1 pistons / rod combo before I touch the head?

I've attached the dyno sheet to show spool in case anyone has ideas about any effects of these pistons. Second image is before & after the cooling improvements. The car runs great and I'm treating it like a stock bottom end. Any input or advice you have is much appreciated!


Tuning session results July 2018


Before & after cooling improvements

 

This will depend on your budget. Cams install is cheap but if you have the funds for rod/piston upgrade, why not fo all at same time? Make sure the machine shop installing rods and pistons also prep the rest of your block and blue print your build. If you were planning on popping in new rods and pistons from the box, then I would say don't touch your bottom end because you will compromise it's reliability.

 

I'd love to do it all at the same time, though I feel that I can do cams without the bottom end...but not the other way around. The difference between a $2k upgrade and a $5k upgrade and I'm not sure I can swing the full build in the upcoming year. What would could compromise the reliability? I would have a reputable shop do the install.

 

Do your research on their build. Make sure they provide a blueprint with their build. You should have the specs for when you need a refresh.
Your decision on what to do will be decided by your budget. Lol

 

It's tough, I'm trying to figure out this mystery machine. Very happy for where it is right now but I'll make sure I cover my bases going forward. Everything depends on budget lol, but i'm really looking for opinions on what others would do given my current situation.

 

 

I'm actually not very far from RRT at all but I didn't even know they were there! EFI Logics has been an excellent shop to work with and their service and tuning are top notch. I see that RRT does drive train services as well though, that is HUGE! I'll make sure I keep them in mind, it looks like an excellent shop.

 

I thought forged pistons couldn't work on stock rods...? If so, I'd assume they did it for detonation resistance.

 

The engine may have needed refreshed and new connecting rods simply weren't in the budget..

How did you confirm that it has aftermarket pistons?

 

edit: NM.

 

The shop that I purchased the car from was doing some general maintenance pre-sale, dropped the oil pan and took pictures. I'll see if i can locate the photo tomorrow and post it.

 

you did a really good job cleaning it up

 

 

Sorry for the long delay. I realize these photos aren't the greatest, but they were what I had when I first purchased the car. It looks like 232 is written on the underside of one of them. Anyone know what that could mean from an engine building perspective?


Aftermarket piston stock rods 1

Aftermarket piston stock rods 2

Aftermarket piston stock rods 3

 

If your goals are sub 500whp I would leave the bottom end alone. That's assuming there aren't any issues with it.