What pistons for build.

[03spoolindmax]

I've been gathering parts for my build and well pistons are the last thing I need before it heads off to the machine shop.

Goal is for around 850-900hp. Truck is not a daily driver but will see some street time on the weekend and heading to the local track also.

Turbo setup will be an s480 over a 68mm 4094. Stage 1 SoCal heads, EDP stage 2 alt firing cam, Carrillos, main & head studs, dual fuelers & 100% over injectors are the main parts to the build.

So it seems I have a few choices of pistons I've been looking at. Fingers oval bowl, mahle race cast, or just C&C lb7/lly pistons. They'll all need .075" valve reliefs put in them due to the cam. Wanting to be somewhere in the lower 16:1 CR.

i know you can't go wrong with fingers or mahle pistons but if I can get away with a lb7/lly pistons id rather run them. Very rarely will it be on the max effort tune. I'll mainly keep it around 700hp or so which is more than enough for the street.

 

[Dirtymaxx03]

How many miles a year will you be putting on the truck? And how often do you want to use 900hp?

 

[03spoolindmax]

Truck will probably see max of 5000 mi a year and only see max effort at the track. Which could be 2-3 times a month depending on the events.

 

[coldLBZ]

I would not risk putting valve reliefs in stock pistons. Either Fingers oval bowls or Mahle race cast would be my choice. But at 5000 miles a year, maybe go forged?

 

[sickdiesel]

if only 5k a year, i would personally go with forged for sure!

if not i would do the mahle race cast

 

[mike diesel]

I would do fingers oval pistons.

 

[03spoolindmax]

Forged hasn't crossed my mind and I really don't want to run them.

A cast piston should get the job done for what I'm after.

I've noticed there's mahle cast with reliefs and mahle race cast with reliefs but the part numbers were the same when I was doing some searching last night. Also found a $500 difference in price between the two on different sites.

Are they the same piston?

 

[Dirtymaxx03]

I don't think you NEED forged pistons at all. However since you're only putting 5,000ish miles a year on the truck, it's not like you really need to worry about re-ringing the pistons on a multi annual bases. Forged would be, in your case, cheap insurance.

I personally wouldn't run worked over stock pistons at all, not worth the savings.

So I would stick to some Mahle cast pistons, standard or oval bowl is up to you.

 

[Cknight199]

Cast fingers pistons is my vote, not a single broken even with several trucks running cast at 1200+ for a while with pullers running much more than that with forged. I would go with cast just incase you change your mind and want to daily drive your truck.

 

[DIESELMAFIAPER.LB7]

I'm running mahle casts in mine but my stock pistons looked perfect living at 700 hp and 260k miles lol

 

[PACougar]

I think you'd be crazy to run modded stock LB7 pistons. I'm not saying they can't last, but considering you bought a Alt.fire cam why would you chance the pistons?

 

[03spoolindmax]

I'll probay run mahle cast. I found summit has them with reliefs for around $1700.

I could of already had an 8 second ls car with half the money I've spent on this motor.

It'll be worth it in the end to see the looks on all the car guys faces when I blow past them

 

[03spoolindmax]

I think you'd be crazy to run modded stock LB7 pistons. I'm not saying they can't last, but considering you bought a Alt.fire cam why would you chance the pistons?

Those were my thoughts. If I could get away with a stock modded piston so be it but at the same time. I'm already this far. Why not just finish is right.

Thanks for all the info guys. I'm hoping to have it done by end of July. I don't plan on putting a cage In it so I'll only be able to run no et. Maybe if I'm not still broke after the build. I'll try and make it out to scheids to hang out.

 

[paint94979]

You gotta put a cage in a regular cab you don't lose very much space going with one

 

[03spoolindmax]

You gotta put a cage in a regular cab you don't lose very much space going with one

One step at a time. How about I get it running first. Plus if I put a cage in it. All the locals will know how quick it is. I'd rather surprise them

 

[smkndmax05]

One step at a time. How about I get it running first. Plus if I put a cage in it. All the locals will know how quick it is. I'd rather surprise them

I bit the bullet, I'm all in for a rollbar and cage to follow if it's fast enough. I would also check into PPE race cast pistons. That's the route I went, I also dropped to 15.5/1 and saw no drivability loss in the awesome Indiana weather....Good luck with your build.


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[PACougar]

Cages are crap if it's a street vehicle. Now if it's just for the track then I'd say it's foolish to not have one.

 

[03spoolindmax]

Cages are crap if it's a street vehicle. Now if it's just for the track then I'd say it's foolish to not have one.

It'll mainly be a street vehicle. We don't have crap in Michigan for any diesel drag events so id have to travel atleast 5+ hrs to go to any. So there's no point in a cage. If I race at no et there's no tech inspection since they're not showing your time. They just hand you your slip at the end.

I'm going for mid to high 10s with it and still be able to daily drive it if I want.

 

[Hot COCOAL]

Goal is for around 850-900hp.Truck is not a daily driver but will see some street time on the weekend and heading to the local track also.

Turbo setup will be an s480 over a 68mm 4094. Stage 1 SoCal heads, EDP stage 2 alt firing cam, Carrillos, main & head studs, dual fuelers & 100% over injectors are the main parts to the build.

They'll all need .075" valve reliefs put in them due to the cam. Wanting to be somewhere in the lower 16:1 CR

i know you can't go wrong with fingers or mahle pistons but if I can get away with a lb7/lly pistons id rather run them..

It'll mainly be a street vehicle. We don't have crap in Michigan for any diesel drag events so id have to travel atleast 5+ hrs to go to any. So there's no point in a cage. If I race at no et there's no tech inspection since they're not showing your time. They just hand you your slip at the end.

I'm going for mid to high 10s with it and still be able to daily drive it if I want.

So, which is it....lol:hello:
A street truck, or mainly track? Is someone feeling conflicted:hug: I suppose it really doesn't matter

Well, I don't have any "experience" or advise or reasoning to try and sway or convince you one way or another, but I'll share why I chose to use what I did in my build, and ask a few things and comment on your engine build.

My truck is going to be a street truck, from day one my build goal was to build an incredibly capable street truck, nothing more. In the beginning I had the starry eyed goal of 1000whp, but no more, I'll be really happy with 750, for now

I am using fingers oval bowl race cast pistons, their strength and benefits are hard to deny and pass up, I also used an AF cam with a higher profile than stock, and because of that I chose to keep my CR stock @ 16.8/1
I am hoping that this will keep my power up on the lower side of the RPM while still providing all the benefits of the higher cam profile in the mid-upper RPM band, cuz remember, my truck is dang near a dedicated street truck that still needs to be able to "willingly" tow a trailer...I'm not concerned too much about the higher CR while using the Oval Bowl pistons, as they are stronger in all the places the standard pistons are weak and break and guys have been making big power on this CR for a long time, just look @ SoCal's MAHLE pistons, they're 16.8/1....
I'm not sold and didn't buy into the lower CR train of thought
Also, since you are going to HAVE to place valve reliefs into the pistons due to the STG2 AF cam, I wouldn't consider using anything different than the OVAL'S, but that's just me man.

Personally, I absolutely wouldn't use worked LB7 pistons, I don't think forged pistons are "really" necessary, and I haven't seen anyone mention ARAIS pistons yet, but I think they are only available in the forged material???

You are running a STG2 cam and only a STG1 head???
You're building it for 850whp?
What are your future goals.... cuz with that cam and dual fuelers, you could have much more given the +100 injectors, and that turbo set up should make north of 850 pretty easy...

I am curious as to why you chose to use a STG2 cam? From my research, I came to the conclusion that the STG2 cam changes so much, adds more work to the order, and raises the power band too much for the street that using one just didn't make sense, and really isn't "necessary" (from what I'm told) for a truck that see's street time and is running under 1000whp.

 

[03spoolindmax]

So, which is it....lol:hello:
A street truck, or mainly track? Is someone feeling conflicted:hug: I suppose it really doesn't matter

Well, I don't have any "experience" or advise or reasoning to try and sway or convince you one way or another, but I'll share why I chose to use what I did in my build, and ask a few things and comment on your engine build.

My truck is going to be a street truck, from day one my build goal was to build an incredibly capable street truck, nothing more. In the beginning I had the starry eyed goal of 1000whp, but no more, I'll be really happy with 750, for now

I am using fingers oval bowl race cast pistons, their strength and benefits are hard to deny and pass up, I also used an AF cam with a higher profile than stock, and because of that I chose to keep my CR stock @ 16.8/1
I am hoping that this will keep my power up on the lower side of the RPM while still providing all the benefits of the higher cam profile in the mid-upper RPM band, cuz remember, my truck is dang near a dedicated street truck that still needs to be able to "willingly" tow a trailer...I'm not concerned too much about the higher CR while using the Oval Bowl pistons, as they are stronger in all the places the standard pistons are weak and break and guys have been making big power on this CR for a long time, just look @ SoCal's MAHLE pistons, they're 16.8/1....
I'm not sold and didn't buy into the lower CR train of thought
Also, since you are going to HAVE to place valve reliefs into the pistons due to the STG2 AF cam, I wouldn't consider using anything different than the OVAL'S, but that's just me man.

Personally, I absolutely wouldn't use worked LB7 pistons, I don't think forged pistons are "really" necessary, and I haven't seen anyone mention ARAIS pistons yet, but I think they are only available in the forged material???

You are running a STG2 cam and only a STG1 head???
You're building it for 850whp?
What are your future goals.... cuz with that cam and dual fuelers, you could have much more given the +100 injectors, and that turbo set up should make north of 850 pretty easy...

I am curious as to why you chose to use a STG2 cam? From my research, I came to the conclusion that the STG2 cam changes so much, adds more work to the order, and raises the power band too much for the street that using one just didn't make sense, and really isn't "necessary" (from what I'm told) for a truck that see's street time and is running under 1000whp.

like I had said the truck will mainly be a street truck with a trip or 2 (maybe more depending on my mood) to the track a month for some fun. I have a daily driver so this truck will only come out to "play" or for an occasional cruise.

I think youre misunderstanding the stages of the cam and head. remember every manufacturer has theyre own version of stages. I picked up a set of socal stg 1 heads for a good price so I went with them. I just ordered a stg 2 edp alt firing order cam. 2 different companys which have theyre own way of rating things. edp rates that cam to be good up for 900hp and considers it a street/competition cam. which is exactly what itll be used for.

now I will NEVER tow with this truck. it doesn't even have a hitch

now heres a twist. from what I learned when I was away at school for performance. although it was for gas engines theyre in a way the same in this theory.

when picking out a cam you will have to pick out a stall to match. seeing this cam is more for mid to high rpm range. I have picked out a converter to match. ill be ditching my MLG and going with an MLGK. which has a stall of 2400-2600. so combining that with the cam will actually mate together and should work out well in my build.

850-900hp was in theory my goal that id be happy with. if I can make more and still be at a safe level then why not go for it.