2008 Stage 3 ROUSH - Rebirth...

[AutoXRacer]

I don't understand that. Every piston that has ever came out of my motors has the skirts scuffed a little. What do they mean "collapsed"?

Why not just have them moly coated.

This is what I could find and what was explained to me:

"Collapsed" refers to the piston skirt. The measurements at the bottom of the skirt will be less than specs by an amount greater than normal wear. A collapsed piston will usually have a noticeable knock. You may not be able to visually see it, but a micrometer will tell the story.

According to the shop my current bore is 3.5565.
The pistons are 3.552.

The finished bore will be 3.5575.

So my understanding is that I need 10 over pistons.

(don't quote me on this...this is all from memory and mine is bad...lol)

 

[05stroker]

According to the shop my current bore is 3.5565.
The pistons are 3.5525.

The finished bore will be 3.5575.

So my understanding is that I need 10 over pistons.

(don't quote me on this...this is all from memory and mine is bad...lol)

.010 over would be 3.562. Wouldn't .20 over pistons be easier and faster to find on the shelf?

 

[AutoXRacer]

.010 over would be 3.562. Wouldn't .20 over pistons be easier and faster to find on the shelf?

No, these are proprietary pistons...the crank, rods, and pistons are not off the shelf kind.

I have to get a set made one off. sigh

 

[BruceH]

No, these are proprietary pistons...the crank, rods, and pistons are not off the shelf kind.

I have to get a set made one off. sigh

You shouldn't. IIRC you have a 3.8" stroke crank with 5.850" rods. The only piston that will work with that combination is a 1.150" compression height.

If my memory is correct your motor was originally based on the Saleen 302 motors. The 3.8" cranks, Manley rods, and cp pistons were selling for a very low cost due to the Saleen bankruptcy. Brenspeed and JDM bought out most of the inventory from horsepower1. JDM decided to go with a Manley 2618 piston when the supply of 4032 cp pistons ran out. Brenspeed contracted out for more 4032 cp pistons.

Somewhere along the way mmr bought some 3.8 cranks. They also have rebranded pistons just for that stroke. As long as you have a 3.8" crank and 5.850" rods then you will need the 1.150" compression height pistons. Have you contacted JDM to see if they have a set in overbore like 3.571? At one time I was contemplating putting a motor together with those components and J3 was willing to sell a set with rings for around $700. That was a few years ago so the price might of changed. I'd start with asking JDM and/or Brenspeed.

 

[skwerl]

You shouldn't. IIRC you have a 3.8" stroke crank with 5.850" rods. The only piston that will work with that combination is a 1.150" compression height.

If my memory is correct your motor was originally based on the Saleen 302 motors. The 3.8" cranks, Manley rods, and cp pistons were selling for a very low cost due to the Saleen bankruptcy. Brenspeed and JDM bought out most of the inventory from horsepower1. JDM decided to go with a Manley 2618 piston when the supply of 4032 cp pistons ran out. Brenspeed contracted out for more 4032 cp pistons.

Somewhere along the way mmr bought some 3.8 cranks. They also have rebranded pistons just for that stroke. As long as you have a 3.8" crank and 5.850" rods then you will need the 1.150" compression height pistons. Have you contacted JDM to see if they have a set in overbore like 3.571? At one time I was contemplating putting a motor together with those components and J3 was willing to sell a set with rings for around $700. That was a few years ago so the price might of changed. I'd start with asking JDM and/or Brenspeed.

Dude, you are such a wealth of information. Guys like you make this forum great. Thanks.

 

[AutoXRacer]

Yeah, I spoke to JDM...they have no shelf stock...hence I need a set made by Manley.
The problem is finding on in 10 over... The stock 5 over and the 20 over are common, not 10 (from what I'm told).


These are the only specs I have which is right off their website:
302 CID Modular 2v, 3v, and 4v
3.554”Bore x 3.800”Stroke
Stock compression (9.8:1)
New FRPP Block plate honed for a truer bore geometry
Speed Pro NASCAR bearings
JDM Spec Ring pack w/ Stainless top rings for better seal and longevity
JDM Spec Kellogg forged steel crankshaft
Induction hardened journals and 8 bolt flange
JDM Spec custom forged CP pistons
Manley Forged steel 4340 connecting rods w/ ARP fasteners

Edit:
I just checked MMR, they have std, +20, and +30; no +10s...

Bruce, would these really be the same pistons as JDMs?
Part Number: MP3800
http://www.modularmotorsportsracing.com/

 

[05stroker]

Dude, you are such a wealth of information. Guys like you make this forum great. Thanks.

I agree, BruceH for president!

 

[BruceH]

Yeah, I spoke to JDM...they have no shelf stock...hence I need a set made by Manley.
The problem is finding on in 10 over... The stock 5 over and the 20 over are common, not 10 (from what I'm told).


These are the only specs I have which is right off their website:
302 CID Modular 2v, 3v, and 4v
3.554”Bore x 3.800”Stroke
Stock compression (9.8:1)
New FRPP Block plate honed for a truer bore geometry
Speed Pro NASCAR bearings
JDM Spec Ring pack w/ Stainless top rings for better seal and longevity
JDM Spec Kellogg forged steel crankshaft
Induction hardened journals and 8 bolt flange
JDM Spec custom forged CP pistons
Manley Forged steel 4340 connecting rods w/ ARP fasteners

Why do you need .010" over? Why not go with .020 over?

 

[AutoXRacer]

I agree, BruceH for president!

+1 lol

Why do you need .010" over? Why not go with .020 over?

We want to keep as much material as possible.
Why remove more side wall than needed?

 

[05stroker]

+1 lol




We want to keep as much material as possible.
Why remove more side wall than needed?

My experience is when things go wrong with a boosted motor you need a sleeve. I wouldn't worry about .010 or .020 and so on.

 

[BruceH]

+1 lol




We want to keep as much material as possible.
Why remove more side wall than needed?

One reason is because .020" overbore are the norm for a 4.6. If you are getting them as a custom order then it makes sense to keep the bore down to .010".

Even custom order pistons aren't that bad. The ordering process is fairly easy provided you know what you are looking for or can base it on a shelf piston with a few modifications. Yours would be fairly easy. Find a 3v piston in the configuration you want and change the compression height and bore. Diamond charges $50 for each change to a shelf piston.

I called cnc motorsports for my modified shelf pistons. Told them what I needed and they found a shelf piston that could be modified to my specs.

Are you going to have JDM order a set of .010" overbore Manley pistons for you?

 

[AutoXRacer]

Yeah, i thought that would be the easiest. I want to keep the motor as JDM speced it. Figured getting the exact same pistons but in whatever size the engine builder recommends.

What would you recommend?

 

[BruceH]

Yeah, i thought that would be the easiest. I want to keep the motor as JDM speced it. Figured getting the exact same pistons but in whatever size the engine builder recommends.

What would you recommend?

I think that Manley makes a good piston. I wouldn't have a problem having JDM order the pistons. I'm not sure what the dish is on your pistons but iirc it comes out to stock compression. I'd go for flattops to bump the compression up and then start driving to the Shell station with E85 by Smokey Point. But that's me, lol.

 

[AutoXRacer]

Haha, i would love to run E85, but i will not get stuck with just one station. lol i drive all over the place and need to be able to fuel anywhere.

 

[BruceH]

Haha, i would love to run E85, but i will not get stuck with just one station. lol i drive all over the place and need to be able to fuel anywhere.

Then just change the tune to a 92 octane version. You could probably even do a high boost e85 tune and a lower boost daily driving 92 octane tune. You would have the best of both worlds.

 

[tigerhonaker]

Engine shop just called... sigh

Need new pistons... Pistons collapsed; thats just a term to indicate the skirts are scuffed.

Need to source out new pistons in a 10 over bore. sigh

Think of all this in a Very Positive way ........

This time it will be right.


Terry

 

[AutoXRacer]

Think of all this in a Very Positive way ........

This time it will be right.


Terry

I guess... lol

 

[BruceH]

Gerald,

I just came across a set of new Jessel rockers for less than half price. The info is in a pm from this forum. I thought I'd post it here just to make sure you get the message. I know you have been talking about the Jessel rockers so this might be the chance you have been looking for.

 

[BadPiggy]

Gerald,

I just came across a set of new Jessel rockers for less than half price. The info is in a pm from this forum. I thought I'd post it here just to make sure you get the message. I know you have been talking about the Jessel rockers so this might be the chance you have been looking for.

He isn't the only one interested in a set!

 

[AutoXRacer]

Haha... Its a shame because I have a set on order of the OEM ones.
If I hadn't ordered the OEM ones, I might have jumped on this.

Thank you for the hook up though!!