7 Bolt build, Components/Specs

[daren_p]

Posted this up on the Link boards but I know there's some guys here that aren't on there with some good info, so I'll ask here as well:

Time has come to pull the 7 bolt & if everything checks good, I'm planning to build it up. Probably sticking to 2.0 & would like to end up around (or close to 9:1).

Car is currently my summer daily driver. Run pump 94 with 50/50 meth injection on my 3052. Daily boost has been ~26psi & 28 or so at the track. Probably bump that up to 28-30 daily & probably around 32-33psi at the track. I may go with a 35R next year so might run abit more boost at the track (though won't get too crazy as I don't want to get to the point of going through trannies like some guys here do ).

So basically 500-550whp depending on street or track (possibly abit more at the track in the future but 600whp is probably about max I'll ever go) & I'm looking for something that will last. I will be removing the oil squirters.

For pistons I'm looking at Wiseco 1400HD or the Mahl's. For rods I'm looking at H beams, Eagle was my origional choice but also looking at Manley or Scat. Starting to think Scat may be the route to go as I've heard they have an extra oiling hole, which may help splash oil on the pistons.

Was going to run ACL Tri Metal bearings, ARP mains & L19's (stock composite & oringed).

Should also mention (don't think its an issue with my choices) but looking for something without piston slap & how does the warm up time on these pistons compare? I don't mind waiting a min before I drive, as thats what I normally do, but I don't want a setup I have to sit & let the car idle for 5min before I can drive. I know not to beat on the car till its properly warmed up & currently don't get into boost until its fully warmed from light driving, so thats not an issue.

 

[Strm Trpr]

Give Bill at MAP a call and tell him what you plan to do.
He is giving guys a deal on custom Wisecos for Long Rod 2.0L for $520 shipped.

Here's a calculator that I use when figuring piston dish volume.
http://www.eaglerod.com/index.php?option=com_frontpage&Itemid=1

Plug the numbers into that calculator from the below link and you'll find that you will need a -10cc dish volume to achieve a static compression ratio of 9:1.

Here's Wiseco's Piston Catalog for Mitsu's.
http://www.wiseco.com/Catalogs/SportCompact/MiniMitsu.pdf

Scat rods are on sale at Race Engineering for $250.
They have two holes on the small end at like 4 and 8 o'clock to help lube the wrist pin.
You can see one of the holes in the picture in the following link.
http://www.raceeng.com/p-967-h-beam-rod4g63-2nd-gen.aspx

 

[Zack Huffman]

Should also mention (don't think its an issue with my choices) but looking for something without piston slap & how does the warm up time on these pistons compare? I don't mind waiting a min before I drive, as thats what I normally do, but I don't want a setup I have to sit & let the car idle for 5min before I can drive. I know not to beat on the car till its properly warmed up & currently don't get into boost until its fully warmed from light driving, so thats not an issue.

Well, the 4032 alloy of the Mahle pistons might be a better choice for you since it has lower thermal expansion than the 2618 alloy of the Wiseco HD and therfore can be run at slightly tighter PTW.

I'll defer the rest of my answer to Tim. What he wrote in post 25 of this other thread is excellent info, but the whole thread is worth a read over.

 

[Strm Trpr]

Mahles come in two flavors, Power Pak - 4032 allloy and Power Pak Plus - 2618 alloy.

Running loose PTW's is not necessary on 2618 alloys.
Here's an example with JE's 2618 alloy pistons for sport compact applications.

http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf

Notice that for a piston range of 2.5000" - 3.625" in diameter they recommend a PTW of .003" - .0036".

It does say that turbo charged applications may require .001"-.003" more clearance.

For a 600whp build I'd imagine PTW of .004 - .0042" would suffice.
Remember you're shooting meth too!

 

[daren_p]

Thanks for the input so far guys. Yes I am aware of the different materials in these two pistons & that the Mahls require tighter PTW clearance. Being in Canada, shipping can be a pain & I'd like this to go as smoothly/quickly as possible, so will be ordering everything from one place. I'm waiting till after the engine builder has looked over my parts to confirm everything checks good & make sure .020 pistions will work, etc. So I don't want my stock parts sitting at the builders for weeks waiting on my parts to come in.

Chris, thanks for that link on rods, thats a damn good price, maybe my source will price match.

I think I'm leaning towards the Wiseco's, I don't want to be worried about having issues with the Mahls. My car is normally tuned well, but I do run meth injection & the only fail safe is I have my CEL to come on a 1deg (as I don't normally see more then this), so that should give me plenty of time to get out of it, but things happen & I don't want something stupied like a failed meth pump, etc hurting my pistons. I haven't heard anyone complain of piston slap with the Wiseco's so I should be fine there. So probably Scat & Wisco 8.5:1's, stock HG & having the block & head decked, should net me around 8.7 - 8.8:1. Should be able to remove more material to achieve 9:1 but I'd rather not take off more material then I have to, just in case for any reason the block or head needs to be decked again, a time or two in the future.

So now I'm wondering what specs to Run on the Wiseco's? I've done some searching & like most things seems everyone has a different opinion. Believe Wiseco specs PTW pretty tight, something like .0030, I've seen guys recommend .0035-.0050 & 1st ring .016-.019, 2nd ring .020-.024.