3.6 Pentastar Tear Down

[gbaumann]

I said I would do it and I'm going to. The Pentastar is on an engine stand. S/C coming off and then tearing down the motor and rotating assembly.

Let's see how it held up to the forces induction.

[2k13jk]

Def interested in this

[UselessPickles]

Do you plan to reassemble it afterward? If so, you may as well consider rebuilding it better with some forged pistons:

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[JeepLab]

what year is the pentastar? i need a 2012 belt tensioner for 1 day.

I want to "amsoil" my intake. Should be a good video.

[gbaumann]

It's a 2013 model year made late 2012.

[Gunner]

This is gonna be very cool to follow.

[gbaumann]

Do you plan to reassemble it afterward? If so, you may as well consider rebuilding it better with some forged pistons:

Let's see what it looks like when she comes apart. I'm very much interested in the possibility of putting it back together with forced induction specific components and perhaps some deck support. My gut tells me forged pistons, forged rods and add deck collars. My ideal solution would be twin turbos and custom calibration. I'm counting on you to do the math!

[UselessPickles]

The stock rods are already forged :)

By "do the math", I hope you aren't counting on me to help choose turbo sizes, pipe sizes, etc! I don't know anything about how to do that.

Maybe you could talk to Prodigy and get some info from them about what is recommended to support some serious boost. As is probably obvious from the forged pistons with their logo on them, they're already working on that idea. I don't know if they have anything planned aside from the pistons.

[gbaumann]

I'm really intrigued by this:

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[JeepLab]

I'm really intrigued by this:

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what is going on with these attachments? What file type?

[FLIPmeOVER]

Baumann, get on instagram or message your pics to JL so i an follow there. Instagram is sooo easy to cut to the chase, Pull a part off, post it.

[gbaumann]

Baumann, get on instagram or message your pics to JL so i an follow there. Instagram is sooo easy to cut to the chase, Pull a part off, post it.

I'm on Instagram. You can find me at "jkujunkie" I often post with #jeeplab.

[gbaumann]

what is going on with these attachments? What file type?

Not sure what happened here.

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[Gunner]

Thats cool. 2 questions. Is that welded? and how did you decide on cooling hole placement?

[gbaumann]

It's not my block. It a motor worked by a speed shop in the Midwest. I posted it as an example of what "deck support" is when setting up for forced induction. The water passages are figured out by the shop based on flow required in the heads.

[gbaumann]

Here is today's progress.

[gbaumann]

Wiring harness off.

[gbaumann]

Nothing am made should require this to operate!

[gbaumann]

Blower off.

[gbaumann]

Intake w/injectors. Slight coloration in the runners but really, really clean.

[gbaumann]

Only disappointment of the day. Oil behind the throttle body.

[gbaumann]

Intercooler. A little oil near the front but I would call this very clean.

[gbaumann]

You could eat out of the supercharger.

[gbaumann]

Ready to take the heads off.

[JeepLab]

Ready to take the heads off.

any signs of wear? the whole thing looks clean to me.

[gbaumann]

Heads off.

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[gbaumann]

Here's a closer look. Some carbon build up but nothing I would consider really bad. After all, the motor had just over 48,000 miles on it with 25,000 supercharged when it came out.

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[gbaumann]

This is my favorite pic. You can still see the factory hone hatch. There is no discernible ridge in the cylinder. No visible deformation. No sign of head leak. Did I mention you can see the factory hone hatch? 50k miles!

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[Yoinkers]

can someone dumb this down for the rookies? what were we expecting? and it looks better than expected right?

[gbaumann]

We weren't expecting anything. We're looking for signs of excessive wear or stress from forced induction. Superchargers and turbos increase cylinder pressures. Some say they exceed design specifications and can damage the engine. I don't see evidence of that so far.

[Yoinkers]

whats a hone hatch and why is it important?

[gbaumann]

whats a hone hatch and why is it important?

A cylinder hone is used to surface the cylinder wall by spinning grinding stones around the cylinder while moving them up and down. Each engine builder will have a hone specification. For example 280 grit hone moved up and down at a rate that produces hatching (scratches) at a 45 degree angle to each other. It's important to get it right for the piston rings to function properly and, among other things, to maintain compression. The surface of the cylinder wears over time and the hatch can disappear. It's good to be able to see it after 50K miles. It means there is no excessive wear in the cylinders. In fact, to me, it means little wear. It leads me to believe that they cylinder sleeves are quite good and can hold the hone for quite some time. It means the piston is well designed and the piston skirts are not coming in contact with the cylinder walls. It means the piston rings are well designed and seating beautifully in the cylinders without generating uneven wear around the cylinder. In short, it's a good thing.

[Pznivy]

Pickles, Baumann may have booted you off the pedestal around here...LOL

JL is a website by geniuses, for the rest of us. Thanks to all of you super scientific jeepers for sharing your info with the rest of us. Other sites are so much BLAH BLAH BLAH. There is not as much posted here as fast but what we do get is gold jerry, GOLD!

[2k13jk]

Looks like these 3.6s are going to be around for a while seeing that yours is held good. Are you doing anything with the factory head bolts? I was in contact with ARP head stud manufactuer he said if i can send them stock head bolts they might be able to make stronger ones to keep the cylinder heads tighter and run more boost

[gbaumann]

ARP certainly makes the bolts and studs of choice for heads. I wouldn't reuse head bolts. They have been loaded (stretched) and may not perform well if reused. As important as the head bolts are we need to consider the seal between the head and block. A good set of ARP head bolts coupled with block and head machining to accept O-ring custom gaskets that ensure a tighter condition would be my recipe for more boost.

[UselessPickles]

Multiple sources have said that the bottom end of the engine is quite strong, so I expect that you have already seen everything that had potential to show unwanted wear/damage.

I'm impressed that the crosshatch marks are still visible at the top of the cylinder. There's where the most wear happens in the cylinder.

This thread is boosting (pun intended) my confidence in the engine's ability to handle bolt-on forced induction :)

[Rexx19]

Multiple sources have said that the bottom end of the engine is quite strong, so I expect that you have already seen everything that had potential to show unwanted wear/damage.

I'm impressed that the crosshatch marks are still visible at the top of the cylinder. There's where the most wear happens in the cylinder.

This thread is boosting (pun intended) my confidence in the engine's ability to handle bolt-on forced induction :)

whats the next part to get stripped off the pentastar?

[gbaumann]

Bottom end comes off next. Want to see crankshaft, rods, pistons and bearings.

[Gunner]

A picture of how far the piston skirt comes out of the hole on bottom dead center would be interesting. If there is much it might explain why there is some blowby into the catch can. Maybe some piston rock at BDC is unseating the rings under boost. It could just be a light oil ring pack too. A fish scale pull with just the oil ring on the piston might give some useful info. When I was building motors I found that the lighter ring tensions would show power but at the expense of an increase of blow by. Some times we just added a vacuum pump and picked up power. And sometimes we just vented it out the crankcase into a catch tank. Either way is would be something to look at. This is interesting.

[Pznivy]

great thread. keep the pics coming.

[Bkeef]

ARP certainly makes the bolts and studs of choice for heads. I wouldn't reuse head bolts. They have been loaded (stretched) and may not perform well if reused. As important as the head bolts are we need to consider the seal between the head and block. A good set of ARP head bolts coupled with block and head machining to accept O-ring custom gaskets that ensure a tighter condition would be my recipe for more boost.

FYI I couldn't find the ARP on my piston swap. We went back with factory new. My build guy thought they wer actually good
BK

[Bkeef]

Not thread jacking and will be following along with the herd. Here is a quick pick from my recent 3.6 piston

These are the blueprinted Diamonds from Prodigy



swap1632

[Yoinkers]

Prodigy makes pistons? Does that mean that you need to upgrade them? Whats the benefit of changing pistons?

[FLIPmeOVER]

Whats the status on the tear down? this thing in pieces yet?

[UselessPickles]

Prodigy makes pistons? Does that mean that you need to upgrade them? Whats the benefit of changing pistons?

The forged pistons will be required to handle higher boost levels. I was told that the stock pistons could probably handle up to 10 psi, but they are playing it safe and won't be recommending running any higher than the current stage 2 boost (about 8.2 psi) on stock pistons.

[FLIPmeOVER]

whats a price tag on forged pistons?

[Pznivy]

whats a price tag on forged pistons?

i think the pistons themselves are not terrible, but the install is deep in the engine. make sure if you plan to do it, your shop has referrences of similar work getting done.