Rebuilding a 6.2 Engine

[letsgetthisdone]

Just order standard size rings, you probably won't even have to file them. Ring gap isn't all that super critical, its more important that their is enough gap. To get ring gaps to casue oil consumption or effect power, it has to get HUGE. Like >.040"...

 

[letsgetthisdone]

And good job on the deck, it looks good!

 

[B E N]

The stock size rings from someone like Mahle are going to be file fit anyway. A simple hone job is only a few thousandths bore diameter. And I agree with @letsgetthisdone you need serious gap to cause problems. I would be looking at a minimum of a .021" top and .024" bottom. You could even go to .025/.029 if you think you are going to boost it beyond 1 bar. And if you expect to be running flat out for long periods you could open both numbers up another .005-.010" without seeing any serious blowby or compression leakage. I would rather have a little blow by and not worry about running flat out on the desert than being puckered every time the tach sat at a sustained >5000rpm.

Excess ring gap doesn't cause engine failures, to tight of gap and you are doing it all again (see my profile pic)

 

[PD1744]

The stock size rings from someone like Mahle are going to be file fit anyway. A simple hone job is only a few thousandths bore diameter. And I agree with @letsgetthisdone you need serious gap to cause problems. I would be looking at a minimum of a .021" top and .024" bottom. You could even go to .025/.029 if you think you are going to boost it beyond 1 bar. And if you expect to be running flat out for long periods you could open both numbers up another .005-.010" without seeing any serious blowby or compression leakage. I would rather have a little blow by and not worry about running flat out on the desert than being puckered every time the tach sat at a sustained >5000rpm.

Excess ring gap doesn't cause engine failures, to tight of gap and you are doing it all again (see my profile pic)

Awesome brother. Thanks for all the info! No plans to boost or run flat out. Just want something reliable for now. But also don't want to rule out anything for the future haha. We'll see what we're working with when the new set of rings gets here. Yes, I'm just replacing them with a stock size set of Mahle's and yeah I expecting some fitting to be involved, but the oversized set was ridiculous.

 

[letsgetthisdone]

The stock size rings from someone like Mahle are going to be file fit anyway. A simple hone job is only a few thousandths bore diameter. And I agree with @letsgetthisdone you need serious gap to cause problems. I would be looking at a minimum of a .021" top and .024" bottom. You could even go to .025/.029 if you think you are going to boost it beyond 1 bar. And if you expect to be running flat out for long periods you could open both numbers up another .005-.010" without seeing any serious blowby or compression leakage. I would rather have a little blow by and not worry about running flat out on the desert than being puckered every time the tach sat at a sustained >5000rpm.

Excess ring gap doesn't cause engine failures, to tight of gap and you are doing it all again (see my profile pic)

The adage goes same for bearing clearance. "If they're a bit loose, you're the only one that will ever know. If they're too tight, everyone will know."

And yes, rings for the next bore size take a lot of filing to fit in the standard bore. I have to do it when we do 85.75mm or 86.75mm in the mitsubishi blocks. Our supplier only Does ring sizing in .5mm increments, so we get 86mm and 87mm ring packs and get to make them fit.

 

[B E N]

If bearings are a bit loose just run some rotella 20w50 and not even you will know >

 

[PD1744]

Played with this a little bit yesterday. I actually went out there with the intention of installing the motor mounts ahead of the engine since I don't have a timeline on actually both finishing this engine and actually putting it in the truck, but would like to see what it feels like with fresh motor mounts. Unfortunately when I got out there and actually unboxed the package, I realized they sent me two right side mounts in the kit.



Ignore the trans mount. That is not for a Raptor. I've already replaced mine. Being that I ordered these way back in March, we'll see if they will help me out or if I just need to order a new driver side mount.

So it was on to the engine. Rings have actually been in for a month now, but I've been both busy and purposely steering clear of this engine. In poking around the forum, I stumbled across @bubblehead93 's engine build. Great information from a member who clearly knows way more about what he's doing than me. Not gonna begin to even compare what we are doing as it isn't even close to being the same thing, but reading his thread definitely inspired me to do better. I started by buying a little food scale just so I could weigh my piston assemblies. And while bubblehead is balancing everything down to a fraction of a gram, mine was really just to satisfy my curiosity.



I had no intention of messing with the re-used parts (1-7), just really wanted to see how the new set matched up. So 1-7 where ±4 grams of each other, but #8 was +13 grams more than their average. I couldn't decide where I'd even begin removing that much material. That coupled with the fact that I've been bothered by this grade 1 piston sitting with a batch of grade 2's prompted me to hold off and order a new grade 2 piston. I'll re-weigh and deal with that when the time comes. So yeah, his thread is making me do better, so thank you sir!

After pulling the pistons back out to resurface the block and knowing was going to be back in anyway to do rings, I went ahead and ordered a ring groove scraper.



Boy am I glad I did. This thing is MONEY. Especially on bank 1 where I did a half-*** cleaning job. Bank 2 I really took my time. But this has to be one of the best purpose built tools I've ever used.

Next I checked end gaps on the new rings.



It was just like @letsgetthisdone said. Stock size rings were perfect. Thankfully no fitting involved as I was really not looking forward to using that chintzy grinder. So factory spec range is 0.0137-0.0196" for end gap. Mahle specs a min of Bore x 0.0045" top and Bore x 0.0050" intermediate for NA which shakes out to around 0.018" top and 0.020" intermediate minimum. I measured 0.021-0.022" on the tops and 0.024" or greater on the bottoms. Using @B E N 's guidance above, I was perfectly content rolling with these. Punched those seven home hopefully for the last time. Ordered a new piston and attempting to sort out the motor mount.

 

[CoronaRaptor]

A lot of valuable information in this thread. Keep the build going and keep sharing. Awesome.

 

[PD1744]

Worked on this a little bit Sunday.

Put the last piston (new grade 2) in and torqued the rod caps down using my new torque angle tool. This one worked much better than the last one:



Decided to order a new heater pipe when I went to install it as it had an o-ring and was crusty. This one:



Install new oil pump and pick-up:






Stopped there. I decided to order a new timing set instead of re-using the old one. Since I'm moving slow, I've just opted to order parts, wait, and install them as I go.

 

[Canuck714]

I feel bad that you had to tear it all down to surface the deck, that should have been done without question from the machine shop. Well at least you are learning a bunch and had the opportunity to add all new rings while apart.
Did the grade #2 piston weigh in a little closer to the other 7?