6.9 IDI oversized piston rings to file fit for a fresh rebuild.

[Captain Spaulding]

Hey guys, new to the forum, but have been lurking for a little while.

I’ve been purchasing parts for my 6.9 rebuild and pretty much have all the parts needed except pistons. The engine has the stock bore of 3.995, but has two cylinders that have some surface rust and fine pitting that I can’t remove with a hone. Its not terrible, yet enough for me to go up in size with fresh pistons.

My question is whether any of you guys have purchased oversize rings (bigger than the already oversized piston) and filed them to get the desired end gap? I found a set of Sealed Power pistons and a set of Hastings piston rings, both being .020 over stock. I’m thinking of looking for the next size up just so I can get the gap I want. Or would I be good to get equal sizes? I’m not familiar with Hastings and I don’t want to deal with buying and returning parts. What do you guys think?

 

[IDIBRONCO]

I don't think that it's a good idea to try to use rings that are oversized when compared to your pistons. I think that you may end up with some trouble if you try to compress the rings that far. Maybe I'm wrong on that.
If you want to try to get smaller end gaps on your rings, they do sell gapless or total seal rings. I believe that you do file them to fit. I don't know if they are sold for a 6.9 though. Honestly, I don't think that there's much to be gained, powerwise, from using them in a daily driver. If you're trying to squeeze out every last 1/4 HP that you possibly can, then there may be a benefit. That's just my opinion and certainly not a fact. Of course if you're trying to get every bit of power that you can out of your engine, you're probably not using it for a driver and you're probably not using a 6.9. If you want to cut down on blowby, then the total seal rings would be a good idea. Personally, it doesn't bother me so I haven't even looked very deep into those rings.

 

[03wr250f]

yes it has been done before.
buddy of mine over on fte did it. standard bore pistons .030 over rings file fit.

my suggestion buy rings for the pistons you buy.

 

[Captain Spaulding]

Cool, thanks guys. I’m going to jump on the piston and matching rings.

 

[Captain Spaulding]

Hey guys, I thought I would share what I purchased and where for pistons and rings. I had to do some serious digging to to find what I was looking for, but found it. Parts seem to be difficult to get for these engines. I plan to start a build thread soon to track all the progress and ask questions should anything come up.

UEM Dualoy Pistons .020 over standard (The picture is generic and doesn't look like what it actual is supposed to look like)

United Engine Machine 7096D.020: Silvolite Dualoy Piston 6.9L Ford/IHC/Navistar V8 1984-87/1983-86 - JEGS

Get the Best Performance with United Engine Machine Silvolite Dualoy Piston 6.9L Ford/IHC/Navistar V8 1984-87/1983-86 7096D.020 parts at JEGS. Shop Now at the Guaranteed Lowest Price!

www.jegs.com

Hastings Piston Rings .020 over standard

https://www.partsgeek.com/ybzx9vy-ford-f350-piston-ring.html

 

[IDIBRONCO]

At least you found some. That's the main thing. I'm kind of surprised that Jegs still had some. I believe that Silvolite stopped making IDI pistons some years back. I have Silvolites in my Blue Truck and have been happy with them for over 4 years and who knows how many miles since the speedometer doesn't work.

 

[Old Goat]

Is that $566.99 for one Piston?
Doesn`t say if the quantity of one is ea, or a box of 8.


Goat

 

[onetonjohn]

FWIW: $550 sounds steep. Race piston? Complete including connecting rod? Haven't bought pistons in a while, but I was thinking around 100 bucks.

 

[Captain Spaulding]

It does sound steep, but it seems like they are all expensive no matter which brand you go with. Summit has them for $92 each! you got to pay to play I guess.

@Old Goat, I'm pretty sure its for the set. I found the same thing on HDP's website for a little more and it called it out as a set. I'll send it back to Jeg's if its just one, but I doubt it. Here's the link to their site, it gives a lot more information.

DUALOY Piston Set, 7096D.020

www.heavydutypros.com

 

[Captain Spaulding]

At least you found some. That's the main thing. I'm kind of surprised that Jegs still had some. I believe that Silvolite stopped making IDI pistons some years back. I have Silvolites in my Blue Truck and have been happy with them for over 4 years and who knows how many miles since the speedometer doesn't work.

Glad to hear they are working for you. I almost bought a set of sealed power, but after talking to Joe at Classic Diesel, he recommended these. He said they were having issues with Sealed Power and Engine Tech.

 

[IDIBRONCO]

Really? I can't remember which ones they were, but we used some either Sealed Power or TRW pistons for a while for these engines at the shop I used to work at. Engine Tech? I don't know anything about them, but I don't think that I'd trust anything with that brand name too far. The only thing about Silvolites was that for a time, the pistons were fine, but the snap rings that held in the wrist pins were made out of material that was too soft. they wouldn't hold tension and would start moving in their grooves. Eventually they would fall out and let the wrist pin walk out and hit the cylinder wall. Then the bomb went off. From what I remember, that was limited to about a 12-18 month window of our engines. It was back in 94-95. There's a date code on the piston box. Mine were made in 2001. There was also a note inside the box to not compress the snap rings any farther than was needed to slide them into their groove. It also seemed to be more difficult to compress them than I remembered it being back in the 90's. Believe me that Silvolite learned a HUGE lesson. Even though the snaprings were sub contracted out to another manufacturer, Silvolite, in their defense, bought A LOT of boat anchors that used to be IDI engines. I have no idea how many it was, but it seemed to be at least three dozen.
Keep in mind that I bought them even after having experienced all of this. I don't know how many miles it would take to lose an engine, but we seemed to be pretty well over it by 1998. I don't remember having any issues after moving into the current building that the business is still in. That was in June, 1999. I felt confident that I wouldn't have any issues with pistons that were made in 2001. I'll bet that I have more than enough miles on my engine that it's well past the bomb stage if there had still been any issues.

 

[Captain Spaulding]

Really? I can't remember which ones they were, but we used some either Sealed Power or TRW pistons for a while for these engines at the shop I used to work at. Engine Tech? I don't know anything about them, but I don't think that I'd trust anything with that brand name too far. The only thing about Silvolites was that for a time, the pistons were fine, but the snap rings that held in the wrist pins were made out of material that was too soft. they wouldn't hold tension and would start moving in their grooves. Eventually they would fall out and let the wrist pin walk out and hit the cylinder wall. Then the bomb went off. From what I remember, that was limited to about a 12-18 month window of our engines. It was back in 94-95. There's a date code on the piston box. Mine were made in 2001. There was also a note inside the box to not compress the snap rings any farther than was needed to slide them into their groove. It also seemed to be more difficult to compress them than I remembered it being back in the 90's. Believe me that Silvolite learned a HUGE lesson. Even though the snaprings were sub contracted out to another manufacturer, Silvolite, in their defense, bought A LOT of boat anchors that used to be IDI engines. I have no idea how many it was, but it seemed to be at least three dozen.
Keep in mind that I bought them even after having experienced all of this. I don't know how many miles it would take to lose an engine, but we seemed to be pretty well over it by 1998. I don't remember having any issues after moving into the current building that the business is still in. That was in June, 1999. I felt confident that I wouldn't have any issues with pistons that were made in 2001. I'll bet that I have more than enough miles on my engine that it's well past the bomb stage if there had still been any issues.

Ya, I read that too. My plan was to use the stock Mahle circlip if it fit in the groove. Silvalite was in a bad spot whe all that happened.

I just got an update from Jegs and they said the manufacturer has discontinued the pistons. I found a set of Sealed Powered pistons so looks like I’m moving to plan B. I hope they can hold up to what I want to do with the engine.

 

[IDIBRONCO]

I just got an update from Jegs and they said the manufacturer has discontinued the pistons.

I was told that over the phone by a Silvolite rep before I bought my pistons. I wanted to make sure that the issue had been taken care of. Naturally, he had no idea what I was talking about. I got the impression that he was probably in grade school when that was going on. Stuff like that is why I'm not impressed by Jegs anymore. If the pistons were discontinued by early 18 or maybe even late 17, and they know that, then why are they still listed on Jegs website? I prefer Summit Racing these days.

 

[Captain Spaulding]

I was told that over the phone by a Silvolite rep before I bought my pistons. I wanted to make sure that the issue had been taken care of. Naturally, he had no idea what I was talking about. I got the impression that he was probably in grade school when that was going on. Stuff like that is why I'm not impressed by Jegs anymore. If the pistons were discontinued by early 18 or maybe even late 17, and they know that, then why are they still listed on Jegs website? I prefer Summit Racing these days.

Yep, my thoughts exactly. Just called Northern about pistons they have listed on their site and he says they actually aren't in stock. Not sure why they all list them them as current inventory, but don't actually stock them.

 

[Captain Spaulding]

I have decided to reuse my pistons and hope there won’t be much of an issue. Honestly though, they look fine other than a little cosmetic damage from the engine digesting a glow plug.

I had the chance to measure the new standard bore Hastings piston rings and the end gap was on the larger end of the ring gap for the top and oil ring. The middle ring was .019 typical. I plan to file fit the middle ring so its in spec and run it. I am comfortable running a bigger gap on the rings. I plan to start a new thread to show progress on the truck and engine build soon. I can’t wait until its up and running!