Lower Intake Thread Repair Solutions.

[Paveltolz]

Decided to start a separate thread since this 'what did you do to your 6.5' episode is getting drawn out.
So, What did I do to my truck's upper intake? Almost FUBAR;d it but, "Hodge Podge for two hundred Alex" and discovered several solutions in order to un boo boo this thing.

Issue: While completing another project that required the upper intake's removal, I discovered that two of the studs (with my set up, I chucked bolts a long time ago) weren't going to torque to 17lbs and were, in fact, going to just pull out. I tried longer studs but, only one got better and I didn't trust it.

I chose to use the Heli Coil thread repair kit as I’ve had this issue occur in the past and this technique worked fine. However, I inadvertently grabbed the M10 x 1.5 kit from my stash. Drilled out the bad threads; tapped the holes with the provide tool; inserted the coils; did a test fit with the M8 x 1.25 studs aaaannnndddd…yeah, not happy with myself. I double checked the tool drawer and I didn't even have an M8 kit anymore.

I have done this repair before to a couple of other lower intakes and discovered that two other holes in this one were already done. Guess I used it up and wither tossed or loaned out the kit to someone else. Probably 635 who's no longer on here so I'll blame Ted. Hindsight right?

Now what? After talking with my machinist friend, whoI recommended using Time-Serts, EZ Lock or something similar like a thread repair / resize insert.

I did some research and the Time-Sert pages didn’t give me the outside diameter size and pitch and I wanted something I could just screw into the two now M10x1.5 helicoils that weren’t going to back out without themselves being drilled out.

Google Searched and sourced Patikil and Luoring thread repair / resizing inserts from Amazon as they had them in the needed M10 x 1.5 Male. and the OEM M8 x 1.25 Female and they were stainless steel.


Still waiting on the Patkil units which are 20mm long vs the 12mm long Luoring's which would fit the middle hole. I decided to just do all of the holes since I'm constantly changing things up with intakes, Turbo's, Injectors etc. Discovered that one middle hole and another corner were already Heli Coiled (guess I did use up the old kit as I found another repaired hole on my other unit.

The Luoring's threaded nicely into the newly resized M10 holes using 3/8" wide flat bladed screw driver. (Note, different intake used for demonstration)

I drilled and tapped the remaining two holes with some challenges.
1. The drill bit into the aluminum and snapped in half on the second hole!!
2. The tap just wasn't cutting it. Literally.
I drilled out the old bit's remains using titanium drill bits starting with a smaller one and then a 7.9mm larger one that did the trick. I fought the tap into that hole to see how far I could get and realized some of the bit was still in the sides so I had to opt for a 12mm insert for that one. There were some more issues resulting in a destroyed insert and re-attempt at tapping the hole a bit deeper.
Yeah, I tossed the tap and picked up a new drill and tap set from Irwin at ACE Hardware. I'll use that tap to cut the other hole when the longer units arrive tomorrow.
But, it is in and looks fine. I'm sure using a 12mm long unit on the other corner would be fine but, they'll be here tomorrow and I can finish it up.

 

[Paveltolz]

I do have a back up intake that, internally, is nicer given it is the extrude honed unit I got from 635 many years ago. Unfortunately, it has a broken ear at the #7 runner. I noticed that one of the middle holes is also Heli Coiled. The mystery of my AWOL M8 Helicoil is gradually getting solved.

I searched on Carparts.com for recycled lowers and the listings either didn't have a picture of the item or a price. "Call for price quote." Many were only for the upper intake. My initial search was Saturday and all the yards I called were closed for the weekend. The ones that did have pictures were for units I'd need a Tetanus shot to handle and that's after the $250 purchase plus who knows what for shipping. Not many listed in the USA but plenty from Canada. No guessing on S&H from our friends up north (plus tariffs I'm sure).

E-Bay was just as just as interesting. $150 was, as I recall, the lowest price and it was actually just for an Upper Intake. For actual 'lower intakes' the prices started around $250 and went all the way up to $400. It seemed that the lower the price, the higher the shipping. Regardless, one was going to pay at around $350 because shipping prices were anywhere from $50 to $150.

I did find this one for $330 and free shipping. It would certainly make a nice replacement if it actually looked like this.


I double checked and it doesn't matter what it looks like, someone dropped the dime. If a crappy looking one goes for $350 with S&H, this is a no brainer for $350 after taxes (if you're not in a state tax free state like MT).

 

[dbrannon79]

Just curious, would it be better to use studs there after all the re-threading is complete?

If you aren't in a rush I may have an intake available once I can get the 6.5 out of my 93. it's intake had the provisions for the FFM ground off iirc. I was planning on using the intake off the cracked 6.2 I have when I get it all together. I have the FFM mounted on the drivers fender for that truck and my 95 doesn't use the FFM, it has a aftermarket filter on the firewall.

your welcome to it once get around to pulling it. that or if the engine dies before then!

P.S. I will also have a non-turbo intake and air cleaner laying around too. that was on the recent 6.2 I just acquired. I don't think I will have any use for that or the exhaust manifolds on it.

 

[Will L.]

Ya might look at hmmwv non turbo manifolds. They are non egr, do not have the mounting tabs for the ffm in the back.
Other than that- same lower intake. There is no upper intake hmmwvs. It’s plastic air horn.

 

[Paveltolz]

Just curious, would it be better to use studs there after all the re-threading is complete?

If you aren't in a rush I may have an intake available once I can get the 6.5 out of my 93. it's intake had the provisions for the FFM ground off iirc. I was planning on using the intake off the cracked 6.2 I have when I get it all together. I have the FFM mounted on the drivers fender for that truck and my 95 doesn't use the FFM, it has a aftermarket filter on the firewall.

your welcome to it once get around to pulling it. that or if the engine dies before then!

Thank you and I greatly appreciate the offer. It would be a good fit for me as I don't use an FFM anymore either.
However, hang on to it and perhaps sell it on E-Bay for a quick $200+ as this one will be fine now and I've got a solution to the other one.

 

[dbrannon79]

the lower non-turbo one I have has the EGR.

 

[Paveltolz]

Ya might look at hmmwv non turbo manifolds. They are non egr, do not have the mounting tabs for the ffm in the back.
Other than that- same lower intake. There is no upper intake hmmwvs. It’s plastic air horn.

Thanks Will.
Some of the HMMWV intakes I've seen attached to the heads with bolts dropped in vertically. I know some are also like ours but, hate to take the chance on a listing without pictures and I have a solution to things.

 

[Paveltolz]

the lower non-turbo one I have has the EGR.

Another change I made was getting rid of the "S" intake system. I found this current one in 2009 while visiting the Salt Flats. There's a local shop that was swapping in a 454 for a customer so I bought the upper and lower for $150. Obviously, prices have gone up. My old S intake had a bunch of broken ears from the previous owner (my story and I'm sticking to it). "You got a lot of carbon scoring on this old [intake unit]. Want a new one?" Hell yeah.


I had the "F" intake powder coated after a lot of media blasting. This is the lower I'm un- er, screwing now.


Here's the extrude honed one before one of the #7 ears got busted.


Since Ted, and now I, use the Penninsular 'Hat' and Cummins Elbow for the upper intake, he tapped the lower for AIT sensor, Boost Pressure sensor (rubber hose) as well as the holes on the back side you can see (plus the "Elbow" for his water mist injection, propane and NOX. Poor thing looked like a Porcupine when he had everything plugged in. I opted out of WMI, Propane and the NOX.

It's hard to notice since everything is silver but, you can see the spacer I designed with taps to accept the boost pressure sensor and AIT sensor in front and in the back it is tapped for after market pressure gauge and, should I choose to add water mist later. I didn't care for the Porcupine look.

 

[Paveltolz]

Here's what I got now.
RED: M10 Heli Coils with the repair inserts.
BLUE: M8 Heli Coils only (As I thought I was doing but....)
GREEN: Thread Repair Inserts Only. The top one has yet to be tapped and the 20mm insert installed.


I meant to add in the previous post, the spacer is why I chose to go with studs. Too tall for the OEM Bolts and other options I tried just didn't look right to me. Hence, some of the frequent changes and subsequent weakening of the threads. Guess you could compare it to 'heat cycles.'

Chris Mursick, the owner/driver of the land speed streamliner I crew on, is my 'machinist friend.' He's designed and machined his own VW engine blocks so he's got some skills.
In talking with him this morning, he's offered to take the other intake with the broken ear and repair it. I've seen his work on other projects and be it my truck's busted shock mount, his racing chassis or a high pressure fuel pipe weld, the work is awesome. Even if he says, 'I'm obviously out of practice,' the finished product is great. So, I'm looking forward to that getting repaired and, in anticipation, decided to try another technique to ensure the bolt holes don't get stripped out with frequent change outs of stuff.

So, since Time-Sert kits start around $150 I opted for a similar product that has great reviews and, I think, that "Project Farm" guy on YouTube included in one of his tests years ago.


Unlike Helicoil, the kit comes with the correct drill bit (8.7mm) along with the tap (M10x1.25), counter sink cutting tool, sert install tool and 10 inserts. This kit, as the cover says, has the 11.7mm deep serts. I ordered 14mm units for the middle hole (one has a Helicoil from previous years), and 16mm units for the corners. I've removed 8 of the 11.7 mm and put in two of the 14mm with the extra holes for when the 16s arrive in a couple of days.


Though not shown, I bolted the OEM upper on in a couple of places so I could use it as a drill guide. Worked quite well as the drill bit is the same diameter as the open holes. It looks crooked because I was hands off to take the shot plus, as close as I was the 'wide angle lens makes things seem' different.



Tapping is easy when the tool is sharp and the aluminum doesn't have old drill shards imbedded in the walls.


All threads cut, cleaned of oil and shavings (lots of vacuum, compressed air and brake clean before acetone and another blow dry). Ready for counter-sink cutting.


After reaming out the counter sinks


Red Lock tight on the 14mm sert before installation.


Installation and...


...the finished job. At least one of the middle holes. Corners will get the 16mm deep serts.

 

[dbrannon79]

Looks like a masterpiece!