Hemi intake bolts keep coming loose

I worried about that with my crossram, but my machinist told me to silicone the upper part of the bolts before putting them in ( not the threads) per info from Barton. I use the right stuff which is a silicone adhesive. I pull the tops off every spring and check them and if the fuel has compromised the silicone I redo the 1s that need it.

Mr P, I used that to try and keep the oil from getting pushed up the threads

3D,did you also use a thread locker??

No thread locker. Torque the bolts several times before the silicone sets up to get things close. The adhesive property of it will keep the bolts from backing out until fuel compromises the silicone, yet because the silicone gives some you can continue to retorque the bolts several times. I usually redo the torque setting 5 or 6 times letting it set a hour in between, I was told because of it being so low ( inch pounds), as the intake settles it sinks into the heads and needs to be retorqued. The shop glues the gasket to the heads with pilabon construction glue then lightly coats the exposed side with vasoline to help the intake settle in. Also superformance makes really nice intake gasket in .030, .047 and .060. Call Greg and he will take care of you, a super nice guy. I used his intakes a month ago after a couple of carb backfires compromised the cometic skeleton style I had used a couple of years ago. This is what has worked for me and I put about 1500 miles on the car last summer and 500 so far this year. Had it at carlisle last yr and I saw your car at the moparts tent but no one was around. Also know a guy that was loctiteing his torq converter bolts and they kept backing out so he did the silicone trick and that took care of it. He did use locker also on those bolts through. Good luck with it

Thanks 3D, sorry I missed ya at the tent
Harbor Freight has a 2500lb electric winch with remote for $50.00,Then I won't need 4 guys to get the blower off
It has to come off to get to the intake bolts

It does that if you tighten it after the rtv sets up....Use less of it, or go to a thinner glue. I use a dab of emblem adhesive in each corner. RTV will remain spongey after it cures and you will never get the intake tight.

i always wrap the bolt and especially the washer with silicone (per barton) i go around the intake until there is no more movement from the bolt. never had any issues and 8 yrs later i still check from time to time and never back off or anything.

I will also ad I have iron heads with an aluminum intake

mine are alum hds and alum intake. fuel breaking down the silicone is the only real issue i've seen (and cleaning the holes out when you have to put new gaskets on for some reason) and with the crossram fuel laying in the plenum is a problem but i'm sure your aware of that. also by smearing the silicon on the bolt body it is probably an inch long area in the bolt hole so it takes some time to completely compromise the silicone

How about blue threadlocker on the threads & silicone above?

Could be ok, I don't know. My concern would be the blue taking a set too quickly, I mentioned that I retorque numerous times, even waiting overnight sometimes. Also, mine is the only hemi I have built where as this shop has done many + Barton is who he got the info from, so I went with their advise. But as said, might work fine!

That certainly is a lot of oil up in there hemi-itis

My recommendation for sealing the bolt threads would be Hylomar Universal Blue. Use sparingly, no need to coat the snot out of them and cause other issues like not getting a proper torque reading.
http://www.hylomarsealant.com/

Now when it comes to maintaining the bolt torque, gasket materials have a direct effect on clamp load longevity.
Soft highly conformable materials tend to loose bolt torque at a faster rate than a dense material. This is mainly due to resisting crush, thereby loading the fastener and maintaining the tension between the two components.
Just imagine if you were to put rubber washers behind your lug nuts what might happen

The other issue is the make up of the gasket material itself. There are a number of different fibers and chemical binders that are mixed together as a formula to create materials with different properties and specifications. All have their place but apparently the ones you have used should not be placed on your motor.

Gasket design can be another factor in aiding long term performance.
Using the Hemi as an example. Gaskets that come in the "Blue package" are profiled to match the cylinder head along the bottom profile. Many times this is done to keep or minimize the gasket materials exposure to engine oil and attempt to reduce wicking effects of the gasket material which in turn causes bolt torque loss.

Superformance takes a all hands on deck approach to the Hemi intake gasket with a Premium material that was developed to reduce fluid wicking over a long period of time and maintain bolt torque. Adding to that the gasket design has a full skirt across the bottom to help maintain structural integrity in the vulnerable area at the base of the port.

The 426 Hemi is a challenging motor on many levels so please don't overlook the importance of having the proper, matching angles top to bottom, front to back or you'll get some good use out of that new hoist

Greg; It was nice to talk with you last week. Your gaskets came last Thursday and after torqueing the intake about 5 times it has taken a set. (The other gaskets took 10-12 retorquings).
Thank You! Dave

Greg,
Thanks for stepping in how do I determine what thickness gasket I need? How do you seal the front & rear of the intake manifold??

I know this / i just want to know if anyone else knows

I picked up the 2500 lb winch at Harbor.After I get the winch mounted I will pull of the intake,and clean and measure everything. Then I choose one I want and figure which one I need.

Might want to consider "locking thread" fastners, they have a hard nylon insert that locks the bolt, and keeps it from loosening under vibration/load etc...McMaster Carr.com has many types to offer