Sidepipe Bolts
 

I'm running a Roush 427SR in SPF 2743 and the bolts between the header and sidepipes are loosening. Some of the nuts have even dropped off. I don't think LocTite will hold up under the heat and am looking for a way to prevent this from happening. Any suggestions?

Grade 8 flanged bolt and cupped flanged locknut or stover nut; all can be had from McMaster Carr.

Mine loosen as well.

I've used both grade 8 and stainless. They both have come loose over time. I would suggest a maintenance schedule.

ARP makes a nut that is slightly oval called a Jet Nut. You can probably buy them from Summit. I bought all mine from ARP direct and have never had one come loose.
Bill Stradtner

Did Roush and/or the SPF dealer have any suggestions ?

buy a set of remflex gaskets, it will take care of it.

Remflex exhaust gaskets (header - manifold - gasket) - OnLine Catalog

Now Howie, if that was my Spf I would weld them to the heads...........:LOL:
I used grade 8 stainless bolts and nuts on Spf 2742. I had my son come over once a month and tighten everything for me. Of course he would have to take the car away for a day or two just to make sure he got it right.
How's the weather in Washington these days?

The first problem I had was chunks of weld around the inside area of the headers and side pipes so they would leak and blow out gaskets. When I put a straight edge on either there were high spots. I fixed that and got new gaskets.

I used regular grade 8 bolts and these if I remember right.

http://www.integy.com/C22975.jpg

but might have been these.

http://shop1.mailordercentral.com/ma...LOCKNUTMOM.JPG

With the flat matching surfaces they never came loose. The bolts are used once and typically break when you take them off.

Never reuse the bolts even if they come off.

I have had nothing but problems with the Remflex gaskets at the header to side pipe flanges. They say to torque them to 10 to 12 FT/LB. I have tried split washers, star washers and crowned nuts. Some of them loosened and fell off within 20 miles.

I still use the Remflex gaskets at the header to head interface and love them there. Just won't use them at the header to side pipe any longer.

Guess I should add that I used three sets of the flange gaskets and always had the same problems.

Years ago I had problems with the header gasket till I changed to Percy's Laminated Aluminum gaskets. Because they worked so well I made my flanged gasket from laminated aluminum sheet stock.

I was blowing out flange gasket within 50 miles. Tried red high temp gasket sealer and a gasket. Lastest 20 miles. So I made a sidepipe to header gasket out of laminated aluminum that I bought from McMaster Carr. Solved my leaking problems.

I used stainless bolts with lock washers.
Dwight

interesting, i had a problem with the bolts falling out before, 2 years now not a loose bolt to be found. I just use the regular bolts and locking nuts and lock washers. I know some people who claim grade 8 bolts make the problem worse but I cant comment.

Grade 8 bolts and plain, metal lock nuts readily available form the local Ace Hardware. A bear to install and torque down but they have yet to come loose.

Castlenated nut and split pin, or lockwire---Mic

Try good old brass nuts

After some research I found "Vibration Proof Washers" and just had them installed on my Superformance sidepipes. They are manufactued in Sweden by Auveco products. The 7/16" size are Auveco #19284. Here thay are referred to as Nord Lock washers. Check Maximum security for bolted joints -Home - Nord-Lock. Here's a video demonstration Nord-Lock Demonstration Video - YouTube. Hopefully this solve the problem.

Interesting demo! Are there direct competing products?

I beat on my car pretty hard, and this works pretty well for me:

No gaskets anywhere in the exhaust system. High temp silicone only.

SS Grade 8 (brand, not rating) header bolts. I gave up using the locking tabs a long time ago - too much of a pain to R&R. On some spots I use the cheaper black metal bolts that FFR supplied. I hand tighten to about *that* much. All bolts have a split lock washer on them. I check them every so often, but they never come loose.

Standard bolts and nuts on the side pipe flanges, standard flat washers. They happen to be a grade 8 (rating, not brand) fine thread. But that's only because I happen to have a box of them lying around I didn't know what to do with. I tighten them down good and they never come loose. They do look a bit rusty and discolored from the heat. Maybe the rust is a natural thread locker?

As the engine and exhaust warm up and cool down, they expand and contract at differant rates. Sometimes the joint is tight, and sometimes it is not; especially with metal gaskets like copper or alum. When the joint is not tight is when the nut will vibrate loose. This is the perfect spot for a split lock washer; they only work when the fastner comes loose a little bit, and allows the ends to spread out.

Put an internal star washer under the bolt head, a split lock washer under the nut, and no flat washers. TTYF. You might even try a locking nut with a internal star washer between them.

If they still come loose, the problem is not the fastner. The problem is the joint is not flat, and is allowed to rock.