Broken headers and side pipes.

[Silverback51]

This is the second year in a row that I have had this problem.

Last year I replaced the side pipes as it was easier than trying to have the stock ones welded up. This year both the side pipes and the headers are cracked. The cracks are at the flanges where the headers and side pipes meet up.

Anyone else have this problem or know what is causing it?

Also, do I need to pull the engine to get the headers our, or can I just raise the engine to do it?

Any help will be greatly appreciated.

[Silverback51]

I forgot to mention, it's a 460 motor.

[Calbullet]

did or do you have poly engine mounts? maybe the motor is rocking to much and causing the cracks. Olthoff and Craig Aylsworth has some nice engine mounts

[Silverback51]

It has the Olthoff poly mounts, so that's not the issue.

I may machine up some solid ones to eliminate all movement.

[Calbullet]

I don't know for sure, but check your tranny mount. maybe under hard accel, the tranny is moving and straining the weld on the header flanges.

[Silverback51]

Originally Posted by Calbullet

I don't know for sure, but check your tranny mount. maybe under hard accel, the tranny is moving and straining the weld on the header flanges.

Thanks for mentioning that. It's still the stock rubber one and does move a fair amount.

[CHANMADD]

When you bolt up the side pipes they need to be free from any tension.. What you should really do is mount the mountings to the sidepipes first,,,and then install and once you have evrything nice with no tension ..then weld the brackets to the frame...remember these are custom cars... you can't expect to just bolt everything up and hope that it will work........a little thought is necessary...

[ekrupa2]

John - I will bet $1 that stock tranny mount is cracked. Mine cracked after 500 miles...the part was made in India and very very flimsy (I also have the Olthoff Motor mounts...great investment). Could be a possible cause. I switched to the Poly Trans Mount sold by Cobra Valley...worth every penny. My pipes dont move at all.

http://performanceunlimited.com/cobr...ransmount.html

I believe you will have to jack the motor up some to get one header out.

[Got the Bug]

Eric,

My trans mounts appear to be fine after 9k miles, but I'm going to go ahead and change them out to the Perf Unlimited mounts. Are they a direct replacement? Is it an easy job?

[ekrupa2]

Doug - your installer may have used a better mount than the one I was supplied in my install kit. The swap is simple...probably 15 - 20 minutes. I did have to shim mine a bit. to keep the driveline angles in check.

[scootter]

I am around 36,000 miles with a 514. I haven't had any cracking on the headers or side pipes. I did replace the motor mounts at 14k miles with stock ones and had to replace the end support mounts on the side pipes once. I just replaced the trans mount since it was starting to crack. No big deal. I have around 600hp with my motor set up
Scott

[Tim Brewer]

Easy fix by doing one or two things...
1) Strap your enging down to the frame.
2) Use rubber muffler hangers to attach the end of your pipes to your frame.

[madmaxx]

May be as simple as a fabrication error with the header and sidepipes, to much heat, not good weld penetration. Find a rig welder in your town, go to the bars on a rainey day and look for the welding truck, give him $50 to swing by your house and make the repairs.

This is the first I have ever heard of this.

[Tom Cimino]

Make sure your hangars on the rear of the side pipes aren't too stiff. I used the straps that were supplied with the side pipes. They're made of old tire sidewalls and only about 1" wide and 1/4" thick and 2 1/2" long. At the time I thought they were kinda flimsy and intended to change them with something more robust, but that was 14 years ago and they've worked very well. No problems.

[PANAVIA]

We havent seen any cracking of headers and / or sidepipes. -- wearing out mufflers yes, --but cracks at the flange NO.

Doug, post a pic of your mount, or we can put it in the air for you.

[Silverback51]

My daughter has my camera so I cannot take pictures at the moment. She is coming over for Christmas, so I will take and post pictures then.

[trularin]

I do not have the same car, but I have had this problem.

I put two piece of hard rubber at the end flange and sort of shock mounted the side pipe.

This allows the pipe to move a little more without shaking the seat and without stressing the flange to the headers.

The other thing I noticed was my first motor mounts were too soft and would allow the engine to rock a lot. I changed to a harder mount. BTW,this took a lot of time as I had to shop around to find harder mounts.

Just my three cents worth.

[Silverback51]

Okay, let me see if I can tell the whole story this time.

Last year I pulled off the stock SPF pipes as I was having a problem with popping when I let off the throttle. I figured it was bad gaskets. When I pulled of the side pipes I could see that the welds and pipes were cracked.

I had read enough stories about how restrictive the stock SPF side pipe were, so I ordered new ones from Stainless Specialities. I installed those pipes last winter at this time.

At that time I used the SPF style flange gaskets. After we returned from our vacation this year, the popping had come back. This time I ordered the Remflex gaskets and installed them. No change, it still popped. I should mention that I did not remove the side pipes. All I did was remove the old gaskets and install the new ones. While it did not sound like I had a leak at the header to head, I decided I would just replace everything this time.

When I pulled the side pipes, I looked at the welds and sure enough, they are cracked at the point where the flange meets the pipes. Okay, that upset me, but it's not the end of the world. Then I started looking at the headers. Same problem. In fact one of the pipes is cracked for a good inch inboard of the flange. I'm not even going to try to save them. I'm going to just order new ones. The side pipes I will try to have welded up as none of the cracks extend into the tubes themselves.

I have poly motor mounts so that's not the issue. However the transmission mount is still stock. I will probably replace it. I'm even thinking of machining up some solid motor mounts so the motor does not move at all.

The aft mounts on the side pipes to the body are in good shape and not cracked or broken. I'm also real careful to make sure they are aligned prior to final tightening of the bolts. So I don't think that is an issue.

Right now I believe I'm over tightening the bolts and causing the issue, however I'm still open to ideas.

By the way, it's a 460 motor, and the passenger side header will come out through the bottom. The drivers side will take a little more work. I'm guessing I will have to jack up the motor approximately 1.5 to 2.0 inches and it will also drop out the bottom.

My daughter has my camera at the moment so I will not be able to get any pictures until Christmas day when they come over.

Right now I'm looking at ordering the headers from Hillbank. Are there any other options? If so, please let me know.

[JST4FUN]

John, I am currently considering changing both my headers and sidepipes on my BB 406. I would like to go to a 2" header and 3" sidepipe. So far, Firefly Performance is my leading candidate as they seem to be good quality, have read some good reports, and understand they're made for the SPF. However, because of price I plan to see them and hear them first before I jump. My builder said I can do the driver's side with just removing the heat shields. I am still looking at options, but want to do something by Spring. So far my stock ones look fine, but they only have 2500 miles on them.

Good luck with your change out!

[madmaxx]

If you are in the market for stainless steel sidepipes for a spf do yourself a big favor and wait 2 or 3 months. All I can say at this point.