Exhaust Weights Stock vs Non-Stock + Thread Warning

Howdy all,

Today I did some more tinkering 'w my Bandit 1250, and I thought someone may find the info useful/interesting.
I pulled the stock headers off my bike, scaled them, and compared the weights against a Delkevic Carbon Slipon and Arrow headers (I got my stock muffler out of storage as well, for comparison)

I borrowed a friends Electronic scale that he uses when charging AC systems, its easy to use and quite accurate, it seems to give very consistent results as well.



Thats the Scale, ready for work.

To hold some of the exhaust parts, I had to use a box as a base/container, so that the entire exhaust was off the ground and no parts were touching the ground. The box had some bubble wrap in it, I left it in there.



Thats the box, it weighs 1lb 2.4oz



The scale has a Zero/Tare function, it makes measurements easier. Every time the contents of the box were emptied, the scale returned to a Zero reading.


Header Comparison:

Stock Headers



19lbs 2.8oz Heavy!

Arrow Headers



Arrow headers: 7lbs 12.4oz
I put the Arrow headers into the Tare box, the smaller hardware I put into a Ziplock back for easy handling.


I forgot that I left a bung O2 sensor adaptor in the bag and an ARROW sticker in the bag.


Ziplock baggy + Bung O2 adapter + Sticker = 0.9oz
So the Arrow header alone is 7lbs 11.5oz (thats 'w the normal o2 bung plug installed)


Slipon Comparison

Stock Muffler



Stock muffler: 14lbs 4.6oz Again, Heavy!

Delkevic SS/CF slipon



Delkevic: 5lbs 11.1oz


Weight Summary:

Stock
Header 19lbs 2.8oz
Slipon 14lbs 4.6oz
Total: 33lbs 7.4oz

Aftermarket
Header 7lbs 11.5oz
Slipon 5lbs 11.1oz
Total: 13lbs 6.6oz

Difference: 20lbs 0.8oz!



Now, for something less fun... & the warning....

Taking out the header bolts, I noticed there was some strong resistance at first, but then the bolts came out easy. I was worried....



It seems that on several bolts (most of them actually) some of the threads had been ripped out!!! darn it!

On the right is a good clean bolt that came out, on the left is another stock bolt with some aluminum stuck to it.....

Luckily it was only 1.5-2 threads max, out of the 9 that were into the head.
I also noticed that the bolts were nowhere close to being bottomed out, so there is more good thread in there that can be utilized with longer header bolts. I will get some new bolts tomorrow (hopefully) and install the arrow headers. Another arrow design bonus is that the section that attaches to the head, is separate from the actual headers (held on by springs) so that once I get the exhaust port portion installed, I don't have to take it off again...

I'm not sure why some of these threads ripped out.
I did notice that a few of the stock header bolts are bent as well, I think they may have been over-torqued at the factory... maybe I have a friday model...

And last, but not least...
The O2 sensor in the stock header broke off when trying to take it off... luckily the stock sensor is useless and long since disabled, plus with the arrow header going on, I don't need it. If I ever put the stock headers back on, I won't need the stock O2 sensor anyway.

I left the remains of the O2 sensor in the headers during scaling. The Arrow headers had their normal O2 sensor hole plug installed.

I think maybe I'll use some anti-seize compound on the header bolts when re-installing the exhaust port portion of the headers...

Darn aluminium + steel bonding...

EF

Thanks for the info. That is some interesting weight savings there! Looks good, too. Post up some installed pics.

difficult as it maybe i always remove those said bolts when the motor is stinking hot, never had threads pull out this way, this is the way i do it please, i accept no resposabillity for any burns or damage to yourself if using this method .

Stainless steel will do this with zero lubrication. I've had ss bolts and nets seize together like that just playing with them while walking to where I wanted to use them on drilling rigs. Learned to spray the whole stock with WD40 or something just to coat the ss to prevent this.
Great on the exhaust system weight savings. I had to put my Yosh Tri can back on my bike a few months back due to dropping a piece of iron on my stock exhaust and putting a pretty good dent on it. :#( Now, if I could get 20 or more pounds off my 240 pound body. But, working on it.

Easy,
Thanks for the informative and well-written post. Be sure to post a follow-up as to how you like the new headers.

Oh, thanks for the pics; now we believe!

20Lbs its a big difference.....Can you feel it while riding ?

I would suggest adding copper slip (high temperature copper based grease) on the header bolts when reassembling. The copper slip is intended for very high temps like you see in the header area and will prevent the bolts from hauling the aluminum threads.. Will make it much easier next time you want to remove them.. Also use a torque wrench on the bolts when putting them back in, it's quite easy to over tighten the bolts and damage the threads.

Gary

Thrasherg said:

I would suggest adding copper slip (high temperature copper based grease) on the header bolts when reassembling. The copper slip is intended for very high temps like you see in the header area and will prevent the bolts from hauling the aluminum threads.. Will make it much easier next time you want to remove them.. Also use a torque wrench on the bolts when putting them back in, it's quite easy to over tighten the bolts and damage the threads.

Gary

Click to expand...

Thanks for that info on the high temp copper based grease Gary. I learn something new every time I get on this site.

I did some hunting for new SS bolts today, no luck
I did get some std steel ones, just to test out fit and see how things go back together, make sure the head threads are ok, and they are.

I did get the old exhaust gaskets out, and to my surprise, they are very different from what I was expecting. They are a copper c-channel type with steel wool woven on the outside, the ones I have to replace them is the std copper style.



I tried a test fitting using the new copper only gaskets, and it seems the flange that holds the exhaust port on is very, very close to the head. So close in fact that I think if I were to tighten down the flange, it may contact the head, and I 'm not sure if I will get a good seal going.

I will order up some stock Suzuki gaskets specific for the bike. The ones I got are aftermarket universals that are the right diameter, but not thickness...
Now I see why there was a big price difference between the suzuki and aftermarket part.

I plugged up all the holes in the bike with rags, and put it away for now (ran out of time and need parts)

Achesley & Thrasherg,
Excellent idea on the lubricant / copper stuff.
Thrasherg, did you mean Copper Anti Seize? its like a grease... its good up to 1800F I hope thats what you meant, because thats what I got..

Whitesands,
Yep, definitely a big weight difference on the bike, but I'm not even close to being able to ride the bike... darn cold here, and bike is in pieces

leedude03,
Yeah, I probably should have tried using a torch or something to heat up the bike, but I think this problem may have stemmed from aluminium-steel reaction, and I have a very strong suspicion that these bolts have been over torqued either at the factory or at some shop. Some of the bolts are actually bent, and the threads look like they change size along the bolt (ie stretching)

GregH & HPTuner,
Thx for the kind words
Once she's all back together, and the weather starts getting nicer, I will definitely post up my impression of the headers, 'w lots o photos.

For now it seems like a long ways off... weather, and soo much work to do on the bike...

EF

I have not looked at this to check for clearance but a stud would stop any future thread problems, may not be enough room for a nut?

That weight savings is quite significant. The OEM parts are heavy.

Anti-seize is an interesting topic. I work in the aircraft engine buisness and we seem to like Nickel based anti-seize for high temps and Moly based for low-intermediate temps. The aluminum head is low temp, so a good Moly based chain lube should work well.

Some of the anti-seize compounds have copper and graphite in them, which while sounding good, can corrode aluminum under the right circumstances - probably not in our general use though.

The scarry thing about seeing the thread on that bolt in the picture above is that the area around the bolt could be overheating and softening up. That can happen around exhaust ports, even with water cooling.

Lets hope it was just because all the bolts are assembled dry (stupid but cheap for them) and it was caused by simple corrosion.

What did you do to repair the damaged thread?

Gabriel51,
I have thought about installing studs instead of the bolts that came originally on the bike. This is the 1st bike I've worked on that did not have studs from the factory, and I'm not sure why Suzuki chose to go this route. I think for now I will try using bolts again (I have 2 complete sets of bolts now, with a 3rd set on its way) the 1st set is m8 1.25 25mm (stock length) 2nd set is m8 1.25 30mm (slightly longer to reach deeper into the head) and 3rd set on its way is the original oem suzuki part. I'm also still waiting on the OEM exhaust gaskets.

There should be enough room to use studs however.

The torque on the header bolts is only 16ft-lbs, whoever wrenched on this bike and over-torqued the header bolts so that they would bend, stretch, and rip threads out, should have a "stern talking to" and that's putting it mildly....

Luckily, the Arrow headers come in pieces, and the exhaust port & flange is installed before the rest of the exhaust, so it should be quite easy to install them, torque them down and hopefully never have to take them off again. Even if I have to take off the entire exhaust, I can do so with out taking off the header bolts/flange/port.

RichBinAZ,
Under what circumstances could the copper anti-seize be a problem with aluminum? I have some copper anti-seize that I want to use on the header bolts....
As far as I can tell, the bolts were installed dry from the factory (no evidence of any anti-seize or other compound on the threads) and these were definitely over torqued..

MetricMetal,
I'm not sure what I could do to the threads.
I have thought about drilling them out, and tapping one size larger, or using heli-coils... however, for now, just the very outer 2 threads are ripped out, the rest of the threads seem to be ok, the bolts thread in all the way with little effort (some are a tad more resistant than others)

I guess I could chase the threads.

The Arrow header flange to head distance is shorter than the oem, so even the stock bolts thread in deeper than before, making up for the 2 outer thread loss.... I also got longer bolts, and as long as they don't bottom out, I'll try to use those.

Plus there is the fact that the torque is only 16ft-lbs... should be easy to hold (hopefully)

EF

I would use studs, then you could use the entire depth of the hole and eliminate any thrust pressure on the threads.
With studs the length is not critical...
Just my opinion...

When I changed out the complete exhaust on my ZRX, I measured the weights.

Stock....36 lbs.
Akropovic carbon.....6 lbs.

Lets not forget that the stock header has the cat still in it so that accounts for a good bit of weight!

Tazman2 said:

Lets not forget that the stock header has the cat still in it so that accounts for a good bit of weight!

Click to expand...

And the OEM header tubes are double walled. I am guessing that this was done to help retain the heat in the exhaust gasses until they reach the cat.