misfiring after wrapping exhaust

[st. augustine]

 

Yesterday I wrapped my exhaust pipes with heat tape (see attach). I rode for a couple of hours (up to the Jax Blues Festival), got a ticket for parking with all the other bikes in the wrong zone, then rode home. The bike ran good until I tried to restart it about 30 minutes later. The engine was missing terribly, wouldn't go over 4000 rpm with out dying and generally acted like "bad Gas". I had filled up at BP but so did my daughter and her bike shows no symptoms. Woke up this morning, the bike started fine, sounds good, but has me worried.

 

Do you know of any reason why wrapping the pipes could cause this defiant behavior?

[Baldini]

...Do you know of any reason why wrapping the pipes could cause this defiant behavior?...

 

...well how would you feel if someone wrapped you in black bandages & sent you out in public???? !!!!

 

KB

[antonio carroccio]

Yeahhh....we like bondage too.

[Guest SDKFZ111]

Whats the tape for ? looks like something off a central heating system!

[st. augustine]

I take it from the replies so far, that there is nothing to indicate that the wrap affects the performance of the machine negatively. You know, what if there was some wireless temperature probe in the exhausts that affected the computer which affected the fuel injection sequence or something!

 

In answer to the use of wrap try reading http://www.thermotec.com/technology/how/how.html

 

I consider the performance enhancement to be equivalent to putting on the new Ti pipes but haven't actually dyno'd it. To see dyno's from racing engines see http://www.thermotec.com/technology/dynamo...ynamometer.html I definately saw the difference on my custom softail, and confederate uses it on all their bikes.

[TX REDNECK (R.I.P.)]

Exhaust wrap is bad, if you want to improve performance go with a ceramic coating. Wrap holds more heat in the exhaust, increasing the decomposition and can cause cracks due to the extra heat (some companies do not warranty their exhausts if they are wrapped) It also holds crap (salt, water) next to the pipes which makes the pipes rust/decompose faster.

 

In short not a great idea

 

http://www.centuryperformance.com/heatwraps.asp

[badmotogoozer]

I don't think your wrapping the pipes is what did it. It sounds like you have the "vapor lock" problem. After a spirited ride, after parking for ~ 1/2 hr, the fuel pump vapor locks and you get exactly the result you describe. Possibly retaining more heat with the pipes wrapped...?? not sure ... Let it cool for an hour and all is back to normal.

 

I am told (as I started having the same problem last summer) that a couple of feet of Aeroquip Fire Sleeve aircraft hosing fed over the fuel lines solves this. I'll try it out once I get a chance to run out to the airport and get some from a supplier.

 

Common problem and I'm sure others have found solutions as well.

 

Then again, I'm not sure your Scura would be susceptable to this...

 

Rj

[TX REDNECK (R.I.P.)]

First, the lowering of air induction temperatures and cooler fuel coming into the engine will increase horse power by over 1% per Degree drop In temperature

 

This B.S. statement is from thermotec. Look at the dyno results & you'll see that they're using methanol/ alcohol which runs cooler than gasoline.

 

Confederate uses wrap to keep from burning the side of your leg off If you can afford a Confederate you can afford new pipes every few years. Most Confederate riders will never put the miles on one to have to replace the pipes.

[al_roethlisberger]

....sounds like you had the classic "vapor lock" symptoms, although sometimes it is hard to tell.

 

Do a search on "vapor" and there are many threads, with various opinions.

 

Here is the FAQ:

 

http://www.v11lemans.com/forums/index.php?showtopic=462

 

 

 

 

BTW, I also agree that wrapping pipes on a street vehicle is generally a "bad idea", especially now that ceramic coatings from folks like Jet Hot are so inexpensive, durable, and good looking But as always, YMMV

 

Good luck!

al

[st. augustine]

Century Performance[/i]]

 

Now I don't know who to believe (other than Tex). One company says one thing the other says another. I will admit that when I hear one party bad mouthing another, their credibility is somewhat suspect.

 

As far as wrap goes, I did inadvertantly burn my jacket sleeve when it fell off or should I say over my tank bag (I was taking a liner out of it at the time), so I decided wrap may have given me emough time to save the $400 jacket. In fact, now that I remember, the reason I put the wrap on my soft-tail exhaust was cuz I was spenging more time cleaning off boot heel rubber than I was spending time riding! So when I get my confed, I'll be ready to change out my exhaust regularly.

 

Seriously, thanks guys for the technical info and links. I was gonna run down to Daytona tomorrow to have the mechanic look at it (www.pcsdaytona.com mute your speakers for this site), but may just go for a ride instead.

 

And as far as the comments with a sexual undertones, I thought about gluing rubber nipples to the horns, but chose black stockings instead.

[st. augustine]

Al, just read through all the threads you posted on vapor lock and am amazed at how much knowledge is held in this forum. I used to work on drilling rigs and experienced vapor lock on diesel engines, but they basically would not run when experiencing VL. I was thrown off a little becuase the V11 would run, just not worth a shit. I noticed you looked into JC Whitney heat shield, did it work? I also know a guy who works at Grumman, maybe he can pick me up some aircraft line like was mentioned.

 

Thanks again.

[JuhaV]

Hi,

 

I don't think that the wrapping can cause any other harm than maybe speed up the deterioration of the exhaust tubes.

 

The wrap is thermal insulation put outside the tubes, while ceramic coating is putting the insulation inside the pipes. Both can improve performance keeping the exhaust hotter and flowing with higher velocity.

 

I kind of like the look of those wrapped pipes If there is any dyno stuff showing that they work in a guzzi, that would be very interesting.

 

br, JuhaV

[coz1100]

Now if I'm not mistaken (and I'm still new to some of this) heat tape is ment to keep the pipes hot. Everything I've learned about themel dynamics states that heat will flow from hot to cold. Well hot pipes wraps in insolation attached to engine case in the wind, it would seem that it is increase your chance of "vapor lock". Just my

 

 

 

Or maybe to many tonight

 

Z

[Guest Nogbad]

Once the gases reach the exhaust, no more work can be extracted from them, and they might as well cool as fast as possible. There is another reason for not wrapping the pipes, and that is the kinematic viscosity of gases increases with temperature, so to hotter they stay, the harder the engine has to work to expel them.

 

Wrapping is a load of old nonsense and pig ugly as well.

[pete roper]

Wrapping pipes? Oh boy!

 

OK, so the idea is to keep the exhaust gasses hotter for longer. More heat = more volume= higher exit speed= greater gas inertia= better scavenge. Look, I'm sorry but we're talking about a simple 2 valve hemi-head motor with a cam profile like a Briggs & Stratton lawnmower motor. I don't know if the difference would even be detectable? Perhaps, just perhaps, when we've exhausted all other tuning possibilities, we *might* try it on the race bike but probably not.

 

Just because some of the Top Fuel types and top of the tree race teams use something does NOT mean it is sensible, practical or even useful on a road going machine. Now whether this has any bearing on your running problems I don't know, but I doubt it. Given that standard header pipes are stainless steel which is more prone to being affected by heat than crappy old mild steel I'd suggest that the downsides of this mod probably far outweigh the upsides.

 

Pete