New pipe setup.

When using a HF type A frame tubing bender , try to bump your bends , 1" at a time.
Count your strokes .
Start your bend , take it just to the point that it starts to deform then move 1" start again. This is bump bending .
You can get some pretty tight bends using this method.
Sand packing works as does Cerro. But you will still get better results from bumping.
Practice practice practice .......
The other nice thing about bump bending is the ability to change angles during the bending process. Compound bends are aw------fly handy...

mapbike said:

bo7ght a roll of the flexable liquidtight steel conduit toda6 at H.Depot, $50 for 25ft but its gonna be excellent for making 3/4" ID exhaust, looks identical to standard galvanized exhaust flex pipe once the sheathing is removed, basically $2 per ft. and thats much less than I paid for the 1"ID flex pipe at autoparts store.

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Your welcome.

Thanks for the tip Neil.

Thanks for the advice and tips Tom

Thanks for the Tips Dave

Thanks for the tip Boxcar/Gregg

Here are just some quick pix I took of the Flexable liquid tite conduit, looks like this will work great for exhaust header pipe and then use the other techniques described in the last few posts to get the rest how ya want it.

T

hanks for the tip Neil.

Thanks for the advice and tips Tom

Thanks for the Tips Dave

Thanks for the tip Boxcar/Gregg

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Not a problem....
I do bend a bunch of tubing.....





I like the Flexible liquid tite conduit idea....
Looks very similar to the tubing we sometimes use on marine exhaust for diesels.... Good stuff.....

2door said:

In defense of my earlier comment about weathertite conduit let me explain. What you buy at Home Depot or any hardware store is not the same stuff used in industrial/commercial applications which DOES have a plastic or teflon inner lining which makes pulling wire through it easier that the less expensive stuff.

Motorbicycleracing is correct about it being metal on the inside diameter but the product I've used has the inner lining. It would not lend itself to exhaust use. Personally I've never purchased weathertite from a big box store but only electrical supply houses which sells a different grade of product.

Tom

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I have seen the type you're talking about Tom and that is precisely why I never gave the stuff even a second thought for using as exhaust pipe, most of the flexable conduit Ive seen working as a Maintenance mechanic for a while and now being an extruder operator in a manufacturing setting was the PVC type that has no steel in it at all and as I said if it was the type with steel it also had a lining.

But, hey we can learn something new everyday sometimes and Im glad Neil shared this little tid bit, I may have noticed it eventually, but I wish I had known sooner, it would sure have saved me some time and trouble in the past.

As far as needing to defend your earlier comment Tom, that isnt needed at all, you were right when you spoke of the product you had in mind, un-be-knowings to you and myself there is a heaper product out there and it looks as though it will work as was told by Neil.

No one was wrong, just two different products and now we all know..... happy happy happy...!!!

Just to give an idea of how much cerro bend it would take to bend a frame tube... I got that 7.5lb ingot in the mail today and it's about 1.5" x1.5" x 7" so to fill a 1.5" tune with this stuff I would need at least 4 more 7.5 lb ingots... and I got that one cheap at $70... I usually see the stuff sold as 1lb ingots or 1lb 2" balls that cost an average of about $30 per pound...
The 7.5lb I just got would do good for bending stuff like exhaust tubing and smaller but I'm gonna keep my eyes out for some more of the larger ingots for my other projects.

I've only done a few practice bends with my pipe bender so far and I will try the bump method next time I play with some scrap tubing. I did notice that somewhere around 22 degrees of bending at the tightest radius the bender will bend is about the Max it can do before the tube starts to distort. I bent one a little further but it started to flatten around the bend then took the pipe to my press and pushed the widened section back down to where it was even with the straight section, this seemed to work pretty well but the pipe tends to lose its roundness at the bend just a little.

I also tried it on a scrap piece of 1" square tubing and it bent it pretty nicely but the outside of the bend starts to cave in and if gone further it will continue to bend without kinking but the caved in walls do tend to pull the side walls in at the outer part of the bend. Trying it again on another piece of square tubing it did better at a larger radius and bending it a lot slower.

Hopefully tomorrow while I'm at the shop I'll get a chance to practice a few more bends and try the bump method on some scrap round and square tubing... I'm gonna save the cerro for the smaller Jon's for now unless I can get enough to fill about 2 feet of 1 1/2" tubing....

VenturiEffect said:

That conduit I seen at home depot looks like it would melt If I breathed on it wrong. Haha. Wouldnt hurt to try if I could get it by the foot and not the whole roll. =)

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If its the solid plastic type it will melt.

If you get what I have its solid galvanized steel flex tubing and only has a somewhat loose pvc outter shell, the outter sheathing can be split very easily with a razor knife and removed.

boxcar said:

T

Not a problem....
I do bend a bunch of tubing.....

I like the Flexible liquid tite conduit idea....
Looks very similar to the tubing we sometimes use on marine exhaust for diesels.... Good stuff.....

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That's a cool looking samurai... I had one of those about 20 hears ago and was really impressed with its offroad capabilities... only thing was I just wished it had more power when on the road since it had a top speed of about 65... if ya had enough highway to do it... found out later after I got rid of it that making an adapter and using a 40mm Harley carb really wakes these little engines up... I wanted to drop in a gm 3.8 v6 in mine but hit a utility pole while out muddin and the insurance company totalled it.... I would buy another one in a heartbeat if I see the right deal... that thing was a lot of fun.

Under power'd was an under statement ..
I solved that little problem with a 2 liter Datsun transplant...



I just have this iate need to customize. I think that's what got me into motorizing bicycles.

2door said:

In defense of my earlier comment about weathertite conduit let me explain. What you buy at Home Depot or any hardware store is not the same stuff used in industrial/commercial applications which DOES have a plastic or teflon inner lining which makes pulling wire through it easier that the less expensive stuff.

Motorbicycleracing is correct about it being metal on the inside diameter but the product I've used has the inner lining. It would not lend itself to exhaust use. Personally I've never purchased weathertite from a big box store but only electrical supply houses which sells a different grade of product.

Tom

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I have run a Lot of all kinds of conduit and only bought supplies from commercial suppliers and have never seen plastic lined watertite flex.
Only used flex for short runs as 10' sticks of hard pipe with watertite fittings are much cheaper, cleaner and faster.
I can't think of many situations that would require a long run of water tite flex.
Anyway I have posted here a few times about making flex exhausts for 4 strokes. The stainless flex is 10 Times as good as the steel flex.
It's a very tough, high quality product.

LOL, I remember one detailed post got deleted when it got into a discussion with EZ Motorbikes, too bad cause it had a lot of good info.

I have seen that flex described at Lowes and Home depot. Cheap too! Awsome stuff

boxcar said:

Under power'd was an under statement ..
I solved that little problem with a 2 liter Datsun transplant...

I just have this iate need to customize. I think that's what got me into motorizing bicycles.

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Very nice!! Yeah, the Datsun L20 has just a little more power than that wimpy 1.3 suzuki... I've seen some turbocharged samurais that were more acceptable, but even with a turbo I think the L20 still has better power.
I got a nissan 720 4x4 now and it has the Z24 engine that's also underpowered for that truck... top speed is around 90 mph after advancing the cam and adding a Weber 2 barrel..... it pulls pretty good up to about 60 but has trouble keeping up on highways where the speed limits are over 75. I was going to turbocharge that engine but I'm looking now for a KA24 out of a newer truck or 240sx to turbocharge or just try to find a 4 liter v6 to put in it... I would really like to find a ZD30 which is a 3 liter diesel that cranks out 300 lb/ft torque and around 220 Hp... I'll definitely go with that engine if I can find a good one at the right price...

Hey Dave , thanks for the interest. I'v built a few Ratsuns in my day..... For your little 720 I'd be looking for the KA. Great engine......Or build the NZ into a hybrid stoker.

2Door has nailed it yet again.....

I like the idea of flex line for applications where vibration or lack of a bender is an issue.
I prefer and will stick to bent seamless tubing . With known flow characteristics...
Any type of metal flex tubing will cause turbulence in the exhaust flow .
If you use it , I'd use it sparingly....( short runs ) no longer than is absolutely needed.

2door said:

Maybe if you knew anything about building/electrical codes you'd know that runs longer than six feet using any kind of flexible conduit are prohibited.

I really don't care what you've seen or haven't seen. With 35 years in the industry I'd be willing to bet that I'm familar with many things you aren't. Why do you feel it necessary to argue any point?

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You can run flexible conduit as long as you want so it is not prohibited.
Yes, I always ran a separate ground wire when I used over 6' of flex.
The flex watertite has a thin copper ground wire.

All my jobs were inspected and passed by building inspectors.

Call it arguing but I guess you don't like to be wrong?

You may use flexible metal conduit in any length as long as you follow the Code rules for support (Sec. 350-18) and grounding (Sec. 250-18). 3. Sec. 250-18 limits flexible metal conduit to 6 ft only for grounding. In lengths over 6 ft, you must install a separate grounding conductor.

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So, back to talking about 4 wheelers?

boxcar said:

2Door has nailed it yet again...............

I like the idea of flex line for applications where vibration or lack of a bender is an issue.
I prefer and will stick to bent seamless tubing . With known flow characteristics...
Any type of metal flex tubing will cause turbulence in the exhaust flow .
If you use it , I'd use it sparingly....( short runs ) no longer than is absolutely needed.

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Have you checked out the stainless flex?
It is very smooth inside when it is pushed together.
A`36" length expands out to about 46"
It is not an electrical flex so it doesn't have a ground.

2door said:

This thread has been cleaned up. The pointless arguments removed.
Keep it on topic.

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The topic is 4 wheelers?

Hey guys i used 1 inch hydraulic hose on my sbp expansion chamber to get rid of the copper parts & the sillacon tubing that melted & wouldn't stay together. I used it because the welding shops neer my house wouldn't weld it 4 me. And it's hi temp & flame resistant it works well also I put a self tapping screw in each of the joints to make more rigid.