Ironhead Drag Pipes on 76 Ironhead-assistance

[volunteerbon]

Trying to put drag pipes on 76 ironhead, the front pipe doesn't slide over the port, does anyone have any suggestions? also, trying to use torque cones that were supposed to be for the 1 3/4 drags and shouldn't the cone slide inside the pipe. Lastly, there were not any type of flange or gasket when I took the old pipe off. I'm not a certified mech but have some mechanical ability so if anyone has any guidance or advice please share with me.

Thanks,

Bobby

[IronMick]

I believe that there are no torque cones for ironheads. Someone will correct me if i am incorrect.

There are no exhaust gaskets in ironheads.

How many slits are cut into the end of the exhaust pipe? If there are only two you may need to cut two more. No deeper than the two already there.

With drag pipes you will want to considet the bolt&washer baffles.

And Welcome! to the IronHead forum.

[ratt2y]

torque cones?well i just don,t think so.pitch m good luck hope you get it going

[bustert]

mick make some good points. also can try a muffler shop to expand the end or buy a expander from the auto parts store. beer cans make excellant gaskets, just cut them out before you drink too much. that is usually my excuse for another one, i cut it wrong but d!!!! i'll get it right eventually!!!!!!

torque cones can be made but there should be some off the shelf item that would work.

[maritimer]

Originally Posted by IronMick

I believe that there are no torque cones for ironheads. Someone will correct me if i am incorrect.

There are no exhaust gaskets in ironheads.

How many slits are cut into the end of the exhaust pipe? If there are only two you may need to cut two more. No deeper than the two already there.

With drag pipes you will want to considet the bolt&washer baffles.

And Welcome! to the IronHead forum.

yeah drags on ironheads dont have torque cones unless they are homemade and the flange should fit over the exhuast port if not expand it a bit if it wont close cut a coupel extra slots in it. also helps to put some permatex hightemp ultra sealent on the inside of the exhuast pip flange * the part that slips over the exhuast port on the head. oh yeah without soem sort of back pressure your gonna lose your low and mid range torque.

i made a homemade set of baffles to try and mimick the BCT monster baffle to an extent my pipes open up from 1 3/4" to 2 1/4" the last 15-16" of pipe


its an adapter fro mthe exhuast section of Canadian tire the big end is 2 1/4 OD and the little end is 1 3/4 ID
i decided t oflare the inlet side * where the washer is welded* to create a "venturi" to help channel gases into it. i used a 2" trailer ball with a flat bottom laid the big end on the ground set the tralier ball into the little end and beat the snot out of it with a heavy hammer til lit got a nice flare on it



the baffle goes into the pipe with the washer closest to the head and bolt side closer to the exit end of the pipe, the bolt is about 3.5" into the pipe measured from shortest or outside of the slash cut which puts the washer about 7-8" into the pipe. in theory it should improve back presure and keep the nice growl.

[BuckIRyder]

My '72 has stock dual head pipes. The front pipe has a flat spot stamped into it to allow it to clear the frame. Maybe a muffler shop could do the same in your drag pipe.

[GA_Ironhead]

Originally Posted by volunteerbon

...does anyone have any suggestions? ...

Bobby, welcome to the forum!

My suggestion is to not run drag pipes, unless you're at the drag strip. They make a lot of noise, but cause a lot of mid-range tuning problems that you have to work around. Others will feel differently...

[Vermonter]

from what I remember no baffle drag pipes are good at increasing horsepower at full throttle, but like GA_Ironhead said, there are mid range issues, and often loss of horsepower in the mid range. now this is ok at the drag strip, but when riding around town, or even on the interstate, your rarely at full throttle. so for the average guy drag pipes only equal a lot of noise.

Of course this is just what I have read on the all knowing internet, but haven't done any tests myself.

[SilverShark96]

By your original post, I would assume that you already have the pipes (ergo, you're going to use them). I'm all about drag pipes. Sure, they make take away from mid-range, but unless you're looking for street performance (come on, we ride Harleys), you'll enjoy the pipes for the blistering sound they project.

Did you try heating up where they should slip on the port? Try what Mick said. If you only have 2 cuts (180 degrees offset), then cut another two cuts (all 4 being 90 degree offset). Heat it up, try to slip it on then. If that doesn't work then keep doing the above method. I would make sure all the cuts are equidistant from each other so you don't have a weak "tab" in the end of the pipe.

Just my $0.02 and what I would do.

[bustert]

too many slits will weaken the pipe at the spigot. then you will have an issue of sealing the slits which will put you back to the same problem. expansion is the key, you would have to go cherry red in order to make the metal stretch, bummer for the chrome unless you are a wrapper!!! muffler shop has a hydraulic setup that can be finely controlled to give the right fit.