Lyle's stock header

[lyletrudell]

OK, plan A is out, Bill and Miles answered my question, the Hawaiian header
won't fit my stock 72 coupe.
Matching up the header pipe like I am doing could be done on a car that has the
heat exchanger still in use. Matching will help HP and MPG.
I will be removing my heater and using straight equal length pipes in it's
place.
So plan B, I went to the shop and started to work on my stock header pipes.
Good news, the stock pipes actually have enough material to match up with the
exhaust ports and tube diameter is perfect for the 1-1/4" OD pipes I want to use
to make the second half of the header!
The header welds are typical production motorcycle, not even and sticking into
the flow path, but easy to grind out.
Here is what I did tonight:
*Made sleeves for the header flange stud holes so they fit tight around the
exhaust studs for alignment, note the stock holes are 11mm to fit an 8mm stud,
talk about mis-aligned!
*Heated the pipes up and bent them so they line up better with the studs, they
were off 1/16" or more!
*Ground out the ID of the header pipes to 1-1/4" to match the ID of the exhaust
ports.
*Ground the other end of the header pipes "heat exchanger flange end" to 1.15 so
it will match standard 1-1/4" OD exhaust tubing.
Next step, I will make a flange just like the heat exchanger one.
That way I can use the stock mounting bracket on the front engine mount. Then
sleeve the header pipe flange bolt holes, so the tubing will match up perfect.
This will also allow me to use the stock exhaust gasket.
That's about as far as I can go until I get the engine back in the car.
See pictures.
Lyle

[lyletrudell]

Made the flange and the flange sleeves.
Used a bandsaw to cut it out, no CNC's.
Ground the ID to match the header flange.
The header pipes and heater flange on the Honda were really mismatched, worse than any motorcycle I have seen.
For sure some lost MPG and HP!
Matching could be done with a dremel, something to think about.
Lyle

--- In
anzhonda600owners@yahoogroups.com
, "lyletrudell" wrote:
> OK, plan A is out, Bill and Miles answered my question, the Hawaiian header
> won't fit my stock 72 coupe.
> Matching up the header pipe like I am doing could be done on a car that has the
> heat exchanger still in use. Matching will help HP and MPG.
> I will be removing my heater and using straight equal length pipes in it's
> place.
> So plan B, I went to the shop and started to work on my stock header pipes.
> Good news, the stock pipes actually have enough material to match up with the
> exhaust ports and tube diameter is perfect for the 1-1/4" OD pipes I want to use
> to make the second half of the header!
> The header welds are typical production motorcycle, not even and sticking into
> the flow path, but easy to grind out.
> Here is what I did tonight:
> *Made sleeves for the header flange stud holes so they fit tight around the
> exhaust studs for alignment, note the stock holes are 11mm to fit an 8mm stud,
> talk about mis-aligned!
> *Heated the pipes up and bent them so they line up better with the studs, they
> were off 1/16" or more!
> *Ground out the ID of the header pipes to 1-1/4" to match the ID of the exhaust
> ports.
> *Ground the other end of the header pipes "heat exchanger flange end" to 1.15 so
> it will match standard 1-1/4" OD exhaust tubing.
> Next step, I will make a flange just like the heat exchanger one.
> That way I can use the stock mounting bracket on the front engine mount. Then
> sleeve the header pipe flange bolt holes, so the tubing will match up perfect.
> This will also allow me to use the stock exhaust gasket.
> That's about as far as I can go until I get the engine back in the car.
> See pictures.
> Lyle