ITB Ascona is finally progressing - Page 3

Travis · #51 (**permalink**) 11-11-2002

Unfortunately adding the chassis to the FEA would likely add a digit or two to the cost

I suppose you could highly simplify parts of the chassis to get an idea of where you'd be.

-Travis

Paul · #52 (**permalink**) 11-22-2002

Check out the header information/calculator at:

http://www.headerdesign.com/

I'd like to know how close/accurate its calculations are for the Opel CIH engine.

Paul

RallyBob · #53 (**permalink**) 11-22-2002

Is this link dead? I can't connect....

Bob

Gary · #54 (**permalink**) 11-22-2002

Originally posted by RallyBob
Is this link dead? I can't connect....

Bob

Try it without the "www" - headerdesign.com

Paul · #55 (**permalink**) 11-22-2002

Works for me

RallyBob · #56 (**permalink**) 11-22-2002

I still can't connect to that site. I tried from work and from home, same results. Hmmm.

Bob

Paul · #57 (**permalink**) 11-23-2002

I see what ya mean... Can't connect from home today, but I could from work yesterday.

Anyone else tried it?

Gary · #58 (**permalink**) 11-23-2002

I just tried both URL's and could not connect. They must be having host or server problems.

RallyBob · #59 (**permalink**) 11-23-2002

I finally got through from home last night. Took a while however.
I tried out the header formula based on certain engines I've built over the years. It seemed to be pretty decent for a 'guesstimate', far better than if you were just 'winging' it. It doesn't however take into consideration existing port dimensions. It would be tough to built a 1.25" primary header on an Opel head! But it does prove a point, headers usually need to be much smaller and longer than those that are supplied by the mainstream manufacturers, at least for street use.

Bob

davegt27 · #60 (**permalink**) 11-23-2002

I cant get it to work either

sure would come in handy-- i picked up this killer merge collector from Japan
the 1.5 primaries seem real small

Davegt74

Travis · #61 (**permalink**) 11-23-2002

RallyBob,

Do you recongnize Todds new 'best header ever made'? I notice it has the usual unequal length tubes...maybe this is tuned to match his mixed compression engines?

http://www.opelsunl.com/anv1.htm

-Travis

RallyBob · #62 (**permalink**) 11-23-2002

Looks just like all the old Pacesetter/Thunderbird/KBD etc headers that date back from the '70's. Still has the sharp bends right off the head, the unequal length primaries (off by 11" from shortest to longest), and the too-short primary lengths (longest is 28" IIRC), and the 'sudden merge' collector with the too-large collector pipe. Maybe it fits, maybe it doesn't, but it is far from an ideal design.

Bob

RallyBob · #63 (**permalink**) 11-23-2002

Got a little bit done on the ITB car again today. I managed to fabricate the fuel cell 'cage'. The cell plops right inside the cage, and is supported not only by the upper flange, but also at the bottom and sides. I merely need to cut a square hole in the trunk area of my car, set the cage into it, and seam-weld the flange from the cage to the sheetmetal. Material is mild steel, 3/4" x 1 1/2" tubing with a .065" wall thickness, and the flange is 1 1/2" x 1/8" angle.

Bob

RallyBob · #64 (**permalink**) 11-23-2002

Here's a closeup of the hold-down bracket attachment. I'm pretty happy with the way it turned out, which is a rarity for me. I'm very critical of my own work.

Bob

RallyBob · #65 (**permalink**) 11-23-2002

Here's the fuel cell fitted to the cage. It's a Fuel Safe Enduro cell. It's as inexpensive as you can get for an SCCA-approved fuel cell. Capacity of this unit is 12 gallons, and I had it made with a fuel sending unit. Remember the dual-purpose nature of this car, it will be raced and street driven. Left hand fuel fitting is the feed, the right hand fitting is the vent line. I came up with a novel ideal for the vent, and also for the prerequisite fuel sampling port. I'll expand on that idea later when I can show photos.

Bob

RallyBob · #66 (**permalink**) 12-29-2002

Here I've cut out the trunk floor to allow the fuel cell to be installed. Note that I also began to scrape the undercoating...I forgot how much I hate that work!

RallyBob · #67 (**permalink**) 12-29-2002

This is the trial test-fit of the fuel cell cage. All is well up to this point, except for interference at the right front corner of the trunk floor where it flares upward. That had to be cut out somewhat, but of course there was another panel (frame rail actually) beneath it. I could have slid the cell further to the left to miss this area completely, but I wanted more room for a larger muffler on the left side between the cell and the spare tire well.

RallyBob · #68 (**permalink**) 12-29-2002

This is the modification to the end of the frame rail. I notched it out with my plasma cutter, then capped the frame rail opening with some 18 ga steel.

RallyBob · #69 (**permalink**) 12-29-2002

Here the fuel cell has been dropped into the fuel cell cage. Note the added clearance for a full-size oval body muffler now. Previously, a round-body muffler would have been a tight fit.
By this time, the entire cage has been welded to the trunk floor, and I started plumbing the rear fuel lines to the fuel pump, the breather vent, and the fuel sample port (SCCA mandated)

RallyBob · #70 (**permalink**) 12-29-2002

Top view of the fuel cell plumbing. All fuel lines are stainless braided #6 AN Earl's. Fuel pump is a Carter 5 psi 'street' pump, and it's regulated underhood down to 3.5 psi, which is what Weber carbs like....

RallyBob · #71 (**permalink**) 12-29-2002

Remember the fuel sample port I commented on earlier? I wanted it to serve two purposes. I wanted a sample port that was easily accessible and would meet the SCCA's rules, and would also serve as a fuel cell drain if needed.

After the fuel pump, there's a t-shaped bulkhead fitting that passes through the floor of the trunk. The straight portion of the 'T' goes to the front of the car, and feeds the carburetor. The bottom of the 'T' goes through the trunk floor, and then leads to a shut-off valve near the original fuel filler neck. As a secondary means of sealing the valve, I installed an 'AN' cap on the line.

I will be wiring the fuel pump with a secondary toggle switch in the trunk area. This will supply power to a momentary push button switch. When the pushbuton switch is depressed, the pump will operate. So, for a fuel test, I merely uncap the valve, open the valve, arm the pump electrically via the toggle switch, then push the momentary switch, discharging just enough fuel for a sample. All very controlled and neat, and I never have to leave the trunk area. That, plus the sample valve is outside the car, so I won't have to worry about spilt fuel and fumes inside the car.

RallyBob · #72 (**permalink**) 12-29-2002

A closeup of the fuel sample valve, mounting bracket, and AN cap.

Nathan Acree · #73 (**permalink**) 12-29-2002

Bob,

What method of welding are you using to construct your headers?
Are you gas welding them or mig?

I am thinking about making a set of "block hugger" headers for my V6 conversion.

Thanks,

Nathan Acree
Albuquerque New Mexico

RallyBob · #74 (**permalink**) 12-29-2002

Originally posted by Nathan Acree
What method of welding are you using to construct your headers?Are you gas welding them or mig?

I am thinking about making a set of "block hugger" headers for my V6 conversion.

I weld the header tubes together with an oxy-acetylene torch. I weld the flange to the tubes as well as the collector with my MIG. Gas welding is much 'softer' or more annealed than MIG welds, so there's less chance of cracking. This doesn't hold true if you quench your gas welds with water while they're still hot! TIG welds are in between gas and MIG in terms of hardness, but obviously look much nicer. But I don't own a TIG welder...yet.

If you build your own block huggers, err on the long side when you choose tubing lengths, the shorty style gives up a lot of torque. In don't know what engine you're running, but on the old racing Chevy 2.8's (IMSA and off-road trucks), they ran 1.5" primary tubes and 38" primary lengths. You almost can't be too long when it comes to primary lengths, but too short will always lose torque.