The 230 Headerfold project

[chriscase]

Headerfold, plus Carter 2BBl BBD carb.

Note how the ex tubes have turned colors?

Anyhow, with the int and ex tubes, the B&B 1bbl was restrictive enough to make 2 inches of vacuum at full revs. So I went to the Carter BBD two bbl, from a 71 318 van.

The two-to-one adapter was fun, got it right the first time. But the Z-bar linkage had me tearing my hair out. I wanted to use the stock linkage as much as possible, rather than adapting to a cable. Plus I needed the height of the adapter to make the air filter rise over the tie rod.

Anyway, runs like the proverbial primate with the striped posterior now, except won't idle well. It's straight from the junk yard. I've got a kit coming in later today. Plus I can leak check my adapter with WD-40 once the paint hardens up

[monkeymissile]

Btw

they look great, can't wait to make mine someday!

[monkeymissile]

pics?

Chris,
I used this stuff on my temporary used manifold (aluminum 2000 degree) and it has held up very well, no discoloration at all.

http://www.hirschauto.com/prodinfo.a...er=EMPT%2DPINT

[chriscase]

Headerfold Final pics

Here's a couple pics of my set of headers and intake. This post is with the Carter B&B 1bbl. I used Duplicolor 1200 degree header paint on the int and ex both. The ex tubes turned black within three miles. I like the two-tone look, but was worried about touch up. Looks like I got the two tones from the same can .

Rather than restrict my header design to what fits under the stock iron intake, I went with big bends, leaving room underneath for valve adjustment access. Then I had to make the intake, since the stocker wouldn't fit. I figured loooong tubes were better anyhow, and lengthening the center runner would help somehow, some where.

[chriscase]

Just two rows of writing on the one belt. It figures that the details you don't want to show come out in the sharpest focus.

[maineSS]

It looks like there are two belts with yellow writing on them in your 1st engine compartment pic- maybe I have double vision. I heard the M37 has a triple sheave pulley set- perhaps something can be done with that.

[chriscase]

Mess, you must be seeing things, I don't have any double groovers. But I have thought about searching out the pieces from various junk yard motors, to put a multi-vee serpentine system on. I THINK it would be doable, but I would have to pack a lunch, it would take all day to check LOTS of pulleys.

[maineSS]

Chris- a slight off-topic question. Where did you get that double-sheave pulley? I'd like to upgrade my power output so I can run MORE accesories!

[chriscase]

I'm working on the intake...

No big plenum, because I want to use the stock carb in the stock location.

I've hammered out a steel 'knuckle', four way tee, one for carb plus three intake runners. Now I'm waiting on some more, tight , u-bends- I'll make the center runner as long as the end ones. I'll probably polish off the welds and paint it- it will look 'organic', like it grew as a tree and roots. My design concept is "any****thingIdo will be better than the stock log".

I'm thinking that the steel tubes, in close proximity to the exhaust header, will stay warm enough to keep the fuel atomized. I've got a digital probe thermometer that might tell me some thing, I'll at least use it in the air filter to check intake temps, what with the radiator and headers. I haven't looked for a way to run a cool-air intake system, no obvious gap between the radiator and hood. Then maybe tape the temp probe to an intake runner?

Got lucky at the pull-your-part place the other day, bought a Flowmaster #50, with a 4' straight exhaust pipe, plus a tail pipe, all for $35. So I decided that 2 1/2" pipes and a Flowmaster #50 are puuurfect. The oval muffler will go in with the oval vertical, low inlet, and the outlet will just be under the frame. Muffler body just a scosh lower than the driveshaft, maybe a good thing that it is an all-welded 16 gauge can.

I'm having fun playing tinker toys with my spaghetti!

Back to the Dyno shop next week, hoping for 10%. But the cams on these flat heads have little overlap, probably even negative.

Ok, Here's some valve specs for Dodge car from Motors manual, 1935-'52, Intake opens at 0, pre '1940; 8-12 btdc, post war. Ex closes 6-9 atdc. So 1946-48 cam had 18 degrees overlap. No duration specs. Plymouth used that same high-overlap racing cam ;) , '46-52.

[Jason Mills]

One problem with using tubing for your intake runners is the smooth interior surface- when fuel hits it, there's no chance of re-atomizing, and it will run into the cylinder as a liquid. If you can find a way to roughen it to at least an 80-grit finish, fuel droplets have a better chance of staying in suspension. .

I have been wondering just this same thing.. and if memory serves me, there is some kind of intake manifold gaskets... is it called "torque plus" manifold gaskets that have a very fine screen across the opening, that improves atomization of the fuel??? they are not supposed to be any good above 4000 RPM, but below it, they are said to improve power and fuel efficency..

[maineSS]

Chris- Looks like another dyno run in your future. It would be interesting to compare the output of your header vs the cast iron freeflow manifolds offered by Stovebolt 6 and Pierce. Tom Langdon of Stovebolt 6 claims that a 10% gain is as much as you can hope for with the stock engine.
One problem with using tubing for your intake runners is the smooth interior surface- when fuel hits it, there's no chance of re-atomizing, and it will run into the cylinder as a liquid. If you can find a way to roughen it to at least an 80-grit finish, fuel droplets have a better chance of staying in suspension. Another thing to consider would be heat gain from the header into the manifold. Coating the header would help, as would elevating the manifold above the header tube plane.Do you happen to know what the cam specs are for the 230/251? If there's no overlap, (combined with the siamesed intake ports) then intake tuning is probably going to be a matter of restriction reduction and keeping airflow speed high.

[MoparNorm]

Plenum/intake:
A large enough area to effectively allow the fuel and air to mix, such as the 75% ratio mentioned, more important is to emulate the Mopar Poly or Offy Dual Plane intake, which gives each cylinder an equal length runner, to provide uniform fuel/air mixture and velocity to each cylinder.

[dave m]

Plenum size

Chris,

Concerning plenum volume, I have heard a rule of thumb as 75% of ine displacement. However Robby Gordons Hummer he ran in the Dakar 2007 rally had a 350" +/- motor with a plenum that was 100 to 110% motor displacement. Hope this gets you started.

Nice job on ther headers.

//dave

[MoparNorm]

Here's the final. I went 6-2-1 for mine, it's easier to fab than two half-headers. And is still easy to get in and out. Plus, looks like more room to adjust valves than stock, though you'll still need asbestos gloves to do it hot.

Waiting for another 90 deg bend for the intake, I used up all the local guys had in stock. Meantime, I guess I can start milling the aluminum plenum-

Anybody got any input on plenum design? Should it have as big a cavern as possible? Small as possible? Or anydamthing?

Nice job Chris! Looks like my Borla header on my Jeep 258....= )

[monkeymissile]

Chris,
bravo, nice work! I am very jealous. We just had our second child (a boy) and the weekend before I got my M43 running again with a used exhaust manifold. It looks like it will be a long time before I work on my own headerfold. Keep those pictures coming!