The 230 Headerfold project

[chriscase]

6-2-1 Header pics

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?

[chriscase]

Making progress on my headerfold

It's coming right along.

Until just this minute, I was planning two headers, thinking that removing one at a time would facilitate valve adjusting. . But now I'm seeing that I have room to adjust the valves with the headers in place, so I may make them 6-2-1. Not a big difference from the two piecer, I would have made two sets of flanges, then wye-pipe, to a single 2 1/2" muffler. The 6-2-1 will make it easier to fabricate, only one set of flage/coupler needed. I built a jig, thinking you folks might become customers. A two piecer system would have a better chance of fitting other models.

You can see the mock-up of the intake. My plan there is to carve out an aluminum plenum, and press tubes into it. That way, I can drill for water heating, and make different plenums for different carb bases.

Nuther thought re: equal lengths systems. At 3,000 rpms, and 6 cylinders, each cylinder makes a pulse 25 times per second. At the speed of sound, the pulses are 533 inches apart. So a 3 into 1 system would have pulses 12 feet apart. So one pulse will be past the muffler before the next valve even opens. Not to mention the curves add resistance, so having one straight tube and one that has an extra 270 degrees of curves, means that they are not equal anyhow. So I don't think equal lengths would benefit us.

[monkeymissile]

split

Hi,
yeah, I'd seen these and there was discussion about the pros/cons of the design. What I concluded is that if I'm going to drop some cash into this project I might as well try to make it the best it can be. The main way to do that is to join pipes by their 180 degree firing order, 1+6, 2+5 and 3+4. A split manifold doesn't allow for this although it does allow for better exhaust evacuation and would therefore be better than stock.

[pybyr]

split manifolds- another option

I've been following this "headerfold" thread on and off out of general curiousity-

for what it's worth, in Googling around for manifold options for my intake, which had some issues, I bumbled across this interesting site:

Kansas Kustoms now offers Split Manifolds (and he describes what's done and how)

http://www.inliners.org/Advertisers/kkk_ad1.html

and then also shows a Dodge 230 done up this way:
(scroll to bottom)
http://www.inliners.org/Advertisers/kkk_ad2.html

it's out of my budget given that I have an OK exhaust manifold and no need for a lot of HP or cost of two exhausts, but it's ingenious!

[monkeymissile]

Justin,

I have not built a set yet as I wanted to get some flowbench work completed... I was considering a reverse flow setup. Now I am 90% sure of not doing that.

If you are considering building a set send me a regular e-mail and I will get you all the dimensional details. some dimensions are visible on the drawing. Straight pipe has length while curves show radius and angle 3-90 is 90 degree bend on a 3" radius. I also have 2-3 sources of low cost mandrel bends and 3:1 collectors.

Do you by chance have a dimensioned drawing of the side of the 251 block? I saw one for a 230 on this site.

//dave

Dave,
I do plan to build a set, but not for a while yet. I'd be interested in the dimensions though so look for an email or PM from me. I did the dimensioned drawing for the 230 a while back, but I don't have one for a 251 because I don't own one! Sorry.

Justin

[dave m]

Justin,

I have not built a set yet as I wanted to get some flowbench work completed... I was considering a reverse flow setup. Now I am 90% sure of not doing that.

If you are considering building a set send me a regular e-mail and I will get you all the dimensional details. some dimensions are visible on the drawing. Straight pipe has length while curves show radius and angle 3-90 is 90 degree bend on a 3" radius. I also have 2-3 sources of low cost mandrel bends and 3:1 collectors.

Do you by chance have a dimensioned drawing of the side of the 251 block? I saw one for a 230 on this site.

//dave

[monkeymissile]

Dave,
this is fantastic info, I figured someone else had wandered down this road too. Have you made a pair yet?
Thanks very much for posting. Once I dig my truck out of the snow, I hope to get active on it again.

best,
Justin

[dave m]

Equal length header design

MM,

Just found this thread. I have a design for equal length headers for a long block 265" motor. This design is the classic 6 cylinder 6-2-1 split along 123/456 based on firing order. The promaries are 1.5" OD and have about a 40" primary length and equal length within about 3/8". All bends are standard mandrel bends. Here are some Visio drawings converted to *.gif.

//dave

[chriscase]

I think a single down draft would fit on top of an intake that that is extended laterally. Isn't there a lot of space towards the fender on an M37? And is there a governor that could be eliminated too, to gain height for more sweeping curves upwards in the runners? Plus a different/ lower carb, probably a small two bbl.

[monkeymissile]

new thread for multi-carb/intake project

Gents,
I bit the bullet and nabbed (3) 38mm Mikunis from eBay and I'm going to start a new thread for this project. Thanks for the input so far...

justin

[maineSS]

MM-For individual carbs no hotspot is needed. You'd have to get some sort of accelerator pump- Mikuni does make a an auxiliary pump, but it's hard to find a supplier that stocks it. The Esslinger setup at http://www.jalopyjournal.com/forum/a...8&d=1182398346 is a good place to start- they're using the 38mm Mikuni. You can get 38 triple sets at snowmobile/ATV salvage yards pretty reasonably- I paid $130 for a Polaris triple set. For a single carb, you want to heat the intake directly under the carb- that's where the fuel drops out and puddles. If it isn't re-atomized, it runs into the cylinder as a river- not good. Hudsonater's posts on multiple carburetion are a very good intro to some of the problems you'll encounter- it can be a tuning nightmare if you mix 'n match carbs, use carbs originally intended as singles, or don't have good troubleshooting skills and persistence. Once everything is dialed in, you can have a glass-smooth idle, amazing low end, and good fuel economy- but it's a lot of work to get there.

[chriscase]

A small balnce tube is a good idead to add.

A small tube, say 3/8" to 1/2", between each intake runner will make it easier to get a smooth idle. Weld or braze some nipples on, and use rubber fuel line between them. Or maybe rubber connectors with longer pieces of steel line, for the sake of the heat from the headers?

Three separate filters, or another welded manifold for a single? to the stock filter?

You may want to look at throttle linkage from a flat head car- the kind that uses a vertical stud in the head for the pivot point. That could be a good spot to transition from rods to cable(s). Keeps the cables away from header heat? Plus more room to work?

[monkeymissile]

interesting links

looky what I done dug up online...... quite a thread!

http://www.jalopyjournal.com/forum/s...d.php?t=189987

and some cool pics too!

[monkeymissile]

best place for the heat?

MM- I don't think a heated carb spacer will help with fuel dropout as it makes the turn into the manifold passages- this is the place where you have to re-vaporize, otherwise it enters the cylinders in liquid form and never burns effectively. That 90 deg turn under the carb is where you lose most of the fuel out of the airflow- it has to be 10 microns or less particle size to make that turn, carbs produce droplet sizes between 10-400 microns.

mSS,
so where'd be the optimum place to add some heat to the mix?

[monkeymissile]

new thread?

should we start a new thread then? How would I figure out what size carbs to get? If intake ports are 1.25" (<32mm) do I just look for that diameter?
I see that a better intake manifold would be cake to make compared to the headerfold. Maybe my project is starting backwards, maybe I should tackle the intake side first?