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Posted: Sun Mar 05, 2006 7:26 pm
by stevec
See earlier posts in this thread - it's the best I can give you.

Y'know, sixvoltguy was all hot on this last year - by the way he was talking, he's got to have something made by now... :roll:

Posted: Mon Mar 06, 2006 3:58 am
by Jimny
Oh yeah that's right, hek he should have 10 made by now!

Posted: Mon Mar 06, 2006 10:34 am
by Demomike
Steve, do I have your dimensions right, looks a little funny...

Posted: Mon Mar 06, 2006 10:46 am
by stevec
Looks right, except I think you're missing the "belly" - basically a length of 3" ID, about 2.7" long. Other than that, your dimensions look right, though I still question the length of the header pipe. (I had changed that before) Also remember that the header pipe will not be straight; it will have to bend around to meet the cylinder exhaust ports.

Posted: Mon Mar 06, 2006 11:18 am
by Demomike
Now "with belly" (see above). Yeah, I figured the muffler shop can bend some 1.75 od x 0.065 wall tube for the header as needed, stinger too if required...

Posted: Mon Mar 06, 2006 1:58 pm
by Jimny

So is that your final answer?

Posted: Mon Mar 06, 2006 5:13 pm
by lj20Colorado
now what kind of power will that produce low end torqe or more horse power.

Posted: Mon Mar 06, 2006 5:37 pm
by Demomike
lj20Colorado wrote:now what kind of power will that produce low end torqe or more horse power.
that would be the $64K question...

Posted: Thu Nov 30, 2006 8:31 pm
by DieselBoy
Hmmmm, i like.

Can you guys that have sat down and worked it out tell me how this would be different for and LJ50??

I "assume" that the only difference would be that the diameter of the pipes would vary, but the lengths would stay the same??

Is that correct??

Someone care to work out the dimensions for an LJ50??

Pleeeeeeeeeeease :D :D :D :D

Posted: Fri Dec 01, 2006 12:16 pm
by stevec
I'll see if I can find the software. One thing I would need is the exhaust duration, how long the exhaust port is open. I had to estimate it on an LJ20 engine, I believe it was 120*. LJ50 is probably similar, but it is an important part of the calculation, so you would want to verify it.

Posted: Sun Dec 03, 2006 1:35 am
by DieselBoy
Hmmmm, so how do i go about working that out exactly???

Tell you what, if the stroke and port size is similar to that of the lj20, i would guess that the duration would be the same, how ever you worked it out.

I can measure the port and the information on the the stroke length is around some where, I'll see if i can find it.

Posted: Sun Dec 03, 2006 5:50 am
by Jimny
I have the software Steve if you can't find it.

Posted: Fri Jan 19, 2007 2:50 pm
by tweeder
i'm in the process of creating templates for this.....gonna add in a 1/4" flange along the join of the cones for either a rivet-together or lap weld... :cool:

Posted: Sat Jan 20, 2007 5:14 am
by Jimny
COOL! Keep us updated!

Posted: Tue Jan 23, 2007 9:10 am
by tweeder
had a brain fart on friday and skipped a step in the math. figured it out while i was drawing the templates in CAD. only time lost. recalculated today, and i think i got it right... gonna redraw it when i get home.

steve, is there i file format that i can send the drawing to you in so that you can check my math out?

Posted: Tue Jan 23, 2007 10:51 am
by stevec
Well, I don't have any CAD progs, so just the basics: Word, Excel, pdf file, etc.

Posted: Tue Jan 23, 2007 12:49 pm
by DieselBoy
Good work!!!

I reckon gettin this expansion chamber and exhaust system made is going to be the most expensive part of my build :))):

:cool: Whatchin and waiting 8)


Posted: Tue Jan 23, 2007 2:57 pm
by tweeder
well, unless i have a photoshop epifany in the next few hours, all i'll be able to come up with is a dimensioned jpeg -- not to ANYONE'S scale -- of the template :roll:

Posted: Fri Jan 26, 2007 1:49 pm
by DieselBoy
You can doooo eeeeeet :cool:

Posted: Tue Apr 03, 2007 10:25 am
by Demomike
Here are some patterns for my earlier .jpg....

edit: sorry, not enough space I guess...

Posted: Mon May 21, 2007 7:12 pm
by tweeder
well, i finally got templates drawed! (who'da thunk it'd be so difficult to remember how to make AutoCAD work? :shock: )

gonna see how they turned out (in other words, if my math works) and then i'll post links to the .dwg files. could be up as soon as wednesday :cool:

good news is all the templates will fit on 8.5"x11" (216mmx279mm) copier paper :cool: 8)

Posted: Tue May 22, 2007 4:39 pm
by Demomike
E-mailed you some layout files to compare against....

Posted: Tue May 22, 2007 5:13 pm
by Smuz
Demomike wrote:Here are some patterns for my earlier .jpg....

edit: sorry, not enough space I guess...
Oops, I guess none of us saw this. Yell louder next time, I upped yer limit.

Posted: Wed May 23, 2007 8:45 am
by Demomike
well then...

Posted: Wed May 23, 2007 12:38 pm
by tweeder
i think some of the numbers are a tiny bit different (thousandths of an inch), and my drawings are of the ENTIRE cone, not just half -- less weld seam = more better.

i'll hafta get my figures out when i get home to be certain.