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oprn
Samba Member
Joined: November 13, 2016
Posts: 12730
Location: Western Canada
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 Posted: Wed Mar 17, 2021 3:41 pm Post subject: Re: Sedan tri-y header |
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Thanks for the tip! I was not aware of that product. I suppose I could figure out a spray gun, I have 3 including a touch up gun left over from when I was a bodyman/painter.  The last system I built I used the VHT flameproof stuff and after 2 years still looks ok. May need to touch it up this summer.
This stuff looks interesting...
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age) |
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Vanapplebomb
Samba Member
Joined: November 03, 2010
Posts: 5412
Location: Holland, MI
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| Posted: Wed Mar 31, 2021 2:18 pm Post subject: Re: Sedan tri-y header |
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Cerakote makes some really cool stuff. The price isn’t bad for how far it would go. I too have used VHT, and it holds up for a couple years, then needs touch up... at least here is humid west Michigan. Next header, I may have to try the Cerakote C7900.
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http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
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mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Wed Mar 31, 2021 5:50 pm Post subject: Re: Sedan tri-y header |
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| I get my coatings directly from tech line coatings, ( manufacture).all have been great,I didnt like the look of the titanium, but A BUDDY DID SO i DID HIS 4 WHEELER. after a few years of lots of mud&shit he said it was still good. I wanted the bright aluminum for mine so...they sent me a experiential coating.....it looked awesome but did not last but a few years.I did not know it was experamentail when they sent it to me( sold it to me) it did not make the grade and was changed.I wish they had told me it was experamential I would of chose another color. thats the only issue Ive had with any coatings that Ive applied . I usualy buy enought to do about 4 engines worth of parts and do everything I can. witch may leave coated bearing on the shelf ofr a while, but they will be there when I need them.I usualy do 6 brass gears at a time.4 sets of bearings,3-4 sets of pistins and more. shelf life of the product means use it all up then put the parts on the shelf ready to go when needed. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Wed Jan 12, 2022 1:56 am Post subject: Re: Sedan tri-y header |
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Tapered primaries are no real gain. I've played with it. Helps some things hurts others, ok but no overall gain.
I have come up with a design which I expect to be superior to my conventional tri-y
There is a small chance I will not get to ever complete this so I will share it now.
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sled
Samba Member
Joined: February 16, 2005
Posts: 6179
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| Posted: Wed Jan 12, 2022 11:12 am Post subject: Re: Sedan tri-y header |
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can you explain what the "volume" chamber does in this design? Thanks!
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UK Luke 72
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Joined: September 07, 2011
Posts: 2867
Location: Little Britain
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Bonesberg55
Samba Member
Joined: January 18, 2012
Posts: 1270
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| Posted: Wed Jan 12, 2022 12:22 pm Post subject: Re: Sedan tri-y header |
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| If I remember correctly, Chevrolet used tri-y headers on the old 409 in the early 60s. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Wed Jan 12, 2022 7:50 pm Post subject: Re: Sedan tri-y header |
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| sled wrote: |
| can you explain what the "volume" chamber does in this design? Thanks! |
Can I explain...maybe. Probably not, but I'll give it a shot.
Is it a helmholtz resonator?.....yes?, but that's not really anything special in itself. Maybe it is a interesting way of increasing the volume of that area of the header without disrupting the flow path. Or maybe it is an anti-reversion geometry. Or maybe it is a "reversion wave trap"
What is special is WHERE it is positioned in the system.
A few months ago I became more interested in studying the flow in the junctions.
Years ago I "knew" that pressure waves can go around any corner, so how the tubes merge together should have minimal importance from the perspective of wave tuning. And that is still mostly true.
But headers are really a mix of wave tuning and high velocity flow.
When began to re-examine flow properties of junctions I began to realize that it REALLY depends on velocity. When the flow velocity is over .5 mach, THEN you see the shape of the junctions start to matter. The usual truths apply. High velocity flow wants to travel in a straight line (no surprise), and Bernoulli's observation starts to be a factor.
So what I really ended up doing is studying velocity traces in different areas of headers to figure out WHEN the flow properties would matter and that itself was quite a trip, really more important than what I set out to learn.
Anyway, it IS a solution, but a solution needs a proper problem to solve so here is one.
MANY "longtube tri-y" headers have the secondary length 0.5-1 times the primary length, and tertiary length no longer than secondaries, (or they use a small choke or a very large diameter tertiary).
You can find some exceptions but the grand majority of truly good designs are no exception.
Why is that?
The longer the tertiary length, the more it will deflect some of the primary pulse back into the other side of the header, and that WILL bounce back. The velocity and length of the active secondary will be what is standing in the way of that positive reflection interrupting the active cylinder's flow. So it makes sense that as the tertiary length becomes longer than the secondary....is headed into a problem. But when this reflection comes back to the final collector, the flow velocity is quite low, low enough to go around a 180 degree sharp turn
So the "whatever you want to call it volume" can absorb that positive reflection and that will allow this oddly proportioned header to work with no hiccups at all.
If this device was added to a header proportioned differently then it may have no overall benefit, but also should not hurt performance either if I am correct. |
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sled
Samba Member
Joined: February 16, 2005
Posts: 6179
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| Posted: Wed Jan 12, 2022 8:15 pm Post subject: Re: Sedan tri-y header |
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how did you determine all of the dimensional proportions?
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drive your split. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Wed Jan 12, 2022 8:19 pm Post subject: Re: Sedan tri-y header |
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So what else? You want some controversy 
shall we talk about "anti-reversion"
Have you ever heard of a "boost bottle"?
Why would merging a header tubes together together at less than 7 degree from centerline have any benefit?
IMO it would only be because doing so increases the volume in that area of the header. Some of you in the know would say it's because it works better. Yes seems to. But why? think about it. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Wed Jan 12, 2022 8:30 pm Post subject: Re: Sedan tri-y header |
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| sled wrote: |
| how did you determine all of the dimensional proportions? |
That sounds like a broad question?
Based on my own experience, the experiences of others, simple math, complicated computer simulations, books, thinking.
Some people say headers will always be in proportions "because harmonics", others disagree. When it comes to general design proportions make sense, but small changes can be tried for fine tuning |
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Chickensoup
Samba Member
Joined: January 06, 2018
Posts: 5368
Location: Good Hope, GA
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| Posted: Thu Jan 13, 2022 5:30 am Post subject: Re: Sedan tri-y header |
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 Great write up and explanation! Always good to see new ideas brought to the table. Hopefully other will use this in future studies and builds.
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-'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge" |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Fri Jan 14, 2022 7:35 pm Post subject: Re: Sedan tri-y header |
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Forgot to add i replaced the muffler this summer.
Here is what it looks like inside. Short tube is the inlet, perforated tube is the outlet. then just wrap it like a burrito.
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evanfrucht
Samba Member
Joined: July 24, 2016
Posts: 2180
Location: Laurel Canyon, CA
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| Posted: Fri Jan 14, 2022 8:55 pm Post subject: Re: Sedan tri-y header |
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Very cool! The inside of the one I made looks kind of similar, it sounds sweet. It would be fun to attempt a tri-y one day and this thread is a great resource.
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1964 Fury Wagon ( the pavement shredder ) |
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daos
Samba Member
Joined: January 01, 2017
Posts: 309
Location: Stockholm, SWE
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| Posted: Sun Nov 13, 2022 2:30 pm Post subject: Re: Sedan tri-y header |
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so i was preparing to build a tri-y for my lowered fastback, only to realise i likely won't be able to make the primaries the recommended 32-34" without going under the block & tins which puts the exhaust on the ground.
then i plugged my engine spec into the jim mcfarland calculation and it gives me 58" pipe length (to the collector) which for a tri-y would mean 38.6" primaries + 19.3" secondaries. the extra 4-6 inches in the primaries might make it feasible, question is if i got the calculation right... |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26788
Location: Colorado Springs
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| Posted: Sun Nov 13, 2022 3:01 pm Post subject: Re: Sedan tri-y header |
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| Maybe possible. The tuned range would be something like 3100-4800 by my guesstimate. |
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daos
Samba Member
Joined: January 01, 2017
Posts: 309
Location: Stockholm, SWE
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| Posted: Sun Nov 13, 2022 4:09 pm Post subject: Re: Sedan tri-y header |
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| plugged in numbers for 4k, 4.5k and 5k rpm peak torque. 5k gave 32,5" primaries (as you recommended), 4k gave much longer 41.5" primaries. 4.5k was the 38.6" middle ground. main issue is i don't know exactly where my peak torque will end up. |
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oprn
Samba Member
Joined: November 13, 2016
Posts: 12730
Location: Western Canada
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| Posted: Mon Nov 14, 2022 6:36 am Post subject: Re: Sedan tri-y header |
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Pictures please as you build this!
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age) |
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daos
Samba Member
Joined: January 01, 2017
Posts: 309
Location: Stockholm, SWE
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| Posted: Mon Nov 14, 2022 10:10 am Post subject: Re: Sedan tri-y header |
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| happy to oblige - though i won't be building anything if i can't get the numbers worked out. |
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daos
Samba Member
Joined: January 01, 2017
Posts: 309
Location: Stockholm, SWE
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| Posted: Sun Feb 12, 2023 3:39 pm Post subject: Re: Sedan tri-y header |
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finally got going with the build. here are a few shots so far – #1 & #3 j-tubes first, then the pipes out to the 2-1, most still just tacked together. and some prep for #2 & #4.
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