Slant Six Forum
https://www.slantsix.org/forum/

Custom headers, intake manifold, and valve cover
https://www.slantsix.org/forum/viewtopic.php?t=20656
Page 1 of 2

Author:  Alumitex [ Tue Nov 07, 2006 5:52 pm ]
Post subject:  Custom headers, intake manifold, and valve cover

Ok, I need some input regarding headers. I am gearing up to fab a pair of stainless steel shorty headers and was curious as to what sized tubes I should use for the primaries and also what size collector would be the preferred choice. These will end up going 2 into 1 most likely and through a single high flow muffler. I will have 1 flange that will be CNC machined from 1/2" thick stainless with tooling tabs to remove once the tubes are all final welded.

As for the intake manifold, I am looking to fab a sheet metal aluminum intake for a 4 barrel (or maybe EFI) and was curious as to whether anyone else has tried this and what opinions would be between short or long intake runners and so on. The flanges for this will be CNC cut from 1/2" thick aluminum with tabs to remove upon completion of welding as well.

Now onto the valve cover...well good news is I have it mostly designed and will be working the next few weeks on the fabrication as time permits...the base will be 3/8" aluminum and sheeting will be tig welded and polished...

Please feel free to throw up any red flags as I am pretty new to the slant game...seeing as how my passion is design and fabrication I just cant bring myself to unloading my pockets for poor customer service, week flanged headers, and just plain off the shelf stuff when I can make it myself...it's worth a shot anyway.

Thanks,
Don

Author:  Patrick Devlin [ Tue Nov 07, 2006 8:12 pm ]
Post subject: 

These sound like some neat projects. I don't really have an actual tubing size to suggest, and a lot will depend on what you are able to get ahold of, but I would keep both the intake and exhaust runners as close to the cylinder head port sizes as possible to keep velocity up and to not create a step from the runner size to the port size.

Author:  Alumitex [ Wed Nov 08, 2006 2:30 am ]
Post subject: 

Cool, I'm looking forward to jumping into these projects anyway...that makes good sense though. I will just pull measurements and find some tubes that have the same area. As far as what is available, I have access to pretty much all sizes and if my supplier does not have it he will find it and get it for me...now I just hope business and work slow down enough for me to get these projects knocked out!...

Thanks for the input!

Don

Author:  emsvitil [ Wed Nov 08, 2006 2:44 am ]
Post subject: 

http://headerdesign.com/index.asp

Author:  Alumitex [ Wed Nov 08, 2006 8:29 pm ]
Post subject: 

thanks for the link...any other tips, comments, or advice is more than welcome!

Don

Author:  zedpapa [ Wed Nov 08, 2006 9:12 pm ]
Post subject: 

the headers should be a two piece design. much easier to install and remove. keep in mind that most manifolds(int. or exh.) use a 3/8" flange. using a 1/2" flange would be a bit of overkill. if the engine is not overheated, then there shouldn't be any warping problems. also think about making a connector pipe to connect the two manifolds so a muffler shop doesn't have to fab something if you want to run a single exhaust.

zedpapa

Author:  Charrlie_S [ Thu Nov 09, 2006 4:40 am ]
Post subject: 

Quote:
keep in mind that most manifolds(int. or exh.) use a 3/8" flange. using a 1/2" flange would be a bit of overkill.

zedpapa
Just went out to the shop and measured Three sets of headers, one Clifford, one Offie, and one stock intake. All have a 1/2 inch thick flange. The headers have an additional welded and machined ring around the port (for sealing) that is an additional .030-.060 thick.

Author:  Alumitex [ Thu Nov 09, 2006 4:58 am ]
Post subject: 

The headers will definitely be a 2 piece design so I can install and remove as easily as possible if needed. Also, I will for sure make a connector pipe while I'm at it...thanks for the input!

As far as the flanges go, 1/2" is the route I'm going (thanks for taking the time to measure Charlie!)...I've seen a lot of headers leak just from tightening the bolts on the thinner flanges...not something I want to experience if I am going to spend the time to fab a one-off set up.

Thanks again for all the input...keep it coming if ya have any ideas/concerns!

Don

Author:  Ron Parker [ Thu Nov 09, 2006 4:39 pm ]
Post subject: 

Could you do a custom header for a turbo app. Thanks Ron Parker :D













It Aint Over Until I Win

Author:  Dart270 [ Thu Nov 09, 2006 6:09 pm ]
Post subject: 

1.5" header pipes seems to work well for a lot of people (racers and others). Best all around power, according to Slant dyno master Cam Tilley, is made with 30-34" primary pipes. That said, a lot of folks use the Clifford shorty headers (14-19" primaries) and make lots of power, plus they fit any body style.

I'd likely be interested in a set when you're done, if you can get someone to duplicate them.

Sheet metal intake size will depend on NA or forced induction.

Lou

Author:  Dago Red [ Thu Nov 09, 2006 6:46 pm ]
Post subject:  I'm Late, As Usual

:DI just got your message Don. And this is exactly what I would have suggested. This group is the best place to bang around ideas. I hope you enjoyed your time at the track, my day was certainly a short one (first round fodder...) I had a host a little problems I was trying to solve. In addition to all this really cool stuff I'm gonna end up having on my Slanter :) Can you deepen an oil pan and lenghten the pickup? Also, my motor is sitting out on the engine stand if you need to do some measuring and figgerin'....RICK

Author:  Alumitex [ Thu Nov 09, 2006 7:55 pm ]
Post subject: 

Ron, I dont see any problem fabricating any type of headers you want. I will most likely do several types as time allows ranging from shorties to twin turbos.

Dart 270, thanks for the input, that is kind of the way I was leaning but was planning to look a little further into it and again will most likely do some experimenting once I get my shorties finished for the Duster. As far as duplication, I will probably build jigs around my first set once complete so I can reproduce them in my shop. Now on the intake, while the Duster was/maybe is intended to be a low cost fun cruiser...which would be right at home with a 4 barrell...I am really itching for some webers and on the flip side also really dig the EFI with forced induction since I can make my own fuel rails etc... I obviously just dont have enough project cars!...something else to work on!

Rick!...It was great getting out there to hang out and meet ya. That was actually my first break away from working in quite some time...I just wished the whole time that my Duster was ready to be in the line up heading down the track. I think I can help ya out with just about anything you can think of needing done...I take it from your message that you had a chance to check out my website...while part of me is about business...when it comes to my hobbies (slants are on top of the list now) the sky is the limit and there is always time for some experimentation. I could use a look but am actually hoping to have my engine pulled by Saturday. Let me know if there's any projects I can help ya out with and we can CAD up whatever and iron out any issues. BTW, should I cut an extra valve cover flange when I get ready to fab up my aluminum valve cover?...shoot, I may just cut a half dozen or so just to have...the sheet metal work is the easy part once the flange is CNC cut.

Thanks,
Don
www.dnacaddworks.com

Author:  Dart270 [ Fri Nov 10, 2006 5:45 am ]
Post subject: 

Don,

Sounds like some great projects. If I were going to build a sheetmetal 4bbl or EFI (NA) intake for a street car, I would make it longer runners than the Clifford/Offy, keep the runner diameter like an offy (about the size of the stock intake port opening dimensions, or slightly smaller), but shorter runners than a hyperpak. Shooting for something like 12-14" runner length should get you great torque and power.

Keep us updated!

Lou

Author:  Ron Parker [ Fri Nov 10, 2006 7:38 pm ]
Post subject: 

Wow let us get our homework together and see what happens this winter. I know what direction i want to go just the right people to help me and i think i have found one. Thanks Ron Parker :D











It Aint Over Until I Win

Author:  Alumitex [ Fri Nov 10, 2006 8:07 pm ]
Post subject: 

Dart270: That is actually pretty much on with what I was thinking...it sure is nice to hear it from someone else though. I'll post up pics of my CAD model once I get it lookin pretty. I will definitely keep ya updated on this stuff...looks like I'm going to have plenty of fab time over the holidays if I dont end up spending all that time setting up a new shop.

Ron: You just let me know when and what ya want to do and we can meet in the middle. Again, I'll be posting pics of my projects as I get through them and maybe that will help you out...but you sure do sound like you know where you want to go with you projects already!...just let me know what I can do.

Thanks,
Don

Page 1 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/