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Community head flow testing?
https://slantsix.org/forum/viewtopic.php?t=34835		 Page 1 of 2
Author:  Joshie225 [ Sun Apr 12, 2009 9:35 pm ]
Post subject:  Community head flow testing?
I have a proposal for anyone who thinks head flow testing would be of benefit to our community.

I was thinking of taking a bone stock "improved" head along with my latest big valve head with different cylinders in both heads in different stages of modification to be flow checked.

This testing program would generate numbers for: 1) Bone stock with a fresh 3-angle valve job. 2) Stock valve size with pocket porting. 3) Stock valve size and thorough porting while maintaining the stock port cross section. 4) Big valve (1.70/1.44") head with pocket port. 5) Big valve with more extensive work and stock port cross section. 6) Big valve with a larger port cross section. This would obviously require 6 different tests at $35 each if memory serves. Hopefully I could get a volume discount. :)

The reasons for each test may not be obvious. 1) Establish a base line. 2) quantify benefit of least expensive modification. 3) Quantify benefits of more labor. 4) Establish benefits of larger valves with basic blending of new valve seat approaches/exits. I feel putting in larger valves without blending is giving up a lot of gain for little labor and I already blended all my valve seats. 5) Quantify gains of more port work without a larger port cross section. 6) Quantify gains of more port work with a larger port cross section.

I would take lots of pictures of each stage of modification with measurements of things like port cross section, valve throat diameter, valve size, valve back cut angle if any.

If I had to pay for all the testing myself I'd probably do just tests #1 and #6. If others would like to contribute to this project, maybe sponsor one test, we can gain more info. If others would like to add a test that I'm able to do I'd be happy to hear your ideas.

I do not plan on testing valves larger than 1.70/1.44" at this time. I feel that larger valves without extensive chamber and cylinder deshrouding may in fact hurt flow. Some of the fastest naturally aspirated slant cars use a 1.72" Chevy valve with big cylinder overbores which gives less shrouding. If someone supplied a head with bigger valves for this test and we had enough donors to cover expenses I wouldn't hesitate to test my theory.

Thoughts?

If enough people approve and the moderators give their blessing I'd like to get started ASAP.
Author:  wjajr [ Mon Apr 13, 2009 4:27 am ]
Post subject: 
Great idea! A lot of work. Very useful information could be gleaned from such a study.

Having just completed a port & bowl job with larger valves project, this multi stage modification analyses would be of interest to me both at the nerd level, and at the cost benefit level as well. I'm not a racer, so all the information for me would be academic, not unlike sound system specifications where one tends to get lost in the numbers, but for the race set, this study would be invaluable. Worthy of a sticky.
Author:  wvenable [ Mon Apr 13, 2009 4:57 am ]
Post subject: 
I would be happy to contibute to the cause. Firm up your prices and let us know. I think this would make an excellent article. I would be very interested in tests 4-6. Shoot me a pm as things progress. Thanks, Wayne.
Author:  66aCUDA [ Mon Apr 13, 2009 5:32 am ]
Post subject: 
Josh
I would be in. Just let us know what /how much you need.
Frank
Author:  runvs_826 [ Mon Apr 13, 2009 11:40 am ]
Post subject: 
I would appreciate and use the information. I'm starting to put together my binder full of slant information, this would be part of it. Great thinking, and thanks in advance!
Author:  rock [ Mon Apr 13, 2009 2:48 pm ]
Post subject:  Joshie, I will pony up for good data any time
Joshie,

I love data. Count me in. Hope it is six tests.

rock
'64d100
Author:  G-Pop Shop [ Mon Apr 13, 2009 2:57 pm ]
Post subject: 
Hello Josh,

You can count G-Pop in for sponsoring one of the heads. Let us know what you need. Thanks,
Author:  Shaker223 [ Mon Apr 13, 2009 3:28 pm ]
Post subject: 
i'll help
Author:  Joshie225 [ Mon Apr 13, 2009 3:47 pm ]
Post subject: 
Thanks for all the offers of support! No one has said anything contrary so we'll push forward.

I just got off the phone with the machine shop. It's normally $60 to do one chamber, but since we'd be doing a few they will charge on an hourly basis. I'm going to take my big valve head down and talk with the shop in a few days to formulate a modification and testing plan. Hopefully they can give me a cost estimate on the testing and only then will I ask for donations.
Author:  Valleyant [ Mon Apr 13, 2009 3:55 pm ]
Post subject: 
Very interested in the results....you can count me in!....nico
Author:  vynn3 [ Tue Apr 14, 2009 3:44 pm ]
Post subject: 
I'll chip in what I can!
Author:  69a100 [ Tue Apr 14, 2009 4:25 pm ]
Post subject: 
Hey Josie- I've been sitting on this info for when I get around to doing my head. FWI, there's some info here that might make you want to delete one of your tests and save some greenbacks, FWIW. http://www.slantsix.org/forum/viewtopic ... rs&start=0
I think it's a great idea to do this.
Author:  Joshie225 [ Tue Apr 14, 2009 4:55 pm ]
Post subject: 
Oh, wow, forgot about that thread. Thanks! Looks like I'll probably just do what I'm going to do with my head and see how it measures up.
Author:  daniel_depetro [ Fri Apr 17, 2009 6:47 am ]
Post subject: 
I think having all the tests done at the same time, by the same tech, at the same shop, on the same flowbench will have much more useful/accurate information.

Testing the same head on two different flow benches can have somewhat different results, let alone how many factors can be changed with different shops testing procedures.

Having all the tests completed at the same time, in the same shop, on the same flowbench by the same tech will definately provide far more accurate data to compare each test against the others.


A test like this would prove to be pretty valuable for the slant six community and it will be nice to have this information on hand everytime someone asks about head flow.


Wow I had no idea the slant head flowed that poorly. I knew it was bad, but didn't think it was that bad. :shock:
Author:  Polara1974 [ Tue Jul 28, 2009 8:14 pm ]
Post subject: 
I know this has a few months, and I know I'm pretty far away (Argentina), but if you could think any way of me helping on this... COUNT ME IN!!! (maybe paypal?)

I'm in the process of planing my new Slant 6 rebuild and I have all pretty much figured out except the head ... and this ... this is what I need!!!
This is what everyone needs!!! Great proyect!!!
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