V-Twin Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
2,300 Posts
Went and read the new website.

Noticed this forum is posted there on the link page.

So, what is your relationship with the company?

If you wanted to we could exchange information as we do some R&D in particular as it applies to late model EFI Harley engines, and we have a thing or two of our own.
BTW, ordered another set of the valves this morning and will build something with it, I'll let you know where it takes us.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #3 · (Edited)
ATAP is just helping to promote the technology For the Harley and V-Twin applications. The financial interest or gains would be defered to folks like yourself that actually build motors, sell bike parts, and basically know what you're doing.

I think that you will be surprised by the results you get. Send a dyno sheet when you're done, and it will be posted up on the site as well.
 

·
Registered
Joined
·
132 Posts
usdm said:
ATAP is just helping to promote the technology For the Harley and V-Twin applications.
I've been reading this page over the past few months and I guess I'm gonna show my stupidity - but I got a question about page two of your explanation of how it works.

Your diagrams show the exhaust valve closed and the intake opening about 0.050 at or after TDC as I remember the diagram and the smart valve seat begining to do it's stuff at this point.

As Iunderstand cam grinds, the exhaust valve and intake valves are open at the same time (typically referred to as valve overlap) at the point shown on your diagram - so the diagram depicting how it works leaves me wondering how the valve overlap period affects it, and too wondering why this overlap was ignored in the discussion.

Too I am lost as to how (taking one intance of time - freezing the action in other words to talk about it) the smart seat makes a difference. Seems to me that if the valve (no smart seat) is open 0.050 then that is the gap available for gas/air mixture to enter - if the valve seals against the smart seat and opens 0.050 and the seat opens (floats whatever) the gap is still going to be 0.050 or very very close to that.

Not trying to be a smart $ss here just trying to understand.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #5 · (Edited)
Your diagrams show the exhaust valve closed and the intake opening about 0.050 at or after TDC as I remember the diagram and the smart valve seat begining to do it's stuff at this point.

As Iunderstand cam grinds, the exhaust valve and intake valves are open at the same time (typically referred to as valve overlap) at the point shown on your diagram - so the diagram depicting how it works leaves me wondering how the valve overlap period affects it, and too wondering why this overlap was ignored in the discussion.
Not all cams run overlap. In fact some ic engines run negative overlap.

As to how the Smart Valve would affect the overlap? It can reduce it @ low rpm, among other things. This is due to the floating seat responding to the pressure between the chamber and intake tract. It allows for the use of cams that you could not ordinarily use without sacrificing some low-midrange power and torque.

As to overlap being ignored, not sure about that. But I will try to edit the site to allow for more devotion to that particualr issue.


I Too I am lost as to how (taking one intance of time - freezing the action in other words to talk about it) the smart seat makes a difference. Seems to me that if the valve (no smart seat) is open 0.050 then that is the gap available for gas/air mixture to enter - if the valve seals against the smart seat and opens 0.050 and the seat opens (floats whatever) the gap is still going to be 0.050 or very very close to that.
The significance of the floating seat is the ability to alter the openning and closing events on the intake side as a direct effect of pressure changes in the intake tract and combustion chamber. So, if the pressure in the chamber is high during the overlap phase, the floating seat can help reduce the amount of exh gas the dillutes the fresh charge, even if the int. valv is already openning. Or, if the chamber starts to go into the compression phase, the floating seat can help retain more a/f to promote potentially greater power through combusting more a/f.

Hope that answers your questions.
 

·
Registered
Joined
·
132 Posts
Thanks for your response - I really am trying to understand this, but

usdm said:
The significance of the floating seat is the ability to alter the openning and closing events on the intake side as a direct effect of pressure changes in the intake tract and combustion chamber. So, if the pressure in the chamber is high during the overlap phase, the floating seat can help reduce the amount of exh gas the dillutes the fresh charge, even if the int. valv is already openning.
As Iunderstand the way it works, and maybe my understanding is just too simplistic - if so please tell me, as the piston rises on the exhaust stroke and 'pushes' the exhaust out of the opening exhaust valve the intake valve is closed. On Harleys usually around 30 degrees BTDC (or earlier with aggressive cam grinds) the intake valve starts to open. At this point in time, all things being optimum, the flow of exhaust out of the pipes is causing a slight vacumm (reversion) and is helping to pull out the exhaust and pull in the air/fuel mixture. I would think that the exhaust gas inside the cyclinder is turbulent and under pressure. You say, if the pressure in the chamber is high during the overlap phase, the floating seat can help reduce the amount of exh gas the dillutes the fresh charge, even if the int. valv is already openning." and this confuses me in light of my understanding. the pressure would be high and the intake valve would have to be open for the smart seat to do anything to the fresh air/fuel mix. I can't see how the smart seat will affect the dilution effect of fresh air/fuel and spent gas.

I have some time today so I can go back and review your pages again - been hectic here lately and I just have been too tied up to do anything - or too tired. Again thanks for your time and patience.
 

·
Registered
Joined
·
2,300 Posts
But I will try to edit the site

Desmo is not VVT. Doesn't look good.


If I may make a suggestion. Every time one sends an e-mail one keeps getting referred to a phone# instead of getting technical answers by e-mail. This is a problem as often ideas or thoughts cross one's mind that are forgotten by the time you get around to make the call and then you don't have a record of the exact technical nuances mentioned. CRS you know.
Promotion might be more effective if you also use the e-mail. Just a thought.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #8 · (Edited)
HIPPO said:



Desmo is not VVT. Doesn't look good.


If I may make a suggestion. Every time one sends an e-mail one keeps getting referred to a phone# instead of getting technical answers by e-mail. This is a problem as often ideas or thoughts cross one's mind that are forgotten by the time you get around to make the call and then you don't have a record of the exact technical nuances mentioned. CRS you know.
Promotion might be more effective if you also use the e-mail. Just a thought.
The Desmo has been the subject of debate among a few folks. I have always followed th line that it is a form of vvt, others don't see it that way. Great thing about America; we can agree to disagree;)

As for the emai thing, i hear you. One of the problems is that there are so many folks that email for basically the same stuff, so it was decided to do things a little different. The majorty do not pose technical questions, they just want to know when the valve will be ready, or can a gb, etc.

As far as being refered to other numbers, i can only recall sending you the 800 one. if you have more, disregard them and use that for now,
 

·
Registered
Joined
·
2,300 Posts
The Desmo has been the subject of debate among a few folks. I have always followed th line that it is a form of vvt, others don't see it that way. Great thing about America; we can agree to disagree




Yup, we sure disagree on this, but it's no problem to agree to disagree.
The AcroTech fella called back today and we had a interesting conversation that lasted over an hour, but in the end he referred me to the Bob fella in CA. Real hard to get hold off dude, but I'll try again tomorrow.
Valves should be here tomorrow also and as soon as the heads get welded up the chips will start to fly.
 

·
Registered
Joined
·
132 Posts
usdm said:
no problem. give your number, and I will contact you direct [/i]
Well thanks for the offer, but I am a hands on type who has to read things several times to get it straight in my mind so talking about it would only drive you nuts - I'll just watch and read what others have to say about it -I'm sure on the 6 lists and 12 forums I visit each day it will come up - (lot of techies on them). Again thanks for your time.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #12 ·
Yeah, Mr Lamadu (Bob), stays busy. He is the person that built the bike described on the Harley page. I will see if I can locate his other number, as he bounces between his work sites.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #13 ·
Rustler said:

Well thanks for the offer, but I am a hands on type who has to read things several times to get it straight in my mind so talking about it would only drive you nuts - I'll just watch and read what others have to say about it -I'm sure on the 6 lists and 12 forums I visit each day it will come up - (lot of techies on them). Again thanks for your time.
:D

Yes, it can be like that sometimes. And I reached nuts about several months ago on some unrelated stuff. It's ok as long as I take my meds, though.

Oh, I only posted it here, so I don't know if anyone would be discussing this anywhere else yet.
 

·
Registered
Joined
·
2,300 Posts
I will see if I can locate his other number, as he bounces between his work sites.

Thanks, that might help as he doesn't seem to have voice mail.

At least we have a target, 111 lb/ft with a 95", shouldn't be a problem if the things pull just a few lf/ft. :D
I actually wanted to have a copy of the dyno sheet of the bike to take a look at the area under the curve, and Reggie was leaving on a trip for a week, but he did mention that the ones on the way were built with .055" lift as opposed to .045" like the ones on the site.

Hope it doesn't turn into one of those "I show you mine if you show me yours" things. One would have expected to find the sheet of that bike on the website.

I can be found HERE, usually get in around 10 am or so.
 

·
Registered
Joined
·
2,300 Posts
Update. Got hold of Bob today. Super nice fellow. Interestingly when we exchanged e-mail adresses I realized that we knew of each other. Small world.


Also got the valves, didn't get to do much, but we threw them in a stock head and ran it thru the flow bench.

At 10" H2O the flow at .050" increments is 13, 15, 30, 38, 52, 70, 88, 101, 106, 108, 108, 108 cfm.

A few obvious things. With stock ports they run into a wall at .500" lift, any cam over that is pi$$ing into the wind.

They flow about 10 cfm less then stock valves in a stock head.

But,

if you change lift at certain points the flow takes a big temporary jump and then stabilizes again. It can be nothing but the secondary valve seat positioning itself even though the flow is only in one direction, ie no reversion, no pressure in the ports at the base and a stationary valve. There might be something to it after all.

I'll post the flow #'s with the welded heads and stock valve sizes when we get around to it.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #16 · (Edited)
Good deal with the contact. Saved me some extra work.:)

One thing that has been consistent in almost all the bikes tested, was an increase in the hp/ tq curves. Some of them were bigger than others, with the smallest gains being the setup on the bike with the cv carb. So unfortunately, it is hard to come up with a hard number regarding power gains. Each setup will reap different numbers, but they would still be impressive for the amount of money invested.

It was expected that some of the flow may be affected by the design of the valves themselves. But as time progresses, and there is valuable feedback coming from folks like you and mr Lamadu, the design can only get better. Not too long ago, the best the could be gotten for independant lift of the floating seat, was .045". Now up to .050"-.055". Step by step, inch by inch..........

I think i may have a copy of the dyno for Mr Lamadu's setup, just have to locate it in one of my folders. The graph is fairly poor, so i did not try to upoad to the site. But if you wish, i can try to send you a copy via fax to look at.
 

·
Registered
Joined
·
2,300 Posts
Just try to e-mail it.

[email protected]

The #'s don't mean much other then beating the next guy over a beer, but it's always interesting to see what trend things follow.
If the a$$ dyno is happy, everyone is happy, that's all there is to it.


The main body of the valves very much resembles stock HD valves. I bet that going to a base valve along the lines of a tulip Kibblewhite Black Diamond would make a significant difference.

How do you keep the ports in the main body from carboning up?
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #18 · (Edited)
HIPPO said:
The main body of the valves very much resembles stock HD valves. I bet that going to a base valve along the lines of a tulip Kibblewhite Black Diamond would make a significant difference.

How do you keep the ports in the main body from carboning up?
That valve design could be something to look into.

As for the carbon issue, the Smart Valve design helps promote self cleaning. The ports serve a variety of functions:

the exhaust gasses or intake charge in the chamber, go through the ports to push up the floating seat to close off the intake tract. This is what helps the floating seat close up against the intake tract, to eliminate or reduce reversion tendancies.

the ports are angled to help promote swirl

during the main valve closing, with the floating seat in the closed position against the intake tract, gasses or fresh charge trapped by the floating seat help to cushion the main valve from shock (commonn with heads running big lobe cams and stiffer springs).

as the main valve closes on top of the floating seat, the cushioning medium is pushed back through the ports of the main valve. This helps reduce any residue from attaching to the valve, flaoting seat, and ports.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #19 ·
Hippo ,

Good to talk to you over the phone.

Got tied up with some stuff recently, so i didn't get the time to send out the graphs to you. I am going to send them today. Sorry for the delay.
 

·
Registered
Joined
·
2,300 Posts
Don't worry, Charlie came back from MT for a couple of days, and we got the graphs. They look good.

We will run a couple of alternative flow bench tests. We are coming up with some unusual numbers, we just have to learn to interpret them correctly as conventional thinking probably does not apply, but we want the #'s anyway to compare them to what we get later in real life.
Maybe we'll play with seat shape a little.
 
1 - 20 of 22 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top