SF Sizes

[Chad Speier]

IMO, they DM and Black Box are two different type units. The Black Box uses the correction factors you enter, either off your bench or your re-calibrated numbers. Doesn't ask for orifice size, cd's, etc. It's only taking what the manometer reads in the software and doing the calculating for you. The BB is a good unit FOR THE SF, because there is NO WAY that bench will be accurate using only one orifice hole. The software allows you to click a box to change it to another factor.

I rotate the disk on the SF.

[larrycavan]

IMO, they DM and Black Box are two different type units. The Black Box uses the correction factors you enter, either off your bench or your re-calibrated numbers. Doesn't ask for orifice size, cd's, etc. It's only taking what the manometer reads in the software and doing the calculating for you. The BB is a good unit FOR THE SF, because there is NO WAY that bench will be accurate using only one orifice hole. The software allows you to click a box to change it to another factor.

I rotate the disk on the SF.

Never used the BB so I'm unfamiliar with it's calibration procedure. However, all the boxes do the same thing essentially. Measure a pressure differential.

As for the 600 being unable to be accurate using a single orifice with say a DM, I would have to disagree somewhat. I believe that's relevant to the amount of air you need to pull through the bench for the type of heads you port. It's precisely there that the cabinet design of the 600 causes problems [IMHO].

It's my "personal" point of view that SF's method of increasing bench capacity via additional motors and and a change of gauge oil S.G. is flawed. Cabinet Capacity and flow chamber were set aside in order to be cost effective for production at the expense of accuracy.

Now...all of that is arguable and we could have one hell of a debate on that My quest is to obtain, if possible, conclusive results on the effect the cabinet design differences of the PTS vs the SF benches themselves. It is my belief at this time that the PTS is superior in design regardless of the gauges used to measure the pressure differential.

That said if you can find the time. If you are truly as determined as you first appeared to be to nail down some important data that can be analyzed by all of us in determining why the head backed up in flow on the SF but didn't on the PTS Bench, please do. You are the only person I know who has the proper equipment to do that at this point in time. Maybe that's asking too much..... That's up to you to decide.

Regards,

LC

PS - I'm not trying to sell benches or manometers for Bruce. Just calling things as I see them. If there's a superior bench design...if it's proven that neither design is superior..... let the chips fall where they may. That was once the primary focus of this forum...a collective effort by the people to share results and information so that we can all learn from it.

By the same notion, I wish Bruce all the success he's deserving of in sales of his products. They're as good as anyone else's....quite possibly better than some as well.

[Chad Speier]

I can, and I will. It's going to be awhile however. I can't dig my way out right now and need to find some time.

[SWAirflowServices]

Cabinet Capacity and flow chamber were set aside in order to be cost effective for production at the expense of accuracy.

I will be using that quote. AWSOME!

Shane

[Chad Speier]

I have had some time to dial the SF and Black Box in. The results are tighter.

#1 Test- PTS w/PTS elctronics. 3.200 plate with a .595 factor
#2 Test- SF no electronics reading manometer using bench factors
#3 Test- SF w/BBII and NEW factors
#4 Test- SF w/BBII and NEW factors w/test on #5 hole
#5 Test- SF w/BBII and OLD factors w/test on #5 hole

.200 141.1/141.6/144.5/146.0/144.1
.300 227.6/222.6/226.9/228.1/225.9
.400 287.8/281.3/285.9/285.2/281.4
.500 318.3/314.8/319.6/321.0/316.7
.600 350.2/341.4/348.2/347.9/343.3
.700 368.6/358.2/367.1/365.9/361.0
.800 383.5/374.0/383.4/381.8/376.9
.900 396.2/386.0/394.6/391.9/386.6
1.00 405.8/391.8/401.8/398.6/393.3

[larrycavan]

I have had some time to dial the SF and Black Box in. The results are tighter.

#1 Test- PTS w/PTS elctronics. 3.200 plate with a .595 factor
#2 Test- SF no electronics reading manometer using bench factors
#3 Test- SF w/BBII and NEW factors
#4 Test- SF w/BBII and NEW factors w/test on #5 hole
#5 Test- SF w/BBII and OLD factors w/test on #5 hole

.200 141.1/141.6/144.5/146.0/144.1
.300 227.6/222.6/226.9/228.1/225.9
.400 287.8/281.3/285.9/285.2/281.4
.500 318.3/314.8/319.6/321.0/316.7
.600 350.2/341.4/348.2/347.9/343.3
.700 368.6/358.2/367.1/365.9/361.0
.800 383.5/374.0/383.4/381.8/376.9
.900 396.2/386.0/394.6/391.9/386.6
1.00 405.8/391.8/401.8/398.6/393.3

On which test did the head make the most HP

Just kidding..... Looks like with the new factors on the SF, in whatever range test #3 was conducted, is pretty closely inline with the PTS bench.

Question is this....which numbers do you believe are correct?

[Chad Speier]

I have had some time to dial the SF and Black Box in. The results are tighter.

#1 Test- PTS w/PTS elctronics. 3.200 plate with a .595 factor
#2 Test- SF no electronics reading manometer using bench factors
#3 Test- SF w/BBII and NEW factors
#4 Test- SF w/BBII and NEW factors w/test on #5 hole
#5 Test- SF w/BBII and OLD factors w/test on #5 hole

.200 141.1/141.6/144.5/146.0/144.1
.300 227.6/222.6/226.9/228.1/225.9
.400 287.8/281.3/285.9/285.2/281.4
.500 318.3/314.8/319.6/321.0/316.7
.600 350.2/341.4/348.2/347.9/343.3
.700 368.6/358.2/367.1/365.9/361.0
.800 383.5/374.0/383.4/381.8/376.9
.900 396.2/386.0/394.6/391.9/386.6
1.00 405.8/391.8/401.8/398.6/393.3

On which test did the head make the most HP

Just kidding..... Looks like with the new factors on the SF, in whatever range test #3 was conducted, is pretty closely inline with the PTS bench.

Question is this....which numbers do you believe are correct?

I'm to the point, it doesn't matter to me. I want to advertise the larger ones, but I don't. I advertise the SF numbers with the new factors, because if people would use some common sense, the bench numbers posted are for a 25" drop. Now, I use the PTS WAY MORE because I can pull some serious drop and that is key to me.

At the end of the day I would build a PTS, buy a PTS/DM and be just be happy!

I learned a lot and that was the goal of this mission. However, I want to be honest here. A head that works properly. Meaning, velocity and choke are in check, will show these type results. A cylinder head with issues, like too fast speed, etc,,, the SF still reads OK but the PTS will find it in a HURRY! In other words, the curve will reflect it. Make sense??

[larrycavan]

No flow bench is worth it's weight in bricks if the guy using it doesn't understand those key elements. What you've accomplished was worth the effort. The testing has resolved a lot of issues, brought forth by other people, including customers. You're better informed to explain things now. As to how well they listen......that's a crap shoot.

You have 2 repeatable benches. Either could be used to accomplish good port work. Not because one is remarkably superior over the other but because both are calibrated properly and you have the knowledge of how to correctly use them to solve problems.

I have said in the past and will continue to say until someone proves me wrong. The most accurate orifice flow bench is the one with the cabinet properly designed for the capacity of air it needs to move at the test pressure you need to move it at

Orifice xxx flows yyy cfm under varying conditions of turbulence influence. Eliminate the turbulence....get a more stable, more accurate measurement of a pressure differential. Sounds easy. But it's not.

[Bakerlite]

I have said in the past and will continue to say until someone proves me wrong. The most accurate orifice flow bench is the one with the cabinet properly designed for the capacity of air it needs to move at the test pressure you need to move it at

What would be a good way to calculate that?

[Flash]

I have said in the past and will continue to say until someone proves me wrong. The most accurate orifice flow bench is the one with the cabinet properly designed for the capacity of air it needs to move at the test pressure you need to move it at

What would be a good way to calculate that?

The head isn't any different then the flow bench.You are trying to get the smoothes air flow from the bench, aka as little turbulance as possable for the air flow you are striving to get!