measureing a pipe

[talonxracer]

I have just started to get the new MAC21ob and Nemesis going and need to know exactly how to measure for the pipe. I have recieved alot of ideas from some friends but they all gave conflicting stories,,,I B So Confused! I measure from the center of the head(glo plug) along the center lineof the spp pipe to where on the pipe?

Doug

 

[james irwin]

I have just started to get the new MAC21ob and Nemesis going and need to know exactly how to measure for the pipe. I have recieved alot of ideas from some friends but they all gave conflicting stories,,,I B So Confused! I measure from the center of the head(glo plug) along the center lineof the spp pipe to where on the pipe?

Doug

HEY TALON , IF YOU HAVE MY PIPE ON , TRY THIS, CUT IT AS SHORT AS POSABLE , HEADER AND PIPE , NOW HEAD TO THE LAKE , TRY THIS , GO FOR THE TOP END FIRST, GET YOOUR BOAT COMPLETELY DIALD , NOW REMEMBER HOW YOU CUT THE HEADER AND PIPE TRY ING TO GET IT SHORTER , SART TRIMING AGAIN . ONLY THIS TIME YOU WATC IT IN THE CORNERS. WHEN YOU SEE IT START TO SAG , THEN STOP. YOU HAVE WENT TO FAR , ( ON THE LAST CUT ) NOW PULL THE PIPE BACK OUT 1/4 INCH . YOU CANT BE ANY BETER THAN HIS . LOL JAMES IRWIN

 

[talonxracer]

Thnx James, I have your pipe and a Cooper and a SPP21ob06. Too many to really try all of them but heck whats there to loose? Time? got lots of that!!!

Doug

 

[Jerry Wyss]

I have just started to get the new MAC21ob and Nemesis going and need to know exactly how to measure for the pipe. I have recieved alot of ideas from some friends but they all gave conflicting stories,,,I B So Confused! I measure from the center of the head(glo plug) along the center lineof the spp pipe to where on the pipe?

Doug

Hey Doug, I do it the way the "Jennings Book" say's,, that would be last paragraph

post 14, page 1 in "MAC 21" in this forum.

In the Jennings book (2 Stroke Tuners Handbook) you run the "PLAN" formula for all

the information asked for and it will put you real close to the right length. It did mine

and it was so close that it was actually exciting,, it came out "8.2" inches,,well jeez, guess where I run it.

8 1/8th

 

[Ronald van Essen]

I have just started to get the new MAC21ob and Nemesis going and need to know exactly how to measure for the pipe. I have recieved alot of ideas from some friends but they all gave conflicting stories,,,I B So Confused! I measure from the center of the head(glo plug) along the center lineof the spp pipe to where on the pipe?

Doug

Doug,

the measuring, isn't that to the part where the pipe is the widest?

Ronald.

 

[RodneyPierce]

Doug,

the measuring, isn't that to the part where the pipe is the widest?

Ronald.

Yessir. It is teh wides point on the pipe, or if it is welded, they are usually welded at the widest point, so you can measure to there.

 

[talonxracer]

Doug,

the measuring, isn't that to the part where the pipe is the widest?

Ronald.

Yessir. It is teh wides point on the pipe, or if it is welded, they are usually welded at the widest point, so you can measure to there.

Yep that is what I have used in the past. But with the darn SPP ob pipe it is kinda touch and go as far as that location. Using a pair of calipers I searched for the widest part, and I found that a vertical measurement and a horizontal measurement had the wide portion at different spots about 3/8" apart, kinda a hit or miss measurement. Just gonna have to play around with it, I will split the difference and go from there.

Doug

 

[RIGGERMORTISE]

Doug,

the measuring, isn't that to the part where the pipe is the widest?

Ronald.

Yessir. It is teh wides point on the pipe, or if it is welded, they are usually welded at the widest point, so you can measure to there.

Yep that is what I have used in the past. But with the darn SPP ob pipe it is kinda touch and go as far as that location. Using a pair of calipers I searched for the widest part, and I found that a vertical measurement and a horizontal measurement had the wide portion at different spots about 3/8" apart, kinda a hit or miss measurement. Just gonna have to play around with it, I will split the difference and go from there.

Doug

Sorry Doug

I must have missed this post, its been a heavy week. If the pipe came to you with the pressure nipple already installed then this is the point that you need to measure from.

If it was not factory installed just pm me and I will send you the details so you can calculate it. On light fast boats set the pipe to 8.5" and shorten from there. If the boat is a nemesis or simalar longer hull then set it at 8.75" and then shorten. If you are using a MAC these will work. if you run a nova then expect to go realy short!!!

I wish I had a nova pto and crank!!

Regards

Dave

 

[talonxracer]

Thnx Dave! I figured that it was gonna be the middle of those measurements and tune from there. Now that both of my questions have been answered I can start having fun! Thnx alot guys!!!

Doug

 

[boaterbill]

I have just started to get the new MAC21ob and Nemesis going and need to know exactly how to measure for the pipe. I have recieved alot of ideas from some friends but they all gave conflicting stories,,,I B So Confused! I measure from the center of the head(glo plug) along the center lineof the spp pipe to where on the pipe?

Doug

Mike Z. of Power Surge Products used to make a template for measuring the pipes attached to the 180 deg headers. Pipe Measuring Tool #115. Easiest tool to use, very simple. Don't know if he still has them. He's the leader of the Outboard Forum on this board. Gary Preusse might still have some. I'll ask him next time I talk to him. Just talked to Gary, he has them in stock, 630-279-2451.

Bill

Mikes Pipe Measuring Tool measures from the center of the glow plug then down the middle of the header out to the pipe. Always works for me and the guys that I know that uses it.

Personally knowing Mike to be a perfectionist, I'm sure he didn't pull the design out of thin air. Oh well, You can lead a horse to water ---------------------------------------------------------------------.

 

[Jerry Wyss]

Yeah, You can have a measuring tool but I think it's still ,"up in the air" as where to measure,

To and From.

We have people talking about the widest point,,,, some pipes have a "constant diameter"

center section,,, where is it?,, "somewhere in there?". You can get way off with that kind of info.

Many here should sit down and read some of the VAST info on this subject,, specially about

"From Here to There"

(Bill, your missing my point, it's not directed at you , MikeZ or his tool.)

 

[boaterbill]

Yeah, You can have a measuring tool but I think it's still ,"up in the air" as where to measure,

To and From.

We have people talking about the widest point,,,, some pipes have a "constant diameter"

center section,,, where is it?,, "somewhere in there?". You can get way off with that kind of info.

Many here should sit down and read some of the VAST info on this subject,, specially about

"From Here to There"

(Bill, your missing my point, it's not directed at you , MikeZ or his tool.)

Jerry,

I didn't think it was directed at me or Mike. I understand your point. I agree with what you are saying. It's, in my point of view, that no matter what one says another will come up with a different thought, thereby unvalidating a good source, and off they go chasing whatever, this is what I meant by leadig a horse-------------.

Bill

 

[Jerry Wyss]

oh, never mind No really, tuned pipe stuff was a big mystery to me too not too long ago.

Just a little reading and figuring did away with most of the mystery,, it was fun and a little hard but

well worth it.