O.S..18 MACS header 4 Nitro Vee
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O.S..18 MACS header 4 Nitro Vee
I am installing a O.S. .18 CVR-MX in a Nitro Vee.I'm going to use MACS marine header #2043.My question is -how many pressure fittings should I use?? What does the pressure fitting do?,is it important?. The Nitro Vee TRX PRO .15 stock has 3 fittings on header,can I get good preformance with 1 on flat of header where it bolts on ?? Like image at www.macspro.com .
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RE: O.S..18 MACS header 4 Nitro Vee
I don't know alot about it,MACS web site says they don't recommed putting fittings on the pipe. What's a mouse motor boat???
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RE: O.S..18 MACS header 4 Nitro Vee
I call them mouse motors because they are the small-blocks of boating, under .21's.
Why they wouldn't put them in the pipe or recommend having them there, I have no idea why they would say that.
You also have to watch how you spell Mac as they get confused with MAC, the engines from Competition Marine Design a.k.a. Andy Brown.
Why they wouldn't put them in the pipe or recommend having them there, I have no idea why they would say that.
You also have to watch how you spell Mac as they get confused with MAC, the engines from Competition Marine Design a.k.a. Andy Brown.
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RE: O.S..18 MACS header 4 Nitro Vee
It says it may weaken header pipe,and theres "unusual pressure waves"on muffler part of tuned pipe.It's called MACS products at www.macspro.com , sorry for any confusion.
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RE: O.S..18 MACS header 4 Nitro Vee
True, you never put the fuel pressure fitting in the muffler but just ahead of the divergent/convergent cone.
Some manufacturers of Ready To Run boats put them wherever they're convenient which is not neccssarily the correct place.
Jim Irwin did a lot of testing years ago on the proper size and position of the fuel pressure fitting. His conclusions were to place it at the divergent/convergent cone are using the smallest pressure fitting available, the Du-Bro with the 4-40 threads for any sized engine. Agree or not, those were his findings.
Some manufacturers of Ready To Run boats put them wherever they're convenient which is not neccssarily the correct place.
Jim Irwin did a lot of testing years ago on the proper size and position of the fuel pressure fitting. His conclusions were to place it at the divergent/convergent cone are using the smallest pressure fitting available, the Du-Bro with the 4-40 threads for any sized engine. Agree or not, those were his findings.
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RE: O.S..18 MACS header 4 Nitro Vee
O.K. I'm feeling dumb now. What is divergent/convergent cone?? Thanks for your help. I was going to use a big fitting(10-32),thinking bigger is better.The smallest I have is 6-32,I'm thinking of putting it in the fat part of my tuned pipe, will this work?? Thanks again.
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RE: O.S..18 MACS header 4 Nitro Vee
You have basically 2 cones that make up a tuned pipe as we know it. There are some other styles like the "ringed" and "hot dog" shaped pipes but forget those for now. The cones each are parts of the whole pipe, one being the convergent and the other the divergent cone. This is why I find it easier to say "the fat part orf the pipe" as that is where the two cones meet.
You can use the 6-32 if you don't have the 4-40 handy as yes, it will work.
You can use the 6-32 if you don't have the 4-40 handy as yes, it will work.
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RE: O.S..18 MACS header 4 Nitro Vee
another thing on the nitro vee, first off yeah the stock header is way restrictive, secondly it has three, 1 for the cooling water exit(which the cooling should be changed anyway). 2nd is on the back and goes to the tank for pressure(so theres one we need), 3rd is on the underside and a line leads from it to a fitting on the driveshaft(exhaust residue gets pushed through here a little at a time and lubes the driveshaft(so I'd put to on there) so I'd say one on the manifold for the lube(bottom of the manifold), and one in the pipe...