New sport 40

[Lay26]

in my humble opinion i would try shorting the pipe it sounds like it might be too long. if you run a smaller prop you could shorten the pipe like 10 1/4 if you run a big 1400 series prop try 10 3/4 and a shallow strut

also what was suggested about the pipe you may want to take into consideration. The Aero 10 cc pipe is really good, also a ops 67 pipe with the stinger reduced and with the muffler it sings as well.

 

[Glenn Gates]

in my humble opinion i would try shorting the pipe it sounds like it might be too long. if you run a smaller prop you could shorten the pipe like 10 1/4 if you run a big 1400 series prop try 10 3/4 and a shallow strut

also what was suggested about the pipe you may want to take into consideration. The Aero 10 cc pipe is really good, also a ops 67 pipe with the stinger reduced and with the muffler it sings as well.

I do have what I think is a ops 67 pipe and the stinger I.D. is only .010" bigger than the parabolic. I can try that or borrow a Muck pipe and muffler to try also. Will do more testing Sunday and try a few different props also.

Thanks,

Glenn

 

[Lay26]

on the ops pipe you have to reduce the stinger diameter....i have to check my notes on the number, but i used some brass tubing and reduced it...if i had to do it again i would have made it like a bushing and soldered the tubing and hand press/hammer tap it into the pipe...just a thought

 

[griz2575]

I run a pt sp 40 with a cmb45 rs. It has a AB parabolic pipe set at 9 3/4 inches running 60% technology fuel turning a x646/3 blade prop. When you use a parabolic pipe I have found that you have to run it shorter on the rs. When I first switched to the rs I saw the same thing happening. Shorten it and hang on!!!!!!!

Where do you get technology fuel?

 

[tnrcboatracer]

X646/3 seems small, also low lift. I run a 1455 on my Betke SP40.

 

[Glenn Gates]

X646/3 seems small, also low lift. I run a 1455 on my Betke SP40.

Gotta remember I run @ 4300 ft elevation- Don't know anyone who runs a prop over 47 MM here-but it's not gonna stop me from trying!

glenn

 

[Mike Culhane]

Where do you get technology fuel?

John Otto, Technology Hobbies,1-813-651-1840

 

[tampa1330]

X646/3 seems small, also low lift. I run a 1455 on my Betke SP40.

I ran a 1455 on my pt sport 40. It screamed. It had 3.2 cup, if I remmeber correctly. I think that prop and the pipe length might be your problem. I've found the 6 series octura props don't do too well on the sport hydros. I think the 2 blade prop with a lower pitch lets the engine rev up higher in the powerband.

 

[Glenn Gates]

X646/3 seems small, also low lift. I run a 1455 on my Betke SP40.

I ran a 1455 on my pt sport 40. It screamed. It had 3.2 cup, if I remmeber correctly. I think that prop and the pipe length might be your problem. I've found the 6 series octura props don't do too well on the sport hydros. I think the 2 blade prop with a lower pitch lets the engine rev up higher in the powerband.

Thank's tampa 1330, It's a whole different ball game up here @ 4300 ft. Most run the X447/3 or X448. With pipes around 10-10 1/2". I did notice one 45 mono running very well last weekend and went over and looked at it .The prop looked very familiar- The owner removed the prop and it was a X646/3. best results so far-Texas cut P-230(3.04 pitch). Also found weak TX batteries that may not have been able to hold throttle wide open. Open water tomorrow and a LOT of props to try.

Glenn

 

[tampa1330]

"It's a whole different ball game up here @ 4300 ft."

This is true. One reason why I don't mind dealing with the killer florida heat. Have you seen anyone running any 14 series props. I ran a x455 and ther was no way my CMB could even come close to swinging it but the 14 series with a little cup did the trick.

 

[Glenn Gates]

"It's a whole different ball game up here @ 4300 ft."

This is true. One reason why I don't mind dealing with the killer florida heat. Have you seen anyone running any 14 series props. I ran a x455 and ther was no way my CMB could even come close to swinging it but the 14 series with a little cup did the trick.

I do have a few 1400 series props(some cut down to 48 MM) I'll give em a try tomorrow. More lift may help.

Thanks,

Glenn