CMB 45RS or 45HR for SGX45 ???
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Duck899
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Either engine is a good choice.....In my opinion, I would go with the HR as it is better suited for a hydro. It is more of an rpm engine while the RS is more torque related in its operation. The mac is unobtainable but by using the HR, you have the option of using the mac at a later date. The RS is also shorter in length and requires a different layout in the engine bay and then to convert to the HR or mac later will require re-work. The RS is also more work maintenence wise as well.....As for pipes, the parabolics work well on the HR.....I'm using the mac 10cc airplane pipe on the RS in a mutt sport hydro because the parabolic and Irwin pipes did not work as well.....
Cheers
Cheers
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steve wood
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the hr and the rs, as well as the older purple head use the identical piston and liner, as well as the head button. the timing numbers are the same on all 3 engines,. stu runs the rs because the carb on the hr sits high and won't fit under the cowl. i don't care for the hr drum rotor. its too much like a mac and i don't like those. the rs runs extreemly well in a hydro , and will turn as much rpm as an hr. they take a little more work to set them up than the hr, though. the new cooper is working very well in monos, but i have no info in a rigger
So does the HR fit under a SGX cowl (without mods)???
And please post results from your XT testing.
ALLAN YUEN
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I am very glad CMB45 HR with CMB header long onto AB Black 45 muffled pipe for my SGX45 and great fast . I tired switched new Andy CNC 45XTP only fit CMDI header tapped(another CMB header wont fit tapped too big) in few month ago and run bit of slow because my CMDI header tapped was short. My good friend built homemake extra 1inches pipe tapped welding onto 45 XTP and better more fast than Brown 45 Parabolic pipe. I can see compare three different CMDI pipes . Yes the HR fit under the SGX cowling My second opionion is better HR than RS for only SGX 45 another better RS for mono,sport 40 and Rigger (Crapshooter and Roadrunner fit under cowling) but depend carb on room tank Cheers Allan
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ALLAN YUEN
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most use 1/4-28 thread collet
Buckshot
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Yes it fits under the SGX cowling with out modifications. It is a direct bolt in from MAC .45 to CMB .45 Hr.
Ran well with the new 45 XT pipe yesterday. Set at 10.5" to the end of the flat band to start.
Seems to hit a little harder (due to harder material?) than the Parabolic.
It will run at a shorter setting and rev really well. It had good drivability allowing the ability to mill the course and return to speed very easily.
I'm very happy with the pipe on my set up.
I also ran the new 21 XT pipe on my SGX-1/MAC .21 and all I can say is WOW.
It's nice when things work correctly!
Regards,
-Buck-
dwb2620
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Buckshot,
Sorry , I couldn't make it yesterday. Just saw your IM late last night. I would have liked to have seen how your boats ran with the new pipes as I run the same boats and engine combos.
David
mark voorhies
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Tim, what pipe are you runnin, and what lenght?
Hey Buck!
What length on the parabolic and also what prop works best?
Thanks
Rich
IMPBA 4510
Buckshot
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I was running around 9.4" with the parabolic pipe and a 1655 with 4.4" cup.
Regards,
-Buck-
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Tim Kish
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