RR Rated M For Mature
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 855 ONLINE 18 EVENTS SEARCH REGISTER  START HERE
 
1 page490 viewsPOST REPLY
Boca Bearings . XHELI.COM . Autography FlightPower

.
.
HIROBO Turbulence - SDX - Freya - Sceadu > X-Spec Engine Swap
 
 
tjn
Senior Heliman
Location: Paris Crossing, IN

My Posts This: Topic  Forum
I cracked the piston in my YS80 this weekend. I'm looking to swap it with a OS91 C-spec with pump. Currently running 8.45 gear ratio on the YS. Going to switch to 7.91 ratio for the OS. Will the fan assembly fit the new engine, or will I need to purchase additional parts? The manual shows part 0404-012 (pulley washer) being good for OS and YS.

I would have put a YS91 in, but can't find one in the states. I've had good luck with a C-spec in my Tempest, but its hard to crank over

Thanks for your opinions!

Tom
06-12-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
P Johnston
Senior Heliman
Location: Near the BIG HOUSE! GO BLUE

My Posts This: Topic  Forum
The head will fit fine width wise but the engine is too tall and the cooling shroud will have to be modified. I do not have one because of this. I got the diamentions off the OS web site so if i am wrong please someone speak up. OS shows the head being around 87mm tall and the YS91 is around 81mm tall. Other than that, it should bolt right in.
And I am not aware of ant different shroud that you can get.

Hope this helps.
06-12-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
tjn
Senior Heliman
Location: Paris Crossing, IN

My Posts This: Topic  Forum
Thanks for the reply P Johnston.
I've seen on other threads where you have to remove the back of the schroud to get clearance, and leave the sides on to allow the schroud to be secured to the frame. So the fan will fit on the crank of the OS with the same adapter that is used on the YS?

Tom
06-12-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
TMoore
rrProfessor
Location: Cookeville, TN

My Posts This: Topic  Forum
This is what the head shroud fit looks like on a Viperhead.



TM
06-12-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   HOMEPAGE   GALLERY
 
 
P Johnston
Senior Heliman
Location: Near the BIG HOUSE! GO BLUE

My Posts This: Topic  Forum
The engin should bolt right in.

TMoore,
Does your engin run hotter with no shroud over the top of it? Seems I read something on RR that there was a 20 to30 degree(f) increase when there is nothing over it.
06-12-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
TMoore
rrProfessor
Location: Cookeville, TN

My Posts This: Topic  Forum
Actually, the engine runs cooler than the one in a standard Freya.


TM
06-13-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   HOMEPAGE   GALLERY
 
 
tjn
Senior Heliman
Location: Paris Crossing, IN

My Posts This: Topic  Forum
Should I go with the 7.91 gear ratio or the 7.75 ratio for the OS91 c-spec?

Thanks

Tom
06-14-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
TMoore
rrProfessor
Location: Cookeville, TN

My Posts This: Topic  Forum
7.91 is what I'm running. 95T Main -12T pinion.

TM
06-14-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   HOMEPAGE   GALLERY
 
 
SceaduFan
Senior Heliman
Location: Phoenix, AZ

My Posts This: Topic  Forum
Do you want to sell the 8.45 ratio gears?

Mark
06-14-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
1 page490 viewsPOST REPLY
Advantage Hobby . Revolution Models . CarbonXtreme

.
.
HIROBO Turbulence - SDX - Freya - Sceadu > X-Spec Engine Swap
 
 
tjn
Senior Heliman
Location: Paris Crossing, IN

My Posts This: Topic  Forum
Mark,
Yes, I'll sell the 8.45 gears (93t main and 11 tooth pinion). The pinion and clutch ssembly are new. I just bought a new assembly to replace my old one that was on the YS80. Then the 80 failed and I bought a C-spec. Send me a PM.

Tom
06-14-2005 Over year old.
PROFILE   PM   EMAIL   POSTS   BUDDY   IGNORE   GALLERY
 
 
1 page490 viewsPOST REPLY
Boca Bearings . XHELI.COM . Autography FlightPower

.
.
HIROBO Turbulence - SDX - Freya - Sceadu > X-Spec Engine Swap
 Print TOPIC Advertisers 

Subscribe to This Topic

Monday, November 23 - 8:48 pm - Copyright © 2000 - 2009 runryder.com | email | link to rr | START HERE | NF