My new mill, an OBR 30.5

[phreerider]

OBR prostock 30.5 gonna be the power for the XB. don't really need race power and finicky tweaking, just good solid juice... and 2 bolt race ported rebuild project as soon as they are switched.


stock mill is starting to overheat after 10mins. so gonna go through it first and see if its worthy of a fresh head.


about 250 hours on the stock 2 bolt not bad considering the load, never seized, and still has decent zip... til the parts grow apart!


the custom billet case was the feature, skipped the china 4 bolt and went right to the premium goods.

 

[Guest]

I have a couple OBR motors. Both have been great. I'm sure you will be pleased.

 

[phreerider]

the 2 bolt stock peaked real nice & held on for alot of abuse. the clutch dust prolly got it. i dropped the prefilter for an easy slip-in choke tab on the 990 and it fell off quick.

 

[phreerider]

here some details others may benefit from

fresh goods obr zenoah 30.5 prostock 5.5hp

the mill is a zenoah 30.5cc head/piston/rod /crank

OBR custom billet case

CY flywheel cover with obr stickers on it(stamped on the inside)

zenoah head shroud

no clutch housing/no clutch (had all that junk)

billet case



ITS A CY COVER that came on it



contact with gas tank mount



the altered tank mount

 

[Guest]

Do the billet cases come with a clutch and clutch case?

 

[rookie101]

Those are a pretty motor! I have one of their older non billet case full mods in my MCD and it's unreal fast.

 

[phreerider]

Do the billet cases come with a clutch and clutch case?

i selected NO CLUTCH, add 990 and thats it.

clutch/black or chrome covers/ carb are the choices

the billet is their standard issue hardware with ALL now as i see it.

the CY cover was a surprise.

with the billet case on the XB its a small issue but present. the billet cases are fairly new standard thing for them since summer/fall '13 i think. so heres to discovery.

i just clipped it off and "impatiently" hacked it out of the way. seems quite minor but should be in the knowledge base.

 

[phreerider]

Those are a pretty motor! I have one of their older non billet case full mods in my MCD and it's unreal fast.

dude, i am as happy as piston with TWO RODS!

 

[Guest]

the CY cover was a surprise.

Not really for me. The billet case is not a Zen, it's their design. The Bajas, Losis, and Redcats all use CYs.

 

[phreerider]

i knew it was CNC billet product from obr and would not be have zen case. thats why i got it from OBR for the billet case... the extra meat in the case is deluxe!

just fired it 4 pulls ! trying my patients with the heat cycles...man its sweet!

my old motor had like zero compression! what a difference definitely pleased.

gonna be fun afternoon!

 

[claude bigelow]

Good luck with it, that's good to know I was looking to purchase that motor.

 

[phreerider]

1/2 dozen heat cycles, pops real nice...and man! what torquey hot box!

 

[claude bigelow]

Sounds great. I want to order that motor to put in the Losi dbxl. But I guess I need to get the car first. So much got stuff out here, I want it all.

 

[Silent_chaos]

Sounds great. I want to order that motor to put in the Losi dbxl. But I guess I need to get the car first. So much got stuff out here, I want it all.

If I had a million dollars, Id get them all.

well I need more than a million, but you got the point

 

[phreerider]

time to rework old motor, 2 bolt race ported 30.5 coming...but first the remains.



this stock HY 30.5 cc covered about 300hours of use , compression dropped off, overheating, a few fried clutches... and thats what you get, add a nice sand diet, couple wrist pin cage parts, maybe a rock, and crank is surely roasted even some plating is gone.



so the fresh parts, a race ported head CY looks to be a decent choice , rod stroke +2mm and crank stuffed as well. can't wait ...for a great roller chassis to come along to put it in!

heres a piston with 300hours from old stock HY 30.5cc



and the cylinder dome

 

[rampage idiot]

WOW that really looks bad!

 

[phreerider]

i checked for carbon on top of the piston at about 200hours. it had some carbon stacked up but did not look like this! once the carbon breaks loss anything goes. and the wrist pin bearing cage was fractured pretty good. the bearings in the case seem solid. looks like they got hot they will at least get fresh seals.... anyway the 2bolt stroked ,stuffed and race ported set up should be fun.

 

[rampage idiot]

i checked for carbon on top of the piston at about 200hours. it had some carbon stacked up but did not look like this! once the carbon breaks loss anything goes. and the wrist pin bearing cage was fractured pretty good. the bearings in the case seem solid. looks like they got hot they will at least get fresh seals.... anyway the 2bolt stroked ,stuffed and race ported set up should be fun.

OHHHH YEH! that is what I did to my first 30.5 worked out great, you will be impressed

 

[phreerider]

cool...i want some power for an XB rally road car set up like rcdads for a CLAY TRACK ...thats what is on my mind!

or at least decent back up unit

 

[phreerider]

ok Old stock unit gets FULL RACE MOD 2 bolt top end kit form OBR .

seemed like a bargain, $109 definitely gonna put some kick in the CY clone. see how long it holds together . pics of the process... right down to the tire roastin' rip at the end.