R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 08-30-2008, 01:04 AM   #1
Tech Addict
 
Join Date: Mar 2006
Posts: 532
Trader Rating: 2 (100%+)
Default Great, My VZ-B Sucked Dirt!

So I noticed today that my VZ-B (in a MBX5R) had much less compression then yesterday so that made me very curious.......I took off the airfilter (which was just checked the other day and was fine) had dirt all on the inside of the boot and some in the venturi....GREAT! Brand new, well 1 gallon brand new VZ-B now has some pretty low compression....

My question is this, will I be ok just buying a new piston and sleeve or is the crank, bearings or conrod probably damaged? It wasn't sucking pepples or heavy heavy dirt but enough to make it lose compression. Any help is greatly appreciated as I do not want to purchase another $300 motor as I just bought it a couple of weeks ago.

__________________
Team Losi SCTE - SNR Chassis, TLR Shock Towers, RPM Skid Plates, Aluminum Stand-offs, Rear TLR Chassis Brace, HD Out Drives, HD Pivot Balls, etc etc etc
Toro Pro 120amp ESC
Tenshock Sc411 4000kv Brushless Motor
www.builtrc.com
Jim Bob is offline   Reply With Quote
Old 08-30-2008, 01:12 AM   #2
Tech Addict
 
smb17's Avatar
 
Join Date: Jun 2008
Posts: 592
Trader Rating: 13 (100%+)
Send a message via AIM to smb17
Default

Take it apart clean it out.. assemble n fire.
__________________
-
smb17 is offline   Reply With Quote
Old 08-30-2008, 01:33 AM   #3
Tech Adept
 
Join Date: Feb 2008
Location: ippy QLD
Posts: 109
Default

cleaning might work, but dont count on it.

if you are worried about spending 300 bucks on an engine, get a Go-Tech 5 port turbo. for 220 odd USD it is awesome AWESOME bang for your buck.
cm27456 is offline   Reply With Quote
Old 08-30-2008, 02:13 AM   #4
Tech Master
 
Join Date: Mar 2007
Location: illinois
Posts: 1,672
Trader Rating: 26 (100%+)
Send a message via AIM to cheesecake
Default

Quote:
Originally Posted by cm27456 View Post
cleaning might work, but dont count on it.

if you are worried about spending 300 bucks on an engine, get a Go-Tech 5 port turbo. for 220 odd USD it is awesome AWESOME bang for your buck.


lol not another reccomend a junk engine lol i would avoid the go.....

and vspecs usually rn on low compression clean it up and see if it still runs
cheesecake is offline   Reply With Quote
Old 08-30-2008, 02:24 AM   #5
Tech Adept
 
Join Date: Jul 2007
Location: Syd, Australia
Posts: 151
Default

I don't think its worth replacing the piston and sleeve on a V-spec because of the price that they are sold at you may as well be buying a new engine.

OP, if you do need to buy a new engine, do a bit of searching around and i suggest getting a GRP MR tuned promokit. These can be found surprising very cheap from Hong Kong sellers. And they are pretty much the Lamborghini of RC engines.
__________________
8ight pro Kit, MassiveMods stage 5 modified MRT GRP .21
Jonro is offline   Reply With Quote
Old 08-30-2008, 02:25 AM   #6
Tech Adept
 
Join Date: Jul 2007
Location: Syd, Australia
Posts: 151
Default

Quote:
Originally Posted by cheesecake View Post
lol not another reccomend a junk engine lol i would avoid the go.....

and vspecs usually rn on low compression clean it up and see if it still runs
V-spec's arnt much better than GOs.
__________________
8ight pro Kit, MassiveMods stage 5 modified MRT GRP .21
Jonro is offline   Reply With Quote
Old 08-30-2008, 02:25 AM   #7
Tech Fanatic
 
Join Date: Jan 2008
Location: All Over So. Fla.
Posts: 985
Trader Rating: 1 (100%+)
Default

It'll run on the low comm. but order a con. rod soon.
The Working Man is offline   Reply With Quote
Old 08-30-2008, 04:39 AM   #8
Tech Regular
 
mremtr's Avatar
 
Join Date: Nov 2005
Posts: 420
Trader Rating: 1 (100%+)
Default

Inspect the con rod and bearings, if they are not all worn and loose after a good cleaning, then you can pinch your sleeve and be as good as new!
You need to be ANAL with airfilters !!! OR I don't care what engine you have ,it will be junk in a heart beat!!
mremtr is offline   Reply With Quote
Old 08-30-2008, 05:18 AM   #9
Tech Elite
 
Join Date: Jun 2006
Location: Omaha,NE
Posts: 2,548
Trader Rating: 85 (99%+)
Default

I wouldn't get to hung up on how much compression it does or doesn't have as Vspec's lose there pinch around a gallon and develop a thump, and imo that's when they run best. Pull the motor apart and clean everything up, double check the sleeve to make sure there aren't any grooves in it reassemble and run. There's no sense in ordering parts for it if it still runs fine.
WideOpenThrottle RC is offline   Reply With Quote
Old 08-30-2008, 05:19 AM   #10
Tech Elite
 
Join Date: Jun 2006
Location: Omaha,NE
Posts: 2,548
Trader Rating: 85 (99%+)
Default

Quote:
Originally Posted by Jonro View Post
I don't think its worth replacing the piston and sleeve on a V-spec because of the price that they are sold at you may as well be buying a new engine.

OP, if you do need to buy a new engine, do a bit of searching around and i suggest getting a GRP MR tuned promokit. These can be found surprising very cheap from Hong Kong sellers. And they are pretty much the Lamborghini of RC engines.
Lamborghini of RC engines
WideOpenThrottle RC is offline   Reply With Quote
Old 08-30-2008, 05:40 AM   #11
Tech Apprentice
 
rcdaddy's Avatar
 
Join Date: May 2008
Location: WCRC Track Manager
Posts: 79
Default

Quote:
Originally Posted by Qmartin View Post
Lamborghini of RC engines
My thoughts exactly
__________________
Drive It Hard and it Will Be Fast
Nova Rossi, Jammin, Team Associated, OS Engines, Futaba, Airtronics, Go Engines, RB Mods, Fusion Motorsports
WCRC Raceway
Big Billy's RC World
Baity's RC
rcdaddy is offline   Reply With Quote
Old 08-30-2008, 07:10 AM   #12
Tech Adept
 
Join Date: Jul 2007
Location: Syd, Australia
Posts: 151
Default

Well you could say that a V-Spec is like a F1 engine before they implemented the 2 per season rule, they haul ass but only last 2 races. GRPs are Italian quality, also haul ass but last 10 times longer, not unlike a Lamborghini.
__________________
8ight pro Kit, MassiveMods stage 5 modified MRT GRP .21
Jonro is offline   Reply With Quote
Old 08-30-2008, 08:22 AM   #13
Tech Elite
 
ezveedub's Avatar
 
Join Date: Aug 2004
Location: Fort Lauderdale, FL
Posts: 2,411
Trader Rating: 14 (100%+)
Send a message via AIM to ezveedub Send a message via Yahoo to ezveedub
Default

Check the engine bearings and the crank for scoring in the shaft. Minor blemishes can be cleaned off. If the bearing feels gritty, then replace it and get the sleeve slightly pinched it needed.
__________________
Kyosho, Mugen Seiki, Maxy's Fuel, KO Propo
O.S., Ninja JX, Novarossi, RMV
ezveedub is offline   Reply With Quote
Old 08-30-2008, 08:47 AM   #14
Tech Addict
 
Join Date: Mar 2006
Posts: 532
Trader Rating: 2 (100%+)
Default

Ok cool, thanks for all the suggestions. We opened up the motor last night and it seemed fine, no grooves or notches but we didn't take the piston out and check the con rod or bearings so maybe I'll do that today.
__________________
Team Losi SCTE - SNR Chassis, TLR Shock Towers, RPM Skid Plates, Aluminum Stand-offs, Rear TLR Chassis Brace, HD Out Drives, HD Pivot Balls, etc etc etc
Toro Pro 120amp ESC
Tenshock Sc411 4000kv Brushless Motor
www.builtrc.com
Jim Bob is offline   Reply With Quote
Old 08-30-2008, 09:11 AM   #15
Tech Addict
 
smb17's Avatar
 
Join Date: Jun 2008
Posts: 592
Trader Rating: 13 (100%+)
Send a message via AIM to smb17
Default

Yeah like i said just clean it out. When you have these little motors out of the car you start to think too much about everything going wrong.

When I put my flywheel together and all I use after run oil in the cylinder to hydro lock it so I can tighten the nut and after I emptied it out it was really easy to turn over. After I kept working it it got better and better. Just little things like that will mess with your head. Just Gotta take it apart and see whats up. If all looks good throw it together.

What filters you run? I wanna make sure i don't buy them!!!
__________________
-
smb17 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
New Dirt Oval Track - Cincinnati Dirt Bowl CCR Oval, Larger Scales and More 10 05-04-2009 07:49 PM
PAVED-DIRT OVAL-DIRT ROAD COURSE-GEORGIA PRIME TIME Track Locator Forum 0 09-11-2008 11:27 AM
Capital Dirt Burners fall dirt challenge Tim W. Northwest Racers 1 07-24-2007 12:26 PM
Spiderman3 SUCKED save your $ and go racing this weekend dawgmeat Electric On-Road 29 05-09-2007 09:59 AM
keeping dirt to stay on dirt tracks corvettecrazy Electric Off-Road 4 07-12-2004 06:54 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 01:43 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net