It is currently Sat Apr 27, 2024 9:22 am

Board index » Tech and Fab » Air Cooled Engines

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 22 posts ] 
Author Message
PostPosted: Sun Jul 21, 2013 9:42 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
took my buggy out over the weekend and it developed a noise that has me going nuts. its loud and sounds awful but it doesn't sound like a bottom end noise and my valve lash is still good. sounds like someone tapping on the exhaust tubing with a wrench. still runs great but has me scared to death my motors coming apart. dumped the oil and it looks good so no spun bearings or anything. took the belt off to eliminate fan or alternator noise. going to pull the motor tomorrow unless anyone has any thoughts. :cry:

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Sun Jul 21, 2013 10:08 pm 
Offline
WB Contributor

Joined: Sat Feb 04, 2012 11:14 pm
Posts: 1418
Location: Birmingham, Alabama
Like a squawk squawk squawk . Check you end play. Thrust bearing wo out. extreme carbon build up on head and piston (Is it hard to turn over right at tdc with plugs out?).Just short guesses.


Top
 Profile  
 
PostPosted: Sun Jul 21, 2013 10:36 pm 
Offline
BOTM winner/Master fabricator
User avatar

Joined: Tue Jan 01, 2008 10:26 pm
Posts: 910
Location: brookpark ohio ---- wellsville
when my flywheel came loose it sounded like a rod knock and it leaked oil. just last memorial weekend my motor was knocking real loud. when I took the motor apart i found that 3 teeth broke off the cam gear I would never have guessed it was the cam gear. I had everyone over there listening to it and they were saying it was a rod knock, a loose fly wheel, all kinds of things. but you never know until you take it all apart. So i would pull your motor apart to find out what is banging, before you do more damage.


Last edited by afterburnt on Sun Jul 21, 2013 10:56 pm, edited 1 time in total.

Top
 Profile  
 
PostPosted: Sun Jul 21, 2013 10:46 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
endplay is good. motor not hard to turn over by hand. to new for excessive carbon build up. when I first heard it I thought maybe rod but it doesn't sound like a knock ive ever heard.

I forgot to mention it kinda goes away under load.

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Sun Jul 21, 2013 11:01 pm 
Offline

Joined: Tue Jul 12, 2011 7:16 pm
Posts: 711
Location: hayden, al
does the sound change when you push in the clutch? just a guess but maybe a loose gland nut and wollowed out dowel pin holes??

_________________
LEGALIZE BLUEGRASS!!!

Save a tree... eat a Beaver


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 12:25 pm 
Offline
WB Contributor

Joined: Sat Feb 04, 2012 11:14 pm
Posts: 1418
Location: Birmingham, Alabama
hpfreak wrote:
endplay is good. motor not hard to turn over by hand. to new for excessive carbon build up. when I first heard it I thought maybe rod but it doesn't sound like a knock ive ever heard.

I forgot to mention it kinda goes away under load.

The 1st time I put together a HIGH compression motor I did not run high octane racing fuel and the heads ran very hot and pinged . in about 6 hours of fun it had a hammer sound. Took the heads off and the carbon build up was incredible. I lowered the comp. ratio a little and ran better gas and solved. With the piston centrifigul force they would stretch out just enough to hammer but with the motor turning over by hand you won't get as much resistance especially cold I'd guess.. Your problem is in the lower end but just keep this in mind for the future. You could see the shape of the piston in the carbon on the head and vise versa.


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 1:19 pm 
Offline
WoodsBuggy Addict
User avatar

Joined: Mon Feb 19, 2007 2:23 pm
Posts: 2039
Location: Central Indiana
Engine will make a clicking noise noise when cranking to start and sometimes at idle.......a rattle type sound.

The dead give-a-way is the aluminum fan belt pulley will have the keyway wallowed out.........
The harmonics of a loose flywheel oscillating absolutely wipes out that keyway.

_________________
Gary

Turbo VW Sand Racer
Polaris Ranger



"If you don't run into the Devil every once in awhile, you must be going in the same direction!"

Davis Motorsports FaceBook Page


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 2:37 pm 
Offline
User avatar

Joined: Mon Jan 10, 2011 12:52 pm
Posts: 917
Location: Calera, Alabama
Did you happen to drop something in the carbs when you put your new covers on??

_________________
IF YA CAN'T RUN WITH IT....RUN FROM IT


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 3:37 pm 
Offline
User avatar

Joined: Thu Jan 26, 2012 7:32 am
Posts: 815
Location: Tcounty Ohio
My friend borrowed a 1835 I had in the shed, he put it on and ran it for a bit then it started knocking. He thought it was a rod but when we took it off the flywheel came loose. Fixed the dowels and has been running it HARD all summer........


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 4:15 pm 
Offline
User avatar

Joined: Tue Jan 18, 2011 9:03 pm
Posts: 121
Location: Proctorville ohio
Something simple to check is header gaskets they made mine sound almost like a knock .

_________________
What do you mean your in limp mode?


Top
 Profile  
 
PostPosted: Mon Jul 22, 2013 8:15 pm 
Offline
WB Contributor
User avatar

Joined: Thu Jul 31, 2008 8:26 pm
Posts: 1125
Location: Gadsden TN
Money520 wrote:
Something simple to check is header gaskets they made mine sound almost like a knock .


x2


Top
 Profile  
 
PostPosted: Tue Aug 06, 2013 6:55 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
Still haven't figured this out. Took engine out flywheel is tight and good. Sounds like it may be coming from the pulley side of the motor. Can I get to the can bolts if I take the oil pump out? It really doesn't sound like a rod but maybe I'm just hoping it isn't. When I turn the motor off and it stops completely it raps a couple more times which makes me think its something that rotates and is springing back and forth a couple times before it stops.

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Tue Aug 06, 2013 7:01 pm 
Offline
WB Contributor

Joined: Wed Jul 04, 2007 8:25 pm
Posts: 1304
Location: tuscaloosa alabama
yes just pull the oil pump and you can get to the cam bolts there.


Top
 Profile  
 
PostPosted: Tue Aug 06, 2013 7:19 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
Thanks Kevin. May try that tonight.

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Sat Aug 10, 2013 8:54 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
I've checked everything I can check. Looks like I'm tearing the motor apart:sad:

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 6:43 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
Took off the driverside jugs off and found lots of slop in the #3 rod bearing. Hope the crank isn't trashed. If the crank is trashed can I go larger stroke with my existing pistons and barrels?

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 8:04 pm 
Offline

Joined: Tue Jul 12, 2011 7:16 pm
Posts: 711
Location: hayden, al
unfortunately you will have to get "B" pistons... you can shim the barrels off the block to make up for a short stroke motor but im not a big fan, shimmed barrels tend to leak oil at the block..

_________________
LEGALIZE BLUEGRASS!!!

Save a tree... eat a Beaver


Top
 Profile  
 
PostPosted: Thu Aug 15, 2013 9:18 pm 
Offline

Joined: Sat Feb 24, 2007 12:02 am
Posts: 349
Location: Germantown Ohio
You can go up to 76mm stroke with the pistons you already have without any issues. You will need barrel shims and a new set of cut to fit pushrods.


Top
 Profile  
 
PostPosted: Fri Aug 16, 2013 11:40 pm 
Offline
WB Contributor
User avatar

Joined: Thu Sep 06, 2012 2:23 pm
Posts: 1212
Location: Chattanooga Tennessee
Freak, that sucks that it was rod bearing. I ran a 76 x 94 engine and they make good power, should work with your carbs as well


Posted using the WoodsBuggy Mobile App

_________________
Water Cooled Consortium, Chairman of the Build (Former AC purist)


Top
 Profile  
 
PostPosted: Sat Aug 17, 2013 10:17 am 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
Thanks guys if the cranks junk ill go bigger for sure. Yes Barron it does suck and I still can't figure out why. I changed the oil every ride and kept it full. Everything only has 3 rides on it. Only thing I can think is a peice of trash stuck in one of the oil galleys decided to come loose and find its way to the rod bearing.

_________________
If it ain't broke ill fix that


Top
 Profile  
 
PostPosted: Sat Aug 17, 2013 1:56 pm 
Offline
WB Contributor
User avatar

Joined: Thu Sep 06, 2012 2:23 pm
Posts: 1212
Location: Chattanooga Tennessee
Sounds like some trash was stuck in the case from machining kind of sucks since it was a new case. If you can when you pull it down pull all of the oil gallery plugs and blow a hurricane of air through them after tanking it. I would hate to see you go through this again.

_________________
Water Cooled Consortium, Chairman of the Build (Former AC purist)


Top
 Profile  
 
PostPosted: Sat Aug 17, 2013 2:59 pm 
Offline
WB Contributor
User avatar

Joined: Wed Nov 30, 2011 6:16 pm
Posts: 1003
Location: columbus, OH
Yeah I certainly plan on pulling all the plugs and tapping them for pipe plugs this time :evil:

_________________
If it ain't broke ill fix that


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 22 posts ] 

Board index » Tech and Fab » Air Cooled Engines

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 27 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group