Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
piston / head dings from foreign object - questions
Forum Index -> Performance/Engines/Transmissions Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
early
Samba Member


Joined: January 19, 2012
Posts: 124

early is offline 

PostPosted: Sun Oct 14, 2012 4:08 pm    Post subject: piston / head dings from foreign object - questions Reply with quote

I pulled my engine a few months ago to find a missing Solex dump tube and to start the body work on the car.

I found the dump tube located in the intake manifold on # 4 it was slightly bent.

months later i have completed the body work and decided to pull the heads since I had engine out and have a look and maybe do a valve job.

what I find is Dents in #4 piston and small dents in the Head .

1600cc dual port, stock mahle 85.5 pistons , mexican 043 heads.

I dont know the complete history of the engine as it was supposedly rebuilt a few years back.

while on the floor, i hooked up starter jig and did a compression test on cold engine #1 -120 #2 - 130, #3- 118 , #4 -135

added a squirt of oil to each cylinder and went another round
#1 - 130, #2 140 , #3 - 135, #4 145

anyway after pulling the heads I have noticed dents in #4

Im wondering if I should replace the pistons & cylinders or if they would be safe to run after cleaning them up a bit.

thanks in advance for your opinions!..


here's some pics:

Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.

_________________
early-

my 73 sports bug project build
http://www.thesamba.com/vw/forum/viewtopic.php?t=497088
Current Projects :
73 Sport Bug - L13M
68 Corvette Roadster - Small Block, 4 Speed
86 GMC Sierra Classic- 4x4, Shortbed
94 Harley Flstn
03 BMW R1150RT
Back to top
View user's profile Send private message Gallery Classifieds Feedback
miniman82
Samba Swamp Donkey


Joined: March 22, 2005
Posts: 9516
Location: Southern Maryland
miniman82 is offline 

PostPosted: Sun Oct 14, 2012 5:49 pm    Post subject: Reply with quote

Compression test was good, why not just buff out the dings and run it?
_________________
Build thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=212747

Glenn wrote:
satterley_sr wrote:

I just wanted to bitch but I'm getting no sympathy.


Welcome to the Samba.
Back to top
View user's profile Send private message Visit poster's website Gallery Classifieds Feedback
slalombuggy
Samba Member


Joined: July 17, 2010
Posts: 7710
Location: Canada 306
slalombuggy is offline 

PostPosted: Sun Oct 14, 2012 6:02 pm    Post subject: Reply with quote

I've had this on a couple of engines. I simply check for cracks in the piston top, make sure the ring moves freely. then I draw file the piston top smooth and use a carbide scraper to remove the rough area from the cylinder head.

As long as there is no sharp edges cause detonation you'll be fine.

brad
_________________
Parts for sale: https://www.thesamba.com/vw/classifieds/search.php?username=slalombuggy

Lucky Monkey Landspeed Racing
1962 Canadian Buggy 121.253mph - Bonneville 2012
1957 Beetle 118.642mph - Bonneville 2014
1957 LSR Buggy 130.583mph - Bonneville 2018
Back to top
View user's profile Send private message Gallery Classifieds Feedback
early
Samba Member


Joined: January 19, 2012
Posts: 124

early is offline 

PostPosted: Sun Oct 14, 2012 6:13 pm    Post subject: dings Reply with quote

miniman. I can clean up the head combustion chamber, but for the piston, i think i will have to remove the piston from the cylinder to avoid causing any damage to cylinder and then I guess I would have to re ring it at that point ? thoughts?
_________________
early-

my 73 sports bug project build
http://www.thesamba.com/vw/forum/viewtopic.php?t=497088
Current Projects :
73 Sport Bug - L13M
68 Corvette Roadster - Small Block, 4 Speed
86 GMC Sierra Classic- 4x4, Shortbed
94 Harley Flstn
03 BMW R1150RT
Back to top
View user's profile Send private message Gallery Classifieds Feedback
miniman82
Samba Swamp Donkey


Joined: March 22, 2005
Posts: 9516
Location: Southern Maryland
miniman82 is offline 

PostPosted: Sun Oct 14, 2012 7:00 pm    Post subject: Reply with quote

Why would you re-ring it, it's going back into the same cylinder isn't it?
_________________
Build thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=212747

Glenn wrote:
satterley_sr wrote:

I just wanted to bitch but I'm getting no sympathy.


Welcome to the Samba.
Back to top
View user's profile Send private message Visit poster's website Gallery Classifieds Feedback
JoeD
Samba Member


Joined: October 09, 2012
Posts: 146

JoeD is offline 

PostPosted: Sun Oct 14, 2012 7:33 pm    Post subject: Reply with quote

Some years ago My wife drove my bug and came back saying that it made a terrible noise but it went away after a while.
Next time I went to do a tuneup I noticed the bolt for the air cleaner was missing. I looked everywhere and just couldnt find it. I completly forgot about what she had said to me about the noise.
About 60,000 miles later I pulled the engine with my daughter during the summer to rebuild the engine.
When I took the head off I noticed the bolt embeded into the head and both the combustion chamber and the top of the piston were completly abraded. Looked like someone took a box of shotgun shells and blew away at them.
But still the bug ran fine for 60,000 miles.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
damicotile
Samba Member


Joined: September 16, 2004
Posts: 1060
Location: WOODLAND CA.
damicotile is offline 

PostPosted: Tue Oct 16, 2012 12:14 pm    Post subject: Reply with quote

slalombuggy wrote:
I've had this on a couple of engines. I simply check for cracks in the piston top, make sure the ring moves freely. then I draw file the piston top smooth and use a carbide scraper to remove the rough area from the cylinder head.

As long as there is no sharp edges cause detonation you'll be fine.

brad
I had this happen to me to. Turned out to be a washer from the intake manifold. I had to replace and balance the piston cause it pinched the top ring groove.
It looks like yours might be pinched too.
Check also that the valves aren't bent.

Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.

_________________
'73 SB
82x94
W-120 w/ CB light weight lifters
Silicon bronze sleeves
Scat 1.25:1
CB H-Beams
Straight cuts
42x37 Steve Tims
44 IDF's
9.2:1
A-1 Sidewinder coated

__________________________________
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
early
Samba Member


Joined: January 19, 2012
Posts: 124

early is offline 

PostPosted: Thu Oct 18, 2012 6:04 am    Post subject: Update Reply with quote

I pulled #4 cylinder and Piston.

Top Compression Ring Land was pretty tight near the damaged area. it measured out at < .05 MM when the spec is > .07 MM. that might explain the Higher compression reading on #4.

anyway I sent the heads to the shop for a 3 angle valve Job and Ordered New Pistons and Cylinders.

Dont want to risk it so I'm gong with new parts.

cheers.. thanks all.
_________________
early-

my 73 sports bug project build
http://www.thesamba.com/vw/forum/viewtopic.php?t=497088
Current Projects :
73 Sport Bug - L13M
68 Corvette Roadster - Small Block, 4 Speed
86 GMC Sierra Classic- 4x4, Shortbed
94 Harley Flstn
03 BMW R1150RT
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Performance/Engines/Transmissions All times are Mountain Standard Time/Pacific Daylight Savings Time
Page 1 of 1

 
Jump to:  
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 vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2018, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB