| Author |
Message |
ezetom
Samba Member
Joined: May 02, 2014
Posts: 12
Location: Calgary
|
 Posted: Sun Feb 26, 2017 9:50 am Post subject: measuring 2.1 cylinders and pistons |
 |
|
Hi Folks,
Im doing a "qausi overhaul" of my 2.1....
I have all of the cylinders out, and my question,, what is the "service limit" for scrapping them?
From my measurments, the cyliders are worn about half a though, and the pistons about 2.. The manual I have states the maximum piston to cylinder clearance is 8 though... but that seems really high!.
What is the consensus of maximum wear/clearance before scrapping them and buying new units?
Cheers
Tom |
|
| Back to top |
|
 |
pablum
Samba Member
Joined: December 17, 2015
Posts: 562
|
| Posted: Sun Feb 26, 2017 10:22 am Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
Not a wear limit per se, but a range is given here:
http://www.vanagonauts.com/2.1l-vanagon-specs234.htm
_________________
The wise man learns from history, the fool from experience.
-
I see [a cat] in the street and i aim for the pest with my car. --  bluebus86 |
|
| Back to top |
|
|
bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
|
| Posted: Sun Feb 26, 2017 10:37 am Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
it would be helpful to add units to the sizes mentioned. 2, 8???????? inches, meters, the kings forearm?
pistons worn half way, half way to what?
then we can talk a bit about out of roundness, surface finsh etc.... and dont foget piston pin fit either since we are talking pistons after all.
_________________
Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
|
| Back to top |
|
|
Terry Kay
Banned
Joined: June 22, 2003
Posts: 13331
|
| Posted: Sun Feb 26, 2017 11:20 am Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
What is the current compression ring end gap when installed in the holes?
Each corresponding ring for it's hole.
Measure the end gap.
You do have a feeler gauge--right?
_________________
T.K. |
|
| Back to top |
|
|
ezetom
Samba Member
Joined: May 02, 2014
Posts: 12
Location: Calgary
|
| Posted: Sun Feb 26, 2017 12:49 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
Sorry I was using English units..
I lightly honed the cylinders... I could probably hone them a tad more,, but they dont look bad...
I didn't measure the wrist pins/piston hole but they seem to fit "nice" (with the ridge removed from the piston beside where the snap ring goes.
Im kind of on the fence about using these... but then again, Im on the fence about using Chinese crap as well..
I come from the aviation business, and we have more more defined limits for new, service, and overhaul...
It kinda seems like the "new" clearance is 0.001-0.002" with the service limit at 0.008" - but I dont think anyone would put an engine together with a clearance of 0.008" as you would immediately wear beyond service limits..
I have a new set of rods coming from VC,, and I can confirm the ones I have are ovaled on the big end... around 0.0025"... 
Thoughts?
Tom
ps I will post some pics of the rod bearings that came out with this... scary...
|
|
| Back to top |
|
|
MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17100
Location: Retired South Florida
|
| Posted: Sun Feb 26, 2017 3:22 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
I see what the book says, but .002" is a tight fit. Agree with the wear limit of .008". At that point, you'd probably have some piston slap.
What is more important is how round the cylinder is top to bottom. You should measure at 3 places with your bore gauge. If the taper is minimal, I'd re-ring it and put it back together.
_________________
☮️ |
|
| Back to top |
|
|
ezetom
Samba Member
Joined: May 02, 2014
Posts: 12
Location: Calgary
|
| Posted: Sun Feb 26, 2017 3:31 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
I did measure the cylinders in a bunch of different places,, and there really wasnt any taper.. just a bit of out of roundness.
It would be interesting to see what a new set of chinese cylinders and pistons would measure...
FYI these are the rod bearings... I think I was getting close to the "end"
Interestingly enough, the crank is still good...
Does anyone have experience with the copper head gaskets? I might get a set waterjet cut locally - think I can get away with making them a tad thinner for a tad more compression?
Tom
|
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32561
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
ezetom
Samba Member
Joined: May 02, 2014
Posts: 12
Location: Calgary
|
| Posted: Sun Feb 26, 2017 6:49 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
Hi Dave,
Have you re ringed pistons with around 3-4 thousands clearance?
I think Im going to be ok, but would be nice to hear from someone that has been in the same ballpark.
Cheers
tom |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32561
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
ezetom
Samba Member
Joined: May 02, 2014
Posts: 12
Location: Calgary
|
| Posted: Sun Feb 26, 2017 8:03 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
cool...
I think Im gonna just re ring it.. save some $$
Did you use the copper gaskets? |
|
| Back to top |
|
|
tencentlife
Samba Member
Joined: May 02, 2006
Posts: 10075
Location: Abiquiu, NM, USA
|
| Posted: Mon Feb 27, 2017 9:46 am Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
Voids in rod bearings are acid damage. That engine likely saw lots of short-run use without full warmup, on top of neglected lube service. Much of the chrome coating on the cam bearings has probably also come off, those are the largish shiny silver flakes you often find.
| Quote: |
| I see what the book says, but .002" is a tight fit. |
No, .002" would be at the edge of tolerable, skirt-edge clearance is ten to fifteen tenths. Four thou may still have slap even when warm.
| Quote: |
| Im on the fence about using Chinese crap as well |
Well you could just get the Chinese good stuff instead, I mean, really, you have choices.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
|
| Back to top |
|
|
dobryan
Samba Member
Joined: March 24, 2006
Posts: 16494
Location: Brookeville, MD
|
|
| Back to top |
|
|
bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
|
| Posted: Mon Feb 27, 2017 10:09 am Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
your cylinder pictured still have scratches (grooves) worn into it even after honing. thats not good. please recheck them for wear grooves.
there are other choices than china as a piston source. JE pistons makes a piston as does keith black good usa made stuff. years back some chinese pistons were known to have the wrist pin in the wrong spot, so compression suffered unless you corrected for it, I heard the pin hole was corrected. I also heard that some sets of four had a wide range of weights. a builder I know would take several sets and select the best wieght match for four of them, mix and match. this was some years ago, quality may be different now. I heard it was getting better (aa brand) But on my motors some ten years ago I used the two afore mentioned American piston makers. I both cases I elected for a larger bore so my 2.1 motor became a 2.2 motor, used stock cylinders, over bored. my air cooled went from 2.0 to 2.1 with new cylinders. at anyrate thereare a lot more choices than china as a supplier.
good luck
_________________
Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
|
| Back to top |
|
|
SSWesty
Samba Member
Joined: August 20, 2008
Posts: 732
Location: Bellevue
|
| Posted: Mon Feb 27, 2017 8:33 pm Post subject: Re: measuring 2.1 cylinders and pistons |
|
|
One other option for a piston kit is a 95.5mm set from Rocky Jennings. I picked up a kit from him a couple years ago and it's working well for me. That kit has the correct deck height so you don't have to mess with offset rods. You can see his stuff in the classifieds if you search for RJE although he doesn't advertise his 95.5 kit. Just give him a call if you are interested in checking out that route. At the time I paid $485 for pistons and liners. He uses rings he likes better than other kits and balances everything really we'll. He may be a source for rings, I can't remember if he sells them separately or not.
It's a slippery slope talking to Rocky because he builds race engines and has quite a few options for the WBX engine. |
|
| Back to top |
|
|
|
