Author |
Message |
tandm1999 Samba Member
Joined: May 14, 2007 Posts: 78 Location: chico
|
Posted: Fri Aug 20, 2010 1:03 pm Post subject: Silicone to seal engine case |
|
|
I've heard alot of people say to never use silicone to seal your engine case. Why not? |
|
Back to top |
|
|
craigman Samba Member
Joined: March 28, 2004 Posts: 2397 Location: redding
|
Posted: Fri Aug 20, 2010 1:05 pm Post subject: |
|
|
Because it will ooze out everywhere and plug up oil galleys, ect..
Not good for vw's. |
|
Back to top |
|
|
smkn_vw Samba Member
Joined: August 22, 2004 Posts: 809
|
Posted: Fri Aug 20, 2010 1:10 pm Post subject: |
|
|
Also you may not get the correct bearing crush, not good to have loose things in there. |
|
Back to top |
|
|
Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
|
Posted: Fri Aug 20, 2010 1:11 pm Post subject: |
|
|
The case halves are a matched set with a machines surface. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare |
|
Back to top |
|
|
perrib Samba Member
Joined: September 14, 2004 Posts: 3402 Location: Chandler, Az
|
Posted: Fri Aug 20, 2010 1:13 pm Post subject: |
|
|
The Search feature on The Samba is priceless.
http://www.thesamba.com/vw/forum/viewtopic.php?t=363486&highlight=silicone+engine+case
One small tube of silicone is enough for about 200 VW engines.
I only seal the jugs to the case with a very tiny bead (like pencil lead size)and smear a transparent film on the oil pump gaskets.
I use Permatex aviation cement to seal the case and most gaskets on my engines. |
|
Back to top |
|
|
Almost Alive Samba Member
Joined: October 12, 2009 Posts: 1345
|
Posted: Fri Aug 20, 2010 1:25 pm Post subject: |
|
|
F**k Silicon.
Use Ketchup |
|
Back to top |
|
|
tandm1999 Samba Member
Joined: May 14, 2007 Posts: 78 Location: chico
|
Posted: Fri Aug 20, 2010 2:22 pm Post subject: silicone |
|
|
well it would'nt ooze into oil galleys if only a small amount was used, bearing crush? I would think if the block was assembled fairly quickly it would'nt cause any issues. As far as the case halves being machined to match? maybe in 69. but it's certainly not perfect anymore. so I would think a small amount of silicone would take care of a few nicks and scratches in the case halves?? |
|
Back to top |
|
|
Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
|
Posted: Fri Aug 20, 2010 2:51 pm Post subject: |
|
|
Don't do it.
Curtil T would be my suggestion. |
|
Back to top |
|
|
perrib Samba Member
Joined: September 14, 2004 Posts: 3402 Location: Chandler, Az
|
Posted: Fri Aug 20, 2010 2:54 pm Post subject: |
|
|
Use silicone it is your engine. Nicks and scratches means there is a raised surface right next to the lower surface that needs to be carefully removed. |
|
Back to top |
|
|
Max Welton Samba Member
Joined: May 19, 2003 Posts: 10697 Location: Black Forest, CO
|
|
Back to top |
|
|
tandm1999 Samba Member
Joined: May 14, 2007 Posts: 78 Location: chico
|
Posted: Fri Aug 20, 2010 4:10 pm Post subject: silicone |
|
|
Thank you max fo the tip on not being in a hurry while assembling the case, you are 100% correct. However I am still wondering if anyone has a good reason for not using it other than "just don't do it". I've seen lots of people that use it and lov it and lots that hate it. For those that don't Why not? |
|
Back to top |
|
|
jd-drafter Samba Member
Joined: June 10, 2006 Posts: 197 Location: northern az
|
Posted: Fri Aug 20, 2010 4:17 pm Post subject: |
|
|
having seen several cases that were sealed with the blue high temp silicone...and had oil passages full of little blue balls of silicone...
was enough to convince me that it is not the best stuff to use...
what did the factory use might be the best question...
i have seen several options... pick your poison... |
|
Back to top |
|
|
jfats808 Samba Member
Joined: December 10, 2007 Posts: 5022 Location: oahu hawaii
|
Posted: Fri Aug 20, 2010 4:22 pm Post subject: |
|
|
I use the same as Perrib. Permatex aviation sealant on everything except the cylinder seal. For that I use grey permatex. Aviation doesn't fully harden. It's good stuff. I even used it on a 200k barrel 30 inch man hole plate. No leaks. Check my photo for the example of grey permatex application. _________________ 2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125
Rockstar Suzuki wrote: |
You might as well put 10 year build in your bullshit sig, as it will NEVER run. Also your a dick |
You can always learn something new, even from a fool.
Check your oil levels routinely!
Last edited by jfats808 on Fri Aug 20, 2010 4:28 pm; edited 1 time in total |
|
Back to top |
|
|
Max Welton Samba Member
Joined: May 19, 2003 Posts: 10697 Location: Black Forest, CO
|
Posted: Fri Aug 20, 2010 4:26 pm Post subject: |
|
|
As was pointed out before, the case halves are made to fit together very precisely. The halves are supposed to be in direct contact with each other all the way around.
The most critical bit is how the main bearings are held at the center. They must be held tightly and in precisely the correct position with respect to the crankshaft journals. Otherwise you get either binding or bearing shells that move around. How they are held are what is being referred to as "bearing crush".
Anything that may not allow the case halves to come together all the way around screws with the very foundation of the engine.
Can we find people who've used silicone and "had no problem"? Sure.
Getting away with something doesn't make it a good idea.
Max _________________ 1967 Type-3 Fastback
Under the Knife https://shoptalkforums.com/viewtopic.php?f=24&t=151582
Home Stretch https://www.thesamba.com/vw/forum/viewtopic.php?t=767836 |
|
Back to top |
|
|
perrib Samba Member
Joined: September 14, 2004 Posts: 3402 Location: Chandler, Az
|
Posted: Fri Aug 20, 2010 4:47 pm Post subject: |
|
|
Like I stated if your machined case half has a dent it in then it has a raised spot around the dent. If I was going to save a case with a dent or scratch that was deep enough not to be sealed by Aviation cement, I might level the surface and use a tiny bit of JB weld and scrape it flat with a razor blade. I've seen way to main engines VW and non VW with silicone clogged oil pick up screens. |
|
Back to top |
|
|
Dale M. Samba Member
Joined: April 12, 2006 Posts: 20365 Location: Just a tiny bit west of Yosemite Valley
|
Posted: Fri Aug 20, 2010 4:52 pm Post subject: |
|
|
Aviation gasket sealer on main case half's.... Utmost tiny bit of high temp silicone on base of jugs.... As others have said any excess silicone squeezed out in to crankcase turns into little balls and plugs oil passages..... Not something you want....
Dale _________________ “Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.
"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ... |
|
Back to top |
|
|
volk263 Samba Member
Joined: November 21, 2006 Posts: 119 Location: Alabama
|
Posted: Fri Aug 20, 2010 7:26 pm Post subject: |
|
|
Silicone belongs around bath tubs not in a engine. |
|
Back to top |
|
|
Hippie Samba Tinner
Joined: August 16, 2004 Posts: 1781 Location: Iowa: The Mud State
|
Posted: Fri Aug 20, 2010 7:31 pm Post subject: |
|
|
I used Permatex 3H. Works great. Hylomar works too if you can find it. |
|
Back to top |
|
|
Howard 111 Samba Member
Joined: July 09, 2005 Posts: 1827 Location: Virginia
|
Posted: Fri Aug 20, 2010 7:53 pm Post subject: |
|
|
Gaskasinch. |
|
Back to top |
|
|
fartfignewtons Samba Member
Joined: May 23, 2007 Posts: 2 Location: H-town
|
Posted: Sun Aug 22, 2010 6:52 am Post subject: |
|
|
Silicone for the case halves is not recommended as it will allow the two haves to rub against each other as it is not tacky once set; the silicone will eventually allow oil to escape.
Here are some options...
Permatex Aviation Formagasket (easy find)
Hylomar Universal Blue
Curil T
Gasgacinch (easy find)
Loctite 518
I would only use Permatex Ultra Grey RTV silicone for sealing under the jugs and the oil pump.
Again, this is just my two cents! |
|
Back to top |
|
|
|