Lotus Elan

Gasket sealant for block to rear oil seal housing

PostPost by: "John Jacobs" » Tue Oct 25, 2005 9:52 pm

The workshop manual says to use a sealant for the block to rear oil
seal housing.
Will Blue Hylomar suffice, or do I need something else?
"John Jacobs"
 

PostPost by: lotuselan2 » Tue Oct 25, 2005 11:05 pm

Blue Hylomar is good because any excess that is squeezed inside does not
solidify and potentially block little galley ways.



Ken

'69 Lotus Elan +2 with BDR
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Third Gear
Third Gear
 
Posts: 377
Joined: 19 Oct 2005
Location: Shamong, NJ

PostPost by: "Tim Engel" » Wed Oct 26, 2005 1:08 am

John,

I like Hylomar and use it for many things. However, given the
inaccessibility of the rear main seal and my desire not to have to go in
there again, I prefer to use something a bit more aggressive. Perma-bond
A-136, Loctite 515 or 518, Permatex Anaerobic Gasket Maker (private
labeled Loctite 518... product number in fine print is 518__), or
Permatex Aviation Form-a-Gasket will produce a more aggressive seal.

Good luck,
Tim Engel
Lotus Owners Oftha North
"Tim Engel"
 

PostPost by: simon.mitchell » Wed Oct 26, 2005 8:06 am

Try ordinary kitchen / bathroom silicone sealant - it'll seal pretty much
anything including the exhaust joints and manifolds. Just don't get too much
inside the engine.
User avatar
simon.mitchell
Second Gear
Second Gear
 
Posts: 148
Joined: 12 Sep 2003
Location: Aylesbury, Bucks

PostPost by: davidallen » Wed Oct 26, 2005 10:50 am

Manifolds/Exhaust joints? Are you sure?

David
davidallen
Third Gear
Third Gear
 
Posts: 293
Joined: 11 Aug 2005

PostPost by: "Tim Engel" » Wed Oct 26, 2005 11:22 am

Try ordinary kitchen / bathroom silicone sealant - it'll seal pretty much anything including the exhaust joints and manifolds. Just don't get too much inside the engine.


Simon,
Be careful there. All silicone sealants are not created equal. Silicone
sealants (RTV, or Room Temperature Vulcanizing rubber) are petroleum
resistant, not petroleum proof. And some are more resistant than others.
House hold RTV's are generally the least resistant. "IF" you use an RTV,
then use a product that is specifically formulated for automotive use, like
the Permatex Ultra series or Silastic.

Many "ordinary" silicone sealants use acetic acid as a cure promoter (they
smell like vinegar). The vinegar vapors you smell will kill an automotive
catalytic converter. That's not an issue on older cars like the Elan, but
it you are going to do your own general mechanical work, and if you have a
modern car, avoid having any of the old-style RTV on the shelf. If you
mistakenly use it on your daily driver, then you put the CAT at risk.
Some (by now, most) of the automotive RTV's use a different, CAT-safe cure
promoter. Read the label

Silicone will not seal exhaust manifold joints reliably. It will burn off.
Maybe use it on exhaust joints that are way down stream from the engine
heat.

Hylomar is superior to silicone for things like the intake manifold,
thermostat housing and water pumps (in general, but Twinks are special).

For flat surface, metal to metal joints like the lip-seal housing, products
like Perma-Bond A-136, Loctite 515 and 518, Permatex Anaerobic Gasket
Maker (518) and Permatex Aviation Form-a-Gasket are better.

For old fashioned cork-gasketed joints like the Twink cam cover, silicone
can be a good joint dressing. However, I'm not a big fan of using
silicone anywhere in an engine and would prefer to use a different sealant
there as well. Any time you use silicone on an engine, be careful about
using too much. If some oozes out of the joint when you tighten it down
(enough to motivate you to wipe it off), then it probably oozed "into" the
joint as well. Once it cures, the silicone ooze inside the engine can
break off in beads that won't necessarily do any direct damage by
themselves, but can end up in places where they might plug a critical oil
passage.

Hylomar never hardens. It gets a little stiffer, but never hardens.

The anaerobics (A-136, 515, 518) don't cure in the presence of air. So
anything that oozes out of the joint never gets hard enough to form a bead
that might break off.

Any Aviation Form-a-Gasket or Wellseal that oozes out generally spreads out
in a thin layer like a paint run instead of forming a bead. A big ooze may
not look professional, but it won't break off inside the engine.

Good luck,
Tim Engel
Lotus Owners Oftha North
"Tim Engel"
 

PostPost by: M100 » Wed Oct 26, 2005 11:22 am

Try ordinary kitchen / bathroom silicone sealant - it'll seal pretty much anything including the exhaust joints and manifolds. Just don't get too much inside the engine.


Loctite do a silicone sealant (5920) that is ok up to 310deg C
continuous.

No bath / kitchen silicone sealant would come anywhere near my car!

--
Martin
72/45
Martin
72 Sprint DHC
User avatar
M100
Fourth Gear
Fourth Gear
 
Posts: 766
Joined: 16 Sep 2003
Location: Yorkshire

Total Online:

Users browsing this forum: checkrail, ianthomson72 and 21 guests