Re-assembly of Rope Seal TC Engine

PostPost by: johnc » Sat Oct 11, 2003 8:57 pm

I need help concerning the re-assembling my rope seal TC engine. My first
question relates to the shape of the sump gaskets in the area of the rope
seal. The ends of the sump gaskets at the rope seal are square whereas Plate
1 in my Lotus Parts List Manual suggests the ends should relieved so as to
surround the rope seal. i.e.

+-------------+ +---+ +---+
| | verses | \ / |
| | | +--+ |
Square Relieved

The gasket set I have says it is for "Ford Pre-X Flow, All --> 1967".

At issue is whether or not the sump gasket should be sandwiched between the
ends of of the rope seal.

I have three different TC engine assembly references (i.e. Elan Workshop
Manual, Lotus Cortina Passenger Car Service Manual by Ford, and Lotus
Twin-Cam Engine by Miles Wilkins) and none provide any clarity to this point.

Second question relates the bearing liner in the central main bearing cap.
The Lotus Cortina service manual describes and shows a "Vee" notch in the
tongue end of the bearing liner. This service manual states:

"NOTE -- An oil feed to the crankshaft rear thrust washer is provided by
means of a "Vee" notch in the bearing liner and a chamfer on the centre main
bearing cap (see Fig. 36)".

The Elan Workshop Manual and Wilkins book do not make mention of a "Vee" notch
in the center bearing liner, nor do my parts list manuals suggest a different
part number for the center main bearing liner.

So my question is should my center main bearing cap liner have a "Vee" notch
or is this unique to the Lotus Cortina ??

Your help is appreciated,

--

John Connin, Longwood, FL <***@***.***>
johnc
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PostPost by: twincamman » Sat Oct 11, 2003 9:03 pm

i just use pump sealing waxed rope and leave a little to seal the on the sump works well ed law
----- Original Message -----
From: John Connin
To: ***@***.***
Sent: Saturday, October 11, 2003 4:58 PM
Subject: [LotusElan.net] Re-assembly of Rope Seal TC Engine



I need help concerning the re-assembling my rope seal TC engine. My first
question relates to the shape of the sump gaskets in the area of the rope
seal. The ends of the sump gaskets at the rope seal are square whereas Plate
1 in my Lotus Parts List Manual suggests the ends should relieved so as to
surround the rope seal. i.e.

+-------------+ +---+ +---+
| | verses | \ / |
| | | +--+ |
Square Relieved

The gasket set I have says it is for "Ford Pre-X Flow, All --> 1967".

At issue is whether or not the sump gasket should be sandwiched between the
ends of of the rope seal.

I have three different TC engine assembly references (i.e. Elan Workshop
Manual, Lotus Cortina Passenger Car Service Manual by Ford, and Lotus
Twin-Cam Engine by Miles Wilkins) and none provide any clarity to this point.

Second question relates the bearing liner in the central main bearing cap.
The Lotus Cortina service manual describes and shows a "Vee" notch in the
tongue end of the bearing liner. This service manual states:

"NOTE -- An oil feed to the crankshaft rear thrust washer is provided by
means of a "Vee" notch in the bearing liner and a chamfer on the centre main
bearing cap (see Fig. 36)".

The Elan Workshop Manual and Wilkins book do not make mention of a "Vee" notch
in the center bearing liner, nor do my parts list manuals suggest a different
part number for the center main bearing liner.

So my question is should my center main bearing cap liner have a "Vee" notch
or is this unique to the Lotus Cortina ??

Your help is appreciated,

--

John Connin, Longwood, FL <***@***.***>
User avatar
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PostPost by: type26owner » Sat Oct 11, 2003 10:41 pm

Hi John,
Using the best rope seal is the most important item to do first. There
are three types that I'm aware of. The ones you want to use are coated
with shiny graphite which if rubbed will coat your fingers like the
lead from a pencil. The other ones are junk. They are a white rope
with a bluish teflon coating on the backside and another which is dull
black. You'll surely have a leak shortly if you use these junk ones
regardless of the assembly techique.

Trim the pan gasket so it butts up to the rope seals but doesn't go in
between them. Use the blus silicone adhesive which is approved to
stick to oily surfaces. Cut your own pan gaskets out of 1/16" cork
which is impegnated with an elastomer. The regular cork which are
laminated on an aluminum foil will weep synthetic oil right through
them. Trim the rope seals so they stick proud by 1/8" at all ends and
coat the ends with silicone adhesive too. Grease the seal lands on the
crankshaft prior to fitting. Use the 1/4" square cork gasket in the
groove for the timing cover because it won't leak through it there.

I'm not aware of any vee notch for the thrust bearings. However there
must be a chamfer on the upstream edge which is about half the
thickness of the shim.
Good luck!
Keith
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PostPost by: johnc » Sat Oct 11, 2003 11:54 pm

Keith, THANK YOU -- excellent input.

I think my rope seals and pan gaskets are of the materials you recommend.

However, I have all ready trimed the upper rope seal to 1/32" (0.80mm) per the
manuals I have. The lower seal has not be cut.

The rope seals I have a quite firm (i.e. considerable force is required to
compress). As a consequence, it is not clear to me that a 1/4" of rope
material (i.e. 1/8" lower + 1/8" upper, per side) can be compressed except by
overly displacing the surrounding pan gasket.

Question: What if I cut the lower (i.e. pan) rope seal 1/8" proud and leave
the upper rope seal at 1/32" proud, or do I need to procure another rope seal
??


By "chamfer on the upstream edge" I presume this is a chamfer on the central
main bearing cap -- correct?

A little background. I didn't notice the reference to the Vee groove in the
Lotus Cortina service manual until after I had installed my crankshaft. The
reason it caught my attention was that I have no memory of seeing any Vee
grooves in the bearings I installed -- they may have been there but I have no
memory of seeing them.

I should have done this before I posted my first message. I just checked the
main bearings which I removed which were Vandervell, and each one has a Vee
groove (i.e all 10). Now I am thinking I probably should pop off the center
main bearing cap and take a peek to put my mind at ease.

--

John Connin, Longwood, FL <***@***.***>
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PostPost by: johnc » Sun Oct 12, 2003 12:16 am

Nuts, I forgot to ask one more question in my last posting.

Keith, you mentioned the use of "blue silicone adhesive" for sealing, and
which is consistent with Miles Wilkins book.

I was thinking about using a Permatix anaerobic gasket maker on the block side
of the pan gasket and on the ends of the rope seal. Then on the opposing
side of the pan gasket using Permatix Hylomar except for a dab of blue RTV in
each corner. Any thoughts?

My thought was the anaerobic sealer would be a better job of sealing deck
height differences in the timing chain area.

--

John Connin, Longwood, FL <***@***.***>
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PostPost by: type26owner » Sun Oct 12, 2003 12:17 am

John,
Okay, leave the side which is 1/32" proud and cut the other side a
little longer. You want to store enough clamping energy at the
interface of the rope seals.

You'll know it is okay if the pregreased crankshaft rotates with about
at least 10 ft/lb force I'm guessing when first rotated.
Keith
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PostPost by: type26owner » Sun Oct 12, 2003 12:24 am

Absolutely use the silicone gasket cement which is rated to adhere to
oily surfaces only. I discovered this stuff by studying the 20+
choices at the local parts store. Ignore the high heat ratings because
that's just advertising hype. Enjoy, it'll likely be leak free if you
do what I advise. I can help you seal the other areas of the engine
from leaking synthetic oil too. Just ask.
Keith
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PostPost by: johnc » Sun Oct 12, 2003 2:21 am


Keith, I am all ears relative to the above, but first the blue RTV silicone
gasket stuff that has adhesion to oily surfaces. I did an Internet search
and ran into the following:

1) Permatex Ultra Blue RTV Silicone Gasket Maker -- I found two different
suppliers who claimed this product offered excellent adhesion to oily
surfaces, BUT www.permatex.com did not make any such claim for the product.

2) Loctite, #587 Blue High Performance Silicone Gasket Maker -- AND the
manufacture does make the claim "offers excellent adhesion to oily surfaces".

What product did you use?

--

John Connin, Longwood, FL <***@***.***>
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PostPost by: saarhus » Sun Oct 12, 2003 2:41 am

Loctite is a division of Permatex, I believe.

Stan

----- Original Message -----
From: John Connin
To: ***@***.***
Sent: Saturday, October 11, 2003 9:23 PM
Subject: [LotusElan.net] Re: Re-assembly of Rope Seal TC Engine




Keith, I am all ears relative to the above, but first the blue RTV silicone
gasket stuff that has adhesion to oily surfaces. I did an Internet search
and ran into the following:

1) Permatex Ultra Blue RTV Silicone Gasket Maker -- I found two different
suppliers who claimed this product offered excellent adhesion to oily
surfaces, BUT www.permatex.com did not make any such claim for the product.

2) Loctite, #587 Blue High Performance Silicone Gasket Maker -- AND the
manufacture does make the claim "offers excellent adhesion to oily surfaces".

What product did you use?

--

John Connin, Longwood, FL <***@***.***>
saarhus
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PostPost by: gobw2 » Sun Oct 12, 2003 5:50 pm

Last time I had pan off was over 20 years ago. I trimmed the gaskets to
just contact the rope. I set the rope seal a bit proud so I was sure it
would be compressed into the top and bottom grooves, but not so proud
that it would be compressed to the point of rubbing too hard on the
crank. Greased crank and rubbing surface of rope so seal would not be dry
and score crank,and back then, used to use Permatex Aviation Form A
gasket on everything. No leaks (from there, anyway) George 67 S3

On Sat, 11 Oct 2003 16:58:41 -0400 John Connin <***@***.***>
writes:

I need help concerning the re-assembling my rope seal TC engine. My
first
question relates to the shape of the sump gaskets in the area of the rope

seal. The ends of the sump gaskets at the rope seal are square whereas
Plate
1 in my Lotus Parts List Manual suggests the ends should relieved so as
to
surround the rope seal. i.e.

+-------------+ +---+ +---+
| | verses | \ / |
| | | +--+ |
Square Relieved

The gasket set I have says it is for "Ford Pre-X Flow, All --> 1967".

At issue is whether or not the sump gasket should be sandwiched between
the
ends of of the rope seal.

I have three different TC engine assembly references (i.e. Elan Workshop
Manual, Lotus Cortina Passenger Car Service Manual by Ford, and Lotus
Twin-Cam Engine by Miles Wilkins) and none provide any clarity to this
point.

Second question relates the bearing liner in the central main bearing
cap.
The Lotus Cortina service manual describes and shows a "Vee" notch in the

tongue end of the bearing liner. This service manual states:

"NOTE -- An oil feed to the crankshaft rear thrust washer is provided
by
means of a "Vee" notch in the bearing liner and a chamfer on the centre
main
bearing cap (see Fig. 36)".

The Elan Workshop Manual and Wilkins book do not make mention of a "Vee"
notch
in the center bearing liner, nor do my parts list manuals suggest a
different
part number for the center main bearing liner.

So my question is should my center main bearing cap liner have a "Vee"
notch
or is this unique to the Lotus Cortina ??

Your help is appreciated,

--

John Connin, Longwood, FL <***@***.***>
gobw2
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PostPost by: type26owner » Mon Oct 13, 2003 2:58 pm

Believe Stan is correct, it's the same product packaged as different
brands. Can't recall the exact brand I used cause it's over at my
folks house which is center of the Franck family vintage racing
operations and general car fiddling on the weekends.

A word of caution when using this adhesive for the first time. It's at
least four times stronger then all the other sealants you've used in
the past. If there's room to slide a thin sharp slicing blade through
the cork or gasket material then removal is relatively easy. If it's a
metal to metal glue-up then use only enough so when it squeezes out,
it is no more then a 1/4" wide or prying apart the pieces without
damaging them might be impossible. This is CRITICALLY important for
sealing the intermediate plate and the timing chain cover area.

Let me start with the top and work my way down the engine recommending
sealing techniques which have a good chance of working consistantly.

The oil filler cap can leak if the cap is not perfectly centered on
the camcover cylindrical boss. If you measure the outside to outside
distance of the springs clips on the underside of the cap and compare
it to the distance between the round protruding bosses in the cover
they clip too you'll find there is barely enough overlap for the two
springs to engage anything. In fact, if the cap is allowed to shift by
about .040-.060" sideways which it has more enough clearance to do it
will become detached on one side tilting the cap slightly off the
sealing gasket and it'll leak. I made a cylindrical spacer which snaps
into the cap and just fits over the outer diameter of the cover boss
so the cap can't shift off center. Problem solved, my cap never leaks
anymore.

I'll post the other things to know about the twincam later.
Keith
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PostPost by: johnc » Mon Oct 13, 2003 4:49 pm

I stopped by my local Grainger Supply and pickup a tube of Loctite 587
Blue High Performance RTV Silicone Gasket Maker this morning. It was
a little more expensive (i.e. $8.59) than the Permatex stuff at
AutoZone, but the manufactures claims contain the right statements.

i.e. forms tough, flexible gaskets directly on flanges, offers
imporved adhesion to oily surfaces, is three
times more oil resistant than generic silicones, fills gaps
to 0.25", etc.

Keith, thank you for making me aware of the differences in RTV
compounds and pointing me in the right direction.

johnc

--- In ***@***.***, "type26owner" <kdfranck@p...> wrote:
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PostPost by: johnc » Mon Oct 13, 2003 11:27 pm


I don't know if Permatex owns Loctitle, but I can tell you that Loctite 587
RTV silicone is different than any Permatex RTV silicone that I have ever
used. All Permatex RTV silicones that I have used were kind of a brilliant
blue in color and somewhat googey, whereas the Loctite product is a lighter
blue in color and has the texture of a thick cream.

--

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PostPost by: "Fred McDonald" » Thu Oct 16, 2003 2:15 am

----- Original Message -----

RTV Silicone Gasket Maker



I have had good results with Dow Corning 735, available at industrial supply
stores.

Fred McDonald
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