Fel-Pro Pan Gasket: Thick or Thin?
01-04-2008, 12:26 AM
#21
Racer
Member Since: Apr 2004
Location: IL
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
A dab of RTV is still required at the "tri-corners" where the pan,block, and timing cover meet. Also needed at the rear corners. The molded in end seals still can not be compressed into the corners and need this as a precaution. Just like the stock ones. Surface prep of chromed pans and timing covers can also be a problem but usually a fine wire brush in an air tool can be used to PREP (not gouge) the surfaces.
Some aftermarket pans have a bead running down the length of the pan (block side rails) that is different than stock. This taller bead height is sometimes "designed in" to "bite" into (more load on )the cork better. Well, this can compress the body and split the gasket and cause leaks despite the load limiters (spacers) at each bolt location. This is the main cause of side rail leakage from "pro builders", they never noticed this difference as a cause.
I can tell you from (personal) testing experience that the rubber out last the cork 5:1 in cyclic testing hours from -20 to 270 f (w/hot oil) when installed correctly.
Previous mention of "thick and thin" info is correct. Measuring ALL aftermarket pans (also GM service/hi-perf) is a good precaution prior to purchasing the gasket. Whether the stock replacement or hiperf 1 pc gasket.
Hope this helps,
Later.
Some aftermarket pans have a bead running down the length of the pan (block side rails) that is different than stock. This taller bead height is sometimes "designed in" to "bite" into (more load on )the cork better. Well, this can compress the body and split the gasket and cause leaks despite the load limiters (spacers) at each bolt location. This is the main cause of side rail leakage from "pro builders", they never noticed this difference as a cause.
I can tell you from (personal) testing experience that the rubber out last the cork 5:1 in cyclic testing hours from -20 to 270 f (w/hot oil) when installed correctly.
Previous mention of "thick and thin" info is correct. Measuring ALL aftermarket pans (also GM service/hi-perf) is a good precaution prior to purchasing the gasket. Whether the stock replacement or hiperf 1 pc gasket.
Hope this helps,
Later.
01-04-2008, 09:21 AM
#22
Team Owner
Member Since: Aug 2006
Location: Columbia Missouri
Posts: 24,125
Likes: 0
Received 9 Likes
on
9 Posts
A dab of RTV is still required at the "tri-corners" where the pan,block, and timing cover meet. Also needed at the rear corners. The molded in end seals still can not be compressed into the corners and need this as a precaution. Just like the stock ones. Surface prep of chromed pans and timing covers can also be a problem but usually a fine wire brush in an air tool can be used to PREP (not gouge) the surfaces.
Some aftermarket pans have a bead running down the length of the pan (block side rails) that is different than stock. This taller bead height is sometimes "designed in" to "bite" into (more load on )the cork better. Well, this can compress the body and split the gasket and cause leaks despite the load limiters (spacers) at each bolt location. This is the main cause of side rail leakage from "pro builders", they never noticed this difference as a cause.
I can tell you from (personal) testing experience that the rubber out last the cork 5:1 in cyclic testing hours from -20 to 270 f (w/hot oil) when installed correctly.
Previous mention of "thick and thin" info is correct. Measuring ALL aftermarket pans (also GM service/hi-perf) is a good precaution prior to purchasing the gasket. Whether the stock replacement or hiperf 1 pc gasket.
Hope this helps,
Later.
Some aftermarket pans have a bead running down the length of the pan (block side rails) that is different than stock. This taller bead height is sometimes "designed in" to "bite" into (more load on )the cork better. Well, this can compress the body and split the gasket and cause leaks despite the load limiters (spacers) at each bolt location. This is the main cause of side rail leakage from "pro builders", they never noticed this difference as a cause.
I can tell you from (personal) testing experience that the rubber out last the cork 5:1 in cyclic testing hours from -20 to 270 f (w/hot oil) when installed correctly.
Previous mention of "thick and thin" info is correct. Measuring ALL aftermarket pans (also GM service/hi-perf) is a good precaution prior to purchasing the gasket. Whether the stock replacement or hiperf 1 pc gasket.
Hope this helps,
Later.
01-04-2008, 10:54 AM
#23
Burning Brakes
Member Since: Dec 2007
Posts: 952
Likes: 0
Received 0 Likes
on
0 Posts
How's 'bout lighten up? Nobody including me said that anyone did say race ... it's just that usually if someone asks here or at summit they're directed to a race part ... even when it's not needed. And the gasket I recommended often in-stock most local chain stores & less $ than race. If the pan's handly ... by all means measure & check it ... I didn't imply otherwise.
OE '75-up sbc came w/ thick seal pan ... & it's been years since I've seen a new aftermarket pan that used a thin seal.
Just trying to help
OE '75-up sbc came w/ thick seal pan ... & it's been years since I've seen a new aftermarket pan that used a thin seal.
Just trying to help
Take it easy.
01-04-2008, 01:11 PM
#24
Instructor
Member Since: Jul 2001
Location: Brighton MI
Posts: 183
Likes: 0
Received 0 Likes
on
0 Posts
Re: Leaking Fel-Pro 1-piecers
Here's a poll going on over at the Chevelle forum:
http://www.chevelles.com/forums/showthread.php?t=147676
http://www.chevelles.com/forums/showthread.php?t=147676
01-04-2008, 01:14 PM
#25
Team Owner
Member Since: Aug 2006
Location: Columbia Missouri
Posts: 24,125
Likes: 0
Received 9 Likes
on
9 Posts
Here's a poll going on over at the Chevelle forum:
http://www.chevelles.com/forums/showthread.php?t=147676
http://www.chevelles.com/forums/showthread.php?t=147676
Looks like it was nailed in the first few posts. After market pans, having the ridge, so when it's torqued down...probably too much, it splits or damages the seal.
I have lost no faith in the one piece seal.
01-04-2008, 01:20 PM
#26
Team Owner
If you have the standard-stamped steel pan, you must flatten out any distortion on the pan rails, if you want it to seal. Lots of folks overtorque pan rail bolts to get a leak to seal. That "dimples" the pan rail at the bolt head sites. If you don't fix damage like that, it doesn't matter what gasket you use...it WON'T seal.
01-04-2008, 01:28 PM
#27
Melting Slicks
09-16-2014, 08:16 PM
#28
3rd Gear
Member Since: Mar 2011
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
