Vizard 427 SBF Rear Main Seal Dilemma

[Warp Speed]

No names here but one very well known circle track engine builders optimized back to back tests showed a 9 hp difference in favor of the Greg seal. I guess that's why just about every NASCAR engine has them
DV

While I am a fan of GST seals, I have to call bs on this, if the baseline seal was of any quality at all. For this big of difference in performance, either the baseline was a 20+year old, OEM design, installed in a way that kept it from holding any descent level of depression, or there was a major amount of noise in the test. It certainly wasn't purely from a frictional gain.
GST builds a quality seal........but let's keep it real here!
When going purely from a frictional standpoint, GST, while being a quality seal, isn't the lowest...........

[David Vizard]

Warp Speed-
You are exactly right on your assumption that the gain was was not solely frictional in nature. As I understand it (a partial assumption on my part) is that the scavenge stage was reduced in size as the seal did a better job. I also heard for a reliable source that one F1 team did a study and the use of Greg Seals in all the engine places applicable plus wheel bearings and other such parts with lubricated relative motion was equal to an 11 hp increase in engine output. While I cannot verify that feel free to take this for what you will.

DV

[David Vizard]

OK Mr. WS I forgot to ask a question about your comment :-
When going purely from a frictional standpoint, GST, while being a quality seal, isn't the lowest...........

Can you spill the beans here and save me going through every seal on the market --- please?

DV

[SchmidtMotorWorks]

Warp, can you ball park what the frictional gains can be?

I am thinking of some small clutches that operate in the range of 3hp that are about 2x the diameter and 10x the contact width of a main seal that hit 800F in a few seconds in operation.

[David Vizard]

mr Vizard, you have my curiosity peaked, so i have to ask. how is the long term durability with these low drag seals?

So far it appears to be much longer than any other seals I have tried - but I have not tested them all! For sure all I can say for certain is that longevity is very good.
DV

[David Vizard]

Here is the commentary from Engine Labs article on Pro Stock rings. This is supposedly a quote from a Pro Stock engine builder.:-

With all eight pistons installed (not including the front and rear seals that are extremely tight and robust to withstand the high crankcase vacuum), the twisting force to rotate the crankshaft on Pro Stock engines can be measured with an inch-pound torque wrench. A conventional BBC might take 25 to 35 foot-pounds of force to turn over the rotating assembly.

Note the mention of tightness of the front and rear seals. such 'tightness' is almost non existent with the Greg Seals.

And BTW we still need more support to get those 351 seals into production.
DV

[GARY C]

If I am not mistaken this is the seal that Keith Dorton recommended....Although I could not find the article where he referenced seals I did find this one in relation to rotational friction. http://hotrodenginetech.com/chevy-small ... g-engines/

David, is this the same seal that Jacky used? I remember a picture of her holding a seal for one of her engines...If I am not mistaken, the purchase does not have to be a 351 seal to promote the 351 seal it can be the purchase of any small block seal?????????? Is this correct?

[David Vizard]

If I am not mistaken this is the seal that Keith Dorton recommended....Although I could not find the article where he referenced seals I did find this one in relation to rotational friction. http://hotrodenginetech.com/chevy-small ... g-engines/

David, is this the same seal that Jacky used? I remember a picture of her holding a seal for one of her engines...If I am not mistaken, the purchase does not have to be a 351 seal to promote the 351 seal it can be the purchase of any small block seal?????????? Is this correct?

Well I guess the cat is out of the bag as far as Kieth Dorton's use of these seals but remember you did NOT hear it from me.

Yes any orders for seals other than the 351 bought by ST posters will count towards the tooling for the 351.

I think all of Jacque's engines from at least 2011 on used Greg Seals. In this shot below she is showing a seal for a BBC short block mule she was building for me at that time. How the Kasey. our dog, got involved in this shot I do not know. this seal went into a two piece seal block.

[GARY C]

Well I guess the cat is out of the bag as far as Kieth Dorton's use of these seals but remember you did NOT hear it from me.

Did I stumble across Top Secrete Data?...Maybe some of Hillary's Emails? No, it was something where top engine builders were asked what little tricks add up to make a big difference and the reference about seals had one that was not available to the public that came from the UK and the 2 piece seal looked like a 1 piece seal.

[David Vizard]

Here is a view of the one piece Greg Seal on one of my 700 hp 496 BB Chevy's. No leaks,easy to fit and no friction (well almost no friction)

DV

[groberts101]

Had to check to see if it was April 1st all over again. Stupid question of the day...

.... how the hell do you install that on the crank?

[lefty o]

Had to check to see if it was April 1st all over again. Stupid question of the day...

.... how the hell do you install that on the crank?

not that stupid, because im wondering too. must be flexible enough to get over the flange without tearing or disforming it, im guessing.

[David Vizard]

I can hardly believe that it has taken anyone to ask how a one piece seal is installed on a two piece seal crank!!
I will see if I can come up with some pics.
DV

[piston guy]

Similar to the one Jon Kaase sells. It has a split in it .

[wyrmrider]

scarf cut?