|
Re: Coan super sprag for street, strengths/drawbacks?
[Re: 440Jim]
#954659
10/15/11 09:20 PM
10/15/11 09:20 PM
|
Joined: Jan 2003
Posts: 74,978
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,978
U.S.S.A.
|
Quote:
Back to the topic at hand... (please)
Quote:
John,
Does the A&A Ultimate Sprag use 1/4 bolts with compression ferrels?
The Coan says it uses 8mm shoulder bolts, and the case bolt holes need to be enlarge since that is slightly larger than the stock 727 5/16 bolts that thread into the case (not the sprag).
Sorry Jim I missed this question the first time around ....
Yes the A+A uses the 1/4" bolts and ferrules , I also machine the case and add the 2 extra bolts that the A+A allows you to use because it is a 6 bolt.
|
|
|
Re: Coan super sprag for street, strengths/drawbacks?
[Re: Clanton]
#954661
10/15/11 11:33 PM
10/15/11 11:33 PM
|
Joined: Jan 2003
Posts: 5,987
Anoka County, MN
Leigh
master
|
master
Joined: Jan 2003
Posts: 5,987
Anoka County, MN
|
For what it's worth, those shoulder bolts from Coan are not the best. The broach of the internal hex, is iffy, at best. The last one I used (3rd unit), I made my own spacers, out of steel tubing (like I have since 1978). MUCH better fit, and no worries about stripping the internal hex for the next builder to hassle with. Also, I personally don't see the need to add the extra 2 bolts. Any application that can sheer off 4 bolts, should have a low band apply V/B anyway. 
|
|
|
Re: Coan super sprag for street, strengths/drawbacks?
[Re: Leigh]
#954663
10/17/11 01:29 PM
10/17/11 01:29 PM
|
Joined: Jan 2003
Posts: 16,923
NC
440Jim
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,923
NC
|
Quote:
For what it's worth, those shoulder bolts from Coan are not the best. The broach of the internal hex, is iffy, at best. The last one I used (3rd unit), I made my own spacers, out of steel tubing (like I have since 1978). MUCH better fit, and no worries about stripping the internal hex for the next builder to hassle with.
Thanks for the info/experience.
Did you use 1/4 bolts instead of the shoulder bolts and drill the case to 5/16 and make a sleeve to fill the case and fit the 1/4" bolts nicely?
Is the Coan race tapped 1/4-28?
The shoulder bolts look like a good idea, but if the hardware is marginal, that defeats the improvement. Although I don't like the compression ferrels to fit smaller (i.e. 1/4") bolts into the case, I have never heard of any problems with them. And many standard bolt-in sprags use that method.
|
|
|
Re: Coan super sprag for street, strengths/drawbacks?
[Re: JohnRR]
#954664
10/17/11 06:32 PM
10/17/11 06:32 PM
|
Joined: Nov 2005
Posts: 1,943
San Angelo, Texas, U.S.A.
1968RR
top fuel
|
top fuel
Joined: Nov 2005
Posts: 1,943
San Angelo, Texas, U.S.A.
|
Quote:
Quote:
Bottom line: your sprag is less likely to fail if it's a bolt-in. They're not that expensive and there really is no drawback in using one.
Only half correct , The facory type sprag wit ha bolt in outer race will still fail by having the rollers rollover , the Cona or A+A sprag has more rollers so it is virtually impossible to have the rollers fail.
Just replacing the outer race to a bolt in type on a trans that has not had the outer race spin in the case is a waste of time and money.
You make a good point about the roller rollover, but even if the outer race has never been spun, installing a bolt-in sprag will still lessen the chance of it ever spinning (the force required would need to be much greater).
"When I'm in a slump, I comfort myself by saying if I believe in dinosaurs, then somewhere, they must be believing in me. And if they believe in me, then I can believe in me." - Mookie Wilson
|
|
|
|
|
