|
screw in rocker stud thread length/engagement Q
#2545179
09/03/18 04:26 PM
09/03/18 04:26 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
EQ mag heads. the comp cams rocker studs 4504-16, the lower 5/16 stud length is .680" and the Lunati 86004-16 studs have a .750" lower 5/16 stud length. these are quality black items (grade 8 or better I would think). I have both sets cuz I needed more upper (above the boss) (3/8) thread length to get my geometry dead on & the Lunati has 1&3/4" up top & the CC has 1&1/2" up top. My 1&3/4" installed height (.100" longer) valves are giving me setup problems & even the Lunatis I might need to shim them up off of the head bosses. My Question is: how much thread engagement down below into the head bosses must I keep to have the max strength against breakage (5/16 coarse threads). I can shim up the Lunatis to how much the CC ones are (.070" gain) which will get me "close" but I may need a bit more so I am wondering how much actual length does that 5/16 stud need for max strength? so I ain't risking breakage especially with these smaller 5/16 studs. thank you for your time.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: RapidRobert]
#2545193
09/03/18 04:52 PM
09/03/18 04:52 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
I think you will find that anything greater than the stud length will give you the max strength of the stud but then it comes down to the strength of the alum around the stud being that they are hardened studs
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: MR_P_BODY]
#2545201
09/03/18 05:01 PM
09/03/18 05:01 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
these are iron heads. iirc 1&1/4 or 1&1/2 times the bolt dia for a length dimention is needed for max strength but I ain't sure on those 2 numbers
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: RapidRobert]
#2545224
09/03/18 05:20 PM
09/03/18 05:20 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Just stud length.. think about it.. anything over the stud dia is just wasted length(its hanging out in space)
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: MR_P_BODY]
#2545237
09/03/18 05:39 PM
09/03/18 05:39 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
Alright it sounds like I have plenty of leeway, thanks Mr P
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: AndyF]
#2545262
09/03/18 06:14 PM
09/03/18 06:14 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
That means I have plenty of length to work with & possibly even the shorter studded CC ones will suffice. Thanks Andy & I was just perusing your book wondering if I can weld a dial indicator to a retainer to check scrub like I saw pictured there.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: AndyF]
#2545277
09/03/18 06:32 PM
09/03/18 06:32 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
1.5 times the diameter or 8 threads will usually give you full strength. In aluminum engineers sometimes go 2x the diameter. If its 1.5 times then why do they say at least the stud dia on wheel studs has to be sticking past..thats why I said at least the dia.. I never heard that 1.5 times even in the fastners lab
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: AndyF]
#2545377
09/03/18 10:25 PM
09/03/18 10:25 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
If my figuring is right to go 1.5X I can raise the CC ones .212" which will put em (in effect) at .892", which is significantly longer than the Lunati .750 ones that are "almost" long enough so I should be plenty good (& have the Lunatis' for a future build. I'm pumped! & I needed this after the preload/wipe pattern/vp clearance dilemma I am haveing with this. thanks again guys.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: wyrmrider]
#2563962
10/14/18 05:31 PM
10/14/18 05:31 PM
|
Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
OP
Circle Track
|
OP
Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
|
I used the lunati longer ones (5/16 & 3/8) & the up top 3/8 stud part is 1&3/4 (iirc). Down below it has way more than 1/2" thread length engagement on the bottom 5/16 stud section. With an 8" pushrod I can get minimal (OK) (~.020) preload with the rocker screwed down 6.2 turns (from 90 deg at zero lift per the straub vid with the cam lift I have) so there is a 90 deg angle at half lift. THE PROBLEM is the 1.6 chebby stud mounted roller rockers are too long & the roller is way too close to the outer (exhaust) edge of the valve. I dont want to at the moment relocate the stud & even if I did it would highly likely on the other side make the pushrods rub on the wall (they're close now) & I might even as is need to slightly file the pushrod wall to thin it slightly for a hair more clearance.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: screw in rocker stud thread length/engagement Q
[Re: wyrmrider]
#2564444
10/15/18 03:36 PM
10/15/18 03:36 PM
|
Joined: Mar 2005
Posts: 403 Colorado front range
BcudaChris
mopar
|
mopar
Joined: Mar 2005
Posts: 403
Colorado front range
|
...chevy rockers are longer fulcrum to roller mopar rockers are short...
Robert, this would seem to confirm what we were discussing on the guide plate thread about fulcrum to roller distance.
|
|
|
|
|
|