Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544635
09/02/18 01:56 PM
09/02/18 01:56 PM
|
Joined: Aug 2011
Posts: 2,861 Pattison Texas
CSK
master
|
master
Joined: Aug 2011
Posts: 2,861
Pattison Texas
|
B3 racing Mike, makes custom shaft shims for your heads & cam combination. Instead of a bunch of stacked funky shims.
Last edited by csk; 09/02/18 01:57 PM.
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544685
09/02/18 03:22 PM
09/02/18 03:22 PM
|
Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
|
master
Joined: Sep 2014
Posts: 4,457
Washington
|
I read that in the last issue. I just shook my head when they machined the spring pockets bigger. They didn't correct the geometry and made the rocker arm weaker.
And this guy is a pro.
He didn't fix a thing, and contrary to what Dave Hughes told me, yes Dave, your rockers need to be correct too.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544699
09/02/18 03:48 PM
09/02/18 03:48 PM
|
Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,206
New York
|
the person who built the engine wasn't paying attention Never happened to me - my cat immediately detects any errors.
No one noticed that geo remark? "Brandes’ method, at rest (valve closed, pushrod not lashed), the tip is centered over the valve-stem tip both longitudinally (edge-on) and laterally (side-on). Shim the shaft spacers and shaft pedestals as needed to get there. Using an adjustable checking pushrod and light checking springs, set the preliminary valve lash to zero, and adjust pushrod length to achieve minimum motion off-center through the cam cycle."
I've been doing this stuff for 40 years, and I have no idea what he said. I'll bet Marlan Davis didn't either.
Boffin Emeritus
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544733
09/02/18 05:20 PM
09/02/18 05:20 PM
|
Joined: Jun 2014
Posts: 5,183
Porter67
master
|
master
Joined: Jun 2014
Posts: 5,183
|
Thats got to be one of the most pathetic articles ive read in a long time, good fodder for the chevy guys.
My take on the lesson learned is have at least one guy in your crew thats not a dumbass. If a build is known to eat rockers, hey lets keep replacing them vs pulling it down and finding the issue NOT.
IMO thats a first time assembler (not builder) rookie mistake, if the valve cuts in the piston are not symmetrical there is always a pattern to follow. And its so easy to lay rolled clay on a full bank, set a head on and turn one cycle and inspect.
I f up alot of things but my builds dont eat parts, they maybe get mocked up 4-5 times and gets the pan and intake pulled for inspection after the dyno but they never eat parts.
Builds dont eat rockers, I could take one that breaks and chalk it up to a bad part, more then one and its time to come apart.
I use a 1.46 diameter spring on a .680 lift cam on my street racer, that build here was crap from the gate.
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544746
09/02/18 06:01 PM
09/02/18 06:01 PM
|
Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
|
master
Joined: Sep 2014
Posts: 4,457
Washington
|
They did mix up pushrod length for a stud mounted rocker with an article on shaft mounted rockers which adds to the confusion. I'm not sure about cutting the Hughes rockers, I would not have done that. That cam didn't seem radical enough to require cutting the rocker arms. A stout beehive or the dual conical spring or a smaller spring of some type most likely would've fit. I'm also not a fan of adding the shims under the shafts. I've worked on a bunch of race engines over the years and I've never had to add shims under the shaft. So when I see that I wonder what is going on.
What I thought was interesting was the root problem. If someone came on here and said their engine was breaking rocker arms how many people would ask if the pistons were installed in the correct holes? That is what the root cause was but it isn't something I'd normally put on the top of the list of problems. The beehive spring would give you some rocker clearance but it still doesn't fix the geometry issue. As you say, that spring wasn't big enough to be a problem. The problem is the shaft is too low, and too close to the valve. Move it up and away from the valve and any retainer would clear.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544761
09/02/18 06:39 PM
09/02/18 06:39 PM
|
Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,206
New York
|
Marlan Davis is an excellent reason not to read Hot Rod.
Boffin Emeritus
|
|
|
Re: Breaking rockers - bad mistake
[Re: AndyF]
#2544797
09/02/18 08:49 PM
09/02/18 08:49 PM
|
Joined: Feb 2003
Posts: 2,810 Sobieski Wi
bee1971
master
|
master
Joined: Feb 2003
Posts: 2,810
Sobieski Wi
|
"Don’t mix Miller time with engine assembly time. "
Sums it up
1971 Dodge Charger Superbee 2011 Ram Sport 1500 Quad Cab Deep Water Blue Loaded Siberian Huskies
|
|
|
Re: Breaking rockers - bad mistake
[Re: Uberpube]
#2544804
09/02/18 09:00 PM
09/02/18 09:00 PM
|
Joined: Jan 2003
Posts: 10,721 North Dakota
6PakBee
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,721
North Dakota
|
I seem to hear my Old Man talking..."Unbelievable".
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
|
|
|
|
|