I have days where i'm excited bout the car and too many days where it is a massive stress on me.. which is stupid cause it can sit for 10 years if it needs to
really odd thing
Why do I keep breaking rocker arms?
- Thread starter Slugfarm
- Start date
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I have days where i'm excited bout the car and too many days where it is a massive stress on me.. which is stupid cause it can sit for 10 years if it needs to
really odd thing
MOPAROFFICIAL
Oogliboogli
It's safe to say maybe all of us can agree that inline engines in general can linger on longer than your typical v8
I dunno.. i just dig em more... the ford big 6 (300 or 302?) is a badass 6... the chevies are kinda meh...
MOPAROFFICIAL
Oogliboogli
Yeah but we can find many more examples of inline engines of all makes going on for decades with a piece of leather belt for a rod bearing, burning oil ...w/ different size piston from a field repair at some point. 1950's ford tractors are a great one.
Good point, i wonder if the V motors just have harmonic/vibration issues that inlines don't
Full of ****.
1) Valve guides weren't cut down for sufficient retainer clearance at the increased lift.
2) Valve springs are going solid because they're not correct or improperly installed/set-up.
3) If they're not getting oil due to plugged passage/wrong or installed wrong shaft etc., they could heat up & try to seize, which may take the temper out of them & allow failure.
(You didn't allude to symtoms of no oil, so this would be unlikely, & be multiple rockers damaged/failed.)
4) The pushrod cups are touching the rocker, suddenly over-lifting the valve near peak lift.
5) Ain't no chance You're "over-revving" any 225, but if the springs aren't anywhere near strong enough for the cam, it could be floating/bouncing enough to try dropping the pushrod with the same consequence as #4 above.
6) The Slanty pushrods are not "on axis" with the lifters, and are just short of 10" stock, at only 5/16" diameter they should've bent if they actually broke a rocker arm.
Looking forward to more details & pics, peace!!
MOPAROFFICIAL
Oogliboogli
That's what I was saying about the push rod..that the ****** would break before that rocker would LOL
But the account of some POS NORS failing out of nowhere on the other member makes Me wonder if these are some bubblegum junk replacements used in the "build", I want to see this failed arm...
Also, not knowing a thing about this 225, My imagination added these;
7) Someone put a hydraulic cam & tappet set in there, & kept the mech adjustable rockers & pushrods, not knowing it don't work that way on a Slanty. Noisy collapsed lifters with a bunch of lash trying to toss a pushrod.
8) The lash is just plain F'd up by somebody that hasn't a clue of what they're doing.
7) Someone put a hydraulic cam & tappet set in there, & kept the mech adjustable rockers & pushrods, not knowing it don't work that way on a Slanty. Noisy collapsed lifters with a bunch of lash trying to toss a pushrod.
8) The lash is just plain F'd up by somebody that hasn't a clue of what they're doing.
MOPAROFFICIAL
Oogliboogli
Bottoming out the plunger on Max lift?
I can't remember the difference in length of the two
Since the Slanty oils hydros from the top down w/dedicated rockers & hollow pushrods(ball&ball ends), they can't just be "swapped in" like an A-LA-B-RB-Magnum-Hemi, so not knowing who-what-&where it's remotely possible. They could drop the Hy cam & lifters in, set the pre-load, and not realize there will be no oil to the tappets.
I'm beginning to have doubts about them myself but haven't had luck finding other local mechanics willing to work on classic cars. Do you have any suggestions?
Dartsun
Mopar Dude
north eugene automotive - Google Search
I’d try here, this was the mopar place locally but unfortunately the owner Rick passed about a decade ago. The guy who owns it now worked for Rick and knows mopar.
Hyper_pak
Old School Chrysler Fan
Where are the pictures?
We might can tell you what is wrong and you can fix it.
We might can tell you what is wrong and you can fix it.
Well, maybe you forget. I had the head milled a lot, BUT also it is a reground camshaft, which kinda "undoes" some of what the head milling does in relation to the pushrods.
Car is still at the shop (they had to pull the head to fish out the broken bits) and I just got back into town after a few days away. Hoping to get over there tomorrow and at least look at it and get pics.
Exactly. Just like every other thread asking for help. No pictures. C'mon man.
I finally have a couple photos and a little more info. So the mechanic is sure that this break is the result of over revving leading to valve float. I've certainly gone into the 5000s some and do tend to drive fairly aggressively. Mech wants to install a rev limiter, which feels sort of like training wheels, but maybe that's what I need. I did read an article about valve float that implied better springs would help guard against it. I'm pretty sure that the pistons, rods, springs, etc are all stock. Do I need to get high performance stuff to safely hit 5000-6000?
On another note, I finally had the chance to try out the distributor I got from @halifaxhops. It's incredible how much better the car drives. The man deserves a trophy or something.
On another note, I finally had the chance to try out the distributor I got from @halifaxhops. It's incredible how much better the car drives. The man deserves a trophy or something.
Charrlie_S
Well-Known Member
I still haven't seen any thing about the cam specs, or valve springs. Or whether the head had any valve guide work done to it.
I have run cams from only .434 lift up to .528 lift. Used 340 style valve springs, and have never broken a rocker arm. Even turning close to 7,000 rpm (170 cid). However in most cases, I did have to machine the valve guide, and/or spring seat for proper clearance.
I have run cams from only .434 lift up to .528 lift. Used 340 style valve springs, and have never broken a rocker arm. Even turning close to 7,000 rpm (170 cid). However in most cases, I did have to machine the valve guide, and/or spring seat for proper clearance.
MOPAROFFICIAL
Oogliboogli
The adjuster is way out.
What does it look like at mid and max lift, pushrod hitting rocker?
There's wear where at the tip, pitting even.
The valve tip should have a * pattern on it from spinning at float.
What so the springs look like at full lift and are the valves all the same height?
What does it look like at mid and max lift, pushrod hitting rocker?
There's wear where at the tip, pitting even.
The valve tip should have a * pattern on it from spinning at float.
What so the springs look like at full lift and are the valves all the same height?
Hyper_pak
Old School Chrysler Fan
That "break" looks suspicious to me.
I have never seen a broken stock rocker, yea they look weird, but they work.
And there were millions of them made and in service for billions of miles.
If that happened in an engine, I think you would see a lot of other damage on the other parts.
I have never seen a broken stock rocker, yea they look weird, but they work.
And there were millions of them made and in service for billions of miles.
If that happened in an engine, I think you would see a lot of other damage on the other parts.
I'm still working on getting specs. It would probably help if I weren't mechanically illiterate.
Here's a few more pics under the valve cover. Not sure why the're sideways, sorry. Valves are definitely not all at the same height but a lot of them are.
.Here's a few more pics under the valve cover. Not sure why the're sideways, sorry. Valves are definitely not all at the same height but a lot of them are.
There is no chance of valve to piston contact in a 225 without serious compression mods and a LOT of valve lift, and floating the valves hard enough to drop-out a properly adjusted pushrod is nearly impossible, BULLSHIT..
1) Why is that rocker a dull gray color? Never ever saw a factory rocker that patina, dirty or clean, Evaporust treated? Were these things rusted to **** & heated with a torch to loosen them &/or the adjusters?
2) The pitting in the rocker tip is atrocious, was that rust pitting? Was it there before the "rebuild"?
3) You have yet to answer; *CAM/VALVES/SPRINGS*
4) I've redlined & neutral dropped the Slanty I ended up building when it was bone-stock in the car I pulled it from, drove it 2yrs. B4 pulling it to drop a 'teener in that car.
5) Those same rockers saw a ton of beating in the K6, including being held at 6K during burnouts, and saw 7K briefly a number of times. That's with oversize(read HEAVIER) 1.74"/1.41"valves, and 340HP single springs that were under-compressed on the exh. because I didn't have the shims to make-up for the longer AMC valves. If ever a valve were going to float & break a factory rocker, I'd have done it.
6) Finally, YES, Hoppy is a great Member & contributor to the Mopar hobby!!!
Why is the adjuster for #2 intake so far out?I'm still working on getting specs. It would probably help if I weren't mechanically illiterate
Here's a few more pics under the valve cover. Not sure why the're sideways, sorry. Valves are definitely not all at the same height but a lot of them are.
View attachment 1716114644
View attachment 1716114645
View attachment 1716114646
Oh, & the idea of a Slanty on the Rev Limiter has almost, (ALMOST) left Me speechless.
What pushrods are those? The pushrod cups look suspiciously large like they would hit the rocker arm at full lift.
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