Rockers

[5.7 hemi]

On a mild 512 (400 based) would the stock rockers be good to use?

 

[IQ52]

If I get an itch, should I scratch it?

I don't know. How much air pressure are you running in your front tires?

 

[5.7 hemi]

Was it a stupid question? I asked cause I don't know for sure. Figured I would get people that know the answer to give me some insight.

 

[Zeppelin264]

If your already spending the money on a big motor, why skip out on the rockers? Just get a set of Crane Iron Ductile rockers and get yourself some Smith Bros. push rods.

The factory rockers can get holes punched through them.

 

[IQ52]

Nobody knows what you mean by a mild 512. You gotta supply the people that know more build information Skippy.

 

[5.7 hemi]

512, stealth heads, mild cam, headers, rpm intake, efi, 4 speed, 3:23 gears, a body. Like I said, mild.

 

[1967coronet440]

On a mild 512 (400 based) would the stock rockers be good to use?

If it was my motor I would upgrade them, I posted a question about rockers not long ago and got the same sarcastic responses... my opinion I would upgrade them.

 

[khryslerkid]

I went with Crane ductile on a "mild build" just for the peace of mind factor. I've also seen the stamped rockers on a higher lift also. Went with the heavier shaft too. They don't distort like the factory shaft.

The way I look at it is, if you are useing flat hydraulic lifters, have to have pushrods made and they end up being noisy, you can always adjust the preload a tad more to correct it. You don't have that option with the stamped rocker. JMO

 

[5.7 hemi]

That's all good info, thanks!!

 

[khryslerkid]

The adjustable also makes a more precise setup too. Takes a bit more time to set up but useing shims and spacers to get the pushrods from rubbing the passages and having the rockers centered over the valve stems, is just a better setup.

 

[Garys1969RR]

What is the lift and type of cam you are using? I used a .509 lift hydraulic cam in a 451 I built, with stock rockers and valve train. The pre load was too high, so I shimmed the rocker shafts .040". That thing ran low 12s for 4 years in a 3600 lb RR, and was still running great when I sold it. The stock rocker arms are quite reliable, as long as you keep valve spring pressures within reasonable limits. Lots of guys run stock rocker gear with no probs. Stay below 6000 RPM, and you will be OK, as long as all the parts are in good condition.

 

[moparnation74]

x2 for crane ductile rockers

 

[66Satellite47]

The Crane ductile setup is good. I preferred the Isky's if they're still available. The hardened tip seemed to be an advantage. Also there are enough reasonably priced roller options.

 

[cryplydog]

5.7, there's nothing at all wrong with the ductile iron rockers and I would recommend them and a couple others on damn near any rebuild other than a stock rebuild, BUT,on your stock rebuild was the block decked? was the heads resurfaced? Was the valves and seats reground? what was the old head gasket thickness? what is the new head gasket thickness? See where this is going and now were going to slide the new hydrolic lifters in and what has changed deminsionaly on those. They say just crankem down basically and they will self adjust hydrolicly and all is groovy, right?Now lets talk about oil, is it new or old? is it multi viscosity or straight viscosity? synthetic or dinosaur squeezins, hot or cold, 10 wt. or 60 wt.. dirty or diluted and what is the oil pressure range in PSI on said enginefrom idle to 6 grand and how does these good many discrepencies effect on the majical hydrolic lifter with the do all MARSHMELLOW trapped inside keeping the entire valvetrain timed and adjusted to near perfection, IT DOESN'T for me. And OH, I must have forgotten the pushrod length to this frenzie also. So here it goes, I'll say it, I like and always use SOLID flat tappet lifters and or Solid rollers and ADJUSTIBLE ROCKERARMS for ADJUSTMENT PURPOSES. Starting,base and overall timing, idle,jetting, running temperature and higher RPMs will show easily the results. Basically a **** load of tuning will be left on the table with hydrolics except for mommas grocery getter. Good luck to all solid and hydrolic.

 

[IQ52]

512, stealth heads, mild cam, headers, rpm intake, efi, 4 speed, 3:23 gears, a body. Like I said, mild.

On a mild 512 (400 based) would the stock rockers be good to use?

No.

 

[PurpleBeeper]

With a "mild cam" I would say "Yes, stock rockers are fine". These guys have all pointed out, correctly, that adjustable rockers have advantages. What they didn't mention is having to pull the valve covers & adjust them a couple times a year.

I first ran a 292/509 purple shaft with plans to upgrade to a solid lifter cam, so I'm running Isky adjustables & double springs. They work fine. I don't "need" them, but I could dial in my lifter pre-load even if my "off the shelf" pushrods aren't exact. I've now moved to a smaller hydraulic cam (instead of a bigger solid) and still don't need the adjustables. I mean, you have to buy new pushrods anyway, right?

It is a judgement call on your part. If you do your work & like to "tune & tinker", then go ahead and get adjustables. If you have other people build your motors and you "just like to drive the car", then go non-adjustable, but I would definitely get a new set on a new motor.

 

[beanhead]

.. dinosaur squeezins,

Lol

 

[HEMI-ITIS]

Stock rockers are just that,,,STOCK.If you modify an engine to be more than stock then your valve train becomes as important as good rods.When you can't afford the "good" parts,then wait and save! If you build it RIGHT the 1st time,your effort will reward you.

 

[5.7 hemi]

Adjustable rockers it is, thanks!!

 

[Zeppelin264]

I disagree with the "adjusting a few times a year". I've had my Iron ductile's in for 4 years and about 7k miles and I've only re adjusted them once and that was because I broke a valve spring (Which BTW, DO NOT USE THE STOCK VALVE SPRINGS WITH THE STEALTH HEADS. /endrant) and had to re adjust them since I had to remove the push rods.

They say their springs are good for like .600 lift, mine broke after 4k miles of MILD usage( I drive like an old man) and at a lift of .533. Do yourself a favor and get some quality springs in it now.