273 mech rocker problem

[furrystump]

I would be afraid of running that rocker ground as much as it is. So, at least the exhaust valves are longer? How much longer? The shim on the bottom looks significant. The rocker shaft needs to move. With valve train, changing one thing can have unexpected consequences and you can NEVER check things too much. Just taking the long exhaust valve, assuming they are shimmed to the same installed height and pressures of the intakes. It is going to change the rocker geometry. It is also going to change how much the adjuster is sticking out of the exhaust rocker. I personally would want the valve stem height uniform. Not anti shim, but valve train is a high attention to detail thing, with catastrophic consequences if you get it wrong. I overstayed my welcome with a set of unbushed comp stainless rockers. (60,000 + miles and 1000’s of runs) A rocker grabbed the shaft and it tagged a valve HARD.

 

[toolmanmike]

View attachment 1716137827

My head is on the left. I bet I bought the wrong valves. I don't have the numbers but I am sure they are too long. (obvious) The shop had to shim the heck out of the springs to get them to work. I shimmed the rocker shafts quite a bit as well. That's before I knew of Mike at B3RE. I should take it apart and fix it right. Right or wrong, as long as it's working I might just leave it alone.

 

[65TerrorCuda]

If it's working and not hitting anything I'd run it. Looked good geometry wise

 

[65TerrorCuda]

My head is on the left. I bet I bought the wrong valves. I don't have the numbers but I am sure they are too long. (obvious) The shop had to shim the heck out of the springs to get them to work. I shimmed the rocker shafts quite a bit as well. That's before I knew of Mike at B3RE. I should take it apart and fix it right. Right or wrong, as long as it's working I might just leave it alone.

Here's a mock up of what mine look like for reference sake. these are stock replacement valves springs etc

 

[toolmanmike]

View attachment 1716147240

View attachment 1716147241
Here's a mock up of what mine look like for reference sake. these are stock replacement valves springs etc

Yep look at how flat the rocker i on the valve tip. Mine not so much.

 

[Dave999]

next time you are in there clean off the valve tips with brake cleaner colour them in with sharpie and see where the contact patch is ideally direct across the middle of the tip
but hey anywhere within the middle 60% would do if its rolling off the front or rear edge of the tip at 1 extereme or the other it will wear/mushroom the tip and wear the valve guides......eventually...

if you have got this far with no issues its probably not doing that


Dave

 

[4spdragtop]

Did you get your rocker clearance issue resolved?
I'm mocking up to see how close our 273 rockers are to our springs. Measured approx .027" rocker to spring.

I have a rebuilt Commando with Purple Shaft 284 set(including valve springs)+ Mopar Perf titanium retainers. Now the stock adjustable rockers won’t clear the springs or retainers. Allready cround off quite a bit. Which aftermarket rockers would?

View attachment 1716137396

 

[onbuicks]

No, not yet. No progress.

 

[4spdragtop]

I was surprised when I chkd specs on springs that the Lunati dbl 73949 has a smaller od(1.440) then comp 901(1.494). But I'm assuming the double doesn't need to be as wide due to dual springs?
We never even thought to chk rocker arm clearance when we did the 273 in 2012 and it has the wider comp 901 springs.
Hope you make some progress soon.
I wonder if Mancinis rocker arm sets give a little more clearance?

No, not yet. No progress.