I'll try to answer best I can, but anyone else who has a better take on these, please chime in...

1) In an effort to reduce noise, don't go overboard on thightening that lash down. Don't know the lash specs for your particular engine, but you shouldn't fool around with different clearances too much.

2) The only problem is typically cost / benefit ratio on relatively stock engines, and possibly valve cover clearance, but...

3) ...if you can get a set cheap, and they either fit under your covers or you're open to replacing them, why not? Are they "name brand" such as CompCams or Crower? You probably want to avoid aluminum, unless you don't drive much, because their fatigue life isn't best suited for a daily driver. Make sure they are the same ratio, or piston to valve clearance problems may present. Also, they need to come with some good quality locking adjuster nuts to help maintain settings.

4) Sorry, never had them on an engine where I could hear much difference, but then I'm about half deaf from gear drive noise.

5) Solids make some noise that takes some getting used to.

6) Love is a never ending act of forgiveness.

7) Once you become proficient, you can knock it out in well under an hour. Tip: affix the valve cover gaskets to the covers with silicone and use grease for sealing to the head.

Hope that helps.

 

Cheap rockers are a disaster waiting to happen. IMHO, If you want to upgrade, get the Crane true 1.5 hardened stock type.

 

Going tighter on lash won't hurt anything. You're just starting the ramps earlier and setting them down softer. Going looser than say .004-.006 will start to beat things up.

Aluminum rockers will outlive all of us. I literally ran a less than $200 set of Cam Dynamics (later Crane Energizers) on my old 427 for over 20 years. MANY 2000 mile roadtrips, who knows how many blasts past 7500 rpm, cams up to .725 lift etc etc. I finally sold them to a guy to keep in his toolbox for spares. GM installed and warranteed Crane aluminum rockers on the LT-4's from the factory.

When I say cheap..I'm talking Pro Form or CAT brand stuff. DON'T use it!! We do have a set of ProForm rollers that are still working fine on a 7000+ rpm 327....but I'm not super enthused about them.

Good call on the adjuster nuts! Often they don't engage enough thread on stud and will break off top few threads if you don't catch it.


JIM

 

As for rockers I use the 1.52 ratio Comp Magnum cast steel roller tip rockers on anthing I build these days. They are very quiet with my solid lifter "30-30" cam (even with them lashed at .030"/.030"). They have been very reliable and cost about $150 or so. They will fit in there under any stock valve cover. I have them on the L-82 Vette as well.

I tried the CAT knock-offs of these rocker arms and they were JUNK! You need the real deal here.

-Mark.

 

Thanks guys!

Ya'll are saving me all kinds of Time and $$$ with you experience and knowledge!

I think I have some clear direction on what I need to do to get these adjusted properly!

 

So if I am reading these articles correctly on setting the lash on the solid lifter LT-1 (http://www.lbfun.com/Corvette/Tech/vettetech.html)
I do not adjust the #1 valves at #1 TDC but rather the #8E and #2I? I am going to try this method over the weekend. I am assuming the reference to #1TDC always means #1TDC on firing stroke. Quick way to tell is if the rotor tip is facing the #1 cylinder while balancer is indicating TDC on the timing tab?
Thanks!

 

I set mine cold and decrease the clearance by .006 because of the aluminum heads. I called comp and they told me I could go .010 on either side of the recommended clearance. My cam calls for .021 so I set them at .015 cold.
I bring the motor to TDC on the compression stroke and set certain valves, I have a chart, I then bump the motor over 180 degrees and set another set of valves. Do this 4 times and you have all the valves set.
I have a chart on the wall of the shop and just follow it.
I set them once in the spring and don't touch them till fall when I back them fully off.
If you have a lifter ticking check for an exhaust leak, they sound the same.
Since I use a ford solenoid I have a push button switch for bumping the starter.

 

The Chilton Manual Says Set it to #1TDC and you can adjust half the valves an and then Bump it around 180 and you can set the other half?

I try this last weekend and and set them cold at .015 and and it seemed to work fine? or at least it did not seem to run bad or run rough...

I thought when i asked this question it would be a simple answer.... Not I have found just about everyone you ask has a different take on the way they shoudl be adjusted...

But at the end of the day I went with the easyiest way I found...

I get to do it again this weekend because I had some rocker nuts that were sorta loose and they have already worked loose and are clacking again...

So I ordered some polly lock rocker nuts from Jegs that just arrived.

I plan to use this easy method again.

 

Look real close at those new locks with setscrews. They are often made with the threads starting a long way up inside the nut. The result is very little thread engagement and the tops of studs breaking off.

They have to be that way for some aftermarket studs with long shank areas...but just double check to get as much thread engagement as possible.

You can set them by rolling the motor only a couple of times...I just find it easier to bump it around and go down the line. Whatever gets you on the base circle of whatever you're setting.

And I agree with setting them while cold. Once you figure out the amount things loosen when hot....the most consistent way is to set them tighter when cold. If you set them hot....you need to be fast. Things cool off fast. Great on the dyno...a little tougher in the car.

I set mine .005-.006 tighter when cold too. I can take it to the track...warm it up to about 130* and pull to the line. After a hard pass..the lash will open up about .003. A few hours of riding around on the street/highway and it will open up the total .005-.006.



JIM

 

The Chilton manual is generic and it will work for many cases. It is not right for all cases. For most hydraulic cams it is fine. For some mechanical cams it might work. It definately will not work for the LT-1 GM sold lifter cam and it will definately not work for the "30-30" GM solid lifter cam as both of these designs will have a lifter on a clearance ramp at that time. You will be too loose and too loud on that valve.

I did not see where you said what solid lifter cam you have in there, GM or aftermarket. Each solid lifter cam design has it's own lash setting. It is specific to the way the cam is ground. If you do not know what is in there you can try to ballpark it using the "more complicated" method rotating the engine 90 degrees at a time or the "exhaust valve starting to open - adjust the intake valve, intake valve starting to close - adjust the exhaust valve" method and probably be fine.

Too tight is somewhat better than too loose. Too loud is probably too loose. Hope this helps.

-Mark.

 

MS69 350/4-speed I'm sure glad you got this thread going! How has it worked out for you so far? I just tried to find someone in town who still carries timing tape on the shelf. No luck. I figured the tape would be more accurate than my wife's sewing tape to figure the 90* timing marks. So that being said, how close to dead on 90* do those marks need to be if I plan on setting lash per the Lar's method. I can order the tape and have it in 3-5 days if its really worth waiting for.

 

Pepto,
You don't need a timing tape. Use a tape measure or a piece of string. Half way around the balancer is 180 degrees, half of that is 90 degrees. If you are using one of the every 90 degree type methods, it is not critical to be that exact. Mark it with a sharpie in a contrasting color that is easy to see. This mark will not fly off when the engine is running like the tape will.

-Mark.