Well the .600 lift beehive springs from Scoggin Dickey went fine. The 1.85 ratio Comp Magnum arm install didn't! This is using stock lifters.
I found no mention of the baffle on the driver's side valve cover needing removed for clearance but it does and the little tab on the inside as well. If you don't the cover will not sit all the way down.
Our biggest problem though is setting the lash. We used the Crane procedure the first time that a couple of people gave us here which says to first start with zero lash by turning the motor over and getting all at zero. Then you are supposed to adjust each one 1/4 turn every 10 minutes until two full turns has been achieved. We did that! That also give you the .082" preload it has been suggested by people here in doing this. We tried to fire it up and it wouldn't run... real rich. Pulled the plugs and they were pretty covered with gas. At that point we went back and loosened them all one full turn and it ran pretty good, no noise but had a little miss like one cylinder was intermittent firing. It threw an SES light P0300 for random misfire. We didn't have new plugs so at that point we went back to zero lash... one by one and went one turn from zero. This time they had clatter like they are loose.
I guess you can say this one beat us. Someone out there has to have info of a sure-fire way of setting the lash when changing to roller rockers because the .082" did not work. Car is just sittting on the lift because we can't figure out what needs done to get this thing running right or if we damaged something early on (bent valve maybe?) or fouled plugs.

As many people that are swapping heads/cam and doing more than once with adjustable rockers... how are you doing it????


If we can't figure this out soon I may just go back to the 1.6 ratio non-adjustable rockers and cut my losses. This was supposed to be an easy bolt-on but isn't!

 

Rockers arent hard, you must be doing something wrong. I do it all the time.... I use the EO-IC method to set lash and never have any problems.

When the Exhast valve starts to Open, you adjust the intake valve to Zero, plus a 1/2 - 3/4 turn.

When the Intake valve is Closing you adjsut the exhast valve valve to Zero, plus a 1/2 - 3/4 turn.

Do that for every cylinder and your engine will run fine. I dont know who would tell you to put in two turns, Ive never heard of that. You could be hangine the valves open at that point.

What lifters are you running?

 

Stock lifters. Every procedure everyone has given me says 2 turns. Some of my searches here turned up don't use 1/2 to 3/4 turn. I have no idea what could be wrong. What rockers are you running and can you give me a step by step on EXACTLY how you are doing it?

 

Possible a valve bent?

 

Here is the the initial thread where I got 2 turns from 405 ZO6:


https://ls1tech.com/forums/generatio...92-92-a-2.html

 

2 turns (.082") is probably too much. Comp says 1/2 turn so that's what I would do. Doesn't this rocker system convert to a stud mount, rather than the OE pedestal mount system? The stud, where the polylock engages, could have a different thread, which could change the amount of preload you get from 1 full turn.

Good luck with it all.

 

It uses studs but it is still 3/8"-24 so we calculated that to be the same

 

24 threads per inch is 1.05 millimeters per inch and the stockers are 1.25 millimeters per inch so it is pretty close.

1 turn preload with the stock metric pitch would be 1.25/1.05 or 1.19 turns on yours to be the same.

1 turn preload on your threads at 3/8-24 is like .84 turns with the 8mm X 1.25 pitch stock threads.

 

I don't understand as the stockers are non-adjustable. Anyone have some info on this?

 

do you have studs and polylocks? If so the only difference is on the threads. If you have adjusters then it's all different.

 

I have screw in studs and guide plates with poly locks

 

then what I said is true. It doesn't matter if the threads are at the top or the bottom.

 

3/8" - 24 is .0416" per turn, so 2 turns is .0833". This is not too much preload for a stock lifter. I've used the Crane method many times and never had an issue. Are you sure you followed the procedure to the letter?

Many don't really understand what '0' lash means. How did you determine '0' lash? Did you use your fingers or a tool to 'feel' for '0' lash? This is the take up point at the rocker arm and valve tip where the rocker arm tip just barely touches the valve tip without ANY additional preload.

 

Done by hand.


He reset them to 3/4 turn today and it is quite and running pretty good. He just called and said it is rich out the exhaust and we have a miss you can hear occasionally through the exhaust. I don't know if this is a possible fouled plug or we have busted something in the motor like bent a valve.

 

.0833 at the middle of the rocker on the polylock pushes the pushrod cup down about 2.85/1.85 or 1.54 ratio in that direction as it's not 1 to 1 unless that was an adjuster right over the pushrod. This equals about .128 preload or almost bottomed out depending on the lifter.

 

Think something got hosed in this?

 

The factory runs around .080 ish so 1 turn on your deal is fine. There are lifters where running .128 could easily work too and the aluminum blocks lose about .010 preload when hot.

I don't ever run that much preload but I know people that do on purpose with higher pring pressure since they aren't worried about pumping up as much as pumping down the lifter so it all depends.

 

well I haven't re read the posts above since I am getting out of here right now about what you did but if you have a bigger cam and no reliefs you might have bent some valves possibly or held them open. Do a leakdown and see if you can hold pressure.

 

It's the stock cam so not high lift

 

You shouldn't really have a problem then.