Hi,
how much preload do you have with 12499225 lifters?
I have ~1/2 turn(3/8-24 stud),and valvetrain is noisy at idle.It is with xfi280 cam.

 

This is from Summit Racing's Tech Questions:

How do I adjust valves / lifters on an adjustable valvetrain?


To properly set the pre-load, the lifter must be located on the base circle of the cam lobe. At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.

• Remove the valve covers, and pick a cylinder that you are going to set the pre-load on.
• Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm.
• Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
• Now, hold the intake pushrod with your fingers while tightening down the rocker arm. When you just take the up and down movement out of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position.
• Continue to hand turn the engine, watching that same intake valve. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder.
• Repeat the procedure as described in steps 3 and 4 for the exhaust valve.
• Both valves on this cylinder are now adjusted. Move to the next cylinder and follow the same procedures above.

Hope this helps.

 

I cannot remember the part number but I have LS7 lifters in the 350 Vortec in my Express van. 1/2 turn was too little and every startup sounded like woodpeckers had invaded the valvetrain until the lifters pumped up. What I found was GM recomeends .060-.100" preload on the LS7s with .080 being about right. The GM smallblock 350 rocker stud is usually a 3/8"-24 thread. When you do the math that is right at 1 1/4 turn from Zero lash. In actuality on the LS7 lifters anything between 1 and 1.5 turns will work. I would run them down to 1.25 turns and see if that does not help. Also keep in mind the XFI lobes are noisy. I had a XFI grind cam in my 2006 Hemi Ram and it was a very noisy valvetrain.

 

The cam in my Hemi was the XFI 265 lobes on both intake and exhaust. The Dodge MDS lifters made some of the noise but alot of it was simply the cam itself. I had a bigger Crower ground cam in the truck before it had the smaller Comp cam and it was much more quiet at idle. Both cams were ground on the smaller 6.1 base circle and both had the same custom length pushrods in them to allow for the correct lifter preload.

https://www.youtube.com/watch?v=TF6eoaqWO3w

 

I'm also running XFI280 and the LS7 lifters. I found that adjusting them hot helped find the sweet spot between noise and oil flow. 1/4 - 3/4 turn should get you close. Too loose and they can fall apart on you, too tight and it can reduce oil flow to the rockers.
The setup is noisy, but old sewing machine noisy, not loose, rattle noisy. If you adjust them running, you'll know what I mean.

 

Seems that 1 or 3 cylinder are more noisy(like small exhaust leak), and rest just noisy at cold,not that bad when at operating temp.I probably must make cardboard walls to place of valve covers, and try adjust rockers at idle and warm engine(if that helps)

 

I had a noise last summer that drive me crazy trying to find because I thought it was valvetrain, but it was even half of that speed. Turns out I had a spark plug loose. Luckily I found and fixed it before it ruined threads in the head.
and yes, cardboard works great. Cut it the length of the inside of the head and slide it down by the springs. Worked perfect for me.

 

When I ran them that loose I had problems with the oil pump sucking the 5qt pan low enough to aerate the oil and cause the oil pressure to drop at sustained RPM higher than 3,500.

 

I had oil pressure problems, but mine were due to cavitation. Switching from 6.5 qts to 5.5 qts fill solved my problem.

 

I found that woodpecker.Decided to check spark plugs at same time when addind 1/4turn more preload.Plugs 3,5,7 porcelain has thin surface soot->leaking exhaust gasket.Now I have Felpro 1404 gaskets,are these Percy's better? https://www.summitracing.com/int/par...make/chevrolet

 

Glad you found it! I'm running Fel-Pro exhaust gaskets and haven't had problems, but I've got less than 1,000 miles on them.