Whats the best method for setting valve lash? I hear a lot of people adjusting them running with cut out valve covers. 347 stroker......twisted wedge heads.....crane roller rockers...... I can hear a bunch of valve chatter and aftet pulling the covers i can feel a few are loose enough to have a hair of up and down play. Its a new to me engine and trans. Thanks
Hydraulic cam??? If so...Just set em to zero lash and add a quarter turn. If you have allready done this and they clack...You need to check rocker arm geometry and pushrod length...Push rods may be too short...You are useing stud mounted rockers right???
I've never used a cut out valve cover, if engine is idling at 600 rpm or less won't make much of a mess... To adj, back off till it clicks, tighten till noise is gone and ½ turn additional...
Here's how I do mine: (hyd cam) Get the #1 cylinder at TDC on the firing stroke, tighten the rocker nut til the pushrod tightens up, then tighten the nut another 1/2 to 3/4 turn, once you do both rockers for that cylinder, turn the crank 1/4 turn, then do the next cylinder in the firing order. As far as rocker noise, if you have roller rockers, you may never get rid of the noise. Mine have always been noisy. And always have some freeplay when moving them afterwards by hand. This is because the lifter plunger will always bleed down a bit when the engine isn't running to supply oil pressure to keep it at zero lash.
Yes hydraulic and yes stud mounted poly lock rollers. I havent set em yet and the car runs and drives just can hear them which always bothers me.
I've used Krazy Comet's method many times however, if your car has a high idle like my Comet things can get messy fast. I use the procedure outlined in this attachment setting my preload at 1/2 turn. If you have not performed lifter adjustments previously, the procedures can be frustrating. You can end up with a miss in your engine if a lifter is adjusted too tightly. Good luck!
Doing them when the cylinder is at TDC on the firing stroke is a whole lot faster and simpler, at that time both valves are on the base circle of the cam.
For the 351/HO 13726548 firing order this is easiest, though I still prefer the engine running method... Note there is also a different procedure for the 15426378 std order, & big blocks... A) #1 TDC compression(verify by position of rotor in dist) 1 I 1 E 4 I 3 E 8 I 7 E B) clockwise 180 deg (1/2 turn on crank) 3 I 2 E 7 I 6 E C) clockwise 270 deg (3/4 turn on crank) 2 I 4 E 5 I 5 E 6 I 8 E
KC's and baddads methods work well enough most of the time but if the cam is much more aggressive than stock(especially the "quicker opening" fast ramp cams) you can start to move off the base of the lobe pretty quickly. Probably not the case here with a hydro flat stick but in a more extreme case but I do it the harder way by using the old "EO/IC rule"(exhaust opening and intake closing). Start at the beginning of the firing order and set the intake valve lash when the exhaust valve is beginning to open. This will put the intake lifter at the base circle which is where you want it to be. Then set the exhaust valve lash when the intake valve is about halfway down on the closing side. When all of the intake and exhaust valves have been set with the proper lash, it is common for all the "AR type" engine builders to perform a double check by rotating the engine and checking each valve again, starting from the first cylinder in the firing order. That keeps you out of trouble with breaking in fresh engines and you can finish it all up after the cam is properly run in. Then you can fine tune at idle speeds for consistent sewing machine type sounds like KC mentions above. As for the pre-load amounts, I rarely go past a 1/4 turn any more. This allows you to avoid standing the valves off the seats as much if you over-rev, float the valves, and pump up the lifters. It also allows you to hear a bad lobe come on much more quickly to catch it right away before the whole engine is trashed with debri. I like 1/8 - 1/4 turn at most and each 1/4 turn is about .025 thou of pre-load on the plunger.
No not at all. Makes perfect sense was really jist curious what the preferred method was. Im not getting any 1 valve ticking or anything but getting the sewing machine sound under the hood.......ill shoot a video tomorrow and post a link here.....it may very well be set perfectly fine and the noise is just causing me to think they arent. As always thanks for the great info guys
I'll try to remember this the next time I do mine (which might be in a year or two LOL) As for Groberts comment about aggressive cams, I'm running the Z303 with 1.7's in mine and it's never floated the valves, it pulls to 6500 and will rev to 7000 if you push it, which I've never done as it's done pulling at 6500, my son pushed it to 7 grand a few times (teenagers !)
The sewing machine noise is normal for roller rockers. Ford even tried to mitigate this noise in the Cobra 5.0's by coming up with the dual shell valve covers these engines came with.
Ah ok. Didnt get a chance to even start the car let alone shoot and upload a vid. Its getting dyno tuned friday anyways so I will be real curious to what the numbers are......any guesses? 347 stroker...scat crank...probe i beam rods....probe pistons Twisted wedge heads Unknown grind can Pro comp victor jr knock off Msd 6 digital box with pro billet dizzy Im guessing 350rwhp on the dynojet as a conservative guess.
