340......PUTTIN' ON THE ROCKERS QUESTIONS

[CFD244]

Hi folks

340 OEM "O" heads. Using a set of OEM 273 banana groove adjustable rockers with hydraulic lifters. 3 Questions......

1) I understand that the FSM specs for torquing the rocker shafts is wrong? What should they be torqued to?

2) Once I get zero lash, how far do I turn my Crane rocker tips with lock-nut to get proper preload?

3) What "total" clearance should I be shooting for between each pair of rockers? I have extra shims if need be.

Thanks FABO

 

[340six]

Adjust until no lash and then 1/2 to 3/4 turn more.

 

[crackedback]

200 inch pounds on stock rocker shaft bolts or about 17 ft/lbs

 

[Jadaharabi]

I would say the amount of preload would be determined by what kind of clip you have holding the plunger in your lifters. Those little wire things can't take a pounding the way that a locking clip can if something gets loose.

 

[Bewy]

The lifters with a paperclip for a circlip can be upgraded to the much stronger internal c/clips with eyelets. I believe they are 16 or 17mm from memory.

 

[CFD244]

My lifters have the wire retainer. Oddly, I do not believe I have seen the snap ring variety, even in the 1971 340 that I tore down. I believe those lifters were original, and have the wire retainer.

 

[Oldmanmopar]

I always used the old direct connection race recommendation. 1/4 turn down from zero lash, No chance of valve float from lifter pump if you gonna twist it to the outer limits. I once had a stock 72 4spd. shut off after second gear. Went to start it and had no compression. I was on a hill and put in in first gear. When I went to get out the car started rolling. I then left it roll in gear and it started lumping around then finally started. The engine cleared out and ran good again. I had the same thing happen on a 70 383 RR.

When ever this song came on and I heard the words I'd float the valves while torching the tires

 

[mygasser]

Adjust until no lash and then 1/2 to 3/4 turn more.

that's the rule for stud mount rockers where you're adjusting at the pivot. with the 273 rockers adjusting at the pushrod you'll need more 'turns' than that. not twice as many due to the rocker ratio but i'd guess 3/4 to 1 1/4 turns
neil.