273 style rocker adjustment baseline(ordering pushrods) - Moparts Forums

Register Log In Moparts Forums Moparts Question and Answer 273 style rocker adjustment baseline(ordering pushrods)

Print Thread

273 style rocker adjustment baseline(ordering pushrods) #1216727 04/15/12 11:50 PM 04/15/12 11:50 PM
Joined: Jan 2003 Posts: 1,607 Western Washington Sixgun OP top fuel
Sixgun OP top fuel Joined: Jan 2003 Posts: 1,607 Western Washington	Got my basic measurement, but wasn't there a preferred amount of adjuster thread you want sticking out the underside of the rocker? (AND not taking the lock nut into consideration, I would assume you want equal amounts of available adjustment both "up and down" when you measure for a pushrod effective length?) so maybe three threads "above" the nut, and three threads "below" the rocker body? Need to order tomorrow, please advise? Casey

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: Sixgun] #1216728 04/16/12 08:51 AM 04/16/12 08:51 AM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.	Casey I sent answered your PM , But ASSuMEing the rule of thumb applies to all , 2-3 thread BELOW the rocker , above doesn't matter though I like to see at least one thread above a nut , if you have none your adjusters are too short. Is this a HYD. or solid cam ? if hyd. don't forget preload in that lengtth calculation, solid don't forget lash.

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: Sixgun] #1216729 04/16/12 12:53 PM 04/16/12 12:53 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	set it to where you have 1 to 1&1/2 threads showing underneath. & Yes figure your lash or preload added in. live every 24 hour block of time like it's your last day on earth

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: RapidRobert] #1216730 04/16/12 01:25 PM 04/16/12 01:25 PM
Joined: Jan 2003 Posts: 1,607 Western Washington Sixgun OP top fuel
Sixgun OP top fuel Joined: Jan 2003 Posts: 1,607 Western Washington	Thanks, guys! Got your PMs,this is a hydraulic flat tappet cam. My base measurement is 6.937, with about 4 threads under the rocker, and close to the same above the nut, with zero lash.(NO preload) Comp wants an .045 plunger preload. I am thinking I will add another .083 to the length, which should move about 2 threads from the bottom of the rocker to the top of the nut,(about .042 per thread on a 3/8 24 bolt), leaving a turn for preload,and a little more room to adjust "down" as nothing should really "grow" as it wears a little with break in,and over time? I just don't want to cut it too close and get too far out where its a 140 dollar "oops". I assume I can go .065 wall "stockies" as this cam is one jump above a stock 340? Do I need anything better? Thanks, Case Last edited by Sixgun; 04/16/12 02:06 PM.

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: Sixgun] #1216731 04/16/12 02:45 PM 04/16/12 02:45 PM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.	Quote: Thanks, guys! Got your PMs,this is a hydraulic flat tappet cam. My base measurement is 6.937, with about 4 threads under the rocker, and close to the same above the nut, with zero lash.(NO preload) Comp wants an .045 plunger preload. I am thinking I will add another .083 to the length, which should move about 2 threads from the bottom of the rocker to the top of the nut,(about .042 per thread on a 3/8 24 bolt), leaving a turn for preload,and a little more room to adjust "down" as nothing should really "grow" as it wears a little with break in,and over time? I just don't want to cut it too close and get too far out where its a 140 dollar "oops". I assume I can go .065 wall "stockies" as this cam is one jump above a stock 340? Do I need anything better? Thanks, Case The adjusters are 3/8-24 on those rockers ? Check a bunch to make sure one length will cut it , if the valve stem heights are off you may need a few different lengths , wouldn't be the first time .

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: JohnRR] #1216732 04/16/12 03:18 PM 04/16/12 03:18 PM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: JohnRR] #1216733 04/16/12 03:44 PM 04/16/12 03:44 PM
Joined: Jan 2003 Posts: 1,607 Western Washington Sixgun OP top fuel
Sixgun OP top fuel Joined: Jan 2003 Posts: 1,607 Western Washington	John, yup the adjusters are 3/8"-24 NF. I went out and ended up running the same checks on over half, after I put a straight edge across both valve stem tops.Hard to see even a .020 variation on all, both sides.I know they may run "uphill/downhill" so this is not all that accurate, just a visual. What I see strongly suggests a 7.02 effective length will give all of them 1-3 threads under the rocker prior to preload.Hope I'm right.

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: Sixgun] #1216734 04/16/12 04:54 PM 04/16/12 04:54 PM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.	Quote: John, yup the adjusters are 3/8"-24 NF. I went out and ended up running the same checks on over half, after I put a straight edge across both valve stem tops.Hard to see even a .020 variation on all, both sides.I know they may run "uphill/downhill" so this is not all that accurate, just a visual. What I see strongly suggests a 7.02 effective length will give all of them 1-3 threads under the rocker prior to preload.Hope I'm right. you want 1-3 threads INCLUDING preload .

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: JohnRR] #1216735 04/16/12 05:23 PM 04/16/12 05:23 PM
Joined: Jan 2003 Posts: 1,607 Western Washington Sixgun OP top fuel
Sixgun OP top fuel Joined: Jan 2003 Posts: 1,607 Western Washington	John, with the inherent inaccuracies of my home made measuring tool in mind,I will shoot for that, but my reality is I am just not 100% confident I can nail it THAT close.I felt the need to leave a tiny bit of room both ways, so I can still make it work even if I am off a few thou either way. God willing, I should be within one turn of the screw both ways. But I honestly respect your attention to detail, that's one of the reasons I like you! Wish me luck.

Re: 273 style rocker adjustment baseline(ordering pushrods) [Re: Sixgun] #1216736 04/16/12 07:05 PM 04/16/12 07:05 PM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.	Quote: John, with the inherent inaccuracies of my home made measuring tool in mind,I will shoot for that, but my reality is I am just not 100% confident I can nail it THAT close.I felt the need to leave a tiny bit of room both ways, so I can still make it work even if I am off a few thou either way. God willing, I should be within one turn of the screw both ways. But I honestly respect your attention to detail, that's one of the reasons I like you! Wish me luck.

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1