[mike76]

Seems to be at an awfully steep angle. The pushrods are still clear of the trunnion at full lift but I still don't like the steep angle. Used the Straub method to set pushrod length. I'm using Butler pushrods with the ball end in the rocker arm cup. Thanks for any thoughts, Mike

[JLMounce]

How's the sweep look? What's the gross lift?

[Tom Vaught]

Is the pattern on the valve tip centered somewhat as you go thru the lobe cycle.
It should sweep across the valve and the 'sweep" should be for the most part centered on the tip if the geometry is correct.

Tom V.

[mike76]

Lift at valve is .570" using the 1.65 HS rockers. ( hydraulic flat tappet cam)The sweep pattern is on outboard side of the valve but is narrow at .050". Like I said the pushrod side at full lift is my concern . With the valve lift I have the rocker is at a very steep angle to the pushrod angle almost to the point that ( without the ball end of the pushrod in the rocker cup) the pushrod might pop out of the rocker.

[tom s]

I use 1.65s on 400 lift hyd rollers with no issue?Tom

[flat-bill]

Pushrods too long? Shorter pushrod will lower the pushrod end of the rocker and, I think, move the contact patch closer to the stud. Billk

[steve25]

HS rockers are closer to 1.72 then 1.65 to compensate for system flex and lash when used with such.

Have you rechecked as Tom V posted with a eye in regards to sweep and not just contact pattern?

[chuckies76ta]

Post a pic if possible of your pattern on the valve stem.. I learned a little trick yesterday using Straub Technologies method. At 7.30 in the video he says you just established proper pushrod geometry. Once you have that, mark the top of the valve stem and move your rocker back on top of the valve stem. Hold your rocker firmly over the tip and do a side to side motion marking the tip of the valve stem with the rocker roller. You can now see exactly where your rocker roller tip is landing on the valve stem. Now all you have to do is remove a turn on the adjuster nut to move your witness mark inboard or add a turn and move your witness mark outboard. You still do all the math he tells you too in the video. The idea of his video and math is to get the rocker tip at half lift in the center of the valve tip. This is just a way to verify his work. Excellent video in my opinion. Anyone, Thoughts?

https://www.youtube.com/watch?v=o5is9BsH5OU&app=desktop

Thanks
Charles

[Formulajones]

I've used that method Chuck and it works well. Especially useful on hydraulic cams where even checker springs will compress the lifter and give inaccurate results.

Steve is correct on the Harlands. I've used those 1.65's and they actually check around 1.72 ratio. Not that it matters much when figuring pushrods, but it can be a player with valve clearance and/or retainer to seal clearances.

[NeighborsComplaint]

If your installed height is around 1.7", your pushrod length should be 9.2" for proper geometry with 1.65 ratio.

[lust4speed]

Every brand and style lifter differs in length. A 9.2" pushrod might change to an 8.8" pushrod with a lifter change. A Harland Sharp lifter will require a different pushrod length from a Crower Stainless or to an aluminum Scorpion, and different aftermarket heads will also require a pushrod change.

[mike76]

Like I said the contact pattern is about .050 wide(the narrowest I can get) and about half way from the center of the valve to the exhaust side of the valve tip. This is because I am using RA4 length valves in a set of #62 heads. Using the half lift method to attain correct valve train geometry it is necessary for me to use 9.55 length pushrods. Also bear in mind that I am using Rhoads v max lifters which are set off the bottom of the the lifter plunger travel. Hence the longer pushrods. Needless to say the rocker arms are running relatively high on the ARP 1.90 rocker studs ( 6 thread engagement with the polylocks) . This combo of parts puts the rocker arm at a steep angle at full lift when compared to the pushrod angle. I am using the ball end of the Butler pushrods to help keep the pushrods engaged in the rocker cup at max lift. I just don't like the steep angle with 340# at max lift. Also wouldn't side loading on the pushrods make them more susceptible to bending? Mike

PS: spring installed height is 1.83''

[chuckies76ta]

Mike: You may want to look at different length 7/16" Rocker studs. I know folks who have broken a stud because of thread engagement from polylocks. The ARP 334-7203 are longer stud.
Also is the trunnion not riding on the threads?

[mike76]

Originally Posted by chuckies76ta

Mike: You may want to look at different length 7/16" Rocker studs. I know folks who have broken a stud because of thread engagement from polylocks. The ARP 334-7203 are longer stud.
Also is the trunnion not riding on the threads?

I've heard somewhere on this forum that 6 thread engagement is okay. The trunnion on HS rockers is a little less than 1/2" diameter through the stud hole. That means the trunnion is completely riding on the threads. Thanks. Mike

[mike76]

Originally Posted by flat-bill

Pushrods too long? Shorter pushrod will lower the pushrod end of the rocker and, I think, move the contact patch closer to the stud. Billk

Shorter pushrods will move the contact pattern closer to the valve centerline but widen the sweep pattern. The half lift method for correct geometry sets the pattern on the exhaust side of the valve tip. The only way to correct this for me would be to buy Ford rocker arms. Longer than stock valves requires longer push rods.