Disaster...360 Engine blew a connecting rod

[chargerdon]

and do you think my method of measuring without changing to a solid lifter or modifying mine is ok ? 

[Chryco Psycho]

Yes I believe you are right in the zone with the measurements assuming you can add approx 1 turn & still have 2 threads showing below the rocker max

[chargerdon]

Sure can...incidently found a good instruction at Hot Rod...  Found it after my long post on how i did it.
 
https://www.hotrod.com/articles/measure-and-select-pushrods-for-mopar-shaft-rocker-systems/  It confirms that on shaft systems you can not alter the lift or swipe area with different length pushrods...   

[Brads70]

It confirms that on shaft systems you can not alter the lift or swipe area with different length pushrods...

agreed, you have to mill off the shaft pedestals and shim up the pillow blocks accordingly to change the geometry.

[1 Wild R/T]

So what wound up as your final desired pushrod length?   Crane has one at 7.185... And there are lots of other lengths available... Comp isn't the only game in town..

[chargerdon]

My measurements showed that i needed 7.250 overall (7.10) to bottom of cup.   In a ball/cup configuration closest i could find was 7.330/7.185.  Both Crane and a couple of others had that size.    I tried setting my pushrod length checker to that length, but, it required the adjuster to be less than 1 thread..real close to the rocker,  so no go.   

I ordered the 7.250/7.1 length custom made from Manton Pushrods in Ca.   Their price was $167 for Chrome Moly 5/16 .083 wall thickness...  So, for only $40 more i felt it better to get the exact length that i measured.   Smith Bros wanted $195 for same thing. 

I'm guessing that the reason i need that much shorter is that my heads were cut to give 65 cc...standard on the j heads are 70-72..   i have no idea how many thousands of an inch were milled off to get down to the 65 CC size.  (where cut by previous owner..my machine shop also "trued" my heads but machinist said that he didn't take off enough to alter the cc measurement by more than 1 cc at most, i also had machinist deck the block to make sure it was true.   I guess the two together altered it that much.)

[chargerdon]

Ok, the end for now of my story.  My new Pushrods from Manton...chrome Moly .083 wall thickness overall length 7.250 came in yesterday.   Today i installed them. 

My process was first running my engine for 2 minutes with the old rockers to insure the lifters were "pumped up".   Then i removed six of the spark plugs left the two that are difficult, #5 and #7 in.   Removed the old rockers and pushrods, I put some Lunati assembly lube on the bottom ball and top cup of each and put them in.   

I also put assembly lube on each shaft, and valve tips and with each rocker set to about .350 depth from end of ball to base of rocker as a starting point, put on the rockers/shafts on each side.    I then rotated the engine until the timing mark was about 5 degrees After TDC.  Next, i removed distributor cap and saw that the rotor was pointing to #6, so i started there with the belief that #6 should be on the base circle for each valve.    I tightened each adjuster until it was "barely touching" so that i should be at zero lash, and then gave another 2/3-3/4 turn on the adjuster.   (in measuring i had found that a full turn on the adjuster would measure around .040-.050...so that should give me about .030-.040 preload.  Lunati recommends .020-.060 so .030-040 was my target. 

Next, i marked the fan pulley with chalk at the top, and both sides 9 oclock and 3 oclock.   Using those lines i then rotated engine a 1/4 turn.   Then i followed the firing order making sure that the rotor always pointed at the appropriate cyl plug wire..   5 was next...did the same adjustments.   Also, as i finished my adjustment on each cylinder, i measured the distance from the top of the adjuster nut to the top of the rocker...   I got usually .25 on each exhaust and .22 on each intake...my measurements would vary by about .03 or less, so that the most was .270 and least was .215...   I did this just to be a sanity check...remember these are used 273 rockers and shafts...  Also, a few of the lifters while up had little resistance to being pushed down some, so, making sure that i started at zero lash was a little difficult.   I believe that these new lifters are defective and will have to be replaced again...someday   if they don't stop doing this.. 

After the fourth turn i was back at the timing mark right at 5 degrees beyond TDC....so my 1/4 turns were pretty accurate...   finished the last four, put the plugs back in, and poured a little bit of oil over each shaft, ball side and pad side, to insure well lubricated..  I started her up while leaving the valve covers off, to observe...   Noisy with valve tap for first 20-40 seconds...   then quieted down and seemed to be all doing well..   There was enough oiling that i started to get some oil splash down onto the headers...   so..with all looking good, i shut her off and put on the valve covers.   Started her up, let it warm up, much quieter and took for a spin..all seems well..   So, i guess im good to go again..   Over the weekend ill try to make a video of what it sounds like on initial start and after it warms up and the exhaust bark...  with that cam and Flowmaster 40's it sounds like a lion roaring !!...LOL..   

[chargerdon]

Oh, one more thing...i swear when it rains it pours...   After getting the measurement for the new pushrods, i went to my machinist shop to see what price he could get from his supplier.   He had originally gotten me the ball/ball pushrods in chrome moly .080 wall for $100, so was hoping he could do that again.   

SURPRISE...   HE CLOSED UP HIS SHOP !!  OUT OF BUSINESS and sold all of the equipment to some wholesaler!!   In talking to a vendor across the parking lot, he said that his fathers health was continuing to get worse and had decided to quit...   He was his only helper and they had been in business for over 15 years.   Well, with his dad retiring, he was getting tired of it alld...   

So, he had gotten a call from his old High School where he used to teach "shop".   They had lost their automotive shop teacher and were in need of one, and he decided to quit being a machinist and go back to teaching !!   No forwarding address and his telephone number at the shop disconnected.   The guy at the near vendor said i was lucky to get my engine built and no issues, as there were a lot of people that still had their blocks, heads, etc in his shop to be worked on.   If they could produce a receipt for their stuff, then he would give them a phone number to call.   GOOD Grief !! 

[Chryco Psycho]

I am happy your engine is complete & running well .
Why do you think the lifters are bad if they will Not compress as you adjust them , that is exactly what they should be doing , holding the pressure !

[chargerdon]

Just the opposite...a few of them DID compress while adjusting trying to find zero lash...   A couple of them would compress just with my fingers pushing on them.   Only the "spring" would push them back up!   Others stayed very tight..     

[Chryco Psycho]

As long as they hold when it is running you are fine