mknittle

That's pretty cool

NJTman

Neat... Holds up to rain and snow ?


course, they get a woman with a really sweet butt to do the video

mknittle

Jeep soft tops do so why not?

NJTman

I have zero experience with them, so that's why I asked.


I do, however, have lots of experience with my 12 x 12 pop up canopy being wiped out by a sudden deluge.....

Always fun to come home to find your canopy in pieces on the ground due to some rogue storm.

jimbo486

Happened to me in the desert once years ago. Took off for a ride and came back after about 30-45 minutes. We didn't see the EZ-Up immediately but as we got closer to our site, we saw it in a twisted mess about 50 yards away. Weighing or tying it down somehow would've been a good idea.

jimbo486

Finished assembling the remaining 3 rocker lever assemblies. Bolted on the oil cooler and filter head package and the water inlet connection.





Set the head on the block and dropped in Hamilton's HD push rods, threaded in the ARP CA625 studs. Ran them in until hand tight as per their instructions.



Something didn't look quite right with the shorties between the exhaust runners. But the head wasn't seated just yet so I waited.



Sure enough...







I did notice that while bottom tapping the bores, the 6 along the exhaust side were about 3/8" deeper than the rest of the bores. I started to think that maybe those didn't need to be tapped. But, after counting 14 threads on the stud and 14 turns until it stopped in the bore, that tells me that all of the threads wouldn't have been engaged if I hadn't tapped them deeper.

Some guys I've talked to said to back them out until they're flush or that ARP says to back them out 1/4 of a turn. None can provide an official ARP document stating to back these studs out 1/4 of a turn and the instructions found on their website and that came with the studs do not say anything about backing them out. Only stating to run them in hand tight only. Nothing more. I ain't about to back them out because then it would be as if I didn't bottom tap and therefore, all of the threads again would not be fully engaged. Is this common for the early 12 valve blocks?

I measured one of the studs I took out with my calipers, 3.424". It appears they need to be 3/8-1/2" longer. Does anyone happen to have a 625+ set for a 12v and be willing measure the short stud for me? Kit #247-4205.



I'm gonna call ARP tomorrow and ask what happened. Before I go any further, I need to ensure that I can get the head seated fully before starting the torque sequence. I don't want to pull the head down with the studs.

Jim Lane

Jimbo,
Do the new core plugs still offer any freeze (expansion) protection or are they for Southern California only?

jimbo486

You got me there. I'm not sure if they still allow expansion. Their main objective is just to keep the excess coolant pressure from pushing them out too far (entirely) while running in the higher RPM range.

jimbo486

According to Zach at ARP, there are variances with the early 12v blocks that they recently became aware of. They're currently working towards producing a kit for the early 12v blocks that will have longer shorties but they won't have them available for about another 6 months. He said a few guys he's spoken with about this have just removed the hardened washer and run only the nut. I mentioned that the washer isn't quite 3/8" of an inch and that the stud may still be a little short. He said that if the stud is 1 or 2 threads below flush, that is acceptable. He also said no to backing the stud out to make it flush for the same reason I suspected, not having full thread engagement in the block.

Once the new kits become available, I may see if they'd let me exchange these for the longer ones. At worst, I'd probably have to buy the new ones.

PapeCAT

My 425 ARPs were just as short for the 1991.0 non i/c block. I bottom tapped as well. I read a lot of good results on just backing out the studs, so I did the same on mine, and am not worried. I've read a lot of forum posts going back 10 years complaining to ARP about this, it isn't something they recently became aware of based on that info.

The threads are engaged enough in this manner to accept full torque. The only length of thread that needs to be engaged to clamp at full strength is equivalent to the width of the stud/bolt itself. To my understanding, the reason we have to bottom tap is to clean the threads (often full of oil and crap) and to get deep enough so the valve covers will clear. (even with the machining)

https://www.dieseltruckresource.com/...-short-257773/

jimbo486

Backing them out just doesn't sound like a good idea to me. Nor was it a recommendation from them when I mentioned hearing about it.

Bottom tapping is really only required for the rocker pedestal bolt bores if the installed height of the stud is above 6.665" (specs say 6.615-6.665" installed height). Milling the pedestals is highly recommended but not required. The idea is so that the stud is the same installed height as a factory bolt when fully torqued which will clear the valve cover webbing.

I'm in agreement with this....

PapeCAT

Welp, do what makes you feel good.

Diesel_Dawg

Finished painting the cab floor after the rust removal and Ospho treatment.
Ordered new door seals (Rockauto) and seat belts (LMC).
Still trying to find G360 for sale west of the Rockies for my auto to manual conversion.

jimbo486

This is a lot better. Between 1 and 2 threads from flush just as ARP said. Whew! Good shoulder workout pulling these down to 150ft. lbs.! Glad to have that out of the way. Also set the valve lash.

Picked up a thermostat housing from a '94-'98 motor which has a vent port and where the coolant bypass will plumb to. Looks like 1/4" NPT though so I'm not sure if that will allow sufficient flow for the bypass. If there's room, I could probably drill it out and tap it to 1/2" NPT.









I just placed an order for a Watts PRV, LF530C in 1/2", for the coolant bypass.

PapeCAT

Looks good. Guess I'll have to remove nuts, remove washers, thread down and torque one at a time now.