Head perkins 4107

[S/V_Surya]

So having injection pump rebuilt and head rebuilt I was continuing on the re-install last weekend. Started tightening head bolts or studs and stripped one while tightening down. Could not get it off so I used the bolt buster to crack it. So I am replacing that stud. While tightening another one I sheared it off at the head. Pretty sure I can get it out easily enough.

So I did some internet searches and found that the camp for replacing all the studs is about even for not replacing. Called TAD diesel and they said they do not replace them. But I am going to replace all of mine.

I am concerned about pulling the stud in the middle of a head that has been partially tightened down. Any comments or advice appreciated.
Thanks

[phorvati]

If you want to be sure get another gasket. I personally would not worry about it. What torque level was the middle stud at?
Did you inspect the health of the threads before putting studs back? I just went through complete assembly after a rebuild (April/May) studs and nuts were original, (1978) didnt have any problems with stripping them.
I used appropriate taps to clean holes in the block, both ends of the stud, and threads in the nuts. Made sure it can all be tightened by hand first.
I was stripping the injector stud nuts so i ordered those new.

[Celestialsailor]

Are you sure that you're not over-tightening these? If not...buy new bolts.

[sww914]

What torque setting are you using?

[S/V_Surya]

The torque settings according to manual should be 42 ft-lbs. Not trusting my old torque wrench I bought another. I am going to set it a 30 ft-lbs for first go round. Head was rebuilt and most of the bolts stayed in the block. I have ordered new bolts (18 at about 8 bucks each). Engine is probably 40 years old so who knows. I talked to guy who rebuilt the head and he thinks I should be OK pulling and replacing one bolt at a time.

[Celestialsailor]

I would recommend using never-seize or at least grease on the threads. Then tighten them down 10 lbs. at a time using the factory torque down sequence. After you run it for a few hours, let it cool down completely (24hrs.) Then re-torque and re-adjust the valves.

[S/V_Surya]

I was thinking about that. Wouldn't the anti seize find its way into the engine?

[Celestialsailor]

Originally Posted by S/V_Surya

I was thinking about that. Wouldn't the anti seize find its way into the engine?

You have a point. On some engines the threaded holes are blind. Some others, perhaps not. I doubt never-seize would hurt but why take the chance. Grease would be fine. You want the threads to slip on one another while torquing.
For the life of me, I'll never understand why these manufacturers don't use studs in their blocks like motorcycles do. It would be soooo much easier!

[Chuck49]

Just my 2 cents worth, but take time to run a thread or die on all the threads to clean them. I rebuilt a Perkens once, and found that help me out a bunch, even on just little bolts, never the less big bolts. Even on the Atomizer bolts.
Go a little at a time on the torgue, and retorgue several times after running.

[S/V_Surya]

Update, I was able to get both bolts out. On the one I snapped I bought one of the Canadian made bolt extractors ($15 bucks). Bolt was loose and came out easily. On the one where the threads were stripped, I first tried using two bolts one to lock the other to get it off but not enough thread available. Reluctantly I went to vise grips to get it off but bolt would not budge. I am very worried at this point. Got out my small grinder and flattened two sides of bolt. Finally came off. I am happy now. I did not torque the bolts any further. I do not trust my NEW torque wrench. I set it for 10 ft lbs and put it on my truck lug bolts and even though I was leaning on it I never heard it click. I am not going to take a chance on over tightening and snapping another bolt. I got lucky on the last two bolts but if I snap one that is stubborn that means the head would need to be pulled again.
Oh, note to self I asked the guy at Baltimore Diesel for a few extra head nuts which he supplied. I later found out they need to be grade 8 which I don,t think he gave me. That is the one that stripped the threads. So remember Grade 8.....