Re-Torque heads and intake?? 390fe

[MaSnaka]

Can anyone walk me through the process of re-torquing my heads and intake manifold. '64 block, '72 stock heads. I have the valve covers off and need to remove some head bolts to seal for possible cracks...(found oil in my coolant, see "oil in coolant" thread). At this time I don't plan to replace any gaskets, ie. head or intake. Missed an invite only car show today because my engine is down and so are my spirits. Gotta get back on the road. PM me for a phone number if that would be the easiest way to discuss. I am a bit novice at this level of repair. I have skills just no experience.

Thanks!!
John

[blykins]

So you're just going to retorque and see if that fixes the problem? I guess it's worth a shot.

It's not a big ordeal, just grab a torque wrench and go through over each head bolt. If you used ARP bolts/studs, I'd set your torque wrench at about 100lb-ft and follow the torque sequence.

Same for the intake manifold, set at required lb-ft spec, and go through the sequence.

[RICK LAKE]

Masnaka John what heads are on the motor Aluminium or iron. IMO you don't torque them to the same torque numbers. Ask KCR or Gessford Machine about this. For the heads you want to start in the middle and work your way to the outside bolts. 5-10 ft per adjustment until you reach spec. The same thing with the intake going side to side on each bolt until you are at spec. Start in the middle of the manifold. I don't go more than 5 ft of torque over the spec. I know you hate to hear this but, pulling the heads and checking everything, putting sealer on the head bolts or studs is the right way to do it. You might see a problem and catch it now then be on the road and do major damage to the motor. Hydro Lock or oil in the coolant or the other way can be a big problem. Buy a pistol battery gun with adaptors for removing the bolts and nuts. They have electric guns to in 1/2" drive. The Battery one is easier to use. This saves alot of time and your arm. Harbor Freight tools sell them or Sears. They are good for a person that just does his own work. Try on line with Harbor freight. I use Loc-Tite on all my nuts and bolts on my motor unless it's in a coolant area, then I go to teflon sealer for these bolts. The reason I add 5 pounds to the torque reading is the drag on the nuts or bolts. If you feel the bolt or nut get wierd, you know the threads are stripping in that hole and will need to repair. Rick Lake Ps put a couple of cold ones in the fridge with a steak, you get this after the job is done.

[undy]

When you retorque, loosen the bolt apprx 90 to 120 rotational degrees then retorque to spec. That way you'll get an accurate retorque. As Blykins hinted, IMO you have about a 5% probability (very slight) that this will fix your coolant leak probs. Since these are original iron heads they could have been subjected to many machine shop/owner/jack leg atrocities over the years. Someone could have minutely busted into a water port during reckless porting or you could have a crack that's causing the leak. I would have the head(s) pressure tested before they went back on. Pay particular attention to the cylinder sidewalls in the lifter valley area of the block. That's a weak spot for OEM FEs (freeze busting). A dye penetrant check of that area wouldn't hurt either. This is all assuming you don't find anything with you head gasket inspection.

Rick, you need to stay up a lill' later in the evening (old fart syndrone) so you can sleep a little later in th AM..

Dave

[c6ae]

The problem is usually lower in the block than the bolt threads, but I might try resealing the two bolts next to the oil feed for the heads. Nothing more.
Just use the minimum torque spec, the tighter you make the bolts the better chance of opening up the crack.
They (the two bolts) are outside of the valve covers. Just try only that and see if it fixes it.
It’s a slim chance but you may be a lucky man…

What I would do - Remove the two bolts and clean out the threaded holes the very best you can, run a bottom tap down in there to remove any rust and debris, then use brake clean or some other volatile solvent, dry with lots of compressed air (the object here is to remove the oil to allow the sealant to work).
Then add some wicking Loctite #290 (this will harden only in the crack) wait a few hrs, clean out the excess Loctite, choose your sealant and reassemble. Be advised that excess sealant can cause a hydraulic lock that may open the crack further, so using a thin anaerobic sealer like Loctite #545 take down the bolts slowly and cautiously giving the excess sealant time to migrate up around the threads. This should be done with your fingers so that you have a feel for the lock-up. After the bolts are seated on the heads torque to the low spec and wait 24 hrs for the sealant to cure.

*Note that even with the engine torn down to a bare block, the problem cannot be seen; it is down inside the water jacket. There are only two places on the FE engine that an oil passage runs directly through the water jacket, the same on both sides.

[Ronbo]

Since no coolant is getting in the oil it doesn't sound like a crack. Coolant is a lot thinner then even hot oil and would migrate through a crack when a hot engine is shut down.

The problem surfaced after the oil pump was swapped to a high pressure unit. Since the 30psi boost in pressure caused the problem this points to gasket sealing to me.

As I stated in the previous thread, I'd go after the cause of the problem. Namely trimming the bypass spring to get the oil pressure back down where it's intended to be and verifying the heads are at the proper torque. (100ft/lbs seems awfull high, 65-75ft/lbs seems to be the level that comes to mind)

I actually prefer to bolt and unbolt heads in stages as stated to keep stresses as even as possible. 10~15lb increments is about right. This is even more critical with aluminum heads. Teflon sealant on head bolt threads is a must unless you know for sure they're blind holes.

If it turns out to be a crack there's only two things to do, weld it or replace the part. No way I'd trust Loctite for what's essentialy metal fatige. If you have a 40yr old casing with cracks forming it's usefull life is done and deserves to be put out to pasture.

[c6ae]

Again, this is a common FE problem attributed to a casting defect.
I will venture to guess that there were thousands of FE’s out there with the standard AERA repair done to them. At one point (mid-seventies) it was advised and considered good practice to do the repair when the block was bare and many were done without any sign or symptom just to avoid comebacks. If you look carefully at a few FE engines on the deck you can often spot the repair tube that has been installed.
The problem (crack, causing oil in the water) can also be caused by debris in the head bolt holes being crushed and forced when the bolts were re-installed after say, a valve job at Joe’s service station. If this is what you have the sealing of those specific bolt holes may fix it temporarily, or until you choose to tear down the engine...
The oil passage is right next to the threaded hole, it can be clearly seen if you bore away the cylinder for a "wet" sleeve.
All FE head bolt holes are “blind”

[MaSnaka]

A couple questions come to mind here. What is a blind hole? And which bolt is it that I should be looking at? All bolts or is there a specific one on each side? Ok that was three...for now. I see I need to remove the rocker shaft to get to the upper bolts, anything trickey about that. Forgive my ignorance. I figure if the problem isn't a simple one the motor has to come out so I am trying the simple steps first. I do plan to reduce oil pressure too. If I get lucky great! If not well that opens another door. Thanks for you help.

John

[Barry_R]

Blind head bolts do not go into water - they are dry at the bottom. This means that the bolt holes themselves are not the problem.

The only places oil will get into water are the aforementioned oil feeds for the heads or the head gasket itself. i have never made the AERA recommended oil feed repair - but I have read about it for years - so it'd be a fair bet that it could either have been done wrong - or could actually be the cure for your problem.

100 pounds is within the factory head bolt torque spec range for an FE using oil. I normally go 90-95 pounds with ARP lube, which BTW is higher than ARP's recommendations....

[blykins]

Do you have a hydraulic cam or a solid cam? Stock non-adjustable rockers, or are they adjustable?

[MaSnaka]

Hydraulic cam, non adjustable rockers.