Another question on my 390 build
When it comes to re-installing the heads I've found a few pointers and need a little clarification..
One is to use the copper gasket spray on the head gasket - I have that.
Another is to use "Thread-eze" (I think that's what it's called) on the threads of the bolts so they torque accurately.
Another is to use RTV blue on the bolts that are near water jackets?
My question would be, how do I use both the "thread-eze" and the RTV blue? Can you guys set me straight here.
I was planning on using the torque specs for a 352 out of my 1959 T-bird shop manual. Those should be the same for a 352 or 390 with stock parts shouldn't they?
I am also using the recommended 3 stage torque sequence from my "How to build max performance FE engines" book.
As for the heads themselves; They were rebuilt and stored a few years ago. They are clean and dry other than a little white grease on some of the valve stem guides. Do I need to prepare (oil or lube) any of the moving pieces before installing them?
My gasket kit came with rubber boots that look like they might go in somewhere, but I have never seen them on heads or rockers before.
Any and all advice would be great!
thx, Dave J
Everyone has a different method. Use what works for you.
I use nothing but dry head gaskets. No grease, no spray.
For bolt threads, I chase them with a tap, pull the chips out with a magnet, then use STP mixed with motor oil (50/50). The deal is, you want something slick like a moly lube with zinc and phosphorous (like STP has).
For bolts in water jackets, I use pipe paste with teflon (not teflon tape), available at HD or Lowe's. RTV is great for intake manifold gaskets, especially around the water holes. I also use it for freeze plugs. The secret is to get your metal CLEAN. Use lacquer thinner to remove all oil, then spread a very thin coat of RTV.
For ALL moving parts (except pistons which get WD-40), I lube with STP mixed with oil. You want the oil to stick without running off. STP is like honey, so mix it to the point of just hanging on. Use torque spec's for the bolt sizes you are tightening.
I think your rubber boots are 'umbrella valve seals', which don't work too well. They get hard and travel with the valve stem. You need to remove the valve keepers and springs to get to them.
Thx Mr. Dare!
Per your earlier instructions I used the RTV on the (brass) freeze plugs and just as you said they went in very nicely.
So when it comes to the head bolts near the water jackets; I can use a thin layer of RTV just around the water passages applied to the block and head? Or, should it be applied to the gasket on both sides instead?
Should I also put a very thin layer around the long slit water jacket at the back of the block?
Sorry I'm having a difficult time picturing this in my minds eye.
I found some pictures on line of the rubber boots and they are valve seals. I won't need those because the valves and springs were already done.
Thx again, dave J
Not all RTV is created equal. I use high-temp gray which is oil-resistant. Put a THIN layer around your coolant holes on the intake manifold gaskets. For the front and rear block rails, I leave the cork off and use gray RTV.
For your Intake Manifold Gasket...
Let me stop right here. Most FE engines have a bear of a time with intake manifold leaks from 'gasket creep' that shouldn't happen. Technique has much to do with this procedure because many times, the intake gasket slips out of position. To make matters worse, the cast iron FE manifold gives my eyes a hernia just looking at it. One suggestion is to cut the heads off two long bolts and put them in opposite ends in one head. Then, lower the intake manifold onto the headless 'studs' as a guide. Whatever method you use, take your time and re-check your work.
Lay your intake manifold gaskets on waxed paper and spray two coats of Hi-Tac (by Loctite) on them and another two coats on the intake manifold's mating surface. Let them dry separately over night. The next day, put two 'guide bolts' through the gasket and offer it to the intake manifold, to locate it evenly.
I use gray RTV sealer on both ends of the block instead of cork strips. Give it a few minutes to cure. Set the intake manifold in place and locate using the distributor. Install all four corner bolts loosely as you tap the manifold with a rubber mallot. Be sure the gasket is not slipping. Start in the middle of the manifold and torque the bolts down to 15 ft pounds. Then follow the tightening pattern in the SM. Increase to 25 ft pounds, then 35, etc.
Let the sealer cure over night, then check your RTV the next day for firmness. I make reference marks on the gasket edges and the heads to make sure the gaskets have not moved. If the marks line up, good. If they are more than 1/16" off, you may need to redo using new gaskets. The key to success is, clean surfaces, and re-torque after a few heat cycles.
My Y-Blocks have bolts that pass directly through coolant ports. Those bolts get pipe dope to seal under the bolt-heads.
Thanks again Dave. I have read a few (nightmare) stories about these intake manifolds. Your instructions and suggestions about the guide bolts sound like a great way to help make this easier. Would have never came up with that in my entire lifetime!
The reason I wanted clarification on the coolant passages on the heads to block assembly was because I had read they can be troublesome for leaks into the cylinders. I will take your tried and tested advice and follow them to the letter. It's a great relief to be following instructions from someone who has done this many times and is willing to give his advise as to what works best from his experiences.
I'll be super patient and take my time - if it doesn't go right then I'll take it off again and do it over. Don't want to get it all together and THEN realize I have to tear it down again.
Appreciate your help. many thx!
In addition ...
to Daves good advice, I always take a center punch and make a staggered pattern on the front and rear of the block and the intake (about 1/4" spacing) to give the silicone something to bite to. I've found that the gray sealer from Ford developed for the 7.3 diesel is the best stuff I've found and use it on most sealing surfaces. I always find it use-full to dry set the intake first and check for any alignment issues before final installation. Mike
Thx Mike, I viewed a video on youtube where the guy recommended the diesel ford 7.3 sealer also. I'll get some and use it.
Alright, I got one head on, all went well. (I know, big deal right) It's late so I'll do the other one tomorrow.
OK, there are 5 holes on each head for the intake manifold bolts. The 2 end holes on each head have a small pin sized hole at the bottom of the threads that will let oil into the bolt and oil passage. Is that normal? Should I put some pipe paste with teflon in those holes?
thx, DAve J
have never had a leak from that area, and didn't recall those holes going through to the to the rocker area, but I don't have a set in front of me to look at. If your concerned you could clean out the holes with some carb cleaner and put a small amount of JB weld on The end of a wooden dowel or a bolt and force it into the hole. Just be sure to keep it off of the threads or run a bottoming tap in after it sets up. Mike
You know, sometimes I take things for granted, and I might have overlooked an important point:
FE intake gaskest should be metal (steel core laminate) and not plain gasket material. There is much discussion around the net about using correct gaskets, and warnings about using certain Fel-Pro gaskets.
These manifolds tend to make the gasket squirm as they are tightened. We covered that part, but I failed to warn against using Fel-Pro Print-O-Seal gaskets. They squirm and they leak.
Not all Fel-Pro gaskets are created equal. Fel-Pro Q1247S3 gasket is a good one because it does have a steel core.
Other brands are good too like Victor Reinz Nitroseal intake gaskets:
95186SG 1.20" x 2.00" Large coolant
95187SG 1.20" x 2.00" Small coolant
95197SG 1.28" x 2.10" Small coolant
Ford Racing and Edelbrock also have good gaskets. Hope this helps. - Dave
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