Exhaust / Intake Manifold Bolts - Open to Antifreeze

[johnjmurray]

I am in the midst of removing the exhaust and intake manifolds off my 1950 Chieftain to replace the gaskets. As I took one of the bolts out I quickly discovered that those bolts are in direct contact with the engine block cooling system (as a steady stream of anti-freeze poured out of the bolt hole). My question is two-fold:

1) When a replace these bolts do they need to be coated with any sealant or utilize a special gasket/ring to keep the fluid from finding its way out past the bolts?

2) Does any one know if all of the manifold bolts are tapped all the way into the cooling jacket of the block or if there are only a few select bolts that go all the way through...

Thanks and have a good week!

John

[Larry]

I can't remember paying any special attention to the engine in my '40 Pontiac when we rebuilt it a long time ago concerning these bolts.

I was thinking that there were studs on mine and not bolts. However, in question of weather the threads go all the way into the jackets, or are bottom tapped, I would guess all the way in. However, you have to be careful to double check my guess. I had a '41 Cadillac with a new military surplus tank engine because some local yokels at a garage tried to run a long head bolt into a short hole-- CRACKED THE BLOCK!

If you are reusing the old bolts, no problem. If you are replacing them, just use the same length. I would also either teflon tape the threads on the ones going into the water jackets, or use a plumber's dope of some kind just to be safe.

Be welcome to drop a note to our Tech Adviser, John Harvey who is an expert on these years of Pontiacs. Look under the "MEMBERS" tab. We also have a Flathead Tech Adviser, Charles Bolton who can help you.

[Budified]

Thanx for the quick tip as I was browsing, I am going to be removing the manifolds soon to clean out and clean up my valves, I guess definitely not before I drain the coolant...

I am pretty sure in the Shop Manual it says to open the valve covers with the engine running to adjust them, this must mean accessing it either with the panel off or through an access in the fender, as getting in there with the whole intake/exhaust system would surely get you burned...

I will be getting in there through the engine compartment for my mission, so I will be removing everything, if I need to access it hot to do adjustments, I will let somebody more skilled do it, LoL.

[Larry]

I have never ventured trying to set these with the engine running. I have always used the "cold" sizes, leaning to the high side to be extra safe. The worst you might have is a little sewing machine noise. The trick is to be super sure that the lifter is as far down as possible- lowest point of the lobe. Just have a good ratchet and bar to turn the engine over, and over, and over, and....

[Budified]

Everybody talks of turning the engine with ratchet or wrench, is there anything that does differently than when I turn the engine by the fan?

[Larry]

If you're turning the engine over with the fan, then you have one heck of a tight fan belt!

It is recommended to use a ratchet on the harmonic balancer bolt in the front end of the crankshaft.

Do not try using the starter as you will probably never get close to the exact lowest points on the lobes.

[Budified]

Yes the fan spins the engine with great ease!

Sorry wrong thread to be discussing anything else, so I won't elaborate further, let's keep this one about coolant, LoL