318 Gasket & Cam questions

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D

D Cluley

Lansing MI
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I am in the process of tearing apart my ’74 318 in order to replace the cylinder heads.

It has been quite a few years since I’ve done anything like this, and never on a SB, so I’ve got some questions.

1. Head Gaskets: Do these go on dry, or with some sort of sealant?

2. The metal gaskets between the heads/intake have raised ridges around the holes. Does the raised side go against the head, the intake, or doesn’t matter?

3. There are two cork gaskets for the front and rear of the intake where it sits on the block. Do these go on dry or with some sort of sealant?

4. The exhaust manifold gaskets are smooth on one side, and metallic with dimples on the other. Does it matter which side goes where?

5. Finally, I noticed that one of the lobes on the cam has a brown stripe that runs most of the way around it. I turned the engine over, and that rocker seems to move just like the others. So, impending doom, or nothing to worry about?

Camcloseup.jpg
 
I like the you are approaching this.Now for the bad news.You will need a cam/lifter kit.First lobe in your picture tells the story.Install a cam/lifter set.(summitt racing does a set for 120).Make sure you have new valvesprings installed.No. 4 ,exhaust gasket shiny bumpy side out.No 3,replace end corks with ultra grey.No 2 shiny side to the intake.No 1, dry.Seriously,you have multiple problems ahead.Swap the cam/lifters out.Break it in at 30 minutes with ZR1 Vwalvoline oil,2200 to 3000 ,30minutes change oil.then it is correct.
 
Block looks newer than a 74. Note the bosses in the lifter valley.

You are showing early signs of excessive cam/lifter wear. Specifically, the lifters are beginning to "dish" on the undersides. At some point in the future, a lifter will stop rotating and wipe out the cam lobe. Might as well do the cam now, you're half way there with the teardown. New timing set too.
 
1. Head Gaskets: Do these go on dry, or with some sort of sealant? The type you're using go on dry. Just make sure you run a thread tap down the head bolt holes, both head and block surfaces are clean and free of ALL grease and oil, including the stuff from your skin. I use laquer thinner or brake clean to wipe things clean.

2. The metal gaskets between the heads/intake have raised ridges around the holes. Does the raised side go against the head, the intake, or doesn’t matter? The embossing can go either way, but the easiest way is embossing up towards the intake.

3. There are two cork gaskets for the front and rear of the intake where it sits on the block. Do these go on dry or with some sort of sealant? You can use them dry, but put a dab of ultra grey silicone in the corners where the heads and block intersect. Or, you can just use a large bead of ultra grey in place of the end seals, but again, use a little extra in the corners. I don't use it on the entire surface of the end seals because it acts as a lubricant and the seal can slip out before the sealer sets up. regardless of your choice, the surfaces have to be grease and oil free, and the intake should be torqued down from the center out (bolts next to carb first, alternating sides) and I think the spec is 35-40ft lbs.

4. The exhaust manifold gaskets are smooth on one side, and metallic with dimples on the other. Does it matter which side goes where? I put the metal towards the manifold. I'm sure it doesnt matter.

5. Finally, I noticed that one of the lobes on the cam has a brown stripe that runs most of the way around it. I turned the engine over, and that rocker seems to move just like the others. So, impending doom, or nothing to worry about? If the car is down, and you're in there anyway, I'd just do the cam and lifters too.
 
Thanks to all for the info and suggestions. At this point due to time and money constraints, I am just going to do the head swap, and plan on cam/lifters/timing chain next summer.


After a couple of days work, this is what it looks like. Have to say a V8 A body with PS/PB and A/C makes me appreciate how much room there is under the hood of my Chrysler. ;)

day2.jpg


Pretty sure I can see why #4 & #6 don't have any compression. I'm expecting #5 to look simlar

old4and6.jpg
 
Have the exhaust valves sunk in the head? Looks like you might need new valves and a valve job on the heads.
 
Please change the cam,the cast iron chips will kill the bores,rings, and the crank,Please, I have been there and lost.
 
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