First time replacing intake manifold gaskets

[johnswie]

First time attempting something as in depth as this. Most of it looks pretty straightforward. What I’m most confused and concerned about, is messing with the timing. Do I absolutely need to rotate the engine to TDC before removing the distributor? I’ve seen some guys just mark the rotor and vacuum diaphragm and then remove it. They don’t however show what happens after. Do they have to retime it? I’ve also never used a timing light. And if you do have to rotate the engine. How do you do it? Like I said, never done anything like this so clear, detailed explanations are appreciated. Also, if in case I do mess up the timing. Will starting it damage the engine? Thank you

 

[johnswie]

Also, if it matters I have 78 C10 350

 

[Radiohead]

While daunting to any first timer, a manifold job is not as precise as is work with most of the rest of the engine.
Drain some coolant off before you start so you don't put a bunch of coolant in the oil via the valve train area, like half a gallon at least. That way when the intake comes off it stays dry.

Yes, you should take the time to find and mark TDC, especially if you're not familiar with the job. It could save you a bunch of time on the back end. And you should always check your timing after anything involving removing the distributor because that's just good practice and points towards avoiding any unnecessary BS. It's really not that hard, you tube videos can let you see what you're most likely up against and see what things should look like before hand. And the whole putting the distributor in 180° off is a real thing and easier to do than you realize. Not only do you need to be at TDC, but at TDC of the compression stroke.

Probably want to pull the spark plugs to make it easier to turn the engine by hand.

I know there are more pointers for you but I'm sure the rest of the folks will have their own to add in shortly. Oh, in case you don't know, the fellas here love pictures of your progress.

 

[fast 99]

Distributor, take cap off rotate engine until rotor pointer is aimed at firewall. Use a sharpie and mark firewall where it is pointed. For reference remember where the advance unit is. Although this disagrees with previous post it is easier to re-align to a firewall mark.

There are short and long intake bolts, remember where they came from. If not put back in correct hole it is possible to jam a pushrod. I usually give both sides of gasket surfaces a LIGHT skim coat of RTV. Bleed air out when refilling with coolant. Use liquid Teflon or some other sealant on intake bolts RTV on china wall. If timing is off on start-up won't hurt anything. Just set timing per manual before driving. May need to change oil if much coolant gets in lifter valley.

And don't over think it.

 

[Craig Nedrow]

Eric is right on. Finger in #1 cylinder, until you feel air pressure which means the piton is coming up on the power stroke/ TDC. Line the pointer, up with the TDC mark. Pull the cap and marks- a- lot or ink pen cap where rotor is pointing, that is #1. mark the dist with a center punch dot. mark block the same way in line with the dot you just did. Un hook both battery cables. Pull the dist, notice that the rotor rotates, this is because the gear on the cam is a spiral. Cover the hole that the dist came out of to keep stuff out. Like a Clinton manual, install in reverse.

 

[Camar068]

First time attempting something as in depth as this. Most of it looks pretty straightforward. What I’m most confused and concerned about, is messing with the timing. Do I absolutely need to rotate the engine to TDC before removing the distributor? I’ve seen some guys just mark the rotor and vacuum diaphragm and then remove it. They don’t however show what happens after. Do they have to retime it? I’ve also never used a timing light. And if you do have to rotate the engine. How do you do it? Like I said, never done anything like this so clear, detailed explanations are appreciated. Also, if in case I do mess up the timing. Will starting it damage the engine? Thank you

mark everything top to bottom and you'll be fine.

-Top to bottom #1 spark plug wire to cap...sharpie
-sharpie cap to dizzy
-sharpie rotor cap to dizzy (double strip to not confuse with cap to dizzy)
-sharpie dizzy to intake.

Simple way to do it without a timing light or dealing with piston TDC. This is of course if your timing is correct before you started and/or ran fine.

Everyone, if I missed a step, please add the step so it's straight forward for OP.

 

[johnswie]

Thank you for your responses. I have to ask though, how to rotate the engine? I believe I attach a socket to the bolt that is on the pulley of the harmonic balancer. Is this correct?

 

[Radiohead]

Yes. Much easier to turn over with the spark plugs out.

 

[johnswie]

Yes. Much easier to turn over with the spark plugs out.

Will do! Should check them anyways.

 

[johnswie]

mark everything top to bottom and you'll be fine.

-Top to bottom #1 spark plug wire to cap...sharpie
-sharpie cap to dizzy
-sharpie rotor cap to dizzy (double strip to not confuse with cap to dizzy)
-sharpie dizzy to intake.

Simple way to do it without a timing light or dealing with piston TDC. This is of course if your timing is correct before you started and/or ran fine.

Everyone, if I missed a step, please add the step so it's straight forward for OP.

Thank you I’ll be sure to do that. It is timed really well right now, that’s why I’m afraid to touch it! Haha

 

[75gmck25]

Definitely remove the plugs if you plan to turn it over by the crankshaft bolt. You do not want to strip that bolt.

You can also use a tool to turn it over by the flywheel teeth, after you remove the inspection cover. Or you can get a tool/gadget that bolts onto the three bolts on the crankshaft damper, and then turn it over with a 1/2” ratchet. However, I’ve always just pulled the plugs and used the crankshaft bolt.

I don’t think the tool borrowing program at Autozone and Advance Auto includes a timing light, so you should try to borrow one. Once you get that intake replaced, the next step is tuneup, and you really need to be able to check your base timing, centrifugal advance and vacuum advance.

 

[johnswie]

Definitely remove the plugs if you plan to turn it over by the crankshaft bolt. You do not want to strip that bolt.

You can also use a tool to turn it over by the flywheel teeth, after you remove the inspection cover. Or you can get a tool/gadget that bolts onto the three bolts on the crankshaft damper, and then turn it over with a 1/2” ratchet. However, I’ve always just pulled the plugs and used the crankshaft bolt.

I don’t think the tool borrowing program at Autozone and Advance Auto includes a timing light, so you should try to borrow one. Once you get that intake replaced, the next step is tuneup, and you really need to be able to check your base timing, centrifugal advance and vacuum advance.

Definitely remove the plugs if you plan to turn it over by the crankshaft bolt. You do not want to strip that bolt.

You can also use a tool to turn it over by the flywheel teeth, after you remove the inspection cover. Or you can get a tool/gadget that bolts onto the three bolts on the crankshaft damper, and then turn it over with a 1/2” ratchet. However, I’ve always just pulled the plugs and used the crankshaft bolt.

I don’t think the tool borrowing program at Autozone and Advance Auto includes a timing light, so you should try to borrow one. Once you get that intake replaced, the next step is tuneup, and you really need to be able to check your base timing, centrifugal advance and vacuum advance.

Thank you, I plan to do it the first way you described. Just seems the simplest way to me. And you are correct. Autozone doesn’t loan out timing lights. I’ll look into those things you mentioned about centrifugal and vacuum advance. Right now it’s all Greek to me.

 

[Radiohead]

Who wants to take a run at the China wall?

 

[Randy and Easton]

Great info here @johnswie. Easton did his when he was 14 and it was not that bad at all, and the timing was the easiest part. You can do it.

 

[hogdaddy]

Stock cast-iron intake or aluminum intake?