|In-Truck Cam Swap|
Written by: Mike Ervin
Installing a cam while the engine is still in the truck can be a little bit of a task but it is not that hard if you know what you are doing. I am quite sure that most of you do know what you're doing, so this article is for the people that are not sure. This is not a step by step description and should be used as a guide and only a guide. If you have some mechanical ability and feel like you are capable of doing this job, this article will help you. So here goes.
The parts you are going to need are as follows:
I recommend buying all new parts. You don't want to do this job but once. Besides timing chain and gears, rocker arms and pushrods are not that expensive. By all means if the rockers are worn and you decide to buy new ones, also buy new pushrods.
Cam and lifters (Most cams are a
set of cam, lifters, and assembly lube)
I am going to be using my 85 C-10 with a 350 as an example which will work as a guide for just about any 73-87 Chevy pickup with a small block. Let's start at the beginning, always a good place to start. First thing you need to do is disconnect the battery. Next drain the radiator, remember don't drain it on the ground. This stuff is dangerous for children and pets. Don't forget to close the petcock when done so you don't forget when you put everything back together. Remove the plugs in the block to drain the coolant there also. Don't forget to put them back in when you are done with some teflon thread sealer or teflon tape on the threads. Next you want to remove the radiator/heater hoses, fan, and fan shroud. Remove the transmission cooling lines from the radiator if your truck is equipped with an auto and then remove the radiator.
You need to remove all of your drive belts. Loosen the bolts for the accessory belt you want to remove. If your truck is equipped with a serpentine belt this is easier, you have to loosen the belt tensioner on a serpentine belt system. The next thing to do is probably one of my least favorite, removing all of the accessories. This is were you really need to make a drawing and label everything so you can remember where it all goes when you reassemble this mess. Take some advise from someone who didn't do this the first time I did it, you'll be sorry if you don't. This is one of the most aggravating things you'll have to do. After you get all these things off, remove the water pump.
Now back up top. Read the article on Distributor Removal/Installation but before you remove the distributor you need to put a mark on the cap for #1 wire. Also it would be a good idea to number the plug wires so they don't get mixed up. The wires are as follows: Drivers side, front to back, 1-3-5-7. Passenger side, front to back, 2-4-6-8. If you want to mark the cap it will be #1, which you should have marked already then going clockwise 8-4-3-6-5-7-2. If you don't know how to find #1 tower, find #1 plug which is the front plug on the drivers side of the engine. Trace the wire up to the cap and that is #1 tower at the cap.
As a safety measure I recommend you label all the wires and vacuum hoses. The best way is to use some white tape and number them. Also number the part that they came off of. It will be a lot easier to put them back this way. Now with the miles of hoses and wires out of the way we are starting to get somewhere. You don't have to remove your carb but it makes it easier to work with the intake bolts if you do. Either way you can remove the intake manifold now. It will probably be stuck, you can use a screwdriver to help pry it loose. Next remove the valve covers. If you are planning to re-use the rockers it will not be necessary to remove them just loosen the nuts enough so you can turn them sideways. Then you can remove the pushrods. If decide to re-use the old pushrods make sure you keep them in the order they were on the engine. Check the rockers and pushrods for substantial wear. You will have to use your own judgment here. As I said before, if the engine has a few miles on it, I highly recommend changing them. Cheap insurance.
Now you need to get under the truck. Raise the truck and support on jack stands. Never work under your truck without the support of sturdy stands (unless of course you don't value your life). You need to remove the oil pan. Of course you need to drain the oil, just as well remove the oil filter while you are at it. You are thinking why do I need to do this. Because you will never get the timing cover back on without it leaking at the oil pan junction. Some will say just loosen the pan a little, more at the front, to where it will drop down enough to give you room to get the timing cover off and back on. I have swapped quite a few cams in my days, and I have never been able to get the timing cover back on without it leaking doing it this way. I don't know about you but, I prefer to to this job one time. Besides on our trucks, we have plenty of room to completely remove it. After the oil pan is off it's back up top again. Now remove the fuel lines from the fuel pump and the pump. Next you need to remove the crank pulley, and the harmonic balancer. I have found the easiest way to remove the balancer bolt is with an impact wrench. This way you don't have to worry about the engine turning while you take it out. To remove the balancer you will need a good puller. If you don't have one you can rent one at AutoZone. Be real careful with the pullers to keep from messing up the threads in the crank. Once you have the balancer off you can remove the timing cover. With the timing cover off you will see the timing chain and gears. Take the bolts out of the cam gear (the one on top) and remove the chain and cam gear. Now you will need a gear puller (this kind usually has 3 arms with hooks on one end) to remove the crank gear. When you pull the gear off of the crank be sure you don't lose the Woodruff key that is between the gear and the crank to make sure it lines up correctly. If you are re-using the old chain and gears (buy new ones) forget about removing the crank gear. Next you need to remove all of the lifters from the block. Usually the best way is to put the cam gear back on the cam with one bolt (you will need it anyway to help pull the cam out) so you can turn the cam. As you turn the cam it will raise the lifters in their bore and you can get hold of them with some pliers and pull them out.
You are going to have to remove the grille, and move the AC condenser out of the way because you need the room to slide the cam out the front of the engine. Don't remove any of the AC hoses. You'll probably have to cut the part that's in the middle of the radiator support and bend it toward the front out of the way. When you put it back together you will need to make a strap out of some heavy metal to fasten it together. There is one other brace you can un-bolt from the top and lay it over out of the way. Once you have all these parts out of the way, use the cam gear like a handle to help you slide the cam out of the block. Be real careful because you don't want to nick the cam bearings that are inside the block. Once the cam is out you need to take some time to clean everything up. Remove all of the gasket material that is left on the engine and oil pan rails. After this boring job is done it is time to start putting everything back together.