Okay, i did a search and didnt really find the answer to my question. I just bought a completely rebuilt 350, and ordered a xe268h cam while i was at it. This means that i will have to put the cam in myself. Because the motor has not been run, i figured i can reuse the lifters that came with the motor. Am i correct? Other than cam lube, what special tools, etc will i need to perform this? What is entailed in the removal and replacement of a camshaft? Detailed and step by step explanations would be incredibly appreciated. Thank you very much. :hail:
Matt

 

I think you should be able to use the current lifters as long as they are flat tappet hydraulics. Your valve springs however may not be up to the task. You may need to look into that.

As far as replacing the cam, pull all the lifters out and unbolt the three bolts holding the timing chain sproket on the cam and remove it(the timing chain). Then use either a tool made for bolting into the end of the cam or use much longer bolts than are currently in there to pull it out. Your want it to come out very straight so you will need the extra leverage to keep it from dropping down in between cam bearings. If it does drop it can mar the bearings.

 

Exactly as jimmy_mac says, and I'd call Crane cams and ask them for their recommendations for what you're running. Would'nt hurt.

I'm assuming you bought a rebuilt engine from a reputable source, and the lifters are new, then yes - use them. It's just not a good idea to use new lifters/old cam and vice-versa. They wear in together.

 

Remove all belts, pulleys and assecories that will get in the way. Drain and remove oil pan, remove the harmonic balancer, remove the water pump, remove timing chain cover, remove rocker arms, remove pushrods, remove the distributor (note its postion), remove intake manifold, remove lifters, then unbolt the 3 bolts from the cam sproket and remove the sproket and timing chain.

You have to remove the oil pan because it shares a gasket with the timing chain cover, which will needs to be replaced when your done.

If you have a roller block then you will need to remove the thrust plate, its held on by two bolts. If are planning on also replacing the timing chain (good time to do it), than you will need to buy the appropriate gear set otherwise the thrust plate bolts will hit the cam sproket.

Reattach the cam sproket without the chain and then use it as a handle to remove the old cam, slide it out gently supporting it as much as you can so it doesn't "fall" and it the cam bearings. Rotate as nessacery to remove.

To install the new cam put assembly lube on the first two journals and lots of breakin lube on the distrubtor gear, then cover the first 4 lobes in break in lube. Slide the cam in until the 2nd journal is in the block, then put breakin lube on the next 4 lobes and assembly lube on the third journal. Insert the cam until the third journal and put breakin lube on the next four lobes put assembly lube on the fourth journal. Insert the cam till the fourth journal then put breakin lube on the last set of lobes and assembly lube on the last journal and insert the cam the rest of the way.

If you get a new gear set you (i recommend highly that you do) then you will need to pull the crank sproket with a gear puller, you can buy a cheap one for about $9 at Discount Auto Parts, NAPA, or a similar store. Timing chain sets are about $20 - $40.

To install the new crank sprocket also pick up a 1-1/2" socket thats at least one and a half inches deep.

Crank the engine over so the crank keyways (2 little metal inserts poking out of the crank nose) are facing 2 o'clock. Place the crank sprocket on the crank aligned with the keyways and then use the big socket and a hammer to pound the new sprocket onto the crank.

Get a large coffer can or bucket and fill it about 1 inch deep with oil, dip the chain and cam sprocket in the oil so that its well lubed.

Line up the cam pin so its a the 3 o'clock position, then attach the cam sprocket and the timing chain, sliding the timing chain onto the crank sprocket as you do so. You will need to use Red locktight on the cam bolts.

There should be a dot on the cam sprocket, it should be at 6 o'clock and a similar dot on the crank sprocket should be at the 12 o'clock position.


Reattach everything using new gaskets and the appropriate adhesives and sealers, setup the distributor, set the valve lash, setup your timing and then fire it up and set the idle at about 1500rpm for 30 minutes to break in the cam.

I have missed or left out some details, your best bet is to get a book on the subject S-A design has a good illustrated guide to a cam swap, or "How to build the Small Block chevrolet".

Good luck.

Edit: Oh, you'll definatly need a torque wrench and a harmonic balancer puller/installer.

 

A diagram of a "straight up" cam installation.

Photo was a little dark so I lightened it so its a bit grainy.

 

Don't forget to say "thanks" to Acidtalons for that. It's a lot of writing

 

Thank you all, especially acidtalon. I appreciate all the help. Its a long block, non roller, so i dont think i need to do a whole lot of the removal of stuff. But is it really necessary to have a harmonic balancer puller? Are they spensive, or can i make my own? Thank you all.
Matt

 

If it didn't come with a harmonic balancer and you are using a new one then you will only need the installer. But if it did come with one or you or using the one from your old motor then you need both the remover and installer.

Or if it did come with one on it already and you don't want to remove it, I think you can fanagle the sproket off without removing it. You just couldn't use the sproket to pull the cam out. You would have to use either longer bolts or a cam remover handle. I prefer not removing the harmonic balancer when ever I can because the threads in the crank can strip out and that is bad news.

All of these tools are pretty inexpensive and the harmonic balacner puller and installer can both be bought at autozone. Longer bolts are really cheap if you decide to use that and I've seen the cam remover handle in summit for like 15 bucks.

 

The harmonic balancer goes over the timing chain cover, it shares an oil gasket with the oil pan, so I don't really see a good way to swap the cam without removing the timing chain cover and thus the harmonic balancer, because the cover isn't going to spin out of the way very easily.

Also, does anyone know if twisting the timing chain cover out of the way might unseat the crank seal from the timing chain cover seal bore and cause an oil leak?

Additionally the timing chain gears come in matched sets, so unless the ones on the engine currently are new or unused I'm not sure reusing the crank sprocket with a different cam sprocket is such a good idea. I am told that variances between gears from different gear sets, or using new gears with old gears can cause a lot of stress on your timing chain and it can fail prematurely.


Powerhouse tools sells a universal harmonic balancer installer/puller for $45 dollars and it even works on fords and other vehicles.

If thats a little too pricey then most auto parts stores will sell balancer pullers of much cheaper construction for around $20. However they are usually only pullers, not installer/pullers, so if you ever plan on doing this whole thing again (on this engine or another) then your probably better off buying the installer/puller for $45. A gear puller for the crank sprocket is about $9.

 

this may be a dumb question but is there anyway to change the cam with engine still in car?

 

Sure. Just have to pull the radiator out and loosen that verticle support bar and move it over. The cam will slide in and out (with all of the front parts of the engine removed as well of course).

 

wow... what about the oin pan step listed above?? theres no way i can get it off with the crossmember of the frame in the way.

 

You just remove all of the oil pan bolts except for the last two and let it drop down so you can get the timing cover off and back on. You might have to loosen those last two bolts a little to get it to drop down far enough but it can be done. Some people trim the timing cover a bit to make it easier to assemble. You will need to clean the surfaces as best you can and use a fair amount of silicone when you reassemble the front of the engine where block/oil pan/timing cover meet. Do some searches on here or the internet in general and I'm sure you will find plenty of illustrations and nicely written articles on the subject (like what Acidtalons wrote above).