Look here for help first!Delta Cam has several options for 3A(C) and 4A(C) motors; I'm using the "260" street grind: DEL854260 for $44 plus shipping (http://www.deltacam.com) . These cams are made from customer cores by, as far as I can tell, grinding down the base circle of the cam and moving the lobe centers. Here's how to do the swap:
Step 1.
Disconnect the negative battery cable. Remove the valve cover (VC), distributor cap and the upper timing belt cover. Removing the water pump pulley gives good access to the timing belt cover bolts. Do NOT remove the timing belt.
Step 2.
Rotate the engine clockwise until piston one (1) is at top dead center (TDC). Once you achieve this engine position, maintain it until the swap is finished. This position is indicated by three things:
The notch on the crank pulley aligns with the zero (0) degree mark on the lower timing belt cover
Cam lobes 1 and 2 (for cylinder 1) point down and rocker arms 1 and 2 are loose. Redundant to this, but worth checking, is that the hole on the cam sprocket aligns with a large arrow on the front cam bearing cap.
The distributor rotor is at the 10-11 o'clock position with respect to the coil.
Step 3.
Loosen the rocker arm assembly bolts slowly, one at a time; as you do this, some valve springs will decompress. Lift the entire assembly by it's ends with the bolts in place and store someplace clean.
An optional step is to now loosen the 2 bolts retaining the timing sprocket (front) and distributor drive sprocket (rear) while the cam is still in the head; this job is easier now because the cam is still supported. The cam has special "flat spot" features cast into it near each end - use a crescent wrench at these locations to keep the cam from rotating and loosen the two bolts with a second wrench.
Loosen the timing belt idler pulley and slip off the timing belt.
Step 4.
Remove the cam bearing caps and place them, in the correct order, on a clean surface with the bolts still in place. Be sure to preserve the correct order and orientation! The front cap has a seal under it and may put up a fight - gently pull the back of the cam up to pry it loose.
Step 5.
Lift out the cam; I was able to do this without removing the fuel pump. If the fuel pump drive arm is in the way, try rotating the cam first. Failing that, remove the fuel pump.
Step 6.
If you did not loosen the sprocket bolts in Step 3, do so now. It's a PITA with a loose, unsupported cam so be careful not to damage the sprockets. Swap the front and rear sprockets onto the new cam with a new oil seal - watch the seal orientation! You can tighten both sprocket bolts now or later, when the cam is installed in the head.
Also, if you have cam lube, apply some to the lobes of the new cam - it's critical to keep these surfaces lubricated during the break-in period. If you don't have cam lube, use a heavy engine oil or grease. Also lube the bearing surfaces with oil.
Step 7.
Check the head bearing saddles for debris; gently install the new cam - make sure the bearing surfaces are aligned with the bearing saddles and that the fuel pump drive arm is seated on the rear lobe. Try to install it such that both the cam and the distributor are in the TDC orientation as described in Step 2. Otherwise, you'll have to pull and re-install the distributor later. Check to make sure that the front seal is seated in the head; add a thin layer of silicone gasket maker to the mating surface of the front bearing cap. Install all bearing caps - make sure to install them into the positions from which they were removed. Torque the bearing caps down using a 2-3-1-4 torque sequence in two or three passes; spin the cam by hand occasionally to check for binding. If you did not tighten the cam sprocket bolts in Step 6, do so now.
Step 8.
Install the rocker arm assembly. According to Delta Cam, new rockers should be used; I'm reusing mine. Torque the rocker arm assembly using the same 2-3-1-4 sequence in two or three passes; as you do so, some of the valve springs will compress - take your time!
Step 9.
Time to put it all together. Check that the crank is still at the TDC mark. Rotate the cam to the TDC position (see Step 2). If you can't rotate the cam by hand via the drive sprocket, use the front sprocket bolt or the cast tool grab locations. If the distributor is not at TDC, loosen the distributor hold-down bolt, pull the distributor, rotate the shaft such that the rotor point to (roughly) TDC and re-install the distributor. Leave the hold-down bolt loose. Slip the timing belt onto the cam sprocket; re-check that the crank, cam and distributor are ALL at TDC. Tighten the timing belt tensioner. Reinstall the upper timing belt cover and the water pump pulley; leave the valve cover off for now.
Step 10.
With the engine still at TDC, adjust valve lash for 8 of the valves. If you are using a Delta Cam, the required lash adjustment should be substantial. Rotate the engine one revolution and adjust the other 8 valves. Reconnect the battery and install a timing light. With the valve cover still off, fire up the car to idle only - this'll make an oily mess but will also let you catch any mistakes early. Watch (and listen to) the valvetrain for flying bits of metal, forgotten tools or lose bolts. A hot cam will sound raspier, but there should not be any metallic noises - listen, in particular, for excessive valve lash or misfires. If all is well, re-check the valve lash and install the valve cover. Fire up the car and time the iginition. Go for a test drive - bring a cell phone.
Congratulations, you're done! The butt dyno reports an increase in torque from 1500-3000. Not dramatic, but certainly worth $44. Time will tell how the cam reflects on fuel economy and high end revs.
