Okay, a buddy of mine has a 1993 5.0 car that he bought with an e303 cam, edlebrock intake, bigger MAF and injectors already on the car. We picked up a set of cast iron gt40 heads from a swap meet a while back and dropped them off at a local machine shop to have checked out and resurfaced before we put them on the car. Everything checked out with the heads. They have a little stiffer valve springs and had a port job done (RAP stamped on the side of the head). Now, the car made no abnormal noises when it was driven into the garage before we tore into it. The only other thing we changed besideds the heads was the weight of the oil, from 20-50 to 5-30, and the balancer was starting to come apart so that was changed. We went ahead and swapped out the stock e7s using felpro 9333pt1 head gaskets and reusing the stock head bolts, lifters, rockers, and pushrods. Got everything back together and went to fire it up and the thing sounds like it has a solid lifter cam in it with too much valve lash, ticks like crazy. We went through the process of checking pushrod length and found the stock rods to be too long, so we ordered the ford racing shim kit for the rockers and shimmed them to 1/2-1 full turn torqued down from zero lash (most were 1/2-3/4 of a turn). This did nothing, noise was still there. We got to looking at the geometry of the stock rockers and found that they were making contact with the valve springs (aftermarket valve springs were a little wider in diameter than the stock e7 springs, 1.400" to 1.550"). So we ordered up a set of scorpion 1.6 roller rockers that were made to clear a 1.625" spring diameter. Put the new rockers on and adjusted them per scorpions instructions (1/2-1 full turn from zero lash) and made sure the roller was in the center of the valve stem. Everything looked good so we bolted the intake back on and fired it up...same noise, no change. After thinking maybe it was an oil pressure issue, we hooked a mechanical oil pressure gauge up and it shows 20psi at idle and 45ish at 2000rpm. At this point, lifters would be the only other component of the valvetrain that we haven't changed, ordered a set of ford racing roller lifters (p/n M-6500-R302). Pulled the intake and old lifters out and for some unknown reason, the previous owner had 2 different kinds of lifters mix matched and thrown in the motor. 3 were the smooth body, and 13 were the ribbed style, there was a little height difference betweeen the two, but the journals where the lifter made contact with the cylinder were all the same height. We soaked the new lifters in oil and pumped them up getting all air out of them, and put them in the car and bolted the rockers back on following the same sequence for adjusting them. This time, none of the rockers needed the shims they needed previously. we jumped the solenoid with the lower intake off and cranked the car over to make sure the lifters weren't lifting up the "dogbone" and in turn lifting the spider that holds them down, thinking maybe this is the noise we are hearing. All looked fine, nothing was abnormal. So we bolted the intake back on, buttoned it all up, fired it up and again, same noise, no change. Now, the only other thing we changed was the weight of the oil, so we went to the parts store, picked up 5 quarts of 20-50, drained the 5-30 out and filled it back up, still no change. The last thing we did was pull the valve covers and ran the car without them hoping to pinpoint the problem... Same noise, all rockers look perfect, all getting oil. You can grab the pushrods and you cannot feel any play in them, all seems solid. At this point, we have no other ideas.. Every part of the vavletrain has been placed except for the cam...
The car runs good, starts up fine, idles fine. We drove it around the block and it runs fine, doesn't overheat. We didn't get too hard on it but it seems to have good power.
Sorry for the long post but I'm at a complete loss on the cause of this. Does anyone have any ideas as to what this noise could be?? It sounds like rockers hitting the valve cover, but as stated above, we ran it without the covers and no this is not the issue.
Thanks, Keith
The car runs good, starts up fine, idles fine. We drove it around the block and it runs fine, doesn't overheat. We didn't get too hard on it but it seems to have good power.
Sorry for the long post but I'm at a complete loss on the cause of this. Does anyone have any ideas as to what this noise could be?? It sounds like rockers hitting the valve cover, but as stated above, we ran it without the covers and no this is not the issue.
Thanks, Keith
