i have a 78' ford f150 with a 400m engine and i had a cam go flat in my truck, so i replaced it with a 252-h compcamsand lfter set, i also replaced the timing chain with a non-retarded one.when i got the motor fired up, i had no oil pressure and the lifters wouldnot pump up, so i went to the parts store and bought ahi-volume/hi-pressure pump, my friend told me to check my main bearings while i had the pan dropped. i did and found the crank was severly scored.i had a friend that was parting out his 78' bronco, and i bought the 400m from him. it was completely stock and he drove it into the shop before we pulled the motor. i got it home and installed the rebuilt heads off my previous motor, the new cam, lifters, timing chain, and hi-volume oil pump. i have also installed new rod and main bearings and they are within factory specs. i have also installed the oil pressure line from the front to the sending unit, and i can not get any oil pressure reading. i have both a factory and a mechanical gauge that i have swapped twice to verify that it is correct. i pulled the oil filter and cranked it over and oil gushes out like crazy. and i have also pulled the sending unit and now oil comes pouring out of there like crazy too. but i still have no oil pressure. i pulled both valve covers and i have absolutly no oil coming to the top end of the motor. what is wrong with this thing!?!?!?
i just dropped the lifters in and set the torue to them in both motors, i have tried letting it run for about 10mins too, i read that i wont have any oil pressure unless there is resistance for the oil to cause pressure, cause im not getting anything, are you sure about the lifters because ive done tons of cam swaps in chevys and did the first one in my 351w maverick a couple moths ago and have had no problems with them not pumping up
why do i adjust them while the engine is running? i just torwued them down to 23ft-lbs like the manual told me
yes they are pedastal rockers, these are comp cams lifters, they came with the cam kit, could they all be bad? they oil gallery plugs are threaded and i didnt mess with any of that. i am really starting to lean towards the camshaft since it is the only thing that was common between 2 seperate motors that had oil pressure before i installed the camshaft, it cant be the bearings cause they are within spec. has anyone ever gotten a bad cam from the factory? i have never heard of it but i guess its always a possibilty
So, the original cam in the original 400 wiped a couple lobes? You put a new cam into that 400 and no oil pressure? You swapped that cam into second 400 and no oil pressure. The second 400 was running until you put your heads and cam in it. I'm wondering if after the first cam got wiped if all the metal from that could have kept the second cam from getting the proper oil and wiped the bearings in it, then when it was transfered into the second 400 it just carried it's problems on over to it? Make any sense? Also, if you put the head gaskets on wrong on a 400 can it block any oil feeds? Just guessing and trying to help. clint
you are right about the cam, but if it was wiping out the bearings wouldnt i have oil pressure initialy? cause i didnt and havent had any oil pressure what so ever in either motor
Guess you would unless the cam journals were toast. But you should have seen that if they were bad. What about head gaskets? If they were on wrong can they block any oil feeds? clint
well thank you everyone for your help, i just bought another cam and lifters and was going to install it today. when i went to pull out my old lifters i noticed taht there was about a 1/16" play, i installed one of the lifters from the new cam and it fit very snug. turns out the idiot at the parts store gave me the wrong lifters with my cam.
