1977 454

i have a 1977 454 chevy and i have wiped out to cams now on break in,i have heard that some of the mid seventies 454 blocks had issue with the lifter bores being missaligned so they had specil cams made for them,like io said i heard that dont know if it true.The cam that was in the motor when we first took it out of the truck was wiped out to but it still ran decent just had low oil pressure so we pulled it.Any help or tips would be great.would definently like too know if the lifter bores are mis aligned cuz i dont want to loose another cam on break in.  

Yes the old 454's did have the missaligned bores, but thats not the reasion. All the motors that GM has ever made has that problem due to core shift at machining stage. Even to this day.

I think that your problem is going to be somewhere in the oiling system. You said you had low presure. your cam gets wet two ways, first through the oil galies that oil the mains as well. They go vert. two the cam berrings. If the cam berrings are not installed right then you can wipe the cam. Those berrings need to be installed with the hole towards the oil pan.

Second, oil is passed through the lifter galie. There are 3 running front to back of motor. The oil flow from the lifter itself and the run off.

If you don't have oil presure, the start looking at the bottom end. Pull your mains off and check them for wear. Bad mains mean low presure and oil not making it to your cam or lifter or rockers ect.

Also check the oil pump good idea to replace it. Make sure there is nothing blocking the oil pathway. Check to make sure all the oil plugs are in. There might be a hiden one.

If this wer me, I would pull the motor and tear it down. Go over it very well. Run compressed air through the oil ports to clear any blocks you might have. pull cam berrings and install new ones. remember holes face oil pan.


hope this helps
good luck

p.s. You can also take the block to the machine shop and lifter bores strightend.  

We did a full rebuild on the bottom end the first time and put a new cam in and stuff,when that first cam failed it took out the main and rod bearings so we went back to square one and did it all again.when we put in the newest cam everything was double checked and triple checked but after break in the very end lobe wore off and we havent pulled it the rest of the way out to see if any others are wore at all.This last time i had 65 pnds of oil pressure at 2300 rpms during break inthe whole time.I just dont know what went wrong this last time.it is getting expensive  

Ok I see what you are talking about now. I had talked to 2 of my big block buddies. all three came to the same conclution. We think that the very last cam bearing in the back of the motor is installed wrong. That bearing has got to be perfect. your going to need to pull the motor and pull cam freeze plug out. Pull out the bearing and look at the oil hole. It is not going to be an up and down hole, it is going to be at an angle. After you verify the hole, make sure oil is flowing through it. If oil is flowing through then put a new bearing in. (needs to be installed pefectly centered up. And the hole at the 45 deg. off center.)

To do this the motor needs to be out. That way you can prelube the motor and see where the oiling problem is if not fixed after that. That way you don't kill another cam. If you have any problem shoot me your email and I'll give you my number. I'm on every day.


good luck  

Wow! every lobe? I have had cams go flat but only 1 or 2 lobes are you sure you are setting the pre load on the lifters correct? And definitley go over the oil system as stated above. Even if you had severe core shift it wouldnt be that bad. I know a guy that had BBC cam issues like this, he gave up the flat tappets and went full roller.