I have a 390 445 stroker I put in a melling HV57 oil pump, Comp cams camshaft and matching lifters, a little bit of head work, and I did not really do anything to the oil system. That I recently was able to get running for the past week i have been taking it out for short trips around town. Nothing farther than a mile. Today I took it out on the highway and up and down some steep hills. I went up and down a few steep hills and no problems what so ever. i got to about the top of a small but kind of steep hill and it started to pop though the carb as i went down a hill to got to some place it steadily became worse. Once i got it parked it was popping and shacking really bad. I checked the timing on it and it was fine. I was about ready to pull it across the street to park it. Tell I could figure out a way to get it home when is started to get better and by the the time i got it to the parking lot it did not pop or shake at all so i took it home. Once I was able to get it home I opened the hood with the engine running and noticed a slight tic or knock from the engine so pulled the passenger valve cover. The lifters on the first cylinder were both not pumped up at all. I have not able to get to the other vavle cover yet. Any help would be greatly appreciated about at the end of the rope with this Build.
Today I was able to look more into the problem. I pulled the lifter on the intake of the number one cylinder and the lifters had big chunks of it missing and part of a spring sticking out of the bottom of it. When I pull the intake I will take some pix of the lifter. Both of the lifters move freely up and down on the cam shaft. When I put the motor together I made Shure that I checked all of the oil galleries and made sure that the lifter moved freely. Before I started it primed it whit a drill. All the lifters were pumped up. I used the camshaft brake in additive both be for and after the oil change. When I broke it in I ran it for 20 minutes shut it off and drained the oil. The oil did not have any metal in it. The motor only has about three hours on it and about four or five miles on it that is it. I don’t understand why a lifter would go bad that quick.
You have a serious problem. Too much going on. the motor has to come out and stripped. Could be anything from too much lift and the piston hit a valve to too long of a push rod to not braking it in properly. Did you put zink back in the new oil change ? Did you work on the heads and put in adjustable rockers ? Did you measure the lifter bore and do the lifters move sideways in the bore ? Are there valve marks on your pistons ? Did you measure valve to piston clearance in the combustion chamber ? That is only 9 possibilities. There are probably 91 more to go.
When I put it together I spent a lot of time checking the out the valve train. I put in ajuable roller rockers, custom length push rods, matched springs to the cam, lifters that came with that cam. Everything but the push rods are from Comp Cams. The first thing that I did was to check all of the lifter bores. I then checked the height of the valve when it comes in contact with the piston. Then I put a light weight spring just to hold the valve up and not depress the lifter .I put on the rocker shaft and tock a push rod length checker and figure out the length of the push rod. After that I spun the motor and checked to see if the valve will hit the piston. At max lift it took a measurement of the valve to see the different in height. Once the push rods came in I did the same thing with the same results it did not hit the piston. I even looked inside the spark plug hole and could see clearance between the valve and piston. All the work that was done to head was to put in larger exhaust valves, harden seats, bronze guides and new valves. When I broke I fallowed the instructions form Comp cams. I ran it for 20 minutes with a zinc additive. Let it sit and cool tell I could change the oil. When the oil came out l looked just like it went in no little metal flakes nothing .The next day I changed the oil and but anther half quart of zinc additive in.
Did that engine idle at any time within the first 20 mins. ? Were the rollers on the rockers
centered on the valve stems ? If the bottoms of two lifters blew out you are definitely
going to have to strip that engine and have the inside of the block power washed to remove any metal particles left in the engine. You are probably going to have to replace
the cam too.
**By what you are saying,** the only negitive variable would be the push rods. They may have been short enough for piston-valve clearance, but your geomitry could be off between the lifter and cam lobe to the end of travel of the valve. What I mean is...the springs may be completely compressed while the cam is still trying to lift. So if the the push rods are too long, something will break at the weakest point. In your case the bottom of the lifter.
You did say you are using adjustible rockers, and you didn't say that all the lifters failed so it may have been the you didn't make the proper adustment and the rocker arm was too tight and then you had lifter failure.
Did you use plenty of lube with zinc in the cam before installing?
When I first started the motor I brought the rpms up above idle. I don’t have a tach so I don’t know what the rpms were. The oil presser was good the whole time during the brake in. I used a half qt. bottle of oil additive. Last week I was able to take the motor apart and found six of the exhaust lifters showed signs of wear. So I’m thinking that I missed something when I measured the pushrods.
Sounds like you didn't geet the right adjustments when you did the exhaust rockers. You should do the proceedure two or even three times to make sure of proper adjustment. You can do the proceedure by how the book tells you, which is the proper proceedure, but I rotate the engine (with a remote starter switch) until intake or valve starts to open, then the exhaust valve will be closed, then make your adjutment. Do the same procceedure with the intake valve, rotate the engine until the exhaust valve starts to open then adust the intake valve. Do the same with all the valves. Watch your geometry, if the springs copletely compress before it can rorate through you'll have problems again.
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