Hello everyone, I have an F-250 with the 460 in it. My father and I rebuilt the motor last summer and dropped it back in the truck only to have the rod bearings spin about 10 minutes into the 20 minute break in period. We have spent the time in between rebuilding it again, and this time we have the same early stages of the problems we had last time. The first problem is that there is oil coming out of the valve cover breather we put on it. I think that we should just put a PCV valve on it and that would draw out enough pressure to keep the oil down. The other problem is the distributor. It is an HEI, and we are not sure exactly how or where to put the initial timing. It was backfiring through the carb, so we advanced the timing a little and that cleared up, but now when it's at 2,000 you can hear it coughing through the carb over the Flowmaster 40's and long tube headers. Do we just need to advance it a little more to clear up the sputtering/coughing? The last thing; when we shut it off and it is just sitting there, it sounds like the oil is boiling inside the motor. Pretty strange if you ask me. I hope for good news, but don't sugarcoat anything. Thanks, Austynn.

 

did you chamfer the new bearings to match the oil feed holes?

 

I didn't touch the new bearings this time. I paid a professional because I obviously suck at building motors.

 

My first thought here and thats exactly all it is. You have an oil drain back problem, and your pulling all the oil out of the pan into the heads and it's not getting back to the pan. Reason I believe this is the spun rod bearings sound like lack of oil, and the oil coming out the breath sounds lke your filling the heads up with oil, so you have 2 things that back up my thoughts.
You need to get that figured out before you worry about the coughing through the carb, but yes you might have the timing off, fuel mixture off, or cam timing not quite right.
So do you have a mechanical oil preasure gauge on it, does and does it fluctuate when your trying to run it or does it stay solid preasure and what is that preasure. Next thing I would do is pull a valve cover and pour some oil in there and see if it drains down or just sits in the heads. You may have to do this on the lifter gallery too, I have actually heard of one block that the oil drain back holes weren't drilled all the way through not sure how that block even survived coming out of the factory but it caused some major problems when they tried to rebuild it.
Another issue may actually be in the oil pump but lets figure out whether the oil is draining back first.
And I wouldn't say you suck at rebuilding engines you just had one go bad on you is all and it happens to everyone sometime.

 

How about the main brgs are they bad too. Did you have the rods big end resized? Are all the bearings installed properly and checked for clearance? Is the oil pump drive shaft installed properly?

 

The motor was stripped back down to the block again to rebuild it the second time and all the bearings were new. I'm sure everything is done correctly because this guy has done quite a few 460's and he built a 514 pulling truck motor that has done very well. Do you think it would be worth the money to get one of those Moroso evacuation systems? Could I weld it into the exhaust right past the headers in case it doesn't work and I want to get rid of it so my headers don't have to be filled in with a weld?

 

The noise you are hearing after shutdown sounds like coolant. Is the thermostat installed backwards? Did you bleed the air out of the engine through the heater hose when you filled it? Oil will splash out of the breather if the valve covers do not have baffles. This engine should have a PVC in the right cover connected to intake vacuum and a vented fill cap in the left cover. Sometimes the head gasket will interfere with the oil draining back into the block. This is an easy check. Pull the valve cover and look, check all four holes. When you say the engine is developing the same early stages of the problems we had last time I sure hope it is not knocking! Sort all these problems out before you get after the 2000 rpm misfire. Check the firing order.

 

Wounder are all the oil galley plugs in and installed correctly

 

If I was to put a PCV valve on would it just eliminate pressure and keep the oil where it's supposed to be, or would it suck the oil up and shoot it into the intake? I want to do a simple PCV for now until I get the money and time for an evac. kit.

 

Forget the evac kit, find and solve the problem. The evac system will just put the oil in the exhaust and make smoke. A new motor shouldn't have blowby if that is what the problem is. Check the oil drain back and valve cover baffles like was suggested.

 

Well it turns out that the oil dribble is the least of my concerns. We pulled the intake today to make sure everything was in order. It wasn't. Three pushrods were bent up real nice and the lifters were broken apart and laying in the motor. So it looks like I'm stepping up to 3/8 pushrods. Oh well.

 

you need to look at what bent those pushrods, it wasn't just the spring preasures I am betting, sounds like you have piston to valve contact most likely your gonna have some bent valves and possibly a busted pistons which would cause your excessive blowby, you need to pull it clear down and find out what caused the pushrods to bend.

 

First off, forget all about the pcv and evac and miss fire... like they said above.

Replace the broken parts and make sure the lifters move freely in the holes. Remove all the metal out of the system and clean it good.

Once you get the motor to where you think it should be, DON'T start it. Remove the dist and put in a oil primer rod attached to a big drill, you can also use a socket on a long extention. remove the valve covers and watch the oil flow, it should overrun the sides. It should also come out the rockers (all of them).

put the valve covers back on, run the drill for a LONG time, check to see if the oil is returning to the pan. If the oil is not returning, look at the return passage. Could be blocked by gaskets / sealer. You can do all this without the intake on.

AFTER you have the oil problem figured out, start working on the rest.

Backfire thru carb is usually lean condition, backfire thru exhaust is usually rich condition.

I have that evac system thru the headers on my 428, it works fine. It needs to be welded about 1/3~1/2" into the exhaust flow and you'll feel it pull air in. Nice and simple system.

What valve covers are you running? I had a set of Cal Customs and they had no mesh or web to block the oil on pcv valve... sucked a bit of oil.

What ever you do, do not run the engine until the oil return problem is fixed, you might also have a blocked passage where the oil if not getting to the bottom end (rods/mains) and is all going to the heads.

someone screwed something up.

 

do you have too much lifter preload? was the wrong length pushrods used?

 

I'm not sure about the valve to piston contact or the lifter preload because I had a professional assemble it all and I would expect him to let me know if the valves were going to be hitting the pistons or something like that. All we did this time aroud was bolt the intake on and the clutch and the accessories and drop it in. Thanks for the advice, I'm actually going to follow it this time.