The 4th main cap from the front of the motor does not go on right. It seems like it's out of alignment with the block. That is also the bearing that was burned up. Could that be why?



right to left = front to back of motor.

 

Wow.... that is a mess.

That main cap has wear that looks centered, to me. Ordinarily if a main cap is in wrong, or is the wrong one, etc., the wear will be off to one side. In what way does it not go on right?

Obviously there was ALOT of metal in the oil. Where was it coming from?

Look at the spot I have circled. Does that bearing REALLY look like that? If so, you don't have an oil pump bolt there; you have some other bolt. The oil pump bolt is a special bolt, 1-15/16" long. In a 400 ESPECIALLY, with the large main bearing bore, if you use a 2" bolt (short head bolt I think), the pump bolt will hit the back of the bearing and smash it against the crank. Go to GM or ARP or something and get the right bolt.

Looks to me like the rear main seal might be backwards. Look at the little grooves in it where it meets the crank; imagine the crank spinning in its normal direction; will that direction be forcing the oil rearwards, or frontwards?

I don't see any sealer on teh end of the rear main cap where it meets the block, or on the ends of the seal, and the ends of the seal are lined up with the main cap. Was that how it was in there? It's alot easier to get it to seal if the ends of the seal are offset a little, maybe ¼", from the cap surfaces.

 

It looked like there was some sealer used on the rear main. Is it backwards? I have no idea.

http://www31.addr.com/~stealthe/irocz/rebuild/toasty/

There are 4 more pictures in there.

I took a picture of the oil pump bolt.

The best guess that we came up with was that the crank had metal in the oil passages. So on startup all the crap that was in the crank ran through.

 

seal is right, i doubt you had much if any dirt i nthe crank that got to the bearings on start up. was the parts cleaned before assembly? i'd suspect oil supply problems.

 

this might sound stupid but, was the hole in the bearing lined up with the hole in the block?

 

this might sound stupid but, was the hole in the bearing lined up with the hole in the block?

 

I looked at the seal pic, it was in there the right way.

Can't tell about the oil pump bolt in the pic, whether it's the right bolt or not. Pop the bearing out of the rear cap and see if the bolt left a gouge in the back of it.

Looks to me like your motor is full of metal shavings. If it was mine, I would take it to the machine shop and get the cam bearings and all the oil gallery plugs removed; I would ask them to call me when this was done, so I could come look at it; then once I had verified that they were in fact out, I'd have them tank the block; then I'd go pick it up, take it to the car wash, and run rifle and shotgun brushes (I keep .22, .30, and .410 brushes around, just for this purpose) through every single oil hole in the block, and use a small wire brush like a toothbrush on the groove behind the cam bearing. I would then paint it, while it had no plugs pr hardware; and install the cam bearings (I have the tool, you might have to take it back to get them to do it for you, which is OK), and the oil passage plugs.

Look down in the oil feed hole in the block that mates with the one I have circled in this pic. There should be a plug down there, about 1¼" down below the main cap register surface. If it's not there, the oil will be allowed to bypass the filter; the filter will fill with oil, and you'll have perfectly good oil pressure (maybe even a little high), but the oil will not be filtered. Oil comes from the pump, through that hole in the cap, into that passage in the block, and horizontally to the outside of the filter; then up through the middle of the filter, horizontally back to that same vertical passage but above the plug, and then up to the rear cam bearing and from there to the 3 passages that run from front to rear of the block. So if the plug was not installed in your block, your oil would have stayed dirty 100% of the time, and any metal shavings in it would have been recirculated instead of getting trapped in the filter; because the oil would come from the pump, intoi the block, and straight up to the rear cam bearing distribution groove, without being forced to detour through the filter.

If you put your cam bearings in yourself, align them such that the oil holes are at about 4:30 or 5:00 viewed from the front of the block; and the front bearing, which has 2 holes, should be put in with them at around 4:00 and 7:00.

I like to tap the 3 plug holes behind the cam gear for ¼" pipe, rather than using the drive plugs; and I drill a small hole, like with about a #65 or #70 drill bit, in the outer 2 ONLY, not the center one, for timing chain oiling.

It looks to me like one consequence of the seal being lined up with the block, may have been that there was seal material caught between the cap and the block, which prevented the rear cap from sitting down on the block all the way.

Also, the hole I have circled in the pic, has full oil pressure on it. There should be a VERY SMALL amount of sealer smeared on the cap around that hole, and in the corner of the cap register step next to it; if there is not, oil WILL find its way out between the cap and the block, along the crack it leaves between the seal and the pan gasket. ALOT of oil can leak out of there that way. It's especially bad if the oil can get from the passage to the outside edge of the cap register step; the cap has a bevel, and it makes a nice little triangular passage that will literally squirt oil out the back of the block right there.

 

How about the pic....

 

Well that picture explains the oil by my starter.

Can I get the block tanked w/o rebone/rehone? The block is .030 already....I want to reuse the pistons.

If I get the block tanked....would I need to blow out the oil passages?

 

No you would not necessarily have to have it bored/honed. Although, I would strongly recommend getting it re-honed anyway; since you'll most likely be putting in new rings, they'll need proper cyl wall prep in order to seat correctly. But as long as the cyl walls aren't so damaged that they require re-bored, you can re-use the pistons. Just make sure you pick as much of the metal shavings as possible out of their skirts so that they don't immediately dig new vertical grooves in the cyl walls.

After getting the block tanked and honed, you need to take the block to the quarter car wash early in the morning on a hot sunny day; get about 3 or 4 cans of Gunk Engine Bright degreaser which is basically diesel fuel in a spray can, or equivalent store-brand product; use the rifle brushes and so forth that I described in all the passages, with the diesel fuel; then blast the hell out of every single hole, groove, crack, passage, etc. etc. etc. you can make water go into, using the hot soapy setting, paying particular attention to the grooves behind the cam bearings; wash the cyl walls with a terry cloth towel and some diesel fuel, and then the towel with soapy water, to get rid of honing grit; if the cooling passages have lots of rust built up in them, squirt some CLR or some such in there and let it soak for a bit, to strip as much as conveniently possible of it out of there; then rinse it THOROUGHLY with hot water; then put it out in the sun and let it dry, turning it over every hour or so to expose every side of it to direct sunlight (heat, breeze). Then paint it, put the cam bearings and plugs in it, and build it. If you don't put the cam bearings in yourself, specify that they be installed as I described, and don't accept it back from the shop unless that's how they are. You can blow passages with compressed air if you want but it isn't of much value, unless you don't get it dry. That's about all it's good for, is blowing out water.

 

My thoughts were if the cylinders looked shiny and undamaged to just reinstall the same pitons/rings. The engine only had 2000 miles on it. I wasn't sure if the hot tanking would affect the bores.

I'm just curious as to why you suggest rifle brushing everything and such. Isn't the point of hot tanking to clean everything?

 

Hot tanking doesn't dissolve metal.

The point of wire brushing, is to get all of the metal shavings out of the oil passages, where if there's ANY left, they only have one place to go.... right straight into the bearings. The procedure I gave you is exactly the one I use, with (as far as I am aware) 100% success at preventing repeat failures for trash in the bearings.

I would not re-use rings, period. That's just a totally bad idea. If you were making a list of places not to compromise in an engine if you want reliability, rings would be uppretty high on it.

 

Well I have a power washer....so If I pick up some rifle brushes and use my power waster would that do it?

My only concern with honing was taking material off. Would just a quick 10 seconds in the bore do it, just enough to clean it up and get a crosshatch?

At this point I dont' care what it costs, or what it takes. I just want the engine to be perfect when it goes back in. Just a matter of me finding out what needs to be redone and what can be left alone.

 

Yup, doesn't take much, just enough to freshen up the cyl walls so they get a good bite on the rings.

Yes a pressure washer would work fine. However, if it was my own yard, it'd be worth a buck or 2 to me not to leave a half gallon of diesel fuel floating around on it. But that's just me.

 

Like he said, but be especially careful of the area in back of the cam bearings, crud can hang out there. Also I preffer to offset the rear main seal so it doesn't line up with the block/main halves.

 

Offset? What do you mean? Any picture?

 

I think he means that if you are looking at the cap mounted on the block from behind the engine, the seams for the cap and block sit at 9 o'clock and 3 o'clock positions.. Make the seal seams happen at say, 10 and 4.

 

yes, that was a better way to explain it.

 

i use a little square to set the amount of offset on the two piece rear seal. set the blade at 1/4" and set one end in and the matching end out the same amount ( by setting the other end in) and you won't have any problems. i use just a bit of ultracopper rtv on the seal ends, as well as the cap.

 

Oh yea....the guy also completely overtorqued the main caps....if that matters. I mean COMPLETELY. Probably 60lbs over spec.

I'm worried about reusing the main cap bolts in case he stretched them by overtorqueing too much.

 

i took some pictures. The one named "offset", is that what you mean to offset the rear main seal?

As for the other 3 pictures, RB, my oil pan had plenty of metal shavings in them....and I couldn't see any oil plugs. Maybe those 3 pictures will let you see....I'm guessing the plug was missing, and my filter wasn't doing a damn thing for me. That would explain the bearings being toasted.


http://www31.addr.com/~stealthe/iroc...d/oilproblems/

 

Yes, the "offset" is exactly what is meant. About that much in fact, is a good amount.

The plug isn't supposed to be in the main cap; it's supposed to be in the block, in the hole that the one in the cap mates with.

In this thread there's a diagram of oil flow in the passages inside the engine. This is what you're looking for.

 

The plug was in place and the back of the rear main cap bearing was not damaged.

There were alot of metal shavings in the oil pan though.