mos68x

Hey guys, been a little bit since I've been on here since I'm trying to get my motor apart to replace what I'm guessing is head gaskets. I was driving the car home from dropping my son off and the car lost drivability and dumped tons of steam out the exhuast. Got home and noticed on the floor of the garage that it had aparently already started to spray a bit of coolant out the pipes before I even left the house, although I'm not sure which one. I'm pretty far in disassembling the motor to replace them, so I thought I'd ask you guys for any suggestions of anything else to look for. I almost have the drivers side head off, just need to remove the head bolts. When I removed the valve cover I seen a lot of milky residue on the inside of the valve cover, but nothing in the head or rockers. When I pulled the #7 plug coolant drained from the hole, and #5 was pretty wet. I still have to remove the exhaust from the pass side, and valve cover, but everything else on the top of the motor is removed.
Can anyone tell me an "easy" way to see if this head is cracked? Or will I have to send it to the local shop to have them check it? I really hope that it is just a busted head gasket, but I wondered what you guys thought.
if the heads are cracked, then I'll probably just wait till taxes and buy a set of alum heads soon as I figure out which ones.

skirkland1980

iTrader: (2)

most commonly crack between the valves. clean the carbon with a wire brush to get a better look

skirkland1980

iTrader: (2)

if your short block has a lot of miles you may want to rebuild to whole engine before going to high performance heads. sometimes the bearings cant handle the power increase.

mos68x

I was planning on replacing the bearings anyways, but I wasn't really expecting too much gain without having a cam in there. A cam is next on the list of things that I want to get, I'm just trying to get parts that will work together real good.

I was planning on taking the heads into work anyways and cleaning them up both carbon and grease so I can get a real good look. I don't really want to have to redo the lash on the heads, but it probably would be best if I did completely disassemble the entire head to get a good look at them and the hardware.

mos68x

I just pulled the drivers side head from the block and to my surprise I see pistons that don't look stock in this thing. It has numbers etched into the top that say 423NP .040, and when I looked them up it shows Fereral Mogul and obviously 040. This was certainly a surprise that I wasn't expecting so I'm trying to get the phone number from the guy that bought the engine from the guy before him, lol. I'd like to at least get some more info on this engine before I start buying stuff for it. If it was real easy to just pull the pan and then a rod and piston to look at the rod and the bearings I would, but as of right now I'm not sure about that. I might go through the hassle of that if I can't get to talk to the guy who built this motor, or rebuilt it. I'm thinking the guy just happened to bore it over 40 to cleanup scoring in the bores, but what else he did below I don't know and I'd really rather hear it from the "horse's mouth".

JakeJr

Both heads should be taken to a machine shop to be pressure tested.

Coolant in the oil causes bearings to fail in short order, so - unfortunately - I suspect you're looking at a rebuild. Since you saw so much evidence of coolant under the valve covers, I suspect the same condition exists inside the oil pan and elsewhere in the engine. The cylinder wall(s) are also going to be effected by the coolant, so you're looking at a rehoning at a minimum.

Only way to know for sure on how extensive the damage is, is to look. Then, depending on what's found you'll know how to proceed. I'd hate to see you confine your repairs to ONLY the heads and head gaskets only to have another failure shortly after re-fireing the engine.

Sorry for your loss.

Jake

mos68x

Oh, yeah, it looks like the head gasket was really tore up on the drivers side real bad. The part of the gasket between cyl 3 & 5 was burnt like the head wasn't sealing real good there. Nearly 2 inches of the metal ring on cyl 7 is missing and it looks like the coolant bypassed the gasket right there and into the cylinder. I'm still not really sure how the coolant got into the oil though, unless it went past the rings in cylinder 7. Any ideas anyone?

edit: on the head gasket at the rear of the number 7 cylinder is where the ring is missing and it looks like two channels in the gasket from the head coolant into the cylinder and then ... past the bolt into the oil??? Does this sound possible to anyone?

mos68x

Funny thing is that I have yet to see milky oil anywhere else. Every other place has been jet black like it's supposed to be, although I still need to drop the plug and oil and take a look at that.

As far as the cylinder walls, there is no damage there at all. Although much damage can be done within minutes, I didn't have the car running for more than 7 minutes one I started seeing the steam out the rear.

mos68x

Well, I retract any statement I might have made about the block being fine. I was rotating the block to get a good look at the #7 cyl and although there is discoloration that could be taken out by honing, there is some pitting that would require another boring job....which would take this block to the max at 060. So I don't think that I'll be bothering with trying to salvage this block, unless I get good word from the local shop. Most shops don't like going to 060 so I'll probably get a "no", so I'll start looking into which block I want to buy. I do know one thing for sure this time though, I WON'T be getting a block from anyone that isn't a professional, lol.

JakeJr

Coolant easily passes by the piston rings and directly into the oil pan. From there the oil pump circulates it through out the rest of the engine.

Sonic testing will show if your block can safely go .060" over; mine tested fine for that amount of over-bore.

Jake

mos68x

The pitting on the top of the #7 cylinder feels deeper than 010 though so I seriously doubt that it would even clean up with another bore job. So now I sit here trying to decide which direction I want to go.

https://www.thirdgen.org/forums/engi...vs-ls1-vs.html

JakeJr

Right, keep looking, i suspect you'll find it.

Oh, I see you did.

Jake

JakeJr

Allowing your machine shop to make that call could save you hundreds of $$$.

Jake

mos68x

I am a machinist