Pulling the engine tonight, anything I should know?

[Classicfordguy]

Well the engine is down to a bare block, just finished. Found my knocking noise, the back piston on the driver side was sloppy and loose in the cylinder. When I pulled the piston the oil ring was in pieces (some of which I found in the oil pan) and the middled ring was in two pieces. I didn't read your posts in time and I already took the heads off, sure hope I didn't crack them.

I've been told I need new studs for sure but do I realy need to spend $350 on studs? I'm a broke college student, is there a way to get cheaper ones, I'm not trying to build any massive hp and never over 10lbs of boost.

I'm planning on heading to a machine shop in the morning, I assume the one sloppy cylinder will need to be bored and sleeved. I imagine they will check to see if any other cylinders need to be done?

Since I have the whole thing down to the block, what things do I realy need to do? I can have only one cylinder sleeved right? Just sleeve the one and buy a new piston top and rings for it? I assume I can keep the same cam bearings, rod bearings and main bearings? Is there a need to do new freeze plugs? if so, is that something I would do or the machine shop?

How can I post some pics? I have never tried.

Thank you guys so much for all the help, I still don't know if there is any way to have this back together in a week but im going to try. Im sure I'll have more questions in the morning, its 2:30 am and im finaly done for the day.

-Rob

 

[Diesel JD]

Hmm, well first you need to make sure those heads aren't warped. Thing is you really don't need to replace those head bolts unless they are strectched, corroded or otherwise damaged I'd clean them up and reuse them(I did on a 6.9 no less) As for the sloppy piston yes you can just sleeve one cylinder, but you better hope that the machine shop knows what they're doing cause dry sleeves are not like wet sleeves used in truly sleeved big rig motors or parent bore that we're all familiar with. I'd almost sooner bore all the pistons .010 over and hope that the Big C doesn't bite until you can build a real nice IDI or buy a newer vehicle. Has this truck has SCA maintenance all or most of its life? If not or if your heads turn out bad, it may be a better option to swap in that 6.9 out of your E350 with new head gaskets assuming it is healthy. Heck I might do that anyway. The 7.3 is a good engine and sleeving is great when done right....but doing it right is not easy.

 

[RLDSL]

If you find a machine shop that specializes in diesels, you should be in good shape on getting a sleeve done.
If the freeze plugs are the original stainless and haven't been fooled with , go ahead and leave them alone. If someone has monkeyd around and swapped them with something else along the line, or replaced them and not seated them all evenly, now is the time to get it done properly.

Supposedly head bolts can be reused, the factory manual gives two different torque specs for used and new bolts, but first time I did a set of heads I had a couple of used bolts try to fail on final torque so I just buy new ones, they're about $60 per head, and naturally after buying some, I just found this place that has them for about $90 for both heads for a 7.3 here. Almost had myself talked into the studs this time, but the cash just wasn't there.

 

[RLDSL]

Don't forget to get a bottoming tap and clean out the head bolt holes in the block or you'll get incorrect torque readings.
It amazes me how few people actually do that but it must not be many judging by how hard it is to find bottoming taps and how few parts places have even heard of the things.

 

[Classicfordguy]

Wow, I guess that would mess up torque readings, I think I have a tap that size but if not I'll be sure to grab one.

Does anyone know the torque specs for new and old head bolts, rod bolts and main bolts as swell as the tightening sequences for the heads? Do the main caps need any special tightening order?

I'll be headed off to a parts place to find out if I need a whole new set of pistons or not, the guy I talked to mentioned honing the cylinder instead of sleeving, I guess that depends on how bad it is worn.

Thanks,

-Rob

 

[sootman73]

when you do tap the holes be very careful an make sure you have the tap tight in the handle. my friend was doin his and when he pulled the tap out it fell down into the water jacket. an hour later and with a extendable stick magnet they got it out. lets just say his dad wasn't very happy at the time.

 

[Classicfordguy]

Took it all to have it checked today. I didn't even notice but the pistons were aftermarket hyperutectic full floating .030 over. So someone has already built it not too long ago. The plan is to bore and sleeve the one hole and hone the rest. Picking up a new piston in the morning. Decided to do all new bearings and all new rings as well as freez plugs. The crank was already turned down .010 and .010 and looks good.



Did these engines come with roller lifters? This one has them. Also are the stock head studs 12 point heads or do I have aftermarket ones?



Any ideas on why this would have happened to the back cylinder? Plugged oiler? dirty injector spray? Don't want to put it back and have it happen again.



Also, the machine shop I've used before said he can do it and have it back to me by thursday, he's a nice old guy who always give me a deal, he knew all about leaving a step and just wanted to make sure the sleeve I was getting was thicker than 3/32, (its 11/32 thick).



We'll see how it goes, hope it all works out.



-Rob

 

[Diesel JD]

Cool that you have somebody to take care of you with the machine work who knows what he's doing. I have no clue about what could have made that oil scraper ring fail unless it was incorrectly installed or something. Well I hope it works out well for you. What's the bill for all this if you don't mind sharing? If someone does good work economically I would sure keep them in mind if/when I do an IDI build as good machine shops are rare in Gainesville especially for diesel.

 

[RLDSL]

Wow, I guess that would mess up torque readings, I think I have a tap that size but if not I'll be sure to grab one.

-Rob

Make sure that you use a bottoming tap and not a regular cutting tap or you won't clean out the bottom 4 or 5 threads.
I just got through doing this on my engine and it's obvious that the machine shop that rebuilt the engine around 5000 miles ago failed to do that little step because a all the holes were nasty at the bottom, a few were bad enough to throw readings way off. One, I'd be surprised if the bolt was even seated all the way down..

 

[icanfixall]

Measure the head thickness plus another 75 thousands for the gasket. Then measure down into the block. The holes are counter bored down 1 inch. Then they are tapped down another 1 1/2 inch of 1/2x13 threads. The bolts don't reach all the way down the available threads. The bolts are about 1/4 to 5/16 from the bottom. So its good to clean all the threads so you know your getting clean threads and a proper torque reading. Nothing worse than a bolt that bottoms out and leaves things loose..... You can make a bottoming tap by cutting the end off a starting or plug tap. Just don't let it get hot and turn blue. It will break off way down in there and thats for sure.... Not an easy thing to get out either for most of us....

 

[mac3]

I rebuilt mine and I left the air condition hooked up.Also when the rad is out and your not to big you will have room to stand between the engine and front of the truck.
Good luck

 

[Classicfordguy]

Well just got called back to the machine shop, read the wrong number on the piston top. The cylinders are .040 over not .030. And two more of the cylinders were worn so its getting 3 sleeves now. My hope is it will last a good number of years then I'll put a cummins in it.

The rings are milla coated, the pistons are sill power I think, I'm getting a full gasket kit and all new rod, main and cam bearings plus 3 sleeves all came to about $900. The machining is 100 a sleeve and 25 to bore each sleeve. Then I went ahead and ordered a solid flywheel plus clutch kit for $430 from the same place I got the parts.

-Rob

 

[obinella]

hyperutectic pistons in a diesel?

 

[Classicfordguy]

Guess so, when I get them back I can post the brand and number

-Rob

 

[Diesel JD]

Yeah the sealed power pistons are hyperteutic. Dave Spounagle says that the OEM Mahle pistons are also hypertuetiuc. .040" over on a 7.3 rebuild? Not a very good idea, you might get away with it with proper SCA maintenance but I wouldn't punch one that far unless I was desperate. Still if you have no signs of cavitation now you'll probably be just fine as long as you sleeve the most cavitation prone ones, #8, 6 and 4 from what I recall, but I might be mistaken. Still if it ain't broke, $100 a sleeve is real expensive it might be best just to take your chances and then save up for the Cummins or a HO IDI build.