Just started my 7.3* build

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
What, exactly are you doing here? I know you said that you're rebuilding your engine, but are you overhauling/reringing it? Are you going to do the whole thing with new pistons?
 

Scotty4

Supporting Member
Supporting Member
Joined
Nov 15, 2019
Posts
1,117
Reaction score
1,081
Location
Franklin County, Massachusetts
Do you know where the engine came from? If you do, ask the previous owner if they maintained SCAs in the coolant and why the engine was removed to begin with. @IDIBRONCO would you say there is concern with getting a used 7.3 and having cavitation? I would personally fear rebuilding an unknown engine and having pin holes hiding on me.
 

79jasper

Chickenhawk
Joined
Oct 13, 2012
Posts
17,367
Reaction score
1,930
Location
Collinsville, Oklahoma
Do you know where the engine came from? If you do, ask the previous owner if they maintained SCAs in the coolant and why the engine was removed to begin with. @IDIBRONCO would you say there is concern with getting a used 7.3 and having cavitation? I would personally fear rebuilding an unknown engine and having pin holes hiding on me.

Being a 89, I'm sure it's changed hands several times.
Imo, that's just a chance you have to take with these engines.
Po's word means nothing. Only rear way to know is to have it checked.

Sent from my SM-N960U using Tapatalk
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
@IDIBRONCO would you say there is concern with getting a used 7.3 and having cavitation?
I would say yes, but... Yes, there's always the possibility of cavitation with a 7.3. But...the general feelings here is that most (if not all) of the blocks that were more prone to it have already had it by now. Like Jasper said, the only way to know is to have it checked. I will go one step farther and say that if you have it bored, have the cooling passages pressure checked if at all possible. Even if it means trying to borrow/rent a set of plates that someone has already made up. Even this isn't 100% certainty. I installed one 7.3 (back in the late 90's) that was pressure checked at the machine shop after the machine work was all finished. It was checked again at our shop before assembly (we used full line pressure of around 120PSI). The block passed just fine. After I installed the engine and was on the test drive, it started blowing a lot of white smoke out of the exhaust. Sure enough, it was antifreeze, so I had to pull it back out and install another one. All we could come up with was that the pin hole was hiding just below the surface of that cylinder. There was enough metal covering it to pass the pressure checks, but the rings must have wore through it pretty quickly. That was probably a one in a million thing, so don't sweat it.
 

Buffetkiller

Full Access Member
Joined
Aug 6, 2019
Posts
103
Reaction score
29
Location
Washington
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
Wow i really came off at the start of this project like i was gonna hit it hard... oh well life gets in the way.

today i was able to tear into it more. Pulled the IP, pulled the intake and the valley pan. Pulled injectors(which looked very nice to my untrained eye) and GP. Picked the valve covers off to find out passenger side head had 1 broken bolt And driver had 3. Pulled the rockers and pushrods. Pulled the heads. Cylinders looked decent to me, although i think you would like to see more crosshatch(not a huge motor guy i just know how to work on things). Heres some pics.

@IDIBRONCO I would like to see maybe about 300hp and what ever torque that would get me too. I am going to have everything checked out. I think that would still be reliable power?? from reading other threads. More power but reliability. I just dont quite know how to get where im going other than bigger injectors, headstuds, tuned up IP, and a larger turbo than i currently have on my 6.9.
You must be registered for see images attach
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
It sounds like you're on the right track. The only other thing that I would recommend is to add an intercooler. I did a quick scan through this whole thread and didn't see it mentioned after the first few posts (if I missed it, I'm sorry), but you do have a 6.9 here, not a 7.3. The tops of the pistons and the block give it away. This picture clearly shows the two differences. this is of my 7.3 as I was reassembling it a couple of years ago. You can see how the tops of the pistons are different. you can also see the cooling port differences. In your bottom picture, look at the shape of the coolant port at the lower, right corner of the block. Now look at mine. They are round and open after I removed the stainless plugs that were in there from the factory.

You must be registered for see images attach
 

Buffetkiller

Full Access Member
Joined
Aug 6, 2019
Posts
103
Reaction score
29
Location
Washington
Well then. Good to know. Intercooler is needed huh?

How far should i go into this thing if im doing all this? If the motor turns over smooth i can assume the low end bearings are in good shape right? And looks like you have new pistons should i do those along with the rings too? Not really trying to break the bank, although i know much of motor work is pretty pricey. But looks to me that you can do alot on these yourself
 

Philip1

Supporting Member
Supporting Member
Joined
Apr 1, 2019
Posts
448
Reaction score
366
Location
Northeastern Nevada
Since you have the engine out, I would at least pull the bearing caps and inspect them for damage and wear. A worn out set of bearings will still have the engine spin smoothly unless there is significant damage.
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
Since you have the engine out, I would at least pull the bearing caps and inspect them for damage and wear. A worn out set of bearings will still have the engine spin smoothly unless there is significant damage.
Good advice. I've rarely seen bad bearings unless there has been a lack of oil or maintenance. I've looked at many engines with 250,000-300,000 miles and the bearings would have run for a long time. That said, it's easy enough to pull the pan and check the bearings too. I'd pull a couple of mains and a couple of rods. If those look good, then the rest probably are too.
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
Well then. Good to know. Intercooler is needed huh?

How far should i go into this thing if im doing all this? If the motor turns over smooth i can assume the low end bearings are in good shape right? And looks like you have new pistons should i do those along with the rings too? Not really trying to break the bank, although i know much of motor work is pretty pricey. But looks to me that you can do alot on these yourself
An intercooler isn't needed, but is highly recommended along with a pyrometer. I can't do any machine work, but I'll do all the rest myself. I did do an overhaul on this one. That's why the pistons are new. When I bought the engine, it had about 120,000 miles on a "rebuild". I wasn't sure if anything had been done to the exhaust valve guides so I decided to pull the heads and have them gone through just for PM and peace of mind. The "machinist" (that's being extremely kind) took too much material off of the heads and didn't hold tolerances very closely. I checked the valve clearances and two only had .0045" clearance between the valves and pistons. That isn't close to being enough. So I had to find some decompression pistons to get my valve clearances back. At that point, all I had left to it being a complete overhaul was the cam bearings so I bought some of those too. I found another, good machine shop to take my parts to. To have the block hot tanked, cylinders honed, and new cam bearings installed cost me $170. I was VERY happy about that. I didn't buy new lifters, since they were supposed to have about 140,000 miles on them. I did put some miles on the engine before pulling the heads. I'm not sure that they had been replaced during the previous "rebuild" since one lifter was too weak to open the Comp 910 springs that I had installed so it got new lifters after that too.
I'm not going to recommend new pistons and rings. That's up to you. I can't tell much from your pictures, you say that you can see some crosshatch in the cylinders (I couldn't but that doesn't mean much) and there doesn't appear to be a lot of cylinder wear, so If you're on a tight budget, I'd probably just run them like they are. Since it sounds like you're going to be pulling the oil pan off, it wouldn't hurt to remove your piston cooling jets and make sure that they're clean by squirting some brake cleaner or carb cleaner through them. I have, rarely, seen them with a piece of RTV stuck in them.
 

Buffetkiller

Full Access Member
Joined
Aug 6, 2019
Posts
103
Reaction score
29
Location
Washington
Piston cooling jets....? Sorry if this is easy stuff haha. My only experience with motor stuff is rebuilding two stroke dirtbikes(top and bottom) and they held Together so im pretty confident!
 

Forum statistics

Threads
91,217
Posts
1,128,487
Members
24,045
Latest member
Ramtough01

Staff online

Top