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Got the passenger side head off and the #7 piston has a crack and carbon build up on it. The original issue with the truck was a major loss of power. How much would this have contributed do you think. This makes me worried about the condition of the rest of the pistons. None of them currently have cracks but is it just a matter of when? So a few questions about the bottom end of the engine.
What causes a piston to crack like this. I would like to address the cause. (I did use to pull a fifth wheel with it)
Should I just replace that piston and then since the engine is out reseal the engine. OR
not chance it and buy something like the KT Performance rebuild kit and do everything.
Anyone have experience with the KT kit? Good, Bad etc.
Full engine rebuild kit from @Riffraff Performance and have your machine work completed locally.
Thank you Bitterroot. I have not looked at Riffraff yet but I will. I have had a few diesel repair shops refer me to the same machine shop so and I spoke with them today. The bad news is they have a 4 month back log at the moment. Uggg. Also, what causes a piston to crack like this?
It's not uncommon. I don't think you did anything wrong. You may think about fancy coatings on your new parts. @SkySkiJason has build some really nice engines. I bet he has some great ideas for you.
Several years ago I had some oil usage issues turned out I just had bad injector orings. In process I checked compression several times all even across the board 350-360. About 3000 miles After That I started having issues with coolant blowing out degas bottle. I ended up swapping engines with another motor but I pulled both heads off original engine. 6 pistons had hair lines cracks just like yours. Engine ran perfect though hardly any blow by at all. Also driver side head gasket had failed causing the coolant issues.
It’s not that uncommon for these pistons to crack. It’s hard to say if your crack was causing a loss of compression. The cracks generally originate in the ‘lip’ on the edge of the piston bowl. It is common practice to mill the pistons and remove that lip. The higher HP engines I’ve gotten to build also got ceramic coated piston tops and Teflon coated skirts.
Mission creep is REAL and it’s hard to do a really good rebuild on a budget. By the easy math, you’ll be about $1200 into a Ford master rebuild kit with new pistons and ALL of the regular engine parts you’ll need. Expect $500-800 at the machine shop depending on what the heads need (valves, etc). I like to port and polish the heads and use a Stage 1 cam. Then at least 910 valve springs and chromoly push rods. Maybe have some stock forged rods cryo’ed or step up to some Carillo or similar rods if you’re a high roller. You’ll still want a fresh HPOP and injectors and of course a new water pump and sensors are always nice. Little things like a weld in dipstick tube, pro bed liner on the oil pan, paint, powder coat, ceramic coatings etc add up fast!!
Really no reason for compound turbos, but is easy to spend another $2-3k on a T4 system and a Borg Warner SXE turbo to match your new Bitterroot Diesel injectors........
I sell good, used engines for $2000-2500 when I have them. Over the years, I’ve installed a bunch of these for people and never had a catastrophic failure. (Knock on wood!!!)
The only place I would buy a rebuilt 7.3 long block from is Asheville Engines.
It’s not that uncommon for these pistons to crack. It’s hard to say if your crack was causing a loss of compression. The cracks generally originate in the ‘lip’ on the edge of the piston bowl. It is common practice to mill the pistons and remove that lip. The higher HP engines I’ve gotten to build also got ceramic coated piston tops and Teflon coated skirts.
Mission creep is REAL and it’s hard to do a really good rebuild on a budget. By the easy math, you’ll be about $1200 into a Ford master rebuild kit with new pistons and ALL of the regular engine parts you’ll need. Expect $500-800 at the machine shop depending on what the heads need (valves, etc). I like to port and polish the heads and use a Stage 1 cam. Then at least 910 valve springs and chromoly push rods. Maybe have some stock forged rods cryo’ed or step up to some Carillo or similar rods if you’re a high roller. You’ll still want a fresh HPOP and injectors and of course a new water pump and sensors are always nice. Little things like a weld in dipstick tube, pro bed liner on the oil pan, paint, powder coat, ceramic coatings etc add up fast!!
Really no reason for compound turbos, but is easy to spend another $2-3k on a T4 system and a Borg Warner SXE turbo to match your new Bitterroot Diesel injectors........
I sell good, used engines for $2000-2500 when I have them. Over the years, I’ve installed a bunch of these for people and never had a catastrophic failure. (Knock on wood!!!)
The only place I would buy a rebuilt 7.3 long block from is Asheville Engines.
Good luck and keep us posted.
SkySkiJason thank you that is some very good information. And that is a great looking engine. I only hope mine will look that good when I am done. I am not in a hurry to get this done as it's not my daily driver. It's a project that in the end I would like to hand down to one of my boys who will hopefully treat it the way it should be treated. Thanks again.
I wouldn’t toss your loss of power problem to the crack. As Jason mentioned, they can have a small crack, have good compression, and run just fine. You just don’t know it until you pull the heads off. Had you already completed a compression test? Was that cylinder low? If so, then that is easy. If not, you probably have another problem waiting to be fixed. I am not advocating to leave it, I just don’t want you to spend the $$ on a build and it still not run well.
I wouldn’t toss your loss of power problem to the crack. As Jason mentioned, they can have a small crack, have good compression, and run just fine. You just don’t know it until you pull the heads off. Had you already completed a compression test? Was that cylinder low? If so, then that is easy. If not, you probably have another problem waiting to be fixed. I am not advocating to leave it, I just don’t want you to spend the $$ on a build and it still not run well.
I wish I had but I did not do a compression check. I do have a video of a time when I got it started a few years ago and it seems to have what I would call a Lope. I would love to post the video but for some reason it wont let me.
