Pending Machine Work

[THSIM9]

Upon tear down of my 7.3 I discovered that I’ve had exhaust valve to piston contact on one cylinder. So I’m looking into machine shops in my area to rebuild the heads for me including some Comp 910 springs that I purchased for this build. Obviously going to need new pistons now, my plan was to keep the stock bore and buy a new set of pistons at stock size. My question is, should I be concerned about the block or any other pieces that may need machine work, and does anyone know a reliable source for new pistons & rings?

The overall build plan is to swap out the banks sidewinder for a CDD stage 2 kit with intercooler, 110 CC pump, Stage 1 injectors, comp 910 springs, new push rods, and some other little goodies. All parts have been ordered already.

Thanks in advance!

You must be registered for see images attach

You must be registered for see images attach

 

[FrozenMerc]

Make sure to check the length of the rod to see if it is bent, and check the main bearing girdles on either side of that hole for cracking. Normally you will just bend a valve or pushrod from that type of contact, but that looks to be pretty heavy contact and I would want a warm and fuzzy.

 

[franklin2]

Someone a month or two ago was having trouble buying pistons, I forget the details about it. I went looking for a driver's side exhaust manifold and they have all dried up.

 

[Lumberjackchuck]

and does anyone know a reliable source for new pistons & rings?

Are you looking for turbo pistons or NA?

 

[THSIM9]

N/A Pistons.


Upon further investigation this evening I found some evidence of what I am assuming is a partially melted piston. For what it’s worth this is the cylinder right next to the valve contact cylinder.

You must be registered for see images attach

 

[Lumberjackchuck]

N/A Pistons.


Upon further investigation this evening I found some evidence of what I am assuming is a partially melted piston. For what it’s worth this is the cylinder right next to the valve contact cylinder.

MAHLE Original 224-3508WR

Free Shipping - MAHLE Original 224-3508WR with qualifying orders of $109. Shop Pistons at Summit Racing.

www.summitracing.com

Though I feel like with all the money youre planning on dumping into it with performance parts and machine work, it’s probably worth while to get turbo pistons and rods. They still make reduced compression turbo pistons too which may help your valve contact issue

 

[Nero]

That's not a melted piston, the sharp edges is junk going through the piston

 

[DrCharles]

Upon further investigation this evening I found some evidence of what I am assuming is a partially melted piston. For what it’s worth this is the cylinder right next to the valve contact cylinder.

That looks more like a piece of something (a washer maybe?) entered the cylinder and got banged into the piston top a bunch of times before going out the exhaust...

 

[THSIM9]

That looks more like a piece of something (a washer maybe?) entered the cylinder and got banged into the piston top a bunch of times before going out the exhaust...

Yeah I think you are right.

MAHLE Original 224-3508WR

Free Shipping - MAHLE Original 224-3508WR with qualifying orders of $109. Shop Pistons at Summit Racing.

www.summitracing.com

Though I feel like with all the money youre planning on dumping into it with performance parts and machine work, it’s probably worth while to get turbo pistons and rods. They still make reduced compression turbo pistons too which may help your valve contact issue

Thanks for the info. I think I might just do the Turbo pistons and rods as you mentioned.

 

[IDIBRONCO]

That's not a melted piston, the sharp edges is junk going through the piston

A little late, but I agree too.
THSIM9, be sure to have the exhaust valve guides done too. You have some worn guides.

 

[THSIM9]

A little late, but I agree too.
THSIM9, be sure to have the exhaust valve guides done too. You have some worn guides.

Thanks for the heads up, I’m planning on having the heads completely rebuilt. There is a shop in town that didn’t shy away when I mentioned I had an IDI so I’m meeting with them tomorrow and hopefully leaving the heads there.

 

[typ4]

Do not let them put in thick margin valves.
Also valve depth should be near 60 thou deep.
Dont let them tell you it will hard start, it wont .
21.1 comp ratio has its advantages.
Ive done many engines this way , near 50, never an issue.
ALSO I have never replaced valves unless stem is worn, the IH valves are amazingly tough and durable.
I am not a fan of the turbo pistons, Ive seen them crack thru the pin hole. Ive never seen an NA piston break, even when turboed .
R&D can shave the pistons if you like , as can any good machine shop.

Also I would reuse the pistons, find a good used one with same letter code for the one with the dents in it. The valve one is fine to use.
I would use total seal rings also.
When I worked for the fleet I built several engines during the tough money times, sanded the tops of the pistons , never an issue and these Helo mechanics abused the hell out of the trucks.

 

[asmith]

Do not let them put in thick margin valves.
Also valve depth should be near 60 thou deep.
Dont let them tell you it will hard start, it wont .
21.1 comp ratio has its advantages.
Ive done many engines this way , near 50, never an issue.
ALSO I have never replaced valves unless stem is worn, the IH valves are amazingly tough and durable.
I am not a fan of the turbo pistons, Ive seen them crack thru the pin hole. Ive never seen an NA piston break, even when turboed .
R&D can shave the pistons if you like , as can any good machine shop.

Also I would reuse the pistons, find a good used one with same letter code for the one with the dents in it. The valve one is fine to use.
I would use total seal rings also.
When I worked for the fleet I built several engines during the tough money times, sanded the tops of the pistons , never an issue and these Helo mechanics abused the hell out of the trucks.

just curious, why would you reuse the pistons? just to save money or are the old pistons better quality than the new ones?

 

[DaveBen]

Unless they show signs of damage, why not? Machining the bore will require new pistons. Just clean them up and you should be GTG.

 

[THSIM9]

Do not let them put in thick margin valves.
Also valve depth should be near 60 thou deep.
Dont let them tell you it will hard start, it wont .
21.1 comp ratio has its advantages.
Ive done many engines this way , near 50, never an issue.
ALSO I have never replaced valves unless stem is worn, the IH valves are amazingly tough and durable.
I am not a fan of the turbo pistons, Ive seen them crack thru the pin hole. Ive never seen an NA piston break, even when turboed .
R&D can shave the pistons if you like , as can any good machine shop.

Also I would reuse the pistons, find a good used one with same letter code for the one with the dents in it. The valve one is fine to use.
I would use total seal rings also.
When I worked for the fleet I built several engines during the tough money times, sanded the tops of the pistons , never an issue and these Helo mechanics abused the hell out of the trucks.

Thanks for the information! Much appreciated.