rebuild help

[KHaines]

I have my engine at a machine shop to have rebuilt. I supplied the parts. I am using all Cummins OEM parts. They called me up & asked for cylinder wall clearance & where it is measured at. I called cummins & they said to find a different machine shop. I call Scheids & they said the same thing. The question I have is what is the spec? Or should I be looking for a different machine shop. This place was recomened by another TDR member.



This engine is a 04.

 

[Spooled-up]

Did Scheids ask what the clearance was or did Scheids tell you to find a different machine shop?



I'd trust whatever Schieds said. They are well known for making incredible horsepower numbers. I would say they know your Cummins inside and out.

 

[JApol]

If they don't know what the clearance should be then how do you know if they have the right clearances or torqes on the rest of the motor.

Kindly pay them for their time, collect your parts and find another shop that has a clue as to what they are doing.

 

[KHaines]

Scheids told me to look for another place.



The machine shop that has the engine now said because I supplied the parts I should get them the info. They say the pistons specs are specific to the piston, not the engine. So in other words the piston manufacture should supply the specs.

 

[lmills]

The pistons are cummins pistons right? If so, find a different shop. That is your best bet. If they are asking about piston clearance they most likely do not have a torque plate either. A torque plate is a necessity for building a 5. 9 properly, regardless of what any says. The only ones that will argue otherwise have not seen the difference first hand. A good machine shop would know what the metal properties are of the piston and know what the expansion rates are and at the very least have a good feel for what the clearances should be at.

Not too mention there is more to it than the metal composition. They should also be asking you what you have for performance and what you do with the truck. A street engine will have entirely different clearances than a motor that was built for performance

 

[TCluff]

a good machinist will make all the parts work together by using specs, like, this piston goes in that hole and that piston goes in this hole, etc. he will bore or set sleeves according to size of piston or sleeve, there really is no exact spec on a high performance engine, parts are mass produced so each part is a little off in size, a good machinist will machine to clearance so each hole might be a little different in size

 

[GCroyle]

I'm no machinist, just a comment.

Working in the Automotive Aftermarket supplying parts, one of the worst starting points for a project is when a customer buys their parts and then takes them to a shop for installation. The shops have a tendency to stand behind their labor, but the parts are your problem.



I don't take my eggs and bacon to a restaurant and hand them to the cook.



Just my $. 02, good luck with your engine.

 

[DerekW]

Working in the Automotive Aftermarket supplying parts, one of the worst starting points for a project is when a customer buys their parts and then takes them to a shop for installation. The shops have a tendency to stand behind their labor, but the parts are your problem.



I don't take my eggs and bacon to a restaurant and hand them to the cook.



Just my $. 02, good luck with your engine.

you've got a point. Its more of a hassle when customer supplies parts thats why alot shops wont do it. then again some shops dont instal the stuff you give them and let it sit around EH HEMMM!!! (somebody)

 

[KHaines]

I understand what you are saying, but when you get into the high performance market things change. I wanted a cam, fluid dampner, coated pistons, & other things. This machine shop had no problems with me suppling the parts. They are basicly saying, you supply the parts, you should also supply the specs. Is that unreasonable?



Im spending alot more money than buying a couple eggs. Lets keep this apples to apples.

Working in the Automotive Aftermarket supplying parts, one of the worst starting points for a project is when a customer buys their parts and then takes them to a shop for installation. The shops have a tendency to stand behind their labor, but the parts are your problem.



I don't take my eggs and bacon to a restaurant and hand them to the cook.



Just my $. 02, good luck with your engine.

 

[Hawk]

What specs are they looking for? Ring gap, torque specs?



I do agree that they must have a plate on the block when boring. IF your using stock pistons and the bore is good then you should only need to re-hone and go from there.



And as far as you bringing parts I don't see the problem. I know that myself and my customers don't have money to throw around so getting parts as money permits and finding your own deals help out in the wallet dept. .

 

[Motorhead]

CYLINDER BORE DIMENSION CHART
DESCRIPTION MEASUREMENT
BORING DIAMETER DIMENSION 1st. REBORE - 102. 469 mm (4. 0342 in. )
2nd. REBORE - 102. 969 mm (4. 0539 in. )
HONING DIAMETER DIMENSIONS STANDARD - 102. 020 ± 0. 020 mm (4. 0165 ± 0. 0008
in. )
1st. REBORE - 102. 520 ± 0. 020 mm (4. 0362 ± 0. 0008
in. )
2nd. REBORE - 103. 020 ± 0. 020 mm 4. 0559 ± 0. 0008
in. )​

CHAMFER DIMENSIONS Approx. 1. 25 mm (0. 049 in. ) by 30°

This was taken from the DODGE 2006 factory shop manual