Engine/Transmission (1998.5 - 2002) pistons???

[dodgediesel91]

if im boring it over do i need to worry about the grading scale?

 

[Bob4x4]

yes... ... ... ... .

 

[Bob4x4]

the a, b, c, grade on the pistons mean that each one is a little larger than the std piston. a is 1 or2 thousands larger than std, b is 1 or 2 thou larger than a, c is 1 or 2 thou larger than b . I do not know how many grades of pistons cummins uses. they use them if the cylinder is smooth, round and within the taper tolerance, and the cyl just needs honeing. the proper cyl to piston clearance can usually be made up using the proper grade piston. if the cyl is not in spec for out of round, taper, and finish, for a grade a, b, c, piston, the cyl must be bored and honed to fit the next oversize piston. now you know the REST of the story !!:-laf

You might want to delete your post to reduce confusion... ... ... .

 

[dodgediesel91]

I have a membership to quick serve cummins when I put in my serial number there's only grade a,b,c for for standard bore, 20 and 40 over kits are just 2 different kits they don't have an a b or c for them ?

 

[KrisKringle]

HO Pistons...maybe just leave well enough alone.

Jeepers...I have a headache. It would appear I have to take the engine apart first to see what grade pistons are in it, then order them...Here in Germany that could be a problem. The truck is my daily driver and down-time is not really possible.
I am wondering if Cummins has a record of the building of the motor and what is in it. I registered on Quick Serve, it came up with the VIN from my truck, so maybe they have even more data.

Started to wonder about putting the HO pistons in my non.HO motor, and stumbled on this thread. Wow...I maintain a stock for critical parts and sensors...No VP though..coming up on 200K, and noticed that the motor does not "chirp" the belts like it used to, so I was wondering about compression loss. However, blow-by (tea-kettle with the filler cap) is negligible.

Probably best to leave well enough alone, and just do the Valve seals and set the valves while I am at it.

 

[Vaughn MacKenzie]

Well, I believe some of the information in this thread is not correct, I am pretty sure the piston grading thing did not start until 2006.5 with the 555 Cummins. At least it's safe to say they did not do it with the VP44 or the 12-valve engines. There is definitely a benefit to going with the HO pistons since it raises the compression since the non HO VP44 engines were only 16.3:1 CR whereas all others are at least 17:1.

 

[KrisKringle]

thought so.

Well, I believe some of the information in this thread is not correct, I am pretty sure the piston grading thing did not start until 2006.5 with the 555 Cummins. At least it's safe to say they did not do it with the VP44 or the 12-valve engines. There is definitely a benefit to going with the HO pistons since it raises the compression since the non HO VP44 engines were only 16.3:1 CR whereas all others are at least 17:1.

I am planning on going over the engine this winter when I have some down-time. Although it is a 2001, it is in great shape, and I am serious when I tell people this is my last truck...So I figured that the extra compression would not be a bad thing if I am tearing it down to do a re-ring and "freshen up."

Thanks again for the info.

 

[KrisKringle]

Picture of Shaun in Holland...

I am planning on going over the engine this winter when I have some down-time. Although it is a 2001, it is in great shape, and I am serious when I tell people this is my last truck...So I figured that the extra compression would not be a bad thing if I am tearing it down to do a re-ring and "freshen up."

Thanks again for the info.

Here is a picture of Shaun in Holland

 

[Vaughn MacKenzie]

The Deutschland Dodge, I like it...short box 2wds have always been my favorite, have had 5 of them (one 3rd gen and 4 second Gens)!

 

[Bob4x4]

Piston grading was done in the oem pick up engines,however as I stated above the graded pistons were not always available for service replacement.When it comes to adding compression by replacing pistons,more power can be obtained from adding boost.