Mahle 155* vs Stock

Blackbumper

Blackbumper

Could be worse!
Joined
Dec 30, 2006
Messages
364
Just thought I would post a couple of pics for people wondering the difference between the stock piston and the Mahle 155* the size of the bowl is visably different. Just FYI.
 

Attachments

  • P1010780.JPG
    P1010780.JPG
    54.2 KB · Views: 189
  • P1010781.JPG
    P1010781.JPG
    54 KB · Views: 172
  • P1010784.JPG
    P1010784.JPG
    52.1 KB · Views: 321
  • P1010782.JPG
    P1010782.JPG
    38.4 KB · Views: 143
Very pretty! It looks like the top ring land is moved down... how much? How much lighter are they?

bnraond.
 
with the 155* pistons, im guessing that you could run MORE timing and still be decently spraying in the bowl of the piston and not on the outer sides of it??? correct?

Lance
 
The difference........ummm, got meat? Those look really nice. :rockwoot:



I wonder how they will affect your rev-gain? :poke:
 
oldsmokey97 said:
with the 155* pistons, im guessing that you could run MORE timing and still be decently spraying in the bowl of the piston and not on the outer sides of it??? correct?

Lance
Click to expand...

Lance that is the plan I hopeing to run some decent timeing with this motor and still have the injector to piston combo functioning as it was designed.

Smokem I won't be makeing the trip still waiting for the baby to show up should be anytime......

I will try and take the pistons over the the shop and weigh them to see the difference.


Cost, let's put it this way they are priced very well compared to a stock piston from cummins or the marine version. I got my set from Harry at Piers but since he is no longer there you can talk to Mark or it would be nice to see if any of the supporting vendors can get these.

Overall I am very happy with the quality and design of these pistons we will just have to see what my opinion is next year when I tear it back down. My only concern with these is that I just got done reading the cummins book on my motor and in 94' they had three different grades of pistons A B and C. According to my part number on the old piston it looks like they are a grade B which has a .024-.028 protrusion I measured to the best of my ability the wrist pin to top height on the new and old and they match up fine so I will just have to check when they are actually in the motor.
 
Last edited:
Smokem said:
They have the same ring landing as the Marine piston, Astross and I had a conversation about this, I did not save the ring landing measurements but I am sure he has them.
Click to expand...
I will try to find them from my home computer
 
what is the reasoning for using the Mahle pistons over stock? I'm assuming it is better to use them when running bigger injectors with larger spray pattern? also where do you obtain these pistons? Are they better used for pulling/racing? or does that even matter.
 
Ok, here they are :

First compression ring from top: 10,5 mm
Second compression fring from top: 17 mm

Oil ring from top: 33mm

Piston bowl teph: 18mm

Piston bowl diam : 64 mm


Piston part number: 3800756 (Cummins Marine 370)

Teflon coated side skirt and steel insert for bouth compression rings.

172-7211_IMG.JPG
 
that is the full fledged marine version, last time i priced them they were 175 bucks each with rings.
 
joefarmer said:
Very pretty! It looks like the top ring land is moved down... how much? How much lighter are they?

bnraond.
Click to expand...

Just got back from the shop and had a chance to throw them on the scale.
Stock Piston with wrist pin and rings = 1957 Grams
Mahle 155* with wrist pin and rings = 1771 Grams

The Mahle is close to 10% lighter.
 
THanks for the specs AstroSS... I wanted to compare them to the RV275 that arrived Monday.

It seemed like Mahle's had more reliefs in the casting, but I didn't know if it was extra material or if it had material left off. Does this mean you'll take 10% out of the crank counter weights? Is that how complete rotating assemblies are balanced together?

brnaond.
 
The piston BP is showing was used in the early non-intercooled Dodges (89-90). I tried putting them in a customers 97 Dodge 2500 4x4. I could not get the black smoke to clear up from 0-8 psi of manifold pressure. I tried everything to clean up the smoke. I played with the AFC, timing, injectors, etc. I ended up pulling the motor and putting in the stock pistons. Once the stock pistons where put back in the problem was cured. I think the problem was due to improper air swirl, ether too high or too low for how the truck was configured (lifted, ATS trans, 35 tires 3.54 gears) and the injection rate of the 911 P7100 pump. I almost tried putting a early 94-95 injection pump in that I had. Thinking that the higher rate of injetion of the early pump might help. By that point I was tired of messing with it.
Mahle pistons are good pistons, there was nothing wrong with the ones I put in, they where just the wrong ones for the application I was trying to put them in. Mahle makes all different flavors of 5.9 pistons. They have the 370 marine pistons with the coated skirts. They are just as good as the Cummins and come with new wrist pins and rings. I like Mahle rings better then the ones that come with the cummins.
It sucks to pull a motor and change out pistons just for smoke you can't get to clear up.
 
I was told stock pistons were made by Mahle anyway. Of course, like pointed out earlier, Mahle makes lots of different styles for the 5.9
 
AsTroSS said:
Ok, here they are :

First compression ring from top: 10,5 mm
Second compression fring from top: 17 mm

Oil ring from top: 33mm

Piston bowl teph: 18mm

Piston bowl diam : 64 mm


Piston part number: 3800756 (Cummins Marine 370)

Teflon coated side skirt and steel insert for bouth compression rings.

172-7211_IMG.JPG
Click to expand...
http://cgi.ebay.com/ebaymotors/Cumm...ryZ33623QQssPageNameZWDVWQQrdZ1QQcmdZViewItem I called these folks this am & the cummins # 3800756 crosses over & cost $348.00 a set ?? I am having him Pull one & make sure it is coated. He will call me later. Anybody know anything?
 
You must log in or register to reply here.
Top