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View Full Version : Mahle 155* vs Stock


Blackbumper
05-09-2007, 01:34 AM
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.

AsTroSS
05-09-2007, 06:32 AM
How much you payd of Mahle 155 pistons?

joefarmer
05-09-2007, 04:23 PM
Very pretty! It looks like the top ring land is moved down... how much? How much lighter are they?

bnraond.

Bobcat698
05-09-2007, 05:20 PM
Those look familiar!

oldsmokey97
05-09-2007, 05:58 PM
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

joefarmer
05-09-2007, 07:12 PM
Thanks... was it in a thread or emailed?

brnaodn.

Burner
05-09-2007, 07:37 PM
The difference........ummm, got meat? Those look really nice. :rockwoot:



I wonder how they will affect your rev-gain? :poke:

Blackbumper
05-10-2007, 12:13 AM
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

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.

AsTroSS
05-10-2007, 08:36 AM
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.
I will try to find them from my home computer

Randall12v
05-10-2007, 10:32 AM
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.

AsTroSS
05-10-2007, 11:08 AM
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.

http://www.competitiondiesel.com/forums/photo/data/500/medium/172-7211_IMG.JPG

gunracer1
05-10-2007, 12:27 PM
that is the full fledged marine version, last time i priced them they were 175 bucks each with rings.

Blackbumper
05-10-2007, 03:37 PM
Very pretty! It looks like the top ring land is moved down... how much? How much lighter are they?

bnraond.

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.

joefarmer
05-10-2007, 04:09 PM
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.

luke h
05-11-2007, 12:18 AM
Brandon you going to TS. Also, you have a PM!
Luke

Hammer Down
06-07-2007, 04:13 PM
If you swap to these mahle pistons does it effect drivability and if so in what ways.

Voodoo Trucker
06-10-2007, 02:18 AM
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.

PRattenbury
06-10-2007, 08:28 AM
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

John Robinson
06-11-2007, 11:06 AM
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.

http://www.competitiondiesel.com/forums/photo/data/500/medium/172-7211_IMG.JPG
http://cgi.ebay.com/ebaymotors/Cummins-6B-Pistons-and-Rings-New-Quality-Set_W0QQitemZ260126807291QQihZ016QQcategoryZ33623Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem 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?

John Robinson
06-11-2007, 11:17 AM
http://cgi.ebay.com/ebaymotors/Cummins-6B-Pistons-and-Rings-New-Quality-Set_W0QQitemZ260126807291QQihZ016QQcategoryZ33623Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem 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? update: 3800756 cross`over to a moly part # 286140-wr. The price is 114.00 per hole.

John Robinson
06-11-2007, 11:49 AM
update: 3800756 cross`over to a moly part # 286140-wr. The price is 114.00 per hole.
Welp, one more thing. I found the original part # 3800756 for $110.00 with rings at Edwards Equipment. 817-573-7755 is their #

Amish Elegance
06-11-2007, 12:15 PM
Welp

:hehe: You freekin Rock John. :rockwoot: I'm keepin that one... "welp" :rockwoot:

joefarmer
06-11-2007, 04:03 PM
Welp, one more thing. I found the original part # 3800756 for $110.00 with rings at Edwards Equipment. 817-573-7755 is their #
That's a lot better than the price I found. The one I found was ~160 a hole.

branodn.

Ridemywideglide
06-11-2007, 08:33 PM
I got my engine kit from those people... I will tell you they are G R E A T to deal with.. But the pistons in the auction are not the marine version and are not coated.. I'm sure they can get them but you'll have to get ahold of them to be sure..

But I have to re-iterate.. they are great people and I had ZERO issues with them..

My $.02

Brad

Red Stroke
06-12-2007, 03:45 PM
Voodo Trucker, I am having the same symptoms with my truck with these pistons. Turning down the fuel never got rid of the black smoke? Was it unstreetable smoke, or liveable? Even with the valet on I get excessive black smoke.
Thanks in advance. Adam

Red Stroke
06-12-2007, 03:57 PM
Here is a video of the valve reliefs being cut in my mahle pistons
http://s40.photobucket.com/albums/e228/RedStroke/Superduty%20Cummins/?action=view&current=MOV01635.flv



http://s40.photobucket.com/albums/e228/RedStroke/Superduty%20Cummins/?action=view&current=MOV01635.flv (http://s40.photobucket.com/albums/e228/RedStroke/Superduty%20Cummins/?action=view&current=MOV01635.flv)

Jim Fulmer
06-13-2007, 09:20 AM
Welp, one more thing. I found the original part # 3800756 for $110.00 with rings at Edwards Equipment. 817-573-7755 is their #

John, what did or does the Mahle pistons cost! Are the ones your talking about that much better......stock bore! I seem to be having good luck with the Mahle (I'm guessing) that PDR put in my short block.

Jim

luke h
06-14-2007, 10:59 AM
Im interested in what pistons everybody is running and how well they perform to different injector/timing configurations. Anybody running the teflon coated skirt marine pistons? Im going to be going together with my motor shortly and cant decide on pistons.

sniperonhigh
06-20-2007, 02:50 PM
Welp, one more thing. I found the original part # 3800756 for $110.00 with rings at Edwards Equipment. 817-573-7755 is their #


Found the part # 286140-wr here, got quoted $99.00 each with rings.http://www.internalengineparts.com

John Robinson
06-20-2007, 03:33 PM
John, what did or does the Mahle pistons cost! Are the ones your talking about that much better......stock bore! I seem to be having good luck with the Mahle (I'm guessing) that PDR put in my short block.

Jim
I found the mahle pistons for $325.00 per set on e-bayI dont have any I dea if they are any "better" but they do have the coating on the sides. Jim have you or anybody else ever measured the cc of these pistons with .060 shaved off ?

luke h
06-20-2007, 06:46 PM
I messaged a guy about these
http://imagehost.vendio.com/bin/viewimage.x/00000000/ncarmysurplus/DSC01536.JPG?vvid=65501108&allow_track_link=1&track=0237e0f502-e2248&sp=1
http://imagehost.vendio.com/bin/imageserver.x/00000000/ncarmysurplus/DSC01538.JPG
But he couldnt get them for a 5.9.

John are the Mahles on ebay the stock ones from car city engine.

Is anybody at all running the Mahle Marine coated pistons in a street truck! Ive heard the compression was to low for street by the time you have them fly cut.
:thankyou2:

AsTroSS
06-21-2007, 01:58 AM
I messaged a guy about these
http://imagehost.vendio.com/bin/viewimage.x/00000000/ncarmysurplus/DSC01536.JPG?vvid=65501108&allow_track_link=1&track=0237e0f502-e2248&sp=1
http://imagehost.vendio.com/bin/imageserver.x/00000000/ncarmysurplus/DSC01538.JPG
But he couldnt get them for a 5.9.

John are the Mahles on ebay the stock ones from car city engine.

Is anybody at all running the Mahle Marine coated pistons in a street truck! Ive heard the compression was to low for street by the time you have them fly cut.
:thankyou2:

Whats the Cummins PN?

Jim Fulmer
06-21-2007, 02:59 AM
Jim have you or anybody else ever measured the cc of these pistons with .060 shaved off ?

Not a clue, Piers told me about 15.5 compression with my .008 milled head and a .010 over gasket.

Jim

luke h
06-21-2007, 10:27 AM
Jim, Which Mahle pistons do you run. How much fly cutting was done.

luke h
06-21-2007, 10:29 AM
Part No. is 4020059
They are for a marine 8.3l
They look nice though!
http://cgi.ebay.com/Cummins-SmartPower-Piston-Kit-Marine-Engine-6CTA8-3M1_W0QQitemZ300117309374QQihZ020QQcategoryZ50441Q QrdZ1QQssPageNameZWD1VQQcmdZViewItem

John Robinson
06-21-2007, 11:51 AM
I messaged a guy about these
http://imagehost.vendio.com/bin/viewimage.x/00000000/ncarmysurplus/DSC01536.JPG?vvid=65501108&allow_track_link=1&track=0237e0f502-e2248&sp=1
http://imagehost.vendio.com/bin/imageserver.x/00000000/ncarmysurplus/DSC01538.JPG
But he couldnt get them for a 5.9.

John are the Mahles on ebay the stock ones from car city engine.

Is anybody at all running the Mahle Marine coated pistons in a street truck! Ive heard the compression was to low for street by the time you have them fly cut.
:thankyou2:
Yes they are from car city. I have not actually ever bought any mahles. 2 days ago I ordered a master overhaul set for a 12v for 525.00 from these guys, they seemed nice enough. I`m sure this ia a knock off kit but for the truck it is going in it should be fine. I`ll let everybody know what the quality looks like when it gets here. A little fyi. I`m going to cc the cummins mariene piston both ways. The cc of the bowl & the cc of the top of the piston. This will be with .060 cut off the top. When I get a solid # there We will get a accurate comp ratio with a .020 gasket

luke h
06-21-2007, 04:30 PM
Well in stock unmolested form they have a 53.0 cc bowl

Ridemywideglide
06-21-2007, 10:17 PM
Yes they are from car city. I have not actually ever bought any mahles. 2 days ago I ordered a master overhaul set for a 12v for 525.00 from these guys, they seemed nice enough. I`m sure this ia a knock off kit but for the truck it is going in it should be fine. I`ll let everybody know what the quality looks like when it gets here. A little fyi. I`m going to cc the cummins mariene piston both ways. The cc of the bowl & the cc of the top of the piston. This will be with .060 cut off the top. When I get a solid # there We will get a accurate comp ratio with a .020 gasket

Same kit I ordered from them.. Everything seemed fine.. Have a Cummins HG sitting in my room incase I blow the gasket from the kit in the future, but so far I've got just over 2k on it with no issues or funny noises..
AND no more leaks :rockwoot:

Jim Fulmer
06-21-2007, 11:05 PM
Jim, Which Mahle pistons do you run. How much fly cutting was done.

Don't know the part number, either .050 or .060 milled off the top, no valve relief. It will clear a .550 cam lift with a .020 gasket easy.

Jim

luke h
06-22-2007, 12:53 AM
Jim thanks for your reply!
I think I will be going with the marine pistons from piers. I will be running a .450 lift cam but plan on getting enough taken off that I can go bigger in the future. How well does the .550 cam act on the street. Do you know the duration?
Thanks for the help. I really want to get this build done right the first time since ive had so many problems with the truck!
Luke

Jim Fulmer
06-22-2007, 02:50 AM
Jim thanks for your reply!
I think I will be going with the marine pistons from piers. I will be running a .450 lift cam but plan on getting enough taken off that I can go bigger in the future. How well does the .550 cam act on the street. Do you know the duration?
Thanks for the help. I really want to get this build done right the first time since ive had so many problems with the truck!
Luke

450? A Stock cam is like 430/470! I'm not running that cam now, I have a stocker in there.

The first big cam sucked on the bottom but pulled really hard on top, so they made some changes to the grind and it was much better but still needed some tweaks to make it perfect.

Are you calling the Marine pistons the same ones I'm running! Marines' are fine but the compression is lower.

Jim

Burner
07-02-2007, 01:06 AM
What gains?

gunracer1
08-31-2007, 05:19 PM
ok what would be the compression ratio of a .020 over with a stock thickness head gasket and a 60cc piston bowl.

gunracer1
08-31-2007, 05:21 PM
and this thread needed to be brought back up for a read. and what about some piston from p.a.i. in georgia???????

f6jbob
09-02-2007, 04:36 PM
Do a google for "how to calculate compression ratio. It will bring up a couple of good sites. The combustion chamber volume is 6.8cc and the head gasket diameter is 4.160". The 2 short blocks I have sitting here have piston above deck measurements of .028. Stock 94 to 98 pistons have 45cc bowls. Marines are 53cc like somebody already mentioned. Jim

f6jbob
09-02-2007, 04:40 PM
I forgot about the head gasket. Stock head gasket is .060. I just received a set of pistons Friday from PAI in Suwanee, Ga. Jim