asavage wrote:The non-steel-top-ring-carrier piston will work OK in a 720. It is not an OEM piston, does not have to use identical construction or mfgr'ing techniques. It's about a quarter the cost of OEM, according to the numbers TDI_Joe was quoted: -SNIP-
In the old days, re-ringing engines and valve jobs well under 100k miles were common. But in the early '70's, the EPA began standards forcing engines to last longer before emissions exceeded limits. Notice that Nissan responded with better pistons having steel ring carriers and EGR (starting in Calif) ... in 1981. And in 1984, both SD23 and SD25, required the road draft crankcase blowby be returned to the intake manifold.
I got my Datsun with 120k miles on it ... and have added 65k more miles in 3yrs, 10 months. Whodda Thunkit? It is still running well and oil loss is still 2500-3000 miles per quart ... though I can see why EPA required a blowby closed system. hahahhaa
Without doubt, the truck has run this SD at higher rpm, harder, and longer than a typical marine / industrial version (CN4 . M4).
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
i recieved an email today regaurding a dry sleeve/block failures.
refer to rover/buick V8-mandrel cast liners in alloy block.
older engines had 3.5 inch bore-the bore size was increased as a standard in later engines.this has increased and international comments of engine failures.and coments have been made that the engine was to unreliable for mass production and landrover has now stopped using this engine.
I degas a/c for the dealer doing repairs.they send the engines to after market repairer.i have a 3.5 inch bore engine that has 4 inch piston/sleeves fitted with out problems.these are dry sleeves pressed in and water contacts in spots where the jackets have been bored into the mandrel sleeves are thin and not always in line.
a P/S on the email has statistics to segest that lean mixture and fuel quality has created this problem.also an after market company is now casting blocks to remedy the problems.from what i can see these are based on the old over engineered design.
the point is that the sleeves must be fitted corectly,some get away with slap happy.
WCJR31 Skyline.3.0 manual.wagon
R31 SKYLINE/Passage GT/PINTARA
LPG Ford Falcon 99-06 93 Disco
Local Shire Southern Zone Mechanic.
philip wrote:In the old days, re-ringing engines and valve jobs well under 100k miles were common.
In the old days, oil-bath air filters were common. Road-draft tube that can allow a direct path for dirt-laden air back into the crankcase (not on the SD22!) were common before California banning them in 1961. Lubricating oil had a very hard time being useful for a full 3000 miles. And oil filters were optional for a lot of engines.
Nissan responded with better pistons having steel ring carriers and EGR (starting in Calif) ... in 1981.
After searching around a bit, I found a picture of an aftermarket MB diesel piston that looks like it has a steel top ring carrier. Does anyone know of other diesel pistons with this feature?
Without doubt, the truck has run this SD at higher rpm, harder, and longer than a typical marine / industrial version (CN4 . M4).
Some of the ag versions are de-rated; others are rated higher output than the automotive version. Industrial engines can run at 80% or higher output for hours at a time, a non-typical situation for automotive engines.
I remember discussing piston speed and piston failure over the years.there is a magic number that you must stay within.its more to do with light load rpm or detonation.
I dont know of examples of the steel ring land insert other than old truck engines-but i think as better quality alloys became available these are not used.in older days metal rings are installed to repair damaged ring lands.engines running at constant speeds can suffer from vibrating ring,also if detonation is common.the ring groove width was modified and a thin metal spacer was installed.
during the late 70's piston failures with the holden GM 6 202 gasoline engine became common as they stoked the engine.the crown would brake off and other versions the skirt would crack.metal inserts was fitted originally.these are unheard of now as better grades of alloy became available.
WCJR31 Skyline.3.0 manual.wagon
R31 SKYLINE/Passage GT/PINTARA
LPG Ford Falcon 99-06 93 Disco
Local Shire Southern Zone Mechanic.
Nissan responded with better pistons having steel ring carriers and EGR (starting in Calif) ... in 1981.
After searching around a bit, I found a picture of an aftermarket MB diesel piston that looks like it has a steel top ring carrier. Does anyone know of other diesel pistons with this feature?
Kolbenschmidt/Mahle
Piston; With Rings; Standard 90.90mm
For models with engine serial number from 085946. These pistons are priced individually but must be purchased as complete engine set of 5 pistons. 1 per cylinder.
Cooled ring carriers for critical areas
With its cooled ring carrier, MAHLE has developed a solution for high volume production, which achieves a significant improvement in piston cooling in the critical areas of the bowl rim and first ring groove and which is already used in new engine concepts with high specific powers.
The cooled ring carrier consists of a Niresist ring carrier onto which a thin austenitic steel sheet is welded with inlet and outlet openings. Cast-in in the piston, the combined insert brings the cooling oil even closer to the combustion chamber and the first ring groove.
In contrast to salt core cooling channels, this new MAHLE solution enables a significantly better cooling of the critical areas. Similar to the transition which took place from spray cooled pistons to salt core cooling channels. MAHLE regards the diesel piston with cooled ring carrier as a pioneering innovation in technology. The series production of this piston started in 2001. By 2006, more than eight million pistons with cooled ring carriers had been produced - in 2007, MAHLE anticipates a volume of another two million.
Ford/navistar 6.9
My point is ... all vehicle diesels I found on EBAY ... show pistons with steel carrier lands. Try "diesel pistons ______" (ford, cummins, Navistar, GM, etc)
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Last edited by philip17 years ago, edited 6 times in total.
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
asavage wrote:
Liner puller. I'm going to have to rent one from Galen or Kevin to do mine. I'm not planning on doing this over and over, so a rented one is the way to go for me. I have a press that can handle pushing the liners out, but not the disk, and since they have already re-invented the OEM tool . . .
Al,
I have no problem loaning you the liner puller disk I made. I also welded up a gantry similar to the OEM but found that my liners were VERY tight. I was only able to pull one with the tool. The next liner I tried was so tight that it distorted the top channel of the gantry. Note the 4 inch channel reinforcement in the photo of the tool.
I found that my shop press worked much better, and used that method for the last three liners. Of the last three, two liners pressed out nicely but one was real tight. I would recommend the press.
The Press in of the new liners was a piece of cake. My OEM liners were a press fit and appear to me to be finished to size, note the cross-hatch in the photos of the liners.
asavage wrote:
Liner puller. I'm going to have to rent one from Galen or Kevin to do mine. I'm not planning on doing this over and over, so a rented one is the way to go for me. I have a press that can handle pushing the liners out, but not the disk, and since they have already re-invented the OEM tool . . .
Al,
I have no problem loaning you the liner puller/press disk I made. I also welded up a gantry similar to the OEM but found that my liners were VERY tight. I was only able to pull one with the tool. The next liner I tried was so tight that it distorted the top channel of the gantry. Note the 6 inch channel reinforcement in the 2nd photo of the tool.
I found that my shop press worked much better, and used that method for the last three liners. Of the last three, two liners pressed out nicely but one was real tight. I would recommend the press.
The Press in of the new liners was a piece of cake. My OEM liners were a press fit and appear to me to be finished to size, note the cross-hatch in the photo of the liners.
TDI_Joe wrote:(snip) The Press in of the new liners was a piece of cake. My OEM liners were a press fit and appear to me to be finished to size, note the cross-hatch in the photo of the liners.(snip)
With the cylinder installed, what was the piston skirt -to- cylinder clearance?
Which piston type did you use? 3 or 5 ring, steel carriers or not.
Nice work, Kevin !
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
It is still running well and oil loss is still 2500-3000 miles per quart ... though I can see why EPA required a blowby closed system. hahahhaa 
