For Sale New 91.1mm Pistons and Rings

[frankendat]

I attempted to post this to the classifieds section, twice, without success.

 

While researching pistons and ring combinations for a Z24 block, I came across an number of postings, across different message boards of using 91.1 pistons from a different brand of automobile to increase  compression and create a 2.5 liter engine. I have been attempting to contact the original creator of this project without success. Also, the more I researched, the more it seemed as if the original creator had purposefully excited the Nissan engine world. I sent a final message, offering to pay for his consultation, without response.

 

 Although I cannot be certain the communications got through, I do not begrudge the man his privacy and stopped pursuit. Without guidance, disregarding bore limits and factory recommendations, makes me uneasy.

 

Unfortunately, what I believe  was an excellent deal on the pistons and rings came up, before I realized that the original creator was no longer participating. There should be enough information on the collection of message board posts pasted below to complete the project, for someone with more knowledge than I.

 

Product information

Silvolite 1288 Std Engine Piston Set 2.6L Chrysler/Mitsubishi 1981-89/1984-89

Made of high strength alloy & silicon, Feature--Hypereutectic, Feature--Designed to retain standard ring gaps in top groove, Feature--Utilizes ISO & QS certified manufacturing, Description--Engine Piston, Feature--Higher strength than cast

 

MFG:Chrysler/Mitsubishi

YEAR RANGE:1981-1989

ENG. DISP. IN.:156

ENG. DISP LITERS:2.6

CROWN TYPE:FLAT TOP

RING SIZES:2-1.5mm,1-4.0mm

BORE MM:91.1

PIN DIA MM:22.0

CYLINDERS:L4

PIN CONFIG.:offset

O.E. ASSEMBLY:MD071172, MD026921

INTERCHANGE:FM H605P

 

Hastings Engine Piston Ring Set- 5667

ENGINE FAMILY:Mitsubishi 4-cylinder

BORE INCH:3.587

COMP. HT. IN:1.418

PIN DIA IN:.867

 

PRICING INFORMATION

I paid $80.50 for the pistons and rings in August

Pistons and rings were not installed "New"

-25% Fool and his money tax.

= $60.00 Free Shipping to the lower 48.

 

Here is the collection of relevant message board posts uncovered by my research. NOTE: Many, if not all, of the posts are written in first person. The person is the original creator. I have no additional information.

(remember the posts are often from different websites or different discussions)

 

naturally you would think that you cant have that piston edge protruding 2mm above the deck surface, and interfering with the combustion chamber edge and headgasket. There is a option to fix this (again aside from shorter rod or piston), and that is to machine the edge of the piston away to clear the headgasket and combustion chamber edge.

 

As far as good oem type aftermarket headgaskets, I would suggest an ITM or ROL gasket over a fel-pro anyday. Felpro does not make the greatest gaskets, we've compared a lot, and do not install felpros on any of our rebuilt engines.

 

For a top of the line oem type replacement gasket in standard thickness, check out rolmfg.com. BTW. they also carry replacement headbolts for ka24e/de. I use this headgasket/headbolt combo on my 2.5l (91.1mm bore). Specs of the gaskets are perfect (i compared about 5 different headgaskets to use on my engine, including a blue line felpro)

 

(With a 91.1 bore) between bores is reduced .080". i have been running for about 2 months with absolutely no problems. i know of one other ka24e (non-turbo of course) at 91mm bore than has been running for over 7 years. no sleeves, i dont really want to tell everyone what my pistons are but they are from different car manufacture, they have a 36.1mm comp. ht, 2 - 2mm cast iron compression rings, 22mm press fit pin, and are flat top. i have no pics but you can imagine the distance between bores reduced .080" so there is very little room for the headgasket. the headgasket actually protrudes into the cylinder a few thousands. the pistons must be modified along with the ka24e rods. took quite a bit of extra thought and machining processes but still well worth it compared to price of other high comp. ka24e piston set.

 

I think im the only one with 2.5l ka? Mine is 2502cc and i achieved this with a 91.1mm bore and stock stroke. It is also rumored that the nismo built CORR racing ka's are 2.5l, although i think this is a marketing ploy, the 2005 frontiers have the 2.5l qr and the 2005 bodied race trucks use ka's.

 

The reason i built the 2.5l was simple at the time, I needed high compression sohc ka pistons that I could find affordably. Boring to 91.1 was a side effect of the 10.5:1 compression ratio that i was after. In order to fit the pistons they had to be modified, both the skirts and the tops. The top edge is machined away so that it clears my headgasket and edge of combustion chamber. The block is a japan rwd 240sx sohc block, which is just about the worst candidate for the 91.1mm bore, the mexico cast ka blocks have thicker cylinder walls. The main point of concern on both blocks is the cooling passages that run between bores 1/2 and 3/4, at 91mm bore the cylinder wall is the thinnest at this point. I was very concerned with hotspot issues, although everything is speculation until it is tested, so i did. It has been running perfectly for 15k miles, 2 years.

The pistons i used are mitsubishi 2.6l I4 pistons, not the starion, but the early model of the mazda/mitsu 2.6l with the flat tops. They are .060" taller compression height, compared to oem nissan 2.4l. The piston pins are also 22mm vs. the 21mm stock nissan pins. My rods were machined for the pins and then press fit. The skirts also had to be clearanced and all piston weights matched after modifications.

 

These pistons are also used in the early model of the dodge caravan 2.6l.

 

Also, a headgasket with 100% proper bore spacing is required, youd actually be surprised how off some are when your comparing a stack of different manufactures. I found ROL to be the best and thats what i use.

 

END OF COLLECTION OF POSTS