Mystery Pistons...Can you guess what these are and their use?

[rick m]

I have always liked running new and different things. These are parts for a motor I am building but I will not give you all the details of the combination.  See if you can guess what these are.  Guess the size, type, composition, use, etc.

Let's test your motor knowledge and the mods on the piston and why.  For many of you this is a no brain-er but we can share the knowledge with others.

Rick Mortensen

[RFbuilt]

hmmm chamber is counter bored wee bit smaller than the pistons bore

dished  for lowering compression


teflon/moly coated skirt? 


LOL thats my best and im betting im wrong 

[Zach Gomulka]

Looks like a small bore, and judging by the pin height, set up for a long stroke. Square engine?

[Donny B.]

Maybe it's for a motorcycle engine....

[Zach Gomulka]

Maybe it's for a motorcycle engine....

Maybe, but I would guess that a bike engine would use slipper skirts, that is if it's "modern"

[RFbuilt]

im curious  as to why the "crown" of the piston is how it is..

pinheight is rather normal i guess, we can find B or A units even in 85.5mm sizes

[Donny B.]

Maybe he's rebuilding the diesel generator for his motorhome....

[rick m]

Don,

That was funny! Motor home generator on steroids!  Nope, but some close comments.

Definitely coated pistons. The top (recessed area) is ceramic coated. Definitely strokers for up to 84mm. They are indeed 85.5's and forged. And Zak was close, using for a square motor.

I've turned a few friends on to these as well.  They do not come with all the mods made to them or the coating but are reasonably priced at around $145 a set, with barrels, pins and pistons with rings.

For those of you running ZERO deck, the top (exterior) of the piston is trimmed for ZERO deck while running a .060 copper gasket between the top of the barrel and the cylinder head. 

These mods work great for any size piston on a street motor. My 2110, in my teal 67, also ran pistons with similar mods.  I used the thick crown 90.5s I had purchased from the BERGs years back in order to modify the top of the pistons.  I ran 8.3 static compression and ran pump gas with no detonation issues or overheating.

Rick M

[RFbuilt]

sounds good!  the only thing i nailed was the skirt coating HAHAHA

good price on those btw.. are they orderable (nice word LOL)  in other bore sizes?


that 85.5  sounds nice with a 74  , makes a narrow  "mouse" 1600 LOL

[RUSS74GHIA]

I don't know about the piston, but the rod looks a lttle on the weak side

[The Ideaman]

Rick,

Are these the pistons I bought from you a couple years ago?

[rick m]

Hey Luke...Yes.  I don't think I had the coating and the tops cut for ZERO deck when you had them. I have since purchased a couple more sets. I am finally building that MILEAGE MOTOR I had planned on.  Steve Hollingsworth liked them and decided to build a motor that I believe is still in his blue car.

When I get the motor done and assembled, I will post some shots.  How have you been? We moved outside of Surprise on to some property where I have more room for my hobby...uninterrupted by HOME OWNERS ASSOCIATIONS. 

Surprise residents had no sense of humor when I would fire up one of my motors for the cam break in period.  :-)

Rick M

[SlingShot]

Surprise residents had no sense of humor when I would fire up one of my motors for the cam break in period.  :-)

Bastards 

[rick m]

I agree. What is it with people. Nothing like a dual carb motor on breakin. It is my type of music!

Rick M

[Taylor]

they look like To#¤ta pistons maybe 94mm?

[Dr P.]

I would have guessed Nissan. Some of the turbo models have similar pistons. A late 90's 2.0 would be a suitable 86mm. One i got hold of had some sort of hollow crown, with approx 5mm holes diagonally. Maybe for cooling or weight reduction?

Hmm, maybe i just found pistons for my next project

/Per

[rick m]

These are pistons made for VW aircooled motors. They were originally produced for some class cars for Off-Road racing. You can get them through CENTURY DISTRIBUTORS.  Here is their address and phone number:

Century Distributors
2417 E Main Street
Visalia, CA 93292
1(877)734-1574

The dish in the piston, the modification for ZERO deck and the coating is not how they come. We made those mods.  They come as a flat top piston. They sell them as a complete set with barrels, pins, pin clips, forged pistons and rings. 

Rick Mortensen