PK Rebuild After Top End Failure

[Fabian]

The pics i have are of the damaged bearings.

Initially, i bought a few caged needle roller bearings and pulled the rollers out with the intention of setting up the crank to run a crowded roller arrangement.

Never got around to doing it though, as the shop where i bought my engine from, gave a very good deal on replacement engines, as i was providing them with valuable info and hi-resolution photos of where engine damage was occuring.
This info was personally delivered to the Nantong Jali factory in Japan, and they decided to go the route of using a crowded needle roller bearing, as it was the cheapest and most effective solution.
Having said that, the factory was already in the process of converting to the crowded roller bearing setup, as it was the only thing left for them to change, as they had significant numbers failing in their prime export market - America.
The photos, just confirmed that they were going in the right direction.

Fabian

 

[210061741]

Ok that's cool.

Ya i like the crowded / Full complement bearing.
Stays alot tighter and i never had 1 fail yet.

But there are lots of options. I was incorrect about my earlier statement.

I measured up several rods and bearings and here's what i found.

-------------------------------------------------------------------------------
GT-5 AF = CON ROD MARKINGS "ZAF60"

bearing = K16X22X12 and are available.
http://medias.schaeffler.de/medias/hp.ec.br.pr/K*K16X22X12;aI-KogwPZIu5?clrsb=1 K16x22x12 $8.00
INA are considered 1 of the best.
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
GT-2B = CON ROD MARKINGS "ZAE50"

bearing = K16X22X12 and are available.
http://medias.schaeffler.de/medias/hp.ec.br.pr/K*K16X22X12;aI-KogwPZIu5?clrsb=1 K16x22x12 $8.00
INA are considered 1 of the best.
-------------------------------------------------------------------------------

PK Cranks vary.
-------------------------------------------------------------------------------
PK80-J = CON ROD MARKINGS "ZAE50"

bearing = K16X22X12 and are available.
http://medias.schaeffler.de/medias/hp.ec.br.pr/K*K16X22X12;aI-KogwPZIu5?clrsb=1 K16x22x12 $8.00
INA are considered 1 of the best.


PK80-J = CON ROD MARKINGS "ZL" (WITH CAGED BEARING)

bearing = K16X20X10 and are available.
http://medias.schaeffler.de/medias/hp.ec.br.pr/K*K16X20X10;a5b0myRjccb8?clrsb=1 k16X20X10 $3.81
INA are considered 1 of the best.

PK80-J = CON ROD MARKINGS "ZL" (WITH CROWDED BEARING)

bearing = CROWDED 2.5MM x 10MM NEEDLE ROLLERS.

OR

http://medias.schaeffler.de/medias/hp.ec.br.pr/K*K16X20X10;a5b0myRjccb8?clrsb=1 k16X20X10 $3.81

IF YOU WANT TO GO ALL OUT COULD MAKE THESE WORK.

http://www.treatland.tv/puch-moped-con-rod-kit-crankshaft-p/puch-crankshaft-con-rod-kit.htm

https://www.1977mopeds.com/product/2055/Puch-Roller-Crank-Rod/

And last but not least the pics of everything.

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11229.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11231.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11230.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11232.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11233.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11234.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11235.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11236.jpg

http://i887.photobucket.com/albums/ac72/RidingRich/crankshafts/SDC11239.jpg

I called erie bearings and the INA Bearings are available.

 

[210061741]

Posted by Fabian and fits good here. Good data all in 1 place. Yessssaaaaa !!!

Rich, you can also go the route of changing the crankshaft pin to 17mm, from the standard 16mm, and run a better caged needle roller bearing measuring - K17 x 10 x 21

The advantage of doing so, is to be able to offset bore the pin hole in the crankshaft halves, so giving an extra 1mm of stroke, or you could use an 18mm offset pin bore for 2mm of extra stroke, by line boring the connecting rod to 22mm and having it case hardened again.

I went through all these options a long time ago and in the end the best method was to use a Suzuki LT80 connecting rod, which has a larger big end diameter but the same centre to centre length as the standard Happy Time rod.

Fabian

 

[210061741]

One other note about the connecting rods.

The center to center distance is different between them.

The GT-5 AF has a longer rod but a shorter stroke than the PK-80.

The PK80-J rod is about the same length as a GT-2B 50cc engine.

I'll post the exact lengths and respective strokes later.

 

[210061741]

Now a couple of other things to consider here.

The center to center length of the connecting rods changes the Con rod to Stroke Ratio.

That affecte the port timing of the engine and the angle of the con rod.
Less con rod angle = more efficcent

The Pistin Pin offset compensates for the difference in lengths.

So remember the pistons are different.

 

[Fabian]

I certainly like the look of the Puch Roller Crank Rod

Rich, where abouts are you up to with production of reed valve intake cylinders for the 69cc engines (47mm bore size).

Fabian

 

[210061741]

Fabian

I am Unemployed and since i got screwed by Pirate Cycles i'm not doing any production.

I was the brain and he was the money.

So you see i don't have the money.

I have offered to build you the engine if you sent the parts i needed to do it.
I have offered to give you a parts list and instructions to do it yourself.
You pay for it and i'll build it.
Heck i won't even charge you labor just because i'll have so much fun building it.

And i mean that.

If you look at the logistics of the situation heres the deal.
I have been running the reed valve modifyed cylinder..and it is awesome.
Between the portwork involved and the welding of the block to the cylinder it is very time consuming. And the crappy thing is your still left with a cheaply plated cylinder that won't last.

So if you want it buy the Puch Top End Kit. $120.00
I have 1 and it is really nice quality.
Has a 3 transfer port and a nikisil lined bore.

Definatly worth the effort.

+ you get a new much better piston.

If you want an engine get me the parts and i'll build it.
I won't charge you any labor and i'll post details the whole way.

For now thats the best i can offer you.

In a couple of mothns when i get a big settlement and have the cash i may start my own thing.

 

[Skyliner70cc]

Rich,
Based on pirate's latest change to their performance engine website (no porting, no reed valve intakes, etc..), I'm thinking you were the brains behind the operation. I wish you luck and hope you are succcessful in producing a high pwoer HT engine.

 

[Fabian]

Hi Rich,

So whats the go here.

After you get your divorce settlement, will you be adapting Puch top end parts to fit on the Happy Time style bottom end?

or

Will it be a Puch top end on a completely redesigned bottom end?

How will it work engine installation work with those who already have a SickBikeParts shift kit, or will you be designing your own custom shift kit to fit your specific engine combination?


Fabian

 

[Joeeastman]

Hey, do any of you guys know exactly what motor used the crank with the ZAF60 con rod and where I could get a replacement? I need one badly! Thanks

joe