134 piston direction?

Tony in Mass. · Jan 20, 2013

OK, for those that don't check the MF forum too. Who's misleading me? Or does the direction of the piston matter anymore? Etching/stamping on top, magic marker dots on the inside, which lead should I follow? Does it matter?

miner09 · Jan 20, 2013

If the piston has no marks or notch it doesn't matter. If wrist pins are off center mark goes toward radiator. Wrist pins in center it doesn't matter. If it has marks and you turn piston opposite it will clatter. Marks on rod goes toward distributor.

Tony in Mass. · Jan 20, 2013

Yeah Mikey, I got the rod numbers toward the cam, if the wrist pins are off center...that's sorta important eh? You think they coulda electric penciled an arrow while they did the other markings.
I will put all the top marks to the cam as well as the rod #'s tomorrow...just because of Murphy's law.... If I'm not shoveling snow again....

miner09 · Jan 20, 2013

In picture I can't see any marks or notch.Sometime there will be a arrow pointing to edge of piston. This goes toward radiator. Looks like your OK. Good luck.

Jason S. · Jan 20, 2013

All the continental pistons I have saw didn't have marks either. I do believe the wrist pin is centered on those engines.

Inno · Jan 20, 2013

All the pistons on my TO35 have arrows on them. I don't want to say that it doesn't which way they go but #1 on my engine had the arrow pointing backwards, 2, 3 and 4 were all pointing forwards....... :?

Thought I had a better picture of it........this is #1.

matt p · Jan 20, 2013

hey Tony I had the same question. the best answer I got was to line up the dots on the bottom to the front of engine. the dot was to show balance of the piston.I tried to get in touch with parts maker but had no success. so I talked to a tractor restorer and thats what told me to do!!!!

Tony in Mass. · Jan 20, 2013

Matt? You see dots? On mine or just yours? The ones near the 'TP'? Inno... someone got into yours before- and those are old pistons, to have the arrows is before the generic stuff lately. Unless they splurged on NOS....and then put one in backwards???

Anonymous-0 · Jan 20, 2013

I haven't had one of these apart .
Looks like you have them installed in two different directions . It may not mean anything , as far as the piston is concerned , but , I would check the rods on the crank end . I would imagine that the crank end of the rod would have a mark , probably the hole number , #1 , #2 , #3 , #4 . You should make sure that the rod caps are bolted to the rod correctly . I would imagine that they should all be in the same direction .
I would check a rebuild manual to make sure that the rods are installed correct . It can be a expensive mistake if they aren't .
Good luck .

matt p · Jan 21, 2013

Tony my dots were underneath, inside the piston on the wrist pin lug . my pistons were made by Balco not sure if yours are the same.matt

2tractors · Jan 21, 2013

It's so hard to remember all the little upsee daisys about these engines but the piston arrow is toward the front and with the piston correctly installed on the rod that would put the oil squirt hole on the rod pointing away from the cam. Or was it toward the cam. Anywho it is covered in the manual and with out an arrow then I wouldn't worry about the one being different----no worry-- no--worry--worry, wait whats that slap I hear.

Tony in Mass. · Jan 21, 2013

The marks were magic marker or etched Matt? That is what I went by, hand done dots on the inside of the piston.... others on these forums say just go by the top marks in a row on the cam side.... holy cow eh?

PackardV8 · Jan 21, 2013

General engine buiding practice REGARDLESS of what kind, type or manufacture of the engine:

When no conspicuous marks are on the piston (or even when there is) the bible is to check for WRIST PIN OFFEST. The wrist pin must set closest to the THRUST side of the cylininder wall in ANY engine. The thrust side of the cylinder is the side of the cylinder that the ROD JOURNAL passes under FIRST when engine is turned in it's appropriate direction. IN this cae of the Cont engine for the Ferguson tractor it would be the rite side of the cylinder (nearest brake pedal, or exhaust/intake manifold).

SOme pistons may or may not have pin offset. If no offset then should make no difference except in the case of T-slotting or other characteristics usually spelled out by a service manual.

Most likely REPOP pistons WILL have pin offset because most likely such repop pistons are simply CLONES of some other more main stream current production piston.

CHECK FOR PIN OFFSET!!!! IF u find offset then u mite want to contact the supplier and let them know that the pistons have offset pins. Probably a 80% chance the supplier has no idea. I've gotten into this too damned many times.

Tony in Mass. · Jan 21, 2013

So, if the offset isn't obvious, then you'd have to balance one on an inspection table and dial indicators?? I know some pistons have a specific direction because of valves or oil slots, but - yep, generic repops is a good discription.. an arrow would be nice tho...

matt p · Jan 21, 2013

My marks were magic marker or paint stick. white dots I studied my pistons measured with digital calipers did'nt measure any offset,their was no marks on piston skirt. I had three etchings same direction one oddball!! so thats how I left it
,

PackardV8 · Jan 21, 2013

Wrist pin offset is measured with a micrometer or caliper.

As a side note there has been mention of " balancing pistons" or other similar such illusions. Altho it is optimal to have all pistons weighing the same it is unnecessary for relatively slow turning engines. Ex: Some of the old prewar buicks used cast iron pistons while the only available OEM SUPPLIED replacements at THAT TIME were Al pistons.
There is absolutely NO correlation between engine balancing and pistons. Pistons have absolutely nothing to do whatsoever with engine balancing. This piston 'balancing' and crank REbalanicng for piston variation is complete nonsense. Makes for great articles to sell magazines to arm chair engine experts.

Pistons are RECIPROCATING weight. NOT rotating weight.

Tony in Mass. · Jan 21, 2013

Upsee daisy??? Daniel Day Louis? Gangs of New York... When throwing knives at his ex step daughter??...or something like that.
Well 2, I am at the point of deciding when to build the courage to look into the back half of this 202... if the engine and clutch were flogged to death, we can guess what the inside of the tranny looks like.
If you decide on a winter vacation up north, don't forget your tools...
It is so cold and raw out there, I will stick to inside jobs all day if I can pull it off...

Inno · Jan 21, 2013

We're at about -32 C today, -42 with the wind chill.........and I'm working outside! Well I'm on a lunch break right now but I was outside most of the morning...........BRRRRRRRRRRRRR!!!!!!
This is why I have a heated shop at home, because I don't have the luxury to work indoors at my day job.
Just slap them pistons in there and call it a day, one of mine is backwards and I'm not losing sleep over it.

Jason S. · Jan 21, 2013

How do you figure that piston weight has nothing to do with
balancing an engine? The counterweights on a crank are there
to balance out the weight of the rod and piston. If you change
the weight of the piston does it throw the motor out of
balance? Yes. The piston and top half of the rod is
recipricating weight, the botttom half of the rod and the crank
journal is bob weight.There is even archive footage of old John
Deere 2 cylinders rotating assemblies being balanced and
they don"t turn much slower than they do.

Jason S. · Jan 21, 2013

Tony, I measured two of my Z120 pistons just now, one of the old ones and one of the new ones and neither one of those had offset in the wristpin. So you should be fine, but it never hurts to double check yours if you want.

PackardV8 · Jan 22, 2013

Perhaps not that it matters in terms of repop pistons but what does the service manual say about piston installation front/rear???? Do the OEM pistons with no pin offset have any marks or notches to indicate front?????

It mite be advisable to look at the oil ring groove (of OEM) to determine if there are any holes in the groove to one side or the other of the piston.

As for my comment above about engine balancing i should have specified engines of FOUR or more cylinders and NOT in a radial configuration such as some airplane engines.

Note that the Z120 has no counterweights. I have several V8 passenger car cranks here and V12. When placed COMPLETELY BARE on leveled knife edges the cranks will hold their position no matter how they are stopped on the knife edges. Piston and/or rod has no effect on crank balance (except 1 and 2 cylinder engines and radials).

Jason S. · Jan 22, 2013

I"ve got a 5.0 liter Ford engine I put together and had to have it
balanced. I went from stock TRW forged pistons to Mahle
forged pistons. The Mahles were about 60 grams lighter per
piston, but they were a matched set and weighed within one
gram of each other. I even verified it because the engine
builder I used at that time said as long as the Mahles each
weighed the same it won"t make any difference in the balance
of the motor. I put it back together and above 2200 rpm"s it
would shake you out of the car. I changed flywheels, pressure
plate, harmonic balancer..nothing changed it. I tore it back
down and took the rotating assembly to my current machine
shop. He laughed and said with that kind of weight difference
of course it would vibrate. He balanced it for me and I put it
back together and it is smooth as silk now. It madea believer
out of me on balancing. Which OEM replacement pistons have
to be within 10% of the original pistons weight or they aren"t
supposed to be sold as OEM replacements.

134 piston direction?

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