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Tue Jul 22, 2008 9:33 am

bill may wrote: Chad M wrote: Spezialist wrote: Its a fuckin race engine "destined to blow anyway" flip it around and run it. The arrows are for balance.

I thought the arrows had to do with the piston pin offset?

there you go.

offset = balance

Tue Jul 22, 2008 9:35 am

um, no.

I don't even know where to begin, but no.

Tue Jul 22, 2008 9:40 am

Spezialist wrote: bill may wrote: Chad M wrote: Spezialist wrote: Its a fuckin race engine "destined to blow anyway" flip it around and run it. The arrows are for balance.

I thought the arrows had to do with the piston pin offset?

there you go.

offset = balance

i call B.S. on balance.

Tue Jul 22, 2008 9:43 am

Spezialist wrote: bill may wrote: Chad M wrote: Spezialist wrote: Its a fuckin race engine "destined to blow anyway" flip it around and run it. The arrows are for balance.

I thought the arrows had to do with the piston pin offset?

there you go.

offset = balance Rodney, sorry you have no offset in your life.

Tue Jul 22, 2008 9:47 am

bill may wrote: Spezialist wrote: bill may wrote: Chad M wrote: Spezialist wrote: Its a fuckin race engine "destined to blow anyway" flip it around and run it. The arrows are for balance.

I thought the arrows had to do with the piston pin offset?

there you go.

offset = balance

i call B.S. on balance.

I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

Tue Jul 22, 2008 9:53 am

glad to see you back Rodney and working on boosting that post count up again, posting in everything you see.

:roll:

Tue Jul 22, 2008 10:03 am

Spezialist wrote:
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

engine will assemble wrong with offset incorrect. have you ever heard the term "piston slap" in your life mr. machinist????? you gave incorrect answer mr. machinist. i do not have to prove anything. you are the one that claims perfect machining ,but don't begin to know why. :shock: do you machine connecting rods so both centerlines are orientated parallel?(pin bushing to main bearing)

Tue Jul 22, 2008 10:11 am

bill may wrote: Spezialist wrote:
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

engine will assemble wrong with offset incorrect. have you ever heard the term "piston slap" in your life mr. machinist????? you gave incorrect answer mr. machinist. i do not have to prove anything. you are the one that claims perfect machining ,but don't begin to know why. :shock: do you machine connecting rods so both centerlines are orientated parallel?(pin bushing to main bearing)

and they call my posts incoherent,,

Mr: Machinist do you understand why the piston slaps? it is out of balance with the rotational forces of the crank and rods, the slap is thereby reduced by creating an offset,
(idiotic part removed by staff)

Tue Jul 22, 2008 10:32 am

Spaz I'd be honored to have you as my next customer.

Tue Jul 22, 2008 11:27 am

Spezialist wrote: bill may wrote: Spezialist wrote:
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

engine will assemble wrong with offset incorrect. have you ever heard the term "piston slap" in your life mr. machinist????? you gave incorrect answer mr. machinist. i do not have to prove anything. you are the one that claims perfect machining ,but don't begin to know why. :shock: do you machine connecting rods so both centerlines are orientated parallel?(pin bushing to main bearing)

and they call my posts incoherent,,

Mr: Machinist do you understand why the piston slaps? it is out of balance with the rotational forces of the crank and rods, the slap is thereby reduced by creating an offset,
(idiotic part removed by staff)

You forgot some in italics

Tue Jul 22, 2008 12:42 pm

Spezialist wrote: I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

not so, you need to be able to back something to even stretch the statement into fact... piston pin offset has about as much to do with balance in the engine as the air in the vehicles tires do... you could have at least tried saying something like "geometry" to get you in the same universe... anyway, if you really want to know, the internet is a great tool, and a quick google search could have given you this *excellent* write-up about piston pin offsets....:
http://www.motorcycleproject.com/motorcycle/text/cows-offset.html
on a motorcycle site, but a very good description of what the piston pin offset is for and what it does... enjoy... or not...

Tue Jul 22, 2008 1:39 pm

bugninva wrote: Spezialist wrote: I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

not so, you need to be able to back something to even stretch the statement into fact... piston pin offset has about as much to do with balance in the engine as the air in the vehicles tires do... you could have at least tried saying something like "geometry" to get you in the same universe... anyway, if you really want to know, the internet is a great tool, and a quick google search could have given you this *excellent* write-up about piston pin offsets....:
http://www.motorcycleproject.com/motorcycle/text/cows-offset.html
on a motorcycle site, but a very good description of what the piston pin offset is for and what it does... enjoy... or not...

Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, but you will eventually get it, which is why I am the rants killer.

Tue Jul 22, 2008 2:07 pm

drop the pan, remove the rod cap, separate from the crank, spin it 180, and re-assemble. You don't even have to pull the piston from the block.

John
Aircooled.Net Inc.

Tue Jul 22, 2008 2:48 pm

Spezialist wrote: bugninva wrote: Spezialist wrote: I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

not so, you need to be able to back something to even stretch the statement into fact... piston pin offset has about as much to do with balance in the engine as the air in the vehicles tires do... you could have at least tried saying something like "geometry" to get you in the same universe... anyway, if you really want to know, the internet is a great tool, and a quick google search could have given you this *excellent* write-up about piston pin offsets....:
http://www.motorcycleproject.com/motorcycle/text/cows-offset.html
on a motorcycle site, but a very good description of what the piston pin offset is for and what it does... enjoy... or not...

Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, but you will eventually get it, which is why I am the rants killer.

At the risk of quoting him, so you have to read this...

From the linked site:

Quote: To summarize, piston pin offset is the manufacturer's way of reducing stress on reciprocating parts. It permits these parts to be lighter, which results in more efficient manufacture and less power loss in the engine, as well as higher rpm. A complementary result of piston pin offset is reduced piston slap due to the more gradual shift from major to minor thrust.

Odd, nothing mentioned about balance there at all.

Tue Jul 22, 2008 3:47 pm

Namocsid wrote: Spezialist wrote: bugninva wrote: Spezialist wrote: I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

not so, you need to be able to back something to even stretch the statement into fact... piston pin offset has about as much to do with balance in the engine as the air in the vehicles tires do... you could have at least tried saying something like "geometry" to get you in the same universe... anyway, if you really want to know, the internet is a great tool, and a quick google search could have given you this *excellent* write-up about piston pin offsets....:
http://www.motorcycleproject.com/motorcycle/text/cows-offset.html
on a motorcycle site, but a very good description of what the piston pin offset is for and what it does... enjoy... or not...

Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, but you will eventually get it, which is why I am the rants killer.

At the risk of quoting him, so you have to read this...

From the linked site:

Quote: To summarize, piston pin offset is the manufacturer's way of reducing stress on reciprocating parts. It permits these parts to be lighter, which results in more efficient manufacture and less power loss in the engine, as well as higher rpm. A complementary result of piston pin offset is reduced piston slap due to the more gradual shift from major to minor thrust.

Odd, nothing mentioned about balance there at all.

Surprised? I'm not. Spaz can't fix a bowl of cereal much less an engine.

Tue Jul 22, 2008 5:32 pm

Namocsid wrote: Spezialist wrote: bugninva wrote: Spezialist wrote: I state a fact, It is your job to dis-prove my fact.
a little hint so you dont waste too much time trying to find an answer, if the relationship of the piston pin offset had anything to do with assembly other than balance, you would not be able to assemble engine, do to interference, correct?

not so, you need to be able to back something to even stretch the statement into fact... piston pin offset has about as much to do with balance in the engine as the air in the vehicles tires do... you could have at least tried saying something like "geometry" to get you in the same universe... anyway, if you really want to know, the internet is a great tool, and a quick google search could have given you this *excellent* write-up about piston pin offsets....:
http://www.motorcycleproject.com/motorcycle/text/cows-offset.html
on a motorcycle site, but a very good description of what the piston pin offset is for and what it does... enjoy... or not...

Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, but you will eventually get it, which is why I am the rants killer.

At the risk of quoting him, so you have to read this...

From the linked site:

Quote: To summarize, piston pin offset is the manufacturer's way of reducing stress on reciprocating parts. It permits these parts to be lighter, which results in more efficient manufacture and less power loss in the engine, as well as higher rpm. A complementary result of piston pin offset is reduced piston slap due to the more gradual shift from major to minor thrust.

Odd, nothing mentioned about balance there at all.

Did you have a question? or do you just want to look stupid? Like ICY :lol:

Tue Jul 22, 2008 6:19 pm

Spezialist wrote:
Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, .

maybe try balancing a geometry book on your head, maybe you can learn by osmosis... i fear that is impossible since the keyword in my statement is "learn"...
trust me, i understand what he wrote about perfectly... one of us has to...

Spezialist wrote:
but you will eventually get it, which is why I am the rants killer.

most of us to get it... but when you can't even stop spewing the above, it's no longer a secret what you really mean... AW

Tue Jul 22, 2008 7:28 pm

Dunebubby wrote: I would have put this in the engine section but since it isn't a v dub engine I'm dealing with I thought this might be better.

I have a ministock racecar,(4 cylinder) that I got from a guy who couldn't find the dipstick to save his life so he wasn't able to pass on what had been done to the car.. This guy is about as clueless as they come automotively speaking.I hadn't raced the car,since it's 120 miles to the closest track that runs ministock around here. I had driven it around my property though and the car was set up well,(to go left :twisted: ),and ran really well but did have some blow by,completely wasted timing gears,(26 degrees of play), and very noisy rear end. My dad wanted the weber carb and intake to get another car running and since I hadn't run the car in a couple years and didn't anticipate racing it soon I told him he could pull the carb and intake. After he did I could see that the intake and exhaust runners had been ported ,(no surprise) but I was wondering if any work had been done to the combustion chambers so I pulled the head. Nothing had been done to the combustion chambers but I was pleasantly surprised to see that it already had a "big bore" kit punching it from 2 liters to a 2130. Then I looked more closely and saw that #2 piston is installed backwards. The arrows on the other three pistons face the flywheel,#2 faces away. I will be interested to see if the connecting rod is backwards also. I was going to rering and slap bearings in it but I was wondering what you guys would do about the flipped piston? At this point I wish I had done compression and leakdown tests before pulling the head. I know it had blow by but I wonder if the readings on #2 were far worse than the others.My feeling is it ran "this long" the way it was so Im tempted to put it back together the way it is.I still need to get it out of the car and pull the pan to see about the con. rod. I know since the rings,not the piston,should be whats contacting the cylinder walls i should be able to flip it the right way but.........Opinions? At this point I'm assuming the conning rod is the right way. If it isn't I will flip at least the rod,(unless I get in there and it's been balanced). What would you do? (Besides getting rid of the non-V Dub)?!

Dude just send it to SPEZ, he will flip everything around in the engine so that the once backwards cylinder is now matched with all the other backwards ones. Done Deal.

Tue Jul 22, 2008 7:32 pm

bugninva wrote: Spezialist wrote:
Explain how, geometry changes {offset in pin} to moving parts effects movement of said parts, I'm waiting,,not :roll:
Your link provides an excellent example that backs up what I said in one word {balance}, its too bad you cant folllow through and actually comprehend what he wrote, and trust what I'm telling you, .

maybe try balancing a geometry book on your head, maybe you can learn by osmosis... i fear that is impossible since the keyword in my statement is "learn"...
trust me, i understand what he wrote about perfectly... one of us has to...

Spezialist wrote:
but you will eventually get it, which is why I am the rants killer.

most of us to get it... but when you can't even stop spewing the above, it's no longer a secret what you really mean... AW

ok something simple, what actually causes the piston to reduce its slap with its pin offset? anyone. Come on you can do it! Think about it, its called visualisation, visualise that piston, rod and the crank going round and round. What do you see?
I pray to Gene Berg you can figure this out before the cleaners come in, its not that difficult.

I know what, what do the thingies* that are welded to a crank do, and what are they called? how could a little weight welded to one side or the other of anything be considered a counterbalance, let alone a simple process of shifting the placement of a pin attachment, after all piston pins were not always this way, they used to be straight.

Ok one last try, imagine if you will, a piston- inside its bore {cylinder} suspended by nothing but its offset pin {that spins freely btw} and its rings. What if anything other than balance keeps it from rattling around in there at 5,000 rpm? so to speak.

I will have to take a break from this thread because honestly, I have gone and run out of ideas on how to teach you this simple process, and really hearing you tell me to read some other guys webpage and defend it, is rather weak, besides I think I have a new friend with a shark avatar!

Aloha, pm me when you figure it out, I will not return to this thread, for it has truly run its course.

*emphasis

(fixed it for ya.*)

drscope wrote: You never told us what engine this is.

Some race engine builders will turn the pistons, or sometimes the rods to get the pin offset they want. This works better in some engines and not at all in others.

In this case, you have 1 that is turned different then the others. My guess would be that the rod is also in backwards and this was simply an assembly error.

In any case, the proper way to deal with this is to take it apart and MEASURE everything.

Take careful notice of the cylinder walls and the surface that is there. You do NOT want a smooth surface on the cylinder walls. There has to ba hatch marks in order for the cylinder walls to retain some oil.

Measure the bore and measure the pistons. reassemble accordingly.

As for this being a "balanced" engine. Engines are balanced prior to assembly. The pistons & rods get balanced OFF the crank and then the crank is balanced using bob weights to simulate the piston/rod assembly. So this would not effect the dynamic balance of the engine.

It may effect the running balance as this one cylinder has the rod centers and maybe the pin center in a different place. The result would be that this cylinder "lays" over at a different point then the others. :twisted:

The bottom line, is that this is just like ANY other engine job. You MUST MEASURE before bolting parts back together.

[quote="Lee."]

Tue Jul 22, 2008 7:37 pm

Spezialist wrote: bugninva wrote: Blah blah blah blah blah

ok something simple, what actually causes the piston to reduce its slap with its pin offset? anyone. Come on you can do it! Think about it, its called visualisation, visualise that piston, rod and the crank going round and round. What do you see?
I pray to Gene Berg you can figure this out before the cleaners come in, its not that difficult.

I know what, what do the thingies* that are welded to a crank do, and what are they called? how could a little weight welded to one side or the other of anything be considered a counterbalance, let alone a simple process of shifting the placement of a pin attachment, after all piston pins were not always this way, they used to be straight.

Ok one last try, imagine if you will, a piston- inside its bore {cylinder} suspended by nothing but its offset pin {that spins freely btw} and its rings. What if anything other than balance keeps it from rattling around in there at 5,000 rpm? so to speak.

I will have to take a break from this thread because honestly, I have gone and run out of ideas on how to teach you this simple process, and really hearing you tell me to read some other guys webpage and defend it, is rather weak, besides I think I have a new friend with a shark avatar!

Aloha, pm me when you figure it out, I will not return to this thread, for it has truly run its course.

*emphasis

you really should have read the link... it is a good accurate description and correct, unlike your "balance" theory... air up your tires, it will "balance/counterbalance" your pistons just as well as an offset pin will.... i predict you will return to this thread, you crave it...