Top Pinning Pistons

[speedracer]

Somebody want to tell me how to get the pins In the ring grove OUT so I can Install a top pin, dam things wont stay In but when you want to remove them you can't get them OUT, anybody Thanks.

[Hottrucks]

I want to see how your going to do this top pin thing???? I'm cheap too but not so cheap to risk an engine .......

as far as getting the pin out try freezing it

I would put them in a box and send to to John when they came back they would be done

[Jay Smith]

The ONLY one on the planet that has a 100% success rate in top pinning pistons is John Marles , there have been many attempts that resulted in destroyed powerheads....He does all our conversion to from side pin to the bullet proof top pin style...

Good luck,

John Marles (1 661 250 7157)
31700 Tick Canyon Rd.
Agua Dulce , Ca 91390

[Hottrucks]

yea what he said thanx for backing me on this Jay...
BUT if he's going to try I would like to see it

[speedracer]

You dont learn If you dont try, Thats how Marles learned Im sure. So once again anybody ever removed one, If so how did you get the grove pin out.

[RBT]

Remove them with EDM.

RT

[YELLOWSS]

i hope your going to use a tig welder. i have weleded all kind of metals, and ran all kind of machines. john does my pistons!!! not worth the chance. if u have motors worth destroying. it can be done though.

good luck

[tinker060]

Tony, There are a number of ways to remove the pin. EDM would be the sure way. If you are adventurious(sp), you can take a thin diamond cutting wheel and grind the pin flat in the groove (you need a steady hand) or you can take an old file, grind it to fit the ring groove and then with a big hammer tap the pin on each side until the pin opens up the hole and it can be extracted. What ever method is used, take a jewelers file and dress up the bottom and sides of the ring groove. I can see it coming...........if you grind the pin off is there not a chance it will come out during engine operation. So what. The riing will keep it from coming out to far. No guts, no glory.

When drilling the new hole, do it in steps and not all at once. Good drill bits are a must. Use coolant, take it slow and do not apply a lot of pressure. Heat the piston and use an arbor press to install the pin. You can also make a "starter" jig to hold the pin straight. Just take a piece of round stock (.375), true on both ends, cut to a length about .125 shorter than the pin, drill a pin size hole, center over the hole and press away. Remove the jig and finish the press. It also helps to grind a small chamfer on the bottom of the pin as this will help starting the pin in the hole.

If you choose to weld the pin in....make sure you chamfer the hole so that you have material left over and around the pin when you dress up the top of the piston. Welding the hole closed can be tricky becasue you are trying to "fill a vacum" so to speak. The steel pin in the middle of the hole does not help either. You can do it with either a tig (tig preferred) or mig. Just don't let the arc start on the steel. The chamfer will also provide a place to start the weld and flow the filler around the pin. Oh, keep the weld as far away as possible from the ring land edge.

Some folks also drill a hole below the ring lands that intersects with the new pin. This allows you to "bend" the pin so that you have a mechanical lock as well as the weld. You can also weld up this hole if you like.

What are you going to use as a "pin"? What ever you use, just make sure it's hard.

It's also a good idea to annel the piston after any welding. Just stick it in a 400 degree oven for about four hours and then let it cool to room temp.

After all this, carefully inspect the ring grooves to make sure the welding did not "droop" them any and that you have proper ring clearance. One way to do this is take an old ring, cut out a section and slide it around the piston and see if it hangs anywhere. Chamfer the ends before sliding..........

Good luck.

Jon

[mendo]

If that last post didn't scare him into sending them out then go!!

bottom line is if you have some spare motors to work with you can learn to do it.

I don't know anyone that became an expert without some damaged parts.

Even me!!!! and I am not an expert. (have damaged lots of parts though!!)

[us1]

I have three EDM machines to remove the old pins. If you leave them in, just grinding them down, they can eventually come loose, egg shape the pin hole and come out over the top of the ring. Thats why I have EDM machines now. Laser welders are the best at not distorting the piston and ring lands. Less heat faster weld. The new pins should be high carbon steel or pin ware through can accrue.

[us1]

If that last post didn't scare him into sending them out then go!!

bottom line is if you have some spare motors to work with you can learn to do it.

I don't know anyone that became an expert without some damaged parts.

Even me!!!! and I am not an expert. (have damaged lots of parts though!!)

When are you coming down to work on the motor?

[speedracer]

Thanks for the help on this, I want to get the old pin out for fear Of It coming out and stopping the ring from moving or getting out all together and then doing some real damage. My plan [tell me If this Is bad] Is only to pin the top ring grove, because the bottom pin never comes out anyway. What's going on here in these OMC factory pistons Is the piston is fine for use in a 200/225 OMC fishing motor except the top pin always comes out eventually. During a simple rebuild I would like to be able to use the factory piston and pin the top groove only, again I have never seen a bottom ring locating pin come out of one of these. What diameter pin should I use? Thanks Again Tony.

[Jay Smith]

John,
I will have a set of .015" over NEW MERC pistons coming to you next week to pin and you to grind the rings.... I KNOW not to even attempt this task... Many have tried this process with many destroyed engines as the end result of attempting a task that is a VERY technically advanced and perfected by John...IMO Engine are too expensive ( Well some of them ) ;) to attempt something like this ...

For the relatatively small cost of letting an expert at a task SUCCESSFULLY do it verses the probabal end result of a novice ATTEMPTING that task IMO its pretty much a wash !

Good luck to ya,

[kingsbiship]

speedracer... I'm with ya! Everyone has ta start at the start! I've thought
about doing this also. I can't give you any info on your OMC top ring only...
but definitely try on one or two bad slugs first. You have 360* of piston top
to play with! (after pin is removed) If everyone thought negative about this
we would still be in caves!

[Hottrucks]

Hey Speedracer takes some pics as you go and let us know what you find works and does not. I was woundering?? How you are going to hold the piston have you made some kind of jig??

John when you say you use a EDM machine I guess I don't understand ( I'm not a machinest) the EDM machines I have worked with use wire to cut material under a pure water bath... is there a differnt type that you use ????

Funny how they will fall out but you cann't just pull them??

[us1]

Thanks for the help on this, I want to get the old pin out for fear Of It coming out and stopping the ring from moving or getting out all together and then doing some real damage. My plan [tell me If this Is bad] Is only to pin the top ring grove, because the bottom pin never comes out anyway. What's going on here in these OMC factory pistons Is the piston is fine for use in a 200/225 OMC fishing motor except the top pin always comes out eventually. During a simple rebuild I would like to be able to use the factory piston and pin the top groove only, again I have never seen a bottom ring locating pin come out of one of these. What diameter pin should I use? Thanks Again Tony.

Unfortunately there is not enough meat to just pin the top land. Welding it wont even keep it from hammering out. You better pin both lands and at least 1/2 inch into the piston.

[us1]

Hey Speedracer takes some pics as you go and let us know what you find works and does not. I was woundering?? How you are going to hold the piston have you made some kind of jig??

John when you say you use a EDM machine I guess I don't understand ( I'm not a machinest) the EDM machines I have worked with use wire to cut material under a pure water bath... is there a differnt type that you use ????

Funny how they will fall out but you cann't just pull them??

There are two kinds of EDM machines. A Wire EDM and a Sinker EDM. The Sinker is what I use. It uses copper electrodes to bore out the pins. The largest machine I have is a 70 amp unit, it can hole a big block Chevy and bore a hole 12 inches wide.

[us1]

Here is a picture of my largest EMD machine. Its a 75 Amp EDM Technologies Inc.

[MarkS1234]

John, just got the pistons today.
Looks great, you can barely see the weld on the piston top.

I quess it's not an issue that the rings gaps will be inline and not staggered ?

Thanks a bunch for doing these for me, and getting them to me in such great time. When I do the other 4 pistons, you will be the first to know ;-)

Thanks agian

[Hottrucks]

I would imagine that it's very accurate.... the demo on the wire one was where he took a penny and cut out all the back ground around Licoln and left the letters of IN GOD WE TRUST...it was very cool

[us1]

John, just got the pistons today.
Looks great, you can barely see the weld on the piston top.

I quess it's not an issue that the rings gaps will be inline and not staggered ?

Thanks a bunch for doing these for me, and getting them to me in such great time. When I do the other 4 pistons, you will be the first to know ;-)

Thanks agian

I am glad you like them, sorry it took a little longer that I expected to get the pistons in. The ring gaps being aligned has no affect on compression. All the new Mercury race pistons have aligned ring gaps. Let me know how they work out. Thanks John:cool:

[us1]

Yes its very accurate. I also have an "Super Indexer" indexable rotary table in the well set at 90 degrees to hold the pistons. That way I can rotate it from pin to pin. It keeps the pin perfectly vertical to the electrode leaving no pin shards.

[bigbore]

John, just got the pistons today.
Looks great, you can barely see the weld on the piston top.

I quess it's not an issue that the rings gaps will be inline and not staggered ?

Thanks a bunch for doing these for me, and getting them to me in such great time. When I do the other 4 pistons, you will be the first to know ;-)

Thanks agian

Obviously,it is a big deal,if the ring gets caught (in a port)it's done,sleeve n all.

[MarkS1234]

Obviously,it is a big deal,if the ring gets caught (in a port)it's done,sleeve n all.
Perhaps you don't understand, or I did not explain it right.

I was referring to the gap in the rings. upper and lower.
When John top pins them, the gaps end up one on top of the other.

Mark

[bigbore]

sorry about that

[tinker060]

Tony, Could have posted info but did not want to give anyone a heart attack with detailed information regarding "open heart" surgery. You know how tricky some of this pesky outboard stuff can be, like removing a pin and moving it somewhere else or...or.... heaven forbid ....boring a block for a new sleeve or "oh no" (someone might faint).....having to actually bore a straight, round hole of the proper size in the new sleeve so that rings don't bash hell out of the ring retaining pin.

John, I took your point regarding the ground off pin coming over the top of the ring to heart. It is a possibility for sure but to see how much of a possibility.... and just for s & g's (it's rainy and cold in KY) I took a piston and cut it in half, loosned the ring pin a bit and then ground it off flush with the bottom of the ring groove. Cut a piston ring in half, put it in place over the pin, bored a piece of 1.0 alum the same dia as a block bore to hold the ring in place, cut the "bore" in half and welded the "bore" and the piston (with the ring pushed out from the piston a bit) to a piece of flat stock. milled a .5" slot in the piston behind the retaining pin (but not touching the pin). With a punch and my trusty "brain surgery" appoved hammer I gave the pin several hard whacks. I did manage to drive it over the ring but it was not easy. "IF" the pin were not loose before grinding it away, I doubt that it would ever come out. EDM is still the way to go but if someone does not have access to this technology and wants to try putting in a top pin, then I hope this post gives them a bit more comfort about their efforts.

To me one of the great things about forums in general is the sharing of information and our experiences. It drives creativity and self reliance. Something that seems to be missing in some quarters of this land. If you never try anything new, why not just crawl in a hole and die. If you don't encourage people to try then you are helping to fill up the hole. With that said, it's also good to explain both sides of the equation and let him/her/it/they, etc make up their own mind about making the effort.

Jon Wright

[Hottrucks]

Just couriuos once you cut the pin could you use your tristy brain hammer and push the pin in for a bit of added safety???

[us1]

Tony, Could have posted info but did not want to give anyone a heart attack with detailed information regarding "open heart" surgery. You know how tricky some of this pesky outboard stuff can be, like removing a pin and moving it somewhere else or...or.... heaven forbid ....boring a block for a new sleeve or "oh no" (someone might faint).....having to actually bore a straight, round hole of the proper size in the new sleeve so that rings don't bash hell out of the ring retaining pin.

John, I took your point regarding the ground off pin coming over the top of the ring to heart. It is a possibility for sure but to see how much of a possibility.... and just for s & g's (it's rainy and cold in KY) I took a piston and cut it in half, loosened the ring pin a bit and then ground it off flush with the bottom of the ring groove. Cut a piston ring in half, put it in place over the pin, bored a piece of 1.0 alum the same dia as a block bore to hold the ring in place, cut the "bore" in half and welded the "bore" and the piston (with the ring pushed out from the piston a bit) to a piece of flat stock. milled a .5" slot in the piston behind the retaining pin (but not touching the pin). With a punch and my trusty "brain surgery" appoved hammer I gave the pin several hard whacks. I did manage to drive it over the ring but it was not easy. "IF" the pin were not loose before grinding it away, I doubt that it would ever come out. EDM is still the way to go but if someone does not have access to this technology and wants to try putting in a top pin, then I hope this post gives them a bit more comfort about their efforts.

To me one of the great things about forums in general is the sharing of information and our experiences. It drives creativity and self reliance. Something that seems to be missing in some quarters of this land. If you never try anything new, why not just crawl in a hole and die. If you don't encourage people to try then you are helping to fill up the hole. With that said, it's also good to explain both sides of the equation and let him/her/it/they, etc make up their own mind about making the effort.

Jon Wright

Well I think you are taking my post a little out of context. I am just stating the problems I have already been through so he can skip that part. At no time have I suggested he send me his pistons. In fact I will state now that I will NOT pin any pistons for him if he asks me too. I have been pinning pistons for 10 years and have had many side pins come out over the ring from grinding them down, these are new pistons too. Thats why I went to the EDM. If he has the resources and time he should definitely attempt the pinning. There is nothing better than learning.

[RBT]

US1, I agree with pinning new Weisco's, but I am curious how you weld the old oil filled pistons, an how you do it without super heating the piston surface...specially near the lan. To me to weld you have the make the surface molten?

RT

[us1]

The more I share my experiences to give tips on how to do it, which I rarely do, the bigger jerk I become. So I don't really want to post on the subject any more.

[RBT]

Don't worry John, I am still a bigger Jerk...... you have your work cut out if you want to surpass me. I still don't see how it can be done, but then I still cannot see how you stuff a hollow pin... or maybe it is like the engineers at said motor builder told me....... they are old 2.4 pins that needed a home.

LOL

[Hottrucks]

I can tell you from powder coating that if you take old oil filled junk ( aluminum value covers) and bake it (Most of ) the oil will come out it just hase to be long and hot enough

[RBT]

I can tell you from powder coating that if you take old oil filled junk ( aluminum value covers) and bake it (Most of ) the oil will come out it just hase to be long and hot enough


Right, but his claim is that his super neato proprietary welder doesn't heat the crown above 100 degrees....

[speedracer]

All I did was ask a simple queston, how do you remove a locating pin and now mr marles will not do any work for me[ never met the man or even talked to him]and J Smith Is pissed cause I did not send them to mr marles In the first place. Makes you think twice before asking a technical queston here at the technical Discussion board :) Any way I have given UPS way to much money on shipping parts all over the country for repair, so just try to do as much In house as I can to help keep the cost down. Sorry this got so out of hand, My last queston here on TECHNICAL DISCUSSION. ps Thanks mr Wright for your help In the matter.

[RBT]

Tony, this is very interesting. This is and issue that everyone, Merc or OMC have had for as long as I can remember. Nobody has seemed to come up with a solution, be it private or a piston mfg.. Weisco, JE, Mahle, CE or Art.
Trying to fugure it out probably isn't as easy as it would seem, maybe US1 has it. I suppose time will tell. All I know is the the piston mfgs don't. I hope that you have or come up with a solution. And there have been some interesting points made here... by some very smart guys.... I think it has been worhtwhile.

RT

[j_martin]

All I did was ask a simple queston, how do you remove a locating pin and now mr marles will not do any work for me[ never met the man or even talked to him]and J Smith Is pissed cause I did not send them to mr marles In the first place. Makes you think twice before asking a technical queston here at the technical Discussion board :) Any way I have given UPS way to much money on shipping parts all over the country for repair, so just try to do as much In house as I can to help keep the cost down. Sorry this got so out of hand, My last queston here on TECHNICAL DISCUSSION. ps Thanks mr Wright for your help In the matter.


Don't expect a mechanic to loan you his tools.

Don't expect a tradesman to tell you his process.

Don't expect a man to freely give you the information that he has spent much time and money acquiring and is now the source of his income.

I am amazed that John Marles, (mr. marles to you) has published as much helpful information here as he has.

It's been a very interesting read. I do most everything myself, but if I ever need some pistons top pinned, I'll just send them off to John Marles and get them done right.

hope it helps

[1BadAction]

well, way to chase somebody away, Jay. I guess someone that tries to do their own porting is wrong because they could ruin a good block too? :rolleyes: Attitudes like that are the exact reason why people don't want to get into REAL tech discussion on here (or any other forum for that matter) you have one or two forum "gods" and if someones thoughts differ from him, they are idiots, etc etc etc. I guess we can always debate something like closed end wristpins that only make a difference in someones head instead of something that REALLY makes a difference, like different schools of thought on block porting and flow.

Signed, #1 young hotshot know nothing.

PS- J_Martin, Tony didn't ask John specifically about this. I can see your point though and truthfully I am surprised he responded.

[Jay Smith]

Speedracer,

I think maybe you've misunderstood my post. IMO this board is for information sharing , via people that have been down the path of a certain project and have been succesfull with it or not and are willing to share that information free gratis thats merely what I've done ( I think ?? )I've tried for years experminting with ways to stop the pin problems with the "staking" process and all have failed causing me MANY messed up bores and lots of $$ out of my pocket till Marles perfected his method. As I said there has been many folks try to reproduce Johns top pinning method and have failed , I was merely trying to keep you from the same fate. As far as me getting mad or caring if you do your own pistons or not or who you send them to or not I can't see how you think this could or would be an issue to me I'm just another guy with an opinion to add to the post??? Just trying to maybe steer you in a known successfull path....My bad.I didn't mean to pour water on your fires at all sorry for the post, I've learned a valuable lesson here and thanks 1Bad for bringing it to my attention........

Good luck with your future endevours,

[Hottrucks]

Now John and Jay don't be like that next thing you know Ruck won't be fixing my junk!!!
We all know how things work and if someone wants to try it great, I'm all ears and eyes!! I know my limitation as do most of us and if he's willing to try it I only wish I could watch and see how...( kinda like that edm machine thing) allot of the things that people do here on the board are science fiction to most, yet as we grow we take on new and more , lets say Dangerou$, projects. This one is way out of my league how ever I would like to play with that machine and some old junk parts and maybe I could learn to do it but why?
I guess I could put in sleeves to but why?? what ever you do for a living is what you do and probably do it well..... I let these guys do there jobs and use there experience like a tool if I can do it most of the time there a great help and willing to help US out. if we get in a bind....
Bla bkla bla bla blabla
what ever SPeed take some pics and lets see what your trying to do...

[tinker060]

Hottrucks - Yes, You could drive the pin in a bit and even put a spot of weld over the hole. You need a good tig man to do it but it can be done. Good thinking.

JohnM - The first part of my post was not directed at you. If it were there would be no doubt as to the direction. However, there are some ambulance chasers skulking around here that should take it to heart. You gave Tony some good advice and for that he should be appreciative as anyone else reading your post. Your comments about the pin coming out over the ring gave me something to think about and that's why I did the test. As the old saying goes, "nothing ventured, nothing gained". No, that's not right. It should be, "never try to teach a pig to sing, it waste your time and annoys the pig"...............

Guys and Gals, Dont' shy away from technical discussions. If you do then the "pigs" win. Ask the tough question and expect a balanced (pros/cons) response that does not require an engineering degree to work the formulas. That is BS of the worst sort. If someone throws out a formula ask them to work it through using the subject matter at hand. Then ask them to "prove" the formula. If you are dealing with egos (mine included) from certain known criminals, and their response to your question goes off on a tangent, just don't read their post anymore. There are some really smart guys on this forum that have years of experience in a lot of different subject matters. Don't let those few who would turn the matter into a pissing contest spoil it for the majority of the board.

Greg, If you are reading this, why not make the "Technical Discussion" just that. If people are afraid to post then that does nothing for S&F or our sport in general. A few guidelines would help keep all of us word happy nuts at bay.

If I have stepped on some toes. Good.

Jon Wright

[1BadAction]

I agree 100% Jon. Thanks for keeping things in perspective.

Jay, sent ya a PM back.

-Jim

[pyro]

Don't expect a mechanic to loan you his tools.

Don't expect a tradesman to tell you his process.

Don't expect a man to freely give you the information that he has spent much time and money acquiring and is now the source of his income.

I am amazed that John Marles, (mr. marles to you) has published as much helpful information here as he has.



I have to agree on this one. There's only so much you can share about a skilled trade. If I told people all of my technical trade secrets, I wouldn't be in demand anymore in my field either. I make many of the tools myself that I use every day.

At the same, kudos to anyone who's skilled and brave enough to do their own work, to try new things. Sometimes it works out, sometimes not...

[Hottrucks]

I was thinking about the pin coming out thing???? this could be bad!!!

If the cut out or ground down pin was flush to the bottom of the ring gland then would it be possible to insert the new top pin directly over the old pin position??? I would think that this would keep the ring gap in the original place avoiding any of that nasty ring catch on the port stuff We all know that would be bad???
Again if the person doing this had the correct tools ( Like that fancy Edm machine John has) removing the old pin wouldn't be an issue but still doen't help me understand what postion you leave the ring gaps.....

John if I understand you correctly both ring gaps are located in the same place...does this cause any sort of leak down issues?? I havn't seen any of your pistons ( hard to see them inside an engine) but people that use them and are more in the know than I am, say that there a must have for big rpm engines.

[RBT]

Mercs 2 ring pistons have one pin location, they seal fine.
Interestingly, I remember reading on here that Racer was critical of breakin, and suggested it had a lot to do with how long the pin lasted. I also recal that Tinker060 stated in his artical that he chamfered the rings to prevent them from eating the pins.
I myself have never had a pin failure... lot of other stuff, but never a pin.

RT

[speedracer]

Jon I am not getting any Of your e mail, Gary said some time back u sent somthing to me and I did not get that also. E MAIL Is [email protected] Phone Is 502 732 4824, This post went way wrong, But thanks again for all your Info, you To US1. Tony Wilson PS Hell All I wanted to do Is get the damn pin out.

[Hottrucks]

A little banter is to be expected but I have learned from it already and I hope you keep us posted on how yur work is going

[Jay Smith]

Tony,
Sorry again for the mis fire. Guess I need to stop reading things into a post that wasn't asked and specificly stick to the question at hand. IMO I still feel that Marles does know MORE than ANYONE on the planet about this subject(with littery thousands of pistons successfully done) also IMO theres nobody on the planet that can set up an Unlimited OB Hydro as Jon Wright can both experts in thier fields, this post just got off track ( as posts do here quite frequently ) Hopefully you will not hold the board at fault for anything I've said...

Jay

[espen]

I had a pin come loose in one of my engines , it was not a pretty sight.
Piston, sleeve,head+++ I wondered if i should take the other engine at the same time ....lots of work...I did and the estimated life time of the other engine with how far the pin had come out was a couple of hours!
New 280s have stuck after 2-3 hours , a estimate is that from 1 to 70 hours the pins are coming out. I think a lot of the got lean and stuck fawlt estimates are realy a loose pin. A steel pin in a alu lump with high vibration and high heat its strange it lasts as long as they do.
I think that Johns work here has saved the Merc high perf cummunity with so much trubble and have done a lot of investments to help us with this that trying to fool him into explaining his prosess that maybe should be patented ! is out of hand. We all get interested if we feel its kind of seecret , but be happy that he has done this reserch and does it for us and send him the pistons. We should have a yearly inovation award of screamandfly ! I wote for the first one to John ;-)

[us1]

Jon I am not getting any Of your e mail, Gary said some time back u sent somthing to me and I did not get that also. E MAIL Is [email protected] Phone Is 502 732 4824, This post went way wrong, But thanks again for all your Info, you To US1. Tony Wilson PS Hell All I wanted to do Is get the damn pin out.

I don't mean to take anything out on you. I would be happy to do work for you if you need it. I never give out information on my process and when I did here I end up getting shot down. Believe me if there is one thing I know about on this plaint its piston pins. I am the only successfully commercial piston pin replacer I know of. (Goggle top pin pistons) You should try it yourself. If I never did I wouldn't have this business.
John Marles

I learned my lesson again: No good dead goes unpunished

[johnrude]

Hey Guys Before I post my CHEAP method of doing this , I will say it DEFINATLY would be better to send the pistons to the Pros, But if you are someone that like to experiment with such things(port heights, Piston pins, compression ETC) this is not THAT HARD, I been doing them 2 different ways for 5-6 years now with no failures i know of, HotTrucks is right on the money For the BackYard mechanic. I have only done wisecos, So this may not work on other brands ,,, Being very careful on every process, Tape the pin on in, you will be suprised how far it will go, Using a small cut off wheel on a battery powered 1/8 dremil with a very thin cut off wheel, (most dremil bit sets come with a supply of these) "carefully" cut off the bit of pin left sicking up, if any?. I use an old V4 wrist pin roller for the pin, It measures .091 so i use a .088 bit to drill the hole directly in front of the pin i pushed on in. Any smaller and tighter it will raise the aluminum around the pin and push it into the cylinder wall, (This is from experience,LOL) Again this should only be done by the adventureus, as you may mess up a few times gettting it down, I do my own boring , poting, sleeving etc, so I am familiar using these tools, I have NEVER seen a lower ring pin come out ? So i see no problem with letting the ring cover the Lower pin after pressing it in, I need to state that all my experience is with OMC and wisecos so maybe the merc guys have seen a lower pin come out? As far as ring gaps being lined up, if you have set the proper endgap clearance there should be no problem with this, also dont forget that you have to cut the end of the ring to fit the new pin, Also put a small bit of Weld over the top of the pin, I have my nephew weld them for me and I pic them up as soon as he is done so i dont think they get any hotter than when they are running, except for the tiny spotyou are welding, If possible I am going to post a pic of a piston i did years ago that came out of an engine that was freshened this winter, it has about 300hrs on it with no problems, TONY , if you are like me and just like learning such stuff? Go for it man, Start on some old pistons, Move on to good ones when you feel you have it down, Just take your time, AGAIN if you are not comfortable grinding and drilling on pistons? SEND IT TO THE PROS !!

[johnrude]

My file was TOO BIG, think I have it now !
J.R.

[roadkill636]

http://aycu26.webshots.com/image/47865/2002197311808517466_th.jpg (http://allyoucanupload.webshots.com/v/2002197311808517466)

[roadkill636]

what happened to this one???http://aycu26.webshots.com/image/47865/2002197311808517466_th.jpg (http://allyoucanupload.webshots.com/v/2002197311808517466)

[us1]

I have a few of those too. The ring wore through the soft stock pin as in this Mercury factory top pin piston.