Liner Squeezers

[Norm Doerr]

This past weekend the topic of "liner squeezing" came up and has me thinking... Being that I somewhat understand how it works, I am seeking comments, information, experiences and etc.

Thanks

Norm Doerr

 

[NITROSNIFER]

I beleive there was a topic allready started but I could not find it. I've been using the Woods Racing liners squeezers on my P-5 and 45ERX Picco's. They worked great and brought back the performance the engines used to have. I also purchased the liner set from Rayaracing and the end results were the same. The rayaracing set did not require you to be as carefull when squeezing to assure your liner does not get out of round but there is limited sizes for this set up. The Woods system has the squeezer built for your liner. My .45 Picco also fixxed a lame MAC .45 for another boater in our club and he was very pleased with the results.

 

[Ken Retallick]

Norm,

I have made several of these devices, tried various ways to use them and came to the

conclusion that they are a great thing to stuff up a liner totally. Yes they can bring back

a nice tight fit that feels like new but i can assure you that the liner is Not round anymore.

The whole design of the squeezers will not reduce the diameter, (which is in effect exactly what

we are trying to do) in a prefect circle. the liner ends up slightly oval shaped to an extent.

My experience, others may vary.

 

[Jerry Wyss]

I use this instead of sqeezing the liner,,it's much safer and you can give the piston this treatment

several times.

 

[Josh Stollfuss]

Jerry, is that a tubing cutter knurling a piston?

Josh-

 

[Jerry Wyss]

Jerry, is that a tubing cutter knurling a piston?

Josh-

Yeah Josh, That's exactly what it does. Usually run the wheel in the top oil groove

if it's close enough to the crown. Sometimes if the groove is down a ways I'll

start a new cut between where the piston wear is and the oil groove. It doesn't

take making much of a mark to do the job, but starting a new line takes a good

set of cutters and a good set of eyeballs.

 

[jimv]

I use this instead of sqeezing the liner,,it's much safer and you can give the piston this treatment

several times.

When you apply this to the piston, how hard do you crank it and how many turns around do you give it? I would belive that you don't want very much. Seems kind of subjective but if it works a bit, it would be worth it. How long does the effect last before the raised material is worn down? I have several sets of Picco 80 pistons and liners that could use a new fit.

Sorry, this is not quite on subject - however - I'm also looking at putting the pistons in the oven on the self clean cycle for about 30 minutes. Quench, reheat, and let air cool. I've done this before to get a small amount of growth, with good success. Anyone do this? I may not have the process quite correct as it was a long time ago.

Jim Vota

 

[Josh Stollfuss]

How do you size the piston back down if the cut expands too much metal on the piston? I knurled a set of pistons years ago on a cheesy engine rebuild I did for my old truck. I used a wire wheel on a bench grinder to take the sharpe edges off the knurling to size the pistons back down, it worked relatively well I ran the engine for another 20,000 miles.

Josh-

 

[Jerry Wyss]

I'm starting to feel a little uncomfortable in Norms topic on "Liner sizing". All I can say is

"light pressure", "little resistance" to the cutter going around the piston. You go too

much and you'll be doing a little lapping with a heat gun and some oil.

JW

Note: it would probably be better to "PM" me on anything further,

there's a size of the cutter that's important.

 

[jimv]

Norm,

I have made several of these devices, tried various ways to use them and came to the

conclusion that they are a great thing to stuff up a liner totally. Yes they can bring back

a nice tight fit that feels like new but i can assure you that the liner is Not round anymore.

The whole design of the squeezers will not reduce the diameter, (which is in effect exactly what

we are trying to do) in a prefect circle. the liner ends up slightly oval shaped to an extent.

My experience, others may vary.

Sorry for getting off topic.

With the liner squeezers, if you just egg shaped the liner, I'd think you wouldn't see much positive impact. You'd get a local fit and somewhere else you'd get more clearance. Net affect, not much if any improvement on compression. Yet, many people have had good results.

If you do this correctly and improve the fit, where does the deformed material go? Does the liner get a little longer? When deforming metals, treat them as an incompressible fluid, you push here, something moves there.

Have I regressed from the original topic again? If so, sorry.

No matter, I'll probably get one of these to try. Parts lying around doing nothing are worthless. What do you have to lose?

JimV

 

[Ronald van Essen]

Here is the topic:

http://www.intlwaters.com/index.php?showto...=liner+squeezer

Ronald

 

[Chris Wood]

The whole idea behind the liner squeezers that we make is to bring the fit back.. Most people think they can let the motor get REALLY loose and then squeeze it.. that defeat's the purpose.. if you continue to montor the fit and "occasitionally" re squeeze the liner it is much better for it than when the fit is totally gone..

As for elongation of the sleeve.. if you use them properly and rotate it every time you squeeze it. so you don't squeeze in the same spot all the time you should have a round sleeve.. my own opinon is that no sleeves are prefect.. even new.. some are better than others but they are not true either.. unless honed after the sleeve has been chromed.

then you still have the piston to deal with.

I have done what jerry showed about cutting groove. In my own opinon it is a emergency thing.. i feel better about squeezing the sleeve than cuttin the piston.

if you do decided to use this to i CANNOT STRESS ENOUGH, TAKE YOUR TIME WITH IT. don't go gorilla on it the first time or you will have to then relap the piston and sleeve.

it is a good tool. just remember to use it right.. one thing i would suggest if you do decide it to invest in a dial torque wrench that is set up for inch pounds that goes to AT LEAST 300 inch pounds that has a memory needle. that way you can keep track of how far you went the previous time so you don't over do it. that will work for 21-90 plus size motors.

any questions let me know

chris

 

[Wally Marsh]

If I might add to what Chris said. I have been using the Wood's designed squeezers for a couple years to tighten up the range from .21 to .84 motors. In no case were the the P & L completely worn out or scored up, just losing the interference fit. A memory dial torque wrench is a MUST, I got mine at McMaster-Carr 2 years ago for $140. As with anything in our hobby, use common sense. I go around ithe liner a quarter at a time, 5 inch pounds at a time, and re-check the fit each squeeze. In my experience, they do work, and save time and $$ on that special mod motor we have.

the Wallster

 

[Geraghty]

Chris,

Basically what you are doing when you squeeze the liner is you are removing the taper out of the liner.For some reason that just flat bothers me to do that. <_< In my opinion,removing that taper just flies in the face of good judgement.

Another consideration......If Novarossi,Picco,OPS,O.S.,etc,etc,etc......didn't want that taper in the liner,they wouldn't build it that way.Building taper into a liner costs $$$$ and the motor manufacturers would not be doing it if there was no benefit to do so.I for one assume that the manufacturers listed above know how to build a motor and I am not going to question that.

Granted,pinching the liner does bring back the idle in a car motor but it also has to increase the drag of the piston in the liner,not to mention that this process has to knock the liner out of absolute round,no matter what.

For the reasons listed above I personally choose to cutter grove the piston and re-lap the piston into the liner.

Every record that David Hall and I have set with the little "A"-.12 motors [2 more records this last weekend in Huntsville] have been set with,by the ebay sellers definition, old worn out ebay .12 car motors with pistons I have re-sized.Not a one of these record motors have a new P&S in them.I just re-size their pistons and the little "A" motors RPM right through the roof.Some of these motors have had their pistons re-sized 3-4 times and they only go faster when we put them back together after a re-fit.

I set them up with a good tight bump at the top and give em' hell right of the chute.They break in after a couple of tanks of fuel and the fit will last as long as a new piston and sleeve if we don't lift the head off the motor.If we have to lift the head and we lose the fit,I just do the process over again and the motor will run great again.

I have done this process literally a hundred times or better to customers motors,of all sizes,with outstanding results.

What you and your dad should do is come up with a good fixture to hold the piston and cutter wheel so the cutter wheel doesn't move around.This fixture also needs a way to "finely" adjust the pressure on the cutter wheel while freely rotating the piston with no drag in the fixture.

If the piston doesn't have oil grooves,I cut in oil grooves with the lathe and then cutter the grooves and re-lap the piston.

This process takes some time,patience and practice but the results are well worth it,and it is a dam sight cheaper than a new P&S.

Liner pinchers don't take the skill,tools or patience and some swear by the results of pinching but,I for one haven't chosen to go that way.

Rod Geraghty

 

[Norm Doerr]

Chris,

Basically what you are doing when you squeeze the liner is you are removing the taper out of the liner.For some reason that just flat bothers me to do that. <_< In my opinion,removing that taper just flies in the face of good judgement.

Another consideration......If Novarossi,Picco,OPS,O.S.,etc,etc,etc......didn't want that taper in the liner,they wouldn't build it that way.Building taper into a liner costs $$$$ and the motor manufacturers would not be doing it if there was no benefit to do so.I for one assume that the manufacturers listed above know how to build a motor and I am not going to question that.

Granted,pinching the liner does bring back the idle in a car motor but it also has to increase the drag of the piston in the liner,not to mention that this process has to knock the liner out of absolute round,no matter what.

For the reasons listed above I personally choose to cutter grove the piston and re-lap the piston into the liner.

Every record that David Hall and I have set with the little "A"-.12 motors [2 more records this last weekend in Huntsville] have been set with,by the ebay sellers definition, old worn out ebay .12 car motors with pistons I have re-sized.Not a one of these record motors have a new P&S in them.I just re-size their pistons and the little "A" motors RPM right through the roof.Some of these motors have had their pistons re-sized 3-4 times and they only go faster when we put them back together after a re-fit.

I set them up with a good tight bump at the top and give em' hell right of the chute.They break in after a couple of tanks of fuel and the fit will last as long as a new piston and sleeve if we don't lift the head off the motor.If we have to lift the head and we lose the fit,I just do the process over again and the motor will run great again.

I have done this process literally a hundred times or better to customers motors,of all sizes,with outstanding results.

What you and your dad should do is come up with a good fixture to hold the piston and cutter wheel so the cutter wheel doesn't move around.This fixture also needs a way to "finely" adjust the pressure on the cutter wheel while freely rotating the piston with no drag in the fixture.

If the piston doesn't have oil grooves,I cut in oil grooves with the lathe and then cutter the grooves and re-lap the piston.

This process takes some time,patience and practice but the results are well worth it,and it is a dam sight cheaper than a new P&S.

Liner pinchers don't take the skill,tools or patience and some swear by the results of pinching but,I for one haven't chosen to go that way.

Rod Geraghty

Rod VERY informative answer... I am a little confused on the fixture deal.. Would a rotor table on a mill work the same.. ??

 

[Chris Wood]

Chris,

Basically what you are doing when you squeeze the liner is you are removing the taper out of the liner.For some reason that just flat bothers me to do that. <_< In my opinion,removing that taper just flies in the face of good judgement.

Another consideration......If Novarossi,Picco,OPS,O.S.,etc,etc,etc......didn't want that taper in the liner,they wouldn't build it that way.Building taper into a liner costs $$$$ and the motor manufacturers would not be doing it if there was no benefit to do so.I for one assume that the manufacturers listed above know how to build a motor and I am not going to question that.

Granted,pinching the liner does bring back the idle in a car motor but it also has to increase the drag of the piston in the liner,not to mention that this process has to knock the liner out of absolute round,no matter what.

For the reasons listed above I personally choose to cutter grove the piston and re-lap the piston into the liner.

Every record that David Hall and I have set with the little "A"-.12 motors [2 more records this last weekend in Huntsville] have been set with,by the ebay sellers definition, old worn out ebay .12 car motors with pistons I have re-sized.Not a one of these record motors have a new P&S in them.I just re-size their pistons and the little "A" motors RPM right through the roof.Some of these motors have had their pistons re-sized 3-4 times and they only go faster when we put them back together after a re-fit.

I set them up with a good tight bump at the top and give em' hell right of the chute.They break in after a couple of tanks of fuel and the fit will last as long as a new piston and sleeve if we don't lift the head off the motor.If we have to lift the head and we lose the fit,I just do the process over again and the motor will run great again.

I have done this process literally a hundred times or better to customers motors,of all sizes,with outstanding results.

What you and your dad should do is come up with a good fixture to hold the piston and cutter wheel so the cutter wheel doesn't move around.This fixture also needs a way to "finely" adjust the pressure on the cutter wheel while freely rotating the piston with no drag in the fixture.

If the piston doesn't have oil grooves,I cut in oil grooves with the lathe and then cutter the grooves and re-lap the piston.

This process takes some time,patience and practice but the results are well worth it,and it is a dam sight cheaper than a new P&S.

Liner pinchers don't take the skill,tools or patience and some swear by the results of pinching but,I for one haven't chosen to go that way.

Rod Geraghty

Rod VERY informative answer... I am a little confused on the fixture deal.. Would a rotor table on a mill work the same.. ??

that's good to no rod. i was also thinking a rotary table.. and try to find a very small saw to put in a collet??

chris

 

[Geraghty]

[quote name='Chris Wood'

that's good to no rod. i was also thinking a rotary table.. and try to find a very small saw to put in a collet??

chris

That won't work.

You need something that is going to deform that oil groove,not cut it.

 

[dave roach]

I have been using the pipe cutter around the top of the piston for 15 years with go results.This will flare out the piston and be careful not to cut the piston.And you can do this several times and you can move down and do this below the top grove when the top gets worn.

Dave Roach

 

[Jerry Wyss]

In relation to the device Rod is desribing (I think) I would like to see something that didn't have rollers

coming behind the cutting wheel crushing what was just made.

 

[Joe_Knesek]

I think the rotary table work if you mounted the piston in the table & indicated it. Then mount the pipe cutting wheel to a bearing that can be chucked in the spindle so the cutter would rotate like it normally does. Rotating the table without running the spindle will have the same effect as using the pipe cutter but the height can be controlled.