DR650 790 Big Bore Installation and Review

[jessepitt]

Sorry to see that.

[slowsuki]

wow thought i was having a bad day, sorry to see that , mabe ring broke when installing it.

[Mr. Canoehead]

Is the damage on the piston on both faces or only one? I can't tell from your photos. Assuming it is on both faces:

I didn't see this kind of damage occurring unless the ring broke and ended up between the piston and cylinder wall.

So, I did some research and here is what I found (this from www.ms-motor-service.com):

Initially, it looks like this:



But in these cases, damage above the skirt should be minimal. So, I did some more research and found this:







It definitely sounds like no end gap could cause this, although it is not identified specifically in the article. Your piston looks like image #4.

However, those who believe in the Motoman break-in strategy might want to take a good look at this....

If anyone wants a little light reading on this: http://www.boosttown.com/engine/piston_damage.pdf

[planemanx15]

Originally Posted by Mr. Canoehead

When you first put the piston in with no rings, did it move freely in the bore? Just wondering what the piston clearance was.

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The clearance was tight. Now without the rings, it fits very sloppy.

[planemanx15]

Originally Posted by Mr. Canoehead

Is the damage on the piston on both faces or only one? I can't tell from your photos. Assuming it is on both faces:

Thank you for the information. I think my problem was the rings were too tight, and didn't allow oil to pass, causing the issue. Running it hard on the highway created more heat, and ultimately chewed themselves up, and the metal chewed up the cylinder and piston.


Procycle is really a great company and Jeff is an outstanding guy. He offered me a new piston and he will look at my cylinder to check if it can be honed out and used again. When I get it back, this time I'll check the ring end gaps…

Later I will take more pictures of the damage, the rings, and how tight they actually are in the cylinder. I feel pretty friggin stupid, but thank you all for the support and advice with this issue. Hopefully the rest of this project goes smoothly.

[davesupreme]

i don't know it off the top of my head, but there's a ratio to the ring gap/bore size that's pretty much universal ..... .xxx ring gap clearance times bore size in inches... here's the weisco one....

http://www.wiseco.com/PDFs/Manuals/RingEndGap.pdf

never hurts to measure twice, cut once.... grasshopper...(i love that shizzit!....)

one of my favorite sayings is... "we learn life thru suffering...."....

[techforlife]

Originally Posted by planemanx15

Thank you for the information. I think my problem was the rings were too tight, and didn't allow oil to pass, causing the issue. Running it hard on the highway created more heat, and ultimately chewed themselves up, and the metal chewed up the cylinder and piston.


Procycle is really a great company and Jeff is an outstanding guy. He offered me a new piston and he will look at my cylinder to check if it can be honed out and used again. When I get it back, this time I'll check the ring end gaps…

Later I will take more pictures of the damage, the rings, and how tight they actually are in the cylinder. I feel pretty friggin stupid, but thank you all for the support and advice with this issue. Hopefully the rest of this project goes smoothly.

So they are offering to give you a new piston even though you caused the failure

If that`s true......you got to give a big hand for that company..........that`s looking after a customer way beyond what they should...

But.......here`s a thought.....if you are selling a piston/ring/cylinder kit to the general public........maybe you should file the ring gap for them to ensure it`s done properly........does the company need to do this,no,but it would have prevented this..

I`ve seen this happen quite a few times......if the seller just sells the piston or cylinder separetely then fine,,you can`t gap the rings.....but if selling in a kit then they should just do it..since they have all the parts......this would take that part out of the hands of a person that`s not a pro builder........

Seems to me that if the seller gives you a new piston he kinda thinks it would have prevented this,,,,and is willing to take the hit to some point to keep the customer happy.......good for them,nice to see a company look after their customer..

B

[planemanx15]

Originally Posted by techforlife

So they are offering to give you a new piston even though you caused the failure

If that`s true......you got to give a big hand for that company..........that`s looking after a customer way beyond what they should...

But.......here`s a thought.....if you are selling a piston/ring/cylinder kit to the general public........maybe you should file the ring gap for them to ensure it`s done properly........does the company need to do this,no,but it would have prevented this..

I`ve seen this happen quite a few times......if the seller just sells the piston or cylinder separetely then fine,,you can`t gap the rings.....but if selling in a kit then they should just do it..since they have all the parts......this would take that part out of the hands of a person that`s not a pro builder........

Seems to me that if the seller gives you a new piston he kinda thinks it would have prevented this,,,,and is willing to take the hit to some point to keep the customer happy.......good for them,nice to see a company look after their customer..

B

Not giving it to me, I am paying for the piston. He could have said you broke it, so buy a whole new kit; but I thank Procycle for not going that direction.

[procycle]

I've offered planemanx15 a deep discount on a replacement piston to help him through this 'learning experience'. But first we'll take a good look at the cylinder and make sure it is salvageable. There's a pretty good chance it can be saved. The nodular iron sleeve material is incredibly durable. I know it looks like toast in the photos but a lot of what looks like damage will turn out to be aluminum from the piston that has transferred onto the cylinder.

[techforlife]

Originally Posted by procycle

I've offered planemanx15 a deep discount on a replacement piston to help him through this 'learning experience'. But first we'll take a good look at the cylinder and make sure it is salvageable. There's a pretty good chance it can be saved. The nodular iron sleeve material is incredibly durable. I know it looks like toast in the photos but a lot of what looks like damage will turn out to be aluminum from the piston that has transferred onto the cylinder.

Looks good on you offering a discount to help him out..that`s looking after the customer..

But.......i`ll say this..i`ve rebuilt a pile of engines,,i know ring gap has to be checked..a newbie isn`t necessarily going to though...

I still think if you are selling to backyard mechanics/do-it-yourselvers and are suppling the piston/rings and cylinder.........then the supllier should gap the rings...they have the means and knowledge to do so and can take this out of the hands of the first time builder.......yes the builder is responsible...but this would go a long way towards ensuring this wouldn`t happen ..

B

[procycle]

Originally Posted by techforlife

I still think if you are selling to backyard mechanics/do-it-yourselvers

When someone orders a BB kit I have no way to know if they are a newby or a vetreran engine builder. I know I would not want to receive 'pre-gapped' rings in a kit I bought. I want to make my own decision about what spec to use. The sheet that comes with the rings gives the specs for ring gap. There are different specs for different kinds of applications. Info about ring gaps is easily found on the web. In addition, the time involved to gap rings would just drive the price up. The cost is already high and anybody who want to do it themselves shouldn't have to pay extra for us to do it. I suppose I could offer it as an additional service but that really shouldn't be necessary. It's a simple enough procedure.

[baloneyskin daddy]

This thread is a perfect example of "don't fix it if it aint broke" Bigger is not always better,extra displacement always brings consequences. One, is more heat and stress on every other part of the drivetrain and engine.Ask a simple ? before doing these mods. Do I really need to spend this much money for a few more HP . Better money would have been spent on portwork and lightening engine internals which would have minimal negative effects.

[desmodab]

Let's not pile on planemanx - he did his best and spent hours writing this up so all of us could learn and follow along vicariously. Mistakes happen, even by veterans and professionals. Let's see what we can do to support him like Procycle is doing. I am far from religious but "do unto others" comes to mind...

[Gale B.T.]

i am far from religious but "do unto others" comes to mind...

+10 Amen!

[techforlife]

Originally Posted by procycle

When someone orders a BB kit I have no way to know if they are a newby or a vetreran engine builder. I know I would not want to receive 'pre-gapped' rings in a kit I bought. I want to make my own decision about what spec to use. The sheet that comes with the rings gives the specs for ring gap. There are different specs for different kinds of applications. Info about ring gaps is easily found on the web. In addition, the time involved to gap rings would just drive the price up. The cost is already high and anybody who want to do it themselves shouldn't have to pay extra for us to do it. I suppose I could offer it as an additional service but that really shouldn't be necessary. It's a simple enough procedure.

You`re right of course.it is simple enough...but gets over looked it seems..

Offering it as an additional service at least would put the customer "on notice" that it needs to be done...kind of a friendly reminder

Nice to see you guys looking after this guy i must say...even if it`s his issue not yours......very nice customer service..

B