Picco P7 Evo 3 engine repinch.

[@Protoproff]

@melas Hi Buddy, well we have ran 3 engines after repinching. All the engines have had aggressive running, without being kind to them to see if pinch holds. Running quite a bit on wide open throttle. All 3 still have unbelievable pinch even when engines are warm, one struggles to turn the flywheel by hand. Approx 2.0 liters of fuel put through engines and pinch still very very strong.

[@crazynitroeverything4482]

I did my os12 with a pipe cutter. Took out the cutter wheel put it in the three bearings and slowly rotated and tightened. Slowly and carefully. Next thing I know I have some pinch as opposed to none. Reassembled runs like new after many tanks idles like a champ has killer power. I'm convinced u can do it. But carefully. I had the piston in there while doing it but down the bore a bit. Only squeezed the very top.

[@Protoproff]

@KINGxCHAOSxx99 Unfortunately this is the most accurate way of compressing the liner, we are talking very small tolerances eg 0.001mm or less to prevent piston blow by.The other method folks use is the jubilee clip around the liner after heating it up, this process will not uniformly compress liner and the heat cycling will mean the liner will expand and return to its original state quickly, resulting in compression loss.Cold forging the metal as we have holds its form,hope this helps.Cheers

[@joelsoler3373]

I can't believe I finally found a video that shows how it's actually don't......Thank you so much!!!! I'm going to buy a lathe

[@Protoproff]

@soverato3 Hello again bud,no heat needed,collar must be a good fit.The only thing we didnt show in the video is that you must really wind down tight on the jaws,infact we had to extend the the handle to bear down some serious pressure on the jaws. Once you have applied pressure you may even leave the pressure on for a couple of min to allow the liner to settle.I assure you this method we have shown here works, you must run at least 2-3 tanks on rich setting,normal ABC eng. Hope this helps.

[@Protoproff]

@soverato3 Hello mate sorry for delayed reply, we found that after the engine had some laps and temps were up it started to act erraticaly. We developed difficult starting when engine was warm and cutting out, hence the repinch which is still holding out. Infact ive repinched a Go engine, its performance is better than when it was new, and im not joking. Its the 3port entry level engine which is performing quite well now. Thx for interest bud.

[@TheFpc20]

Hi Protoproff, i want to make the compression collar/ring that you made, i want do it for for a sh.18 engine that when it get hot it shut down by the low compression but i need to know how did you determinated the dimensions of the ring like the diameter of inside and out the ring and the bulk of this i need to know how did you determinated if the diameter inside the ring gotta be the same that have the sleeve.

[@sketchy19]

Hi Great video and very useful thanks. I have one question. Would it be better to turn the sleeve in the collar three times instead of the collar in the jaws or is it the same thing? I was just thinking that the main compression point is the saw cut so you should move this around the sleeve. thanks again

[@Protoproff]

Hi thx for the positive feedback, in all i have repinched 4 different makes of liners. The other 3 liners were rotated in the collar as well as being compressed in turn in each jaw, this ensured best possible even compression and would illiminate any discprencies in the jaws. I would recommend rotating as many times as possible though, the more the better. We just didnt apply this method to Andy`s liner on his call. Protoproff in reply to sketchy19 1 second ago

[@Protoproff]

@bobbymalta73 No probs mate thats what youtube is about, hope you enjoyed the video. Most of all hope it helps you salvage any engines you may have that need the treatment. :)

[@markbradbury7959]

Hi fellas Great idea I just di it to my sleeve to but maybe a bit too much the piston now stops about 8 mm from the top. What should I do I don't want to break the con rod by just firing her up straight away any suggestions? ?

[@rc_teo_nade_216]

Heat it up alot

[@Protoproff]

@badboyazza2009 Sorry mate the collars have to be custom made, not an off the shelf item sorry.

[@1ktmsx]

hi, i was wondering if i could make a pincher out of brass bar ? or does it have to be steel, thanks dave

[@Protoproff]

@dacooter Bud your liner needs the treatment, v.low compression by the sounds of it. What engine are you running?

[@Protoproff]

@NasherRC Hello mate i dont think a four jaw would be accurate enough as you would clamp the jaws in pairs and centering would be an issue. This process with your your knowledge should be easy for you. Let me know if you manage to implement this method.. Thanks for the interest.

[@RS_]

now that is very cool idea! How long do you think the engine would hold compression after repinching?

[@linkinminius977]

imperesionante

[@archienepomuceno76]

hi just wondering ..is it applicable to nitro plane and heli angine?

[@blaqkyellow]

After you pitch the piston. Did you have to break in the engine 5-7 tanks? Or was it good to run?

[@Protoproff]

Benny Lara we ran the engine rich, 3 tanks later we started tuning and bringing engine upto upper range.

[@bobbymalta73]

Thanks for sharing mate!

[@rcrmodelismomanutencaomanu8124]

gostei do som que estar tocando showw

[@Protoproff]

Unfortunately we don't sell kits or collars

[@77z2the8]

do you sell kits

[@vatanenj]

I think it is not done right! The sleeve should be rotated in the collar, not the complete sleeve/collar as an assembly. You can do the final touch by rotating the piston in the sleeve UPSIDE DOWN, Then you get a sslight taper on the piston which helps the piston to have slightly less friction in running state. If you go too far with the pinch, heat the sleeve on an electric plate so it expands back a bit.

[@MoodyDemiGod]

i know this is old but still i cant believe this idiot thinks he's evenly pinched the sleeve by rotating it in the same place every time.

[@Mad_Scientist2052]

That's correct. Rotating the sleeve in the collar in small amounts will result in a proper re pinch. Excellent video and the only one I have found that explians how to do it. Nowadays it's treated like some sort of proprietary process and not shown. Anyone that has machineing experience can do this and could be tought how to do it. Excellent video mate! I wish you made more.

[@Blacklamass]

This must be so out of round it’s probably just touching here and there, and the compression on a new engine is only about .5 mm at the top not 5.85 Anyway good luck it will probably strip the chrome off the bore after start up

[@ashermorales8276]

You need a stupidly precise tool to have it be perfectly round. That’s why you still have to break in the engine for a several tanks after a repinch (it’ll vary depending on the tightness of the repinch) I will say though. This method is definitely not the best out there. They didn’t pinch it with the piston in the sleeve so the entire sleeve is now tighter than before and the piston does help keep the sleeve from warping and having a tight spot. They definitely pinched it too tight or didn’t heat it up enough because I’m 95% sure that it kept dying out because the piston was getting stuck in the pinch. Honestly you’ll get better results from from a two piece clamping collar and a piece of copper tubing. There’s a video by MRC designs that shows how to do it

[@bradleymorgan8223]

please use more cooling fluid...

[@Protoproff]

More cutting\cooling fluid means more mess especially when you're using a video camera. Thanks for the info though.

[@longimanusisurus132]

Eso es una chapuza

[@robertobianchi5651]

Cavolo ma non si poteva fare il commento in italiano