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Rex P5 Piston
Hi yall just wanted to see how many of you out there are having the same problem as i am with the P5, i have had mine for a month and already i have shattered 2 pistons ! i have never had an engine thats done that. Ive had a hyper 4 port that just keeps on hummin.. Im dissapointed
Interesting fact , you can buy 4 pistons, Cylinders , Rings, Wrist pins and conrods for a "TRACTOR" for $245 US and a tiny weeny little Pisotn sleeve and rod set for a 21 nitro engine for about $140 US ... Now where is the logic in that ? These guys must be makign a fortune in rc parts ... |
RE: Rex P5 Piston
supply and demand ;)
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RE: Rex P5 Piston
Are you running the right % of Nitro? Sounds like you're getting detination to me. I'd check out your shim spacers under the head and see if you're set up right for the % fuel you're running.
Is that tractor radio controlled you talked about? Boat engine parts are just a bad. I dropped my boat off this spring to have the oil changed in the engine. It's a 4 stroke outboard and the oil change cost me $94 plus tax![:@] 2.5 Quarts of oil, a filter, and 15 minutes labor was $94! What a rip!!!![>:] Next time I'll ask before I drop it off for something! If you wanna play you gotta pay!;) |
RE: Rex P5 Piston
Kinda messed up, I just shattered mine last night, it was in a million little pieces broke apart from the wrist pin down.
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RE: Rex P5 Piston
Where do I go on the web to find out what the proper shims are? I know Nova recommends 25% and I am running 30% Odonnel. The guy at my LHS says the pistons shatter only if they have been overheated. I really need to find out why this happened Don't want to spend another 140 on a p/s set.
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RE: Rex P5 Piston
Will you take a picture of a "shattered" piston for me? I don't think I have ever seen anything like this. Like shattered in the way of a baseball bat to a car window, or like just split in half or what?
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RE: Rex P5 Piston
yeah mine shattered just like that half way across the wrist pin down it was shattered, my digi cam is off line so i cant take a pic but it looks like the bat through the window thing..
Im using %25 and have the stock spacers in, it wasnt overheating either i have a nova race pro head and its running just right... i think they are made to shatter so you have to buy more parts, im rebuilding my P5 to spec and selling it. Not delaing with people who make crap, Ive had 3 Hyper engines that cost half the money and they never break ! Ive had one of them that is on its 3rd pinch and is now ported and with original bearings , crank and rod and it belts ! still ! Im Switching over to CMB, they have a much better engine base and quality of engine .. And the tractor is a full sized farm tractor, the metal used in one of the wrist pins could make 10 P/S/R sets. |
RE: Rex P5 Piston
ORIGINAL: MassiveMods yeah mine shattered just like that half way across the wrist pin down it was shattered, my digi cam is off line so i cant take a pic but it looks like the bat through the window thing.. Im using %25 and have the stock spacers in, it wasnt overheating either i have a nova race pro head and its running just right... i think they are made to shatter so you have to buy more parts, im rebuilding my P5 to spec and selling it. Not delaing with people who make crap, Ive had 3 Hyper engines that cost half the money and they never break ! Ive had one of them that is on its 3rd pinch and is now ported and with original bearings , crank and rod and it belts ! still ! Im Switching over to CMB, they have a much better engine base and quality of engine .. And the tractor is a full sized farm tractor, the metal used in one of the wrist pins could make 10 P/S/R sets. WOW- Your doing something completely wrong if you have shattered 3 nova pistons. That is damn near physically impossible with someone who knows what they are doing. And that too- Novarossi Pistons? LoL- No way- your doing something wrong. |
RE: Rex P5 Piston
Hmm well can you tell me what it is because ive been running and modifying engines for years and have never come across such brittle pistons before.. Skyline its a total supprise to me too man ! But im not the only one its happening to ..
I guess if you read my signiature you will realise that i drive cars to their limit. i break stuff all the time but thats why im in this sport... still have never had this happen.. puzzled.. |
RE: Rex P5 Piston
ORIGINAL: MassiveMods ive been running and modifying engines for years |
RE: Rex P5 Piston
you cen get them for less than $100.... you are probably running too low clearance... the head thats aftermarket might have a longer combuston button and may require more shims?
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RE: Rex P5 Piston
ORIGINAL: fhm101 ORIGINAL: MassiveMods ive been running and modifying engines for years |
RE: Rex P5 Piston
ORIGINAL: killer89 you cen get them for less than $100.... you are probably running too low clearance... the head thats aftermarket might have a longer combuston button and may require more shims? The after market head uses the original button, so i dont think thats it.. Ill try a thicker head shim and see if i break any more.. Where can you get a P/S/R set from for $100? |
RE: Rex P5 Piston
Well there Massive-
You didnt originally state that you bought the motor USED! That has a lot to do with it. You have no idea how the motor was treated- broke in- what was robbed from the motor before it was sold to you. |
RE: Rex P5 Piston
ok , the motor i bought when i inspected it was in great shape, no scoring on the piston, bearings and rod in great shape, not even a scratch on the head, the engine was fine, i am merely puzzled as to why this is happening, as it turned out Kanaikiller gave some CONSTRUCTIVE advise and i think i may have found the problem ,
I dont see why you are taking it personally its not like im dissing an engine you made.. Im just after advise this is why we have forums, not to be bashed. |
RE: Rex P5 Piston
Oh I;m not bashing- don't take me the wrong way- I'm just wondering how someone goes through 3 nova pistons.
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RE: Rex P5 Piston
ORIGINAL: SKYLINE350GT Well there Massive- You didnt originally state that you bought the motor USED! That has a lot to do with it. You have no idea how the motor was treated- broke in- what was robbed from the motor before it was sold to you. Next time if your gonna dog a motor about it breaking parts or being fualty- MAKE SURE you are talking about a brand new motor that YOU have had since day 1. NOT SOMEONE ELSE'S TRASH! |
RE: Rex P5 Piston
ORIGINAL: SKYLINE350GT Oh I;m not bashing- don't take me the wrong way- I'm just wondering how someone goes through 3 nova pistons. |
RE: Rex P5 Piston
ORIGINAL: MassiveMods ORIGINAL: SKYLINE350GT Oh I;m not bashing- don't take me the wrong way- I'm just wondering how someone goes through 3 nova pistons. Your wrong. I wasnt bashing. All I can say is check your head clearance. If the motor hasnt been tweaked it should have 1 thick silver and 2 thin copper head shims. for 30% and 1 less for 20%. 0.022 head clearance is ideal. Was the sleeve pinched? |
RE: Rex P5 Piston
this is nothing to do with the P5, but skyline you just mentioned "head shims". I still have the HB .26 engine, and i have noticed when i take the head off, there is only the big silver plate that the glo-plug screws into, (no shims???). Is this normal on some engines or are they missing???.I can't possibly think i have lost them when taking off the head, in the past!!!
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RE: Rex P5 Piston
ORIGINAL: monte100 this is nothing to do with the P5, but skyline you just mentioned "head shims". I still have the HB .26 engine, and i have noticed when i take the head off, there is only the big silver plate that the glo-plug screws into, (no shims???). Is this normal on some engines or are they missing???.I can't possibly think i have lost them when taking off the head, in the past!!! I honestly don't know. every motor is different. Some need shims- some don't- to aquire the right head clearance. I'm not too familair with the HB .26's. Sorry |
RE: Rex P5 Piston
Many engine come with extra shims, not installed in the engine
the need to add shims depends on many things Most cases you don't need them. but if you're running high nitro% sometimes you will need to add a shim. Massivsmods, You sure you have the right connecting rod for that motor?? Are you sure it's a P5? the cases all look much the same you maybe putting a P5 P/S into a BS21SB which is a short stroke motor Or the guy you got it from sold you a "Frankin Motor" Just a guess Good luck |
RE: Rex P5 Piston
Now I had this the other month with a 421B. The piston was slapping the button though.
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RE: Rex P5 Piston
yeah that could be wear on your rod , bottom yoke may have play in it ..
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RE: Rex P5 Piston
Nope, that was because there were no shims in it from the factory. And it was only during break in and nothing had been adjusted. It also snapped the rod and threw it out the side of the block.
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