tcode1568908558 Posted February 7, 2010 Author Report Share Posted February 7, 2010 The engine finally gave up . I always thought that rods will go first, however it seems I reached a different weakest link.Over 2,3 bar of boost, 500+ Nm and 450+HP on stock internals were the limit in my case . Enough of experimenting, time to do some work on the engine now . Link to comment Share on other sites More sharing options...
GerBeGurGya Posted February 7, 2010 Report Share Posted February 7, 2010 Sorry to see this tcode.How many miles did you have on these internals?To break some rings isnt hard even under stock conditions when they are weakened and that 2.3Bar doesnt sound like something for the light hearths.I dont see any melting there which is a good sign but have you thought about lowering the compression ratio further then stock when you will rebuilt this engine to have a fighting chance against that 2.3bar? Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 7, 2010 Author Report Share Posted February 7, 2010 GerBeGurGya wrote on Sun, 07 February 2010 18:59Sorry to see this tcode.How many miles did you have on these internals?To break some rings isnt hard even under stock conditions when they are weakened and that 2.3Bar doesnt sound like something for the light hearths.I dont see any melting there which is a good sign but have you thought about lowering the compression ratio further then stock when you will rebuilt this engine to have a fighting chance against that 2.3bar?Thank you. The engine has 80k miles, last 20k with GT3071r turbo. There's no any melting or detonation signs. The piston just wasn't strong enough to handle that power. Forged pistons with same compression ratio should be fine I guess. Link to comment Share on other sites More sharing options...
GerBeGurGya Posted February 7, 2010 Report Share Posted February 7, 2010 tcode wrote on Sun, 07 February 2010 13:27GerBeGurGya wrote on Sun, 07 February 2010 18:59Sorry to see this tcode.How many miles did you have on these internals?To break some rings isnt hard even under stock conditions when they are weakened and that 2.3Bar doesnt sound like something for the light hearths.I dont see any melting there which is a good sign but have you thought about lowering the compression ratio further then stock when you will rebuilt this engine to have a fighting chance against that 2.3bar?Thank you. The engine has 80k miles, last 20k with GT3071r turbo. There's no any melting or detonation signs. The piston just wasn't strong enough to handle that power. Forged pistons with same compression ratio should be fine I guess.No arguments here just trying make a point.When the engine has many miles the rings are thinning meaning less sitting surface in the groove less to hold it right and will start to move up and down as the piston moves.Give it some extra work and the ring will snap taking the piston with it.What I'm trying to say here its not the piston that gives away but the ring.Now to prevent this from happening you have to lower the top pressure inside the chamber and/or get some upgraded reinforced rings.Still I think a new set of OEM ring would work just fine until it thins out to a point when it breaks just lower the compression ratio a tad more. . Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 7, 2010 Author Report Share Posted February 7, 2010 GerBeGurGya wrote on Sun, 07 February 2010 19:49No arguments here just trying make a point.When the engine has many miles the rings are thinning meaning less sitting surface in the groove less to hold it right and will start to move up and down as the piston moves.Give it some extra work and the ring will snap taking the piston with it.What I'm trying to say here its not the piston that gives away but the ring.Now to prevent this from happening you have to lower the top pressure inside the chamber and/or get some upgraded reinforced rings.Still I think a new set of OEM ring would work just fine until it thins out to a point when it breaks just lower the compression ratio a tad more. .I see your point, it makes sense. However, there's a several statements on this and some other Volvo related boards of max. power OEM pistons can handle, most of them sates a 450HP number as a limit. Since I broke that limit it was just a matter of time for happening what happened. Quality forged piston kits includes better rings too, that's I was told so far. Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 7, 2010 Author Report Share Posted February 7, 2010 Speaking of forged pistons, I'm listening for a suggestions .Also, what about crankshaft bearings, are OEM good enough for a 600HP engine setup? What about head gasket? Tropis, can you give some advice on this ? Link to comment Share on other sites More sharing options...
Sute1568908560 Posted February 7, 2010 Report Share Posted February 7, 2010 Exactly the same happend to my phase 2 T4 pistons just at 350 hp. No signs from detonation...Well my 700 hp engine will be equipped with this kind of piston:JE with thermal barrier crown... Link to comment Share on other sites More sharing options...
ByTor Posted February 8, 2010 Report Share Posted February 8, 2010 I'm sorry about your engine. Good luck with the next one. Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 8, 2010 Author Report Share Posted February 8, 2010 "New" engine is in, H brace also . Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 8, 2010 Author Report Share Posted February 8, 2010 ByTor wrote on Mon, 08 February 2010 03:32I'm sorry about your engine. Good luck with the next one. Thank you . Although I wouldn't be so sad, that wasn't bad luck, I was pushing it to the very limit and it was really matter of time for hazard to hapen. Actually that engine lasted enormous long assuming it's operating conditions. Link to comment Share on other sites More sharing options...
theForgottenone Posted February 8, 2010 Report Share Posted February 8, 2010 tcode wrote on Mon, 08 February 2010 07:27"New" engine is in, H brace also .That's a quick turn around time. Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 8, 2010 Author Report Share Posted February 8, 2010 xcites40 wrote on Mon, 08 February 2010 16:32tcode wrote on Mon, 08 February 2010 07:27"New" engine is in, H brace also .That's a quick turn around time. Yeah, luckily I had good spare engine waiting for forging. That engine is now in, and the other one with bad piston will be used for forging. A complete swap took me and friend of mine a day . Link to comment Share on other sites More sharing options...
Sute1568908560 Posted February 8, 2010 Report Share Posted February 8, 2010 tcode, which is your turbo choice for 600hp hunt? Link to comment Share on other sites More sharing options...
tcode1568908558 Posted February 8, 2010 Author Report Share Posted February 8, 2010 Thinking about Borg Warner 83-75 . Link to comment Share on other sites More sharing options...
Sute1568908560 Posted February 9, 2010 Report Share Posted February 9, 2010 tcode wrote on Mon, 08 February 2010 13:33Thinking about Borg Warner 83-75 . Hmm..60mm compressor inducer..friend of mine reached 600 hp with gasoline and Holset HX40 Super, which has 60mm compressor inducer. Yeah, it is possible but you are pushing it to the limits. Turbine wheel seems to be large enough. My new turbo will be Holset HX50 hybrid with 69mm compressor inducer and 72mm turbine wheel. Exhaust housing is from Schwitzer S2B and housing size is #18 ~ 1.00 A/R.. Link to comment Share on other sites More sharing options...
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