Well my motor finally gave out. Was checking my fuel pressure and while getting on it felt my cars power give out and looked back and nothing but smoke. Took it back and opened the hood. There was oil in my IC and intake piping. Actually blew oil out my HKS BOV onto the engine bay. We then took out all the plugs and all looked well until we got to cylinder #6 where we discovered oil on top of the piston and on the plug. Then did a compression test on it and here are the readings 110,110,110,110,110,25 (cyl. #6). Probably the rings that gave out, but might be the headgasket and cracked from the oil galley to the cylinder. Would be nice if it was just the headgasket, but probably the rings or piston.
Any thoughts or ideas would be helpful.Also has anyone done a compression test on there RB25, if so what were your readings?.....to me 110 seems pretty low for a 9.0:1 motor.
The RB25 is down!
Re: The RB25 is down! (DETurbine)
you should be getting anything from 160 going up. probably your rings are shot. crack her open and throw in some forged slugs while you are at it.
Re: The RB25 is down! (gani)
not true, compression tests should be judged by the number from cylinder to cylinder, if you have 5 cylinders with 140 and 1 with 75, there is a serious problem with that cylinder. most gauges will give accurate readings but ive seen N/A race engines put down 80 compression on each cylinder and its 100% normal because of valve overlap.
have a leakdown test performed if you want to be sure where the problem lies before you tear the block down.
have a leakdown test performed if you want to be sure where the problem lies before you tear the block down.
Well finally got around to doing a leak down on it. Put it at top dead center for cylinder #1 & #6 and tested cylinder #1 first and air was leaking out the valve cover oil blow-by stems. Then tested cylinder #6 and same thing. There is no leaks coming from the head gasket, so has to be the rings. Nothing new though, just my luck! It is going away for the winter and will be putting some forged pistons, metal headgasket, and ARP head studs in. Money I didn't want to spend, but I guess that happends some times.
Re: (DETurbine)
Man that really stinks, sorry to hear it man...
Maybe it will rise from its ashes to be a bigger stronger beast!
Maybe it will rise from its ashes to be a bigger stronger beast!
Re: (DETurbine)
remember, it has to be TDC on the COMPRESSION stroke. not TDC on exhaust.
also, open the oil cap and listen for air, that will tell you if its the rings.
also, open the oil cap and listen for air, that will tell you if its the rings.
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Imissmyturbo
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Re: (Kamin)
What did you have done to the motor? Did it give out with the stock turbo? Was your timing setup? That kinda feaks me out since I am shooting for 350+ WHP.
Sorry to hear man... and good luck with the motor build. It might be easier to find JUST a new rb25 motor without the clip wiring or anything - it might not actually cost too much.
Also just as a heads up. Once you have it back together, watch for weird things. You dont want to take down another motor if a problem (most likely fuel related) still exists. I would get a wideband before you put the motor back in.
Murray
Also just as a heads up. Once you have it back together, watch for weird things. You dont want to take down another motor if a problem (most likely fuel related) still exists. I would get a wideband before you put the motor back in.
Murray
Imissmyturbo- Nothing was done to my motor except for upping the boost and exhuast. Timing was dead on, just got an unlucky motor.
DSM's_Suck- I don't know if it is possible to find a long block for any cheaper then $2000. Probably will cost me the same amount as if I were to build it, so I would rather keep mine and have forged pistons, metal headgasket, and ARP studs. I did hook up a wideband to it and it is way to rich, were getting down to the 9's, so leaning it out wasn't the problem. I did cut into the turbo elbow when I was grinding it down and had a decent size whole right by the o2, so I am sure the fuel map was always changing do to that. Still rich though.
DSM's_Suck- I don't know if it is possible to find a long block for any cheaper then $2000. Probably will cost me the same amount as if I were to build it, so I would rather keep mine and have forged pistons, metal headgasket, and ARP studs. I did hook up a wideband to it and it is way to rich, were getting down to the 9's, so leaning it out wasn't the problem. I did cut into the turbo elbow when I was grinding it down and had a decent size whole right by the o2, so I am sure the fuel map was always changing do to that. Still rich though.
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Nameless EJ6
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Re: (DETurbine)
How much boost did it take to do the damage?
Re: (Nameless EJ6)
I had 13psi for less then 5min. Before that it was set at a constant 10psi. The motor was slowly going, I could feel power loss for a while now (probably loosing compression) and never checked the compression which I should have.
With any motor, you are going to have good ones and bad ones. Mine was the poor example of the RB25, but a good one is 585hp on the stock motor (stock internals, head, and not even a aftermarket head gasket or aftermarket head studs).
With any motor, you are going to have good ones and bad ones. Mine was the poor example of the RB25, but a good one is 585hp on the stock motor (stock internals, head, and not even a aftermarket head gasket or aftermarket head studs).
Re: (DETurbine)
Man, that's terrible to hear DETurbine.
There's absolutely no chance of a rebuild?
I would think you could bore and rebuild easily, but...
Keep us posted.
There's absolutely no chance of a rebuild?
I would think you could bore and rebuild easily, but...
Keep us posted.
Re: (Dramier)
No it can be rebuilt, that's what I was saying. I am more then likely going to bore it out, new forged pistons, rings, metal head gasket, and probably ARP head studs. Going to run me between $1500-2k.