Trouble in River City!

[patalive]

Uh oh! I think I have major problems that will require a top end rebuild to remedy. You thoughts and advice most welcome and appreciated.

Went to a local garage party today, (Curry's Bash) - they were doing discount dynos so I signed up. (BTW, there was a blown Supra that turned 560hp at the wheels!) -
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My 83 SC (with 137k miles) turned a 166hp at the wheels - I was expecting a bit more since I am running those SSIs.
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The problem - - - -when the engine hit about 5500 - 6000, considerable black smoke came out the exhaust, none until the 5500 - - -then, when they backed off down to idle, white smoke came out the exhaust. Not good. Happened twice. One of the techs running the dyno guessed it might be rings or valve guides
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So, I think I need to have a leak down test done immediately to see if the problem can be pin pointed.
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However, any of you folks have ideas on the problem? The engine appears to run very strongly, without miss. It does use about a quart of oil every 500/600 miles. Will it hurt to keep driving it? I am scheduled to go to VIR for a DE at the end of the month but I suspect I had better cancel out of that. Hate to bring the engine parts back home in a basket.
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Depending on what we find, I suspect my next series of questions will be rebuild option levels.
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RATS! I was thinking about selling this car and getting something newer. This changes the economics drastically.

see
http://www.patalive.com/por


Chuck
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[Zeke]

Oh man! Nice car. If you're gonna sell it, sell it as is. Don't put another dime in it. Not everyone drives these cars hard all the time. Apparently you didn't, because before the dyno, you thought all was well. If you were closer, I'd come take a look. Yes, nice car. (I like red SCs).

[RazorRacer]

You should be getting 180HP at 5500 rpm. You also should get a 9.3 to 1 compression ratio. Let us know what you find out about the leak down test.

[patalive]

I know these cars are rated at 180 hp, but I believe that is a factory rating at the flywheel. The dyno measures the hp at the wheels, where it is always less than flywheel due to transmission and other loses. I'm not sure of the acceptable percentage that wheel hp should be of flywheel hp. Anyone know?

Zeke, thanks for the comments.

Chuck

[TimT]

166 at the wheels equals 191 at the flywheel, using a conservative 15% loss for wheel friction losses on the dyno, and drivetrain losses.

[beepbeep]

well HP rating seems to be spot-on considering tranny losses. 191 flywheel-HP is more that factory-stated 180 , those extra 11 HP probably came from SSI's

Black smoke is just excess fuel...white smoke? Well, probably just some burned oil :-) Who cares...as long as it doesn't drink too much it's OK...

[47silver]

hi
the skeptic in me sees a loss leader marketing strategy by this mechanic. free dyno? how could they afford to give free dyno testing and why? i think that there is nothing wrong with your engine and suspect that the mechanic is picking up quite a few rebuilds with this campaign


g

[Rick Lee]

Well, that's a bit of a buzzkill about your oil consumption. Ironically, I was at Curry's about 4=5 weeks ago when I first discovered that my Carrera was using a lot more oil than usual. In Curry's defense, I'll say Matt is a great guy who runs a first-rate operation. If I ever needed something done, which I couldn't do myself, I'd happily give him my business, except that he's so far from me. I think his four-wheel dyno is pretty new and he's trying to get the word out about it. When I was last there, the local Pantera club was doing dyno runs and a few Ferraris showed up too. He's got a great reputation locally and I'd take him at his word. He's also a very generous friend of our local Potomac PCA.

[47silver]

sorry
should not speculate.

g