A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster. Posts: 2755 | From: Elliott Lake,Ontario,Canada | Registered: Feb 2008
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posted
There is no exact hp they will bend at but they have been proven to take over 500rwhp for a few dyno pulls and take around 420-430rwhp for quite a few 1/4 mile passes when the tune is dialed in. Seahag bent all of his rods running high 10's which is right around that hp.
posted
It was detonation that killed my rod not RPM at all. I was shifting well under 6000 rpm and my #1 let go in fourth with 30 psi. when it let go there were no signs of detonation. The run before it let go there was well quite a bit.
-------------------- 11.42@120 no wideband. Posts: 9402 | From: Grants Pass, OR, USA | Registered: Dec 2000
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I had one go, but this thing had taken so much abuse (bad tunes, alcohol, 35+ psi boost runs) that it's not really all that surprising.
-------------------- E36 with a Ford: 2.5, A237, HY35 ... waiting on numbers this spring. '05 Benz C320 4Matic. Nice quiet daily driver. Posts: 3858 | From: St. Paul, MN, USA | Registered: Feb 2002
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quote:Originally posted by BGjohnson: Is it the rods that fail or the rod bolts?
I wonder if they would live longer after being shot peened with ARP rod bolts?
Mine were 'peened with good bolts (not ARP but a competitive upgrade, I forget the brand).
They are a cast rod and while they are beefy for 200 horsepower, they are marginal for 400 horsepower. If you're looking to make 400+ horsepower reliably ... then it's worth getting a good set of rods/pistons. They really aren't THAT expensive anymore.
-------------------- E36 with a Ford: 2.5, A237, HY35 ... waiting on numbers this spring. '05 Benz C320 4Matic. Nice quiet daily driver. Posts: 3858 | From: St. Paul, MN, USA | Registered: Feb 2002
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posted
correction they are forged steel rods......
yes its usually rpm that kills rods on 90% of engines but we run so much boost at low rpms or just we run so much boost!!! the pressures are wow!!!
and when the rod is at an angle with 30 psi above it and begins to compress the air high angle loading huge torque etc.... we are hard on rods.....
seems like some other high powered boosted motors have problems with bending rods as well
the rods are surprisingly durable.... but in adequate for endless flogging.....
-------------------- NEW TECHNOLOGY FOR OLD IRON! 7.5 to 1 compression aint no way to make power...UNLESS YOU BLOW ON IT H A R D! 88,89,88 merk 70 cougar,89 heap,66f250 Posts: 3783 | From: palmer lake , Co boostin at 7300 ft | Registered: Jun 2003
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-------------------- steve 75 pinto turbo 73 pintowagon turbo 76 mustang cobra II id like obama to stay out of my pockets, im fully capable of stimulating myself..... Posts: 2501 | From: west columbia, sc, usa | Registered: Oct 2005
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posted
Normally, I would think that a cast part would be more likely just break instead of bending like quite a few people here have. A forged rod would be more likely to bend.
-------------------- Sold - 1988 mustang: 12.2@111mph. :( Daily Driver - 1997 Mustang GT 14.0@99mph. New Project: Factory Five Roadster Posts: 4285 | From: Olathe, KS | Registered: Mar 2002
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Where in the world did you find that document? Do such documents exist for the Fox cars?
If so, I want one BADDDDD!
-------------------- Project Phoenix - A TF RX7 rises from the ashes The one, the only, Folvo MGB Posts: 2060 | From: Claremont, VA, USA | Registered: Dec 2000
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If you google the alloy they mentioned, it would appear that was almost a "default" ford spec for conn. rods. I found 5-6 different 70's era fords that mention that as the rod specification. Having worked at much smaller companies, I know sometimes parts/accepted parts get changed, but an overly aggressive spec is left in place (either because it was never changed, or as CYA). I can't imagine the bean counters truly accepted a forged rod in a 25hp/cylinder engine for two decades.
-------------------- 86 Mazda RX7, 2.3 swap, t5, MS3 sequential, BW EFR 6758 "If you can't dazzle them with knowledge, baffle them with bull sh*t" Posts: 7014 | From: Charlotte, NC, USA | Registered: Dec 2003
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posted
Its not just the peak power but the mileage you expect out of them. All of mine were bent after 75K miles and 24psi. They were not bent when I when I built it.
I started to notice a drop in the compression at around 60K miles. Which continued to get worse over time.
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they are forged in a machine shop you have stacks and stacks of rods laying around and the cast ones stick out like a sore thumb.
the parting lines give it away instantly.
the 2.3 rods arent particularly strong or anything but they are forged
cast rods almost never get spot faced bolt locations "the football headed bolt" its less expensive to do a straight cut
-------------------- NEW TECHNOLOGY FOR OLD IRON! 7.5 to 1 compression aint no way to make power...UNLESS YOU BLOW ON IT H A R D! 88,89,88 merk 70 cougar,89 heap,66f250 Posts: 3783 | From: palmer lake , Co boostin at 7300 ft | Registered: Jun 2003
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+1 everything I've observed prior to this thread has not disturbed my assumption that the stock rods are forged. Mine have since gone to a better place, but I think I have photos to take another look at. My rods were squished (precursor to being bent) in mildly abusive service. For that reason I upgraded to Crower Sportsmans. Let's face it. The stock rods were not designed for 2000psi+ cylinder pressures.
-------------------- Geoff - 85 XR DD back in service - with a vengeance! "Beyond the Palace, Hemi powered drones scream down the boulevard" - Bruce Springsteen Posts: 4126 | From: Chicago SW burbs | Registered: Mar 2003
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posted
Hmmn, I'd be pretty damn happy with an engine that could hold 2000psi BMEP! I was talking peak...
-------------------- Geoff - 85 XR DD back in service - with a vengeance! "Beyond the Palace, Hemi powered drones scream down the boulevard" - Bruce Springsteen Posts: 4126 | From: Chicago SW burbs | Registered: Mar 2003
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posted
I have read somewhere They came from a HI 289 rod. Just in turbo 2.3s they get a new number.I just wish I could remember where. It was most likely in a car mag, but I still have it so I'll have to look in the pile. Billy v
-------------------- What do u get when u feed booost to a dinosaur???? Booostalotopuss.T for Turbo-S for Supercharged. Posts: 2853 | From: Kingston, PA, USA | Registered: Nov 2003
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quote:Originally posted by booostalotopuss: I have read somewhere They came from a HI 289 rod. Just in turbo 2.3s they get a new number.I just wish I could remember where. It was most likely in a car mag, but I still have it so I'll have to look in the pile. Billy v
Once upon a time I read that in a car magazine also, but if you look at the specs for the two rods there are enough differences that I doubt it.
-------------------- Mark 1985 XR4Ti 1987 Turbo Coupe Posts: 122 | From: Richmond, VA, USA | Registered: Oct 2001
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