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Registered User
Join Date: May 2003
Posts: 832
After 3 race motor falures could it be the twin plug electromotive or plug wires on c

Yeah, the first two engines blew up after a major rod bearing falure, We put the third motor in and had the lines, coolers,and replaced the thermostat, and then it had a rod bearing falure as well. With 12 plug wires would it have been possible to have one of the plug wires mislocated or problem with the electromotive which would cause the motor to pre ignite and beet the rod??
looking for anyone with any help,
Old 09-20-2005, 06:54 AM
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asphaltgambler's Avatar
Join Date: Nov 2004
Location: Nokesville, Va.
Posts: 5,451
Man, ............................sorry to hear your misfortune with THREE engines, I think that if the bearings are failing that the ignition would be the last place to look.

I think it would be time to replace your mechanic or the machine shop that did the work. This is reg*damndiculous!
'07 Jeep SRT-8 - Hauls groceries and Hauls *ss
'85 Guards Red Targa - F@#king Money Pit
'95 Road King w/117ci - No time to ride, see above
'77 Sportster Pro-Street Drag Bike w/93ci - Sold to collector
'72 Yamaha CS5 200 Twin - Sold to fellow Pelicanite

Last edited by asphaltgambler; 09-20-2005 at 02:30 PM..
Old 09-20-2005, 01:11 PM
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Walt Fricke's Avatar
Join Date: May 2004
Location: Boulder, Colorado
Posts: 5,082
Porsche Crest

I passed a 550 Spyder (the real thing) in the '91 Carrera Panamericana in my VW beetle cabriolet. So the Porsche obviously was not running right. Its mechanic later asked me what the firing order was for his four cam engine. Huh? The only time I had even seen such an engine before was in Grady Clay's shop once. No, no - it's the same as a VW. Ah, that I knew. Turns out they had some of the plugs (it is a twin plug engine) wired wrong, plus a condensor going bad. Beat the pants off of me after they fixed that, as it should.

The moral here - if you miswired your plugs you should have noticed that the engine wasn't running quite right. If one goes off when its piston is one third of the way up the compression cycle you'd think that might fire off the charge and you would notice it. And you won't have wired just one wrong - there will be two out of place.

More insidious could be having this pair firing where they might not slow the engine - like during the intake and power strokes. That would mean that the plugs for those holes that were firing correctly were acting like a single plug. If your compression and octane require twin plug action to avoid detonation, that could damage your rod bearings. On a street car you'd think you'd hear something, but with straight pipes, maybe not?

This isn't that hard to check, though, if you marked them (I assume they have been removed from the engine). See if a pair is mismarked. I have mine loomed in such a way that it is obvious that each connector can only go into one hole so I can't make this kind of mistake. I also marked the coil units so I can trace things if I get uncertain or unplug anything at that end.

Which rod bearings went? 2 or 5? That is usually an oiling problem.

Walt Fricke (just guessing here since you aren't getting a lot of responses)
Old 09-20-2005, 06:04 PM
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