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STOCK F20C2 Snapped a Conrod?! Friend's Car - Need Help
With a heavy heart I post this thread. My friend has a 2006 DBW EuroDM spec F20 S2K. He said he installed a rebuilt, 4.7 final drive diff just recently. He bought the old stock diff from me and got the final drive swapped out with a 4.7. Last Saturday after the install he decided to go test it by doing drag racing... he got up to fourth gear after maxing out every gear before that and then noticed a lot of smoke out the back and then the engine switched off...see pics of the carnage below... I'm stumped as to why a stock ECU'd, non-boosted, non modified (except for the new diff) F20 engine with about 95000 miles on the clock and a one owner car (he said he never over-revved it before) would break like this...? Even the sleeve of cylinder four broke?! Oil he has been running is Liqui Moly 10W40 which is a semi synth oil. He runs on Shell V Power 95 octane pump fuel. Looking for advice to help the dude out please?
Maybe oil starvation in cylinder 4? #4 tends to suffer most under heavy load, though a single 1/4 mile run isn't super stressing. Agree it's unusual for a stock motor to let go quite so spectacularly, even at 12 yrs/ 95k miles. As far as the damage, if the rod broke first, the sleeve and piston damage are just collateral.
Maybe oil starvation in cylinder 4? #4 tends to suffer most under heavy load, though a single 1/4 mile run isn't super stressing. Agree it's unusual for a stock motor to let go quite so spectacularly, even at 12 yrs/ 95k miles. As far as the damage, if the rod broke first, the sleeve and piston damage are just collateral.
Thanks for the reply. This oil starvation thing is the first thing I thought of but the owner said his oil level has never been low in the past. I'm not sure exactly how many runs he might have done post the new diff install but like you said, it shouldn't be super stressing on a strong engine like this (a single run in particular)... I would have thought that oil jets could have caused starvation but Honda changed them out back in '03 for higher flow ones and people have commented about that banjo bolt issue that they wouldn't cause oil starvation unless you are running your car at 250km/h or something on the autobahn for 30 mins straight.
So the sleeve and piston were collateral due to the rod, ok.
Unfortunately there are always outliers in engine production. There are so many people that race these engines every weekend modified....everything we suggest could be just a guess at this point.
11-26-2018, 09:34 PM
STOCK F20C2 Snapped a Conrod?! Friend's Car - Need Help
Was he using OEM rods and wrist pins?