ShakeNBake

A friend had a mishap with his car, counted 110 level 5 revs. Crank-pully bolts backed out and accessory belt came off. Seemed to be a 4->3 shift instead of a 4->5 shift.

How would one go about confirming no damage?

thx

cgfen

ouch
disassemble and inspect for mechanical interference damage as a starter?

aircavscout

Put the belt back on and run it... I don't think you can determine anything without... I guess you could pull the plugs, test, compression etc.. hook up to diagnostics etc.. My understanding is if you don't have an issue with the motor after a level 5 within some number of hours after the event you are in the clear.. I know I read that somewhere but can't put a finger on the hours.

Serge944

You can't confirm "no damage."

While I personally know of some Cup motors that went in for rebuild after overreving to 11k rpm without blowing up, it is likely that a rebuild is warranted. It'll be cheaper to rebuild now, before you throw a rod. It's really up to your friend if he wants to risk it by continuing to run the engine. You can't "see" remaining service life of overstressed hardware.

Maybe turn this misfortune into an adventure by building a 4.0?

ShakeNBake

Thanks guys,

I hope it turns out ok.

sechsgang

as per porsche its after 40 hours you're in the clear...

Jamie_GT3

40 Hours is a long long time...

sharkster

Obviously drain the oil and check the filter too and see if there's any metal... Take the headers off and poke up in there any see if there's anything. Turn the crank manually etc...

Izzone

Dontrisk ur block

Replace rod bearings....probably deformed

New main and rod bolts...prob stretched

It's not as expensive to do as unthink

sechsgang

Guess they want to be safe vs sorry...

Alan C.

Ask your friend if he would buy a car with 110 hits in range 5 which happened in the last hour of operation. That should help the decision process. I looked at a GT3 with 30 hits in range 5 and it was CPO'd at a dealer. I passed.

Spiffyjiff

Deleted

Serge944

Ranges for GT3 cars are different than the rest of the 911 lineup.

Seth Thomas

Level 5 over revs will damage the rod bearings and stretch the rod bolts. If there wasn't any interference where pistons came in contact with the valves then the damage will not be apparent. Yes you can run the motor afterwards but the life of the engine will be limited. Be sure to take oil samples regularly if he doesn't do a rebuild as this will be the sign of wear on the engine.

I would personally replace the parts listed above at a minimum. This is the best preventative maintenance you can do other than a full rebuild. On our race cars we replace the bearings and bolts after similar number of level 3 type over revs. Level 5 would be immediate replacements.

ShakeNBake

great advice guys