My engine BLEW OFF today!!
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Joined: Jun 2001
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From: Almaden Valley, CA
HondaS2001 & SJsharks - I love how you both know what happened and yet neither of you were there. I also love your theories on the rev limiter with nothing but generalizations to back it up. I think everyone here understands the concept of F=MA, so thanks for the flashback to Physics 101. Let's wait for some actual facts before assuming what happened.
r2d2 - keep us posted.
Jimbo
r2d2 - keep us posted.
Jimbo
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Joined: Jun 2001
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From: Milwaukee
HondaS2001 & SJsharks, I do engine development every day for a major engine manufacturer. The purpose of a rev limiter is to prevent engine damage, that is why it is there. The limiter will come in before damage is done, or it serves no purpose. Furthermore, the limiting factor is nearly always the valve train, not the bottom end. Ever notice that folks with mechanical overrevs always crash pistons into valves, and/or pop the heads off of valves?
Now I don't claim to know Honda's internal durability qualification targets, but most engine companies are similar. It is not uncommon to have a target of 20*10^6 cycles against the rev limiter with no failures. At our 9000 rpm redline, that is 74 hours against the limiter.
You cannot compare F1 engines and a street car engine. F1 engines only need to last for about 2 hours. If they last much longer than that, they are over designed and too heavy. I was at the SAE expo in Detroit when Yutaka Otobe from Honda did a technical session for the paper he co-authored on the design of the engine. He was the chief engineer on the F20C, and an engineer for Honda's F1 program before that. Someone in the room asked about the durability targets of the engine and he said they were nearly the same as for their other production car engines. When pressed he refused to elaborate further.
Now I don't claim to know Honda's internal durability qualification targets, but most engine companies are similar. It is not uncommon to have a target of 20*10^6 cycles against the rev limiter with no failures. At our 9000 rpm redline, that is 74 hours against the limiter.
You cannot compare F1 engines and a street car engine. F1 engines only need to last for about 2 hours. If they last much longer than that, they are over designed and too heavy. I was at the SAE expo in Detroit when Yutaka Otobe from Honda did a technical session for the paper he co-authored on the design of the engine. He was the chief engineer on the F20C, and an engineer for Honda's F1 program before that. Someone in the room asked about the durability targets of the engine and he said they were nearly the same as for their other production car engines. When pressed he refused to elaborate further.
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From: Drunk In Da Pub
windscreen and jimbo, if you do not think revving to 9k rpms hurts the motor and does not do any damage then rev yours to the limiter everytime you shift and youll end up like him.... no I was not there, but a pool of oil can only mean one of two things, jiffy lube screwed up (which he says they did not) or a rod went out the side of the block..... I never said the limiter didnt prevent damage, all I said was that if you keep revving your car to the limiter then you are wearing down parts faster..... you think taking your car all the way up to redline everytime you shift isnt wearing out parts more so then someone who shifts at 4 or 5 everytime??? windscreen, you say the limiter comes in before any damage is done? I didnt know the limiter comes on at 9K rpms to help prevent extra wear on rod bolts, thanks for that info, 9k rpms creates A LOT more wear on rod bolts and this is what will happen.....
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From: Drunk In Da Pub
for the record........ I was NOT saying that the limiter didnt prevent damage, and I was not questioned what it did.... I was however saying, that someone who takes their car up near the rev limiter very often is putting that motor at a higher risk to have a failure then someone who drives the car normal with the occassional high rpms.... if it did not make a difference, then motors would last forever...... but since parts wear out they do not...... and what makes them wear out? force/use and the difference between 4 or 5K rpms all the time and 9k rpms all the time is very great.... If it is indeed a thrown rod, what other indication would you have that caused this, that honda put a bad rod or rod bolt in? lol
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From: Drunk In Da Pub
skybolt, read up a bit before you get started into the oil jet bolts, do a search on oil jet bolts or banjo bolts and there will be a lot of threads covering it...... you may already have the new bolts, look on your engine block and there should be a number, if it is greater than 1025386 you have the new bolts.....
Joined: Oct 2000
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From: South of the pier, Huntington Beach, CA
Originally posted by hondaS2001
I didnt know the limiter comes on at 9K rpms to help prevent extra wear on rod bolts, thanks for that info, 9k rpms creates A LOT more wear on rod bolts and this is what will happen.....
I didnt know the limiter comes on at 9K rpms to help prevent extra wear on rod bolts, thanks for that info, 9k rpms creates A LOT more wear on rod bolts and this is what will happen.....