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Could i have i damaged my engine?

Posted: Fri Feb 25, 2011 4:30 pm
by bullyboy
Hi

Started up my rv8 4.6 today to show a friend and after a couple of mins at idle i revved it a couple of times to hear the lovely sound of the engine revving.
Unfortunately i had a spanner near the throttle linkage which jammed the throttle on full, after a couple seconds of panic i turned the engine of.
It was running at full revs for about 5/6 secs, is this bad?
The engine has done about 500 miles.
It sounds ok im just a little paranoid that i may have done something.
Your thoughts are appreciated.

Thanks

Chris

Posted: Fri Feb 25, 2011 4:33 pm
by ChrisJC
Probably OK. The hydraulic lifters prevent the engine overrevving too much anyway.

Chris.

Posted: Fri Feb 25, 2011 9:42 pm
by mgbv8
I wouldnt worry. Its no different form caning it for a few seconds on the road is it ??

Posted: Fri Feb 25, 2011 10:15 pm
by Ian Anderson
What efi system are you using?
I was advised by a dyno owner the Hotwire has a rev limiter at 6750

Ian

Posted: Fri Feb 25, 2011 11:23 pm
by bullyboy
its on a Webber 500 carb so no rev limiter.

Posted: Sat Feb 26, 2011 12:34 am
by DaveEFI
Ian Anderson wrote:What efi system are you using?
I was advised by a dyno owner the Hotwire has a rev limiter at 6750

Ian
Don't think any standard RV8 will get anywhere near 6750 rpm.

Posted: Sat Feb 26, 2011 7:19 am
by Ian Anderson
DaveEFI wrote:
Ian Anderson wrote:What efi system are you using?
I was advised by a dyno owner the Hotwire has a rev limiter at 6750

Ian
Don't think any standard RV8 will get anywhere near 6750 rpm.
Mine does but it;s not that standard!

Ian

Posted: Sat Feb 26, 2011 11:22 am
by need4speed
mgbv8 wrote:I wouldnt worry. Its no different form caning it for a few seconds on the road is it ??
Sorry but i disagree with you there. Its far more damaging for an engine to be held at 6500rpm for a while in neutral than it is revving at the same revs under load, ie driving in gear....

That being said, given the length of time the engine was revving, i think it will be ok.

Posted: Mon Feb 28, 2011 11:18 am
by kiwicar
Wouldn't worry myself I doubt you have taken 10 minutes off it's life. Have you ever tried to rev an engine to death :twisted: :twisted: :lol: ? you would be amazed how long it takes! The engine in question was in a Tolbert Solaira, full throttle in neutral about 15 minutes as far as I remember, it acatually siezed from over heating rather than going bang, my mate who owned the thing was most dissapointed, teach it to fail it's MOT for being a rust bucket.
Best regards
Mike

Posted: Mon Feb 28, 2011 12:42 pm
by mgbv8
need4speed wrote:
mgbv8 wrote:I wouldnt worry. Its no different form caning it for a few seconds on the road is it ??
Sorry but i disagree with you there. Its far more damaging for an engine to be held at 6500rpm for a while in neutral than it is revving at the same revs under load, ie driving in gear....

That being said, given the length of time the engine was revving, i think it will be ok.

You disagree and then agree ???

I see your point though :)
I accidentally revved my 3500c to over 8000 for a few seconds once. It survived !!
And its had a few good sessione recently when its hit the 7000 + mark as traction has been lost.

Posted: Tue Mar 01, 2011 8:18 am
by bullyboy
Great stuff.
Thanks for the help.

Posted: Tue Mar 01, 2011 9:41 am
by V8Smudge
kiwicar wrote:Wouldn't worry myself I doubt you have taken 10 minutes off it's life. Have you ever tried to rev an engine to death :twisted: :twisted: :lol: ? you would be amazed how long it takes! The engine in question was in a Tolbert Solaira, full throttle in neutral about 15 minutes as far as I remember, it acatually siezed from over heating rather than going bang, my mate who owned the thing was most dissapointed, teach it to fail it's MOT for being a rust bucket.
Best regards
Mike
We did a similar thing many years ago when I was doing my City & Guilds. The college had been given an MOT failure MK1 Fiesta 1.1, we jammed the throttle open and started it up, after 15 minutes we went for a tea break, when we got back it was still running. Our instructor knocked a screwdriver into the bottom corner of the sump to drain the oil out (pre-H&S :wink: ), the revs dropped a fraction and the engine became a bit rattly, but ran flat out for a good 15-20 minutes before we all became bored and poured some ball bearings into the carb and destroyed it :twisted: !!

Posted: Tue Mar 01, 2011 10:52 am
by kiwicar
Hi Smudge
I like your style alot :lol:
I think the solaira engine might already have been on it's way out as it had been used to see how fast we could get it to go in second gear. We sort of met a platau at about 55 from what I remember, couldn't get it to rev any faster due to valve bounce. That was until said owner came in one day and said "I got 83 in second", after the storm od disbelief settled down he explained how. . . Bottom of the M3 he got the car up to 85 in top (on the speedo) down hill keeping the throttle jammed open with one foot he declutched, slammed it into second and dumped the clutch, reconed he was still doing 83 when he got the clutch out! ! ! :twisted: :twisted: though he did admit that from the tyre smoke the wheels might not have been turning that fast.
Best regards
Mike

Posted: Wed Mar 16, 2011 6:26 pm
by Will Reeve
I remember at one of the shows a few years ago they drained the oil and water from a "breaker" and started it up and ran it to destruction. It takes ages, a good 10minutes before the engine seized and bits of metal shot out of the exhaust! Probably can't do it no due to H&S!