4500 rpms in your IDI???

[hce]

6" stroke cummins spinning 2200 rpm comes to about 37 ft/s. Thats with 12lb monotherms pumping up and down not to mention some hefty rods.
I sat and watched a large cummins governed out at 3000rpm (50ft/s) for minutes on end free reving in a blow up competition which it did not.
It would be interesting to see the lbs of force needed to reverse the direction of this piston and compared with the idi, g-force is cool but changing direction of a 2lb object vs a 12lb object at a given g takes a lot more force.

 

[hce]

found a piston inertia force calculator and approximate weight of a idi piston of 1000 grams, 12lb mono them 5444 grams.

idi at 4500 is 2650 lbs average between up and down
4000 2090
3800 1890
3200 1340
12lbs 2000rpm and 6" stroke is 4090 lbs.
1500 2300
1200 1472

 

[Dieselcrawler]

Had my 4.9 buzzing around 5500 a few times. A stock i6 sounds funny that high

 

[crash-harris]

Had my 4.9 buzzing around 5500 a few times. A stock i6 sounds funny that high

Before to rockers loosened up on my 300 and I rebuilt the top end, I revved it to about 6K ONCE at a classmate (way back in high school) that was revving his '0somethingorother camero at me. I swear she yelled "ouch!" And to this day, even with cheb rockers, hardened pushrodes, guideplates and steel gears, I won't rev that high.

 

[laserjock]

My 88 302 was screaming for mercy at 5500... that poor 300 I-6.

 

[crash-harris]

Oh yeah. It was a quick punch up to it, but never again. I'm still suprised that the lower end hasn't been touched at 600K and just about then the blowby got to the point that I could smell oil while cruising on the highway (crankcase vented to atmosphere). But there are numerous reports of a perfectly running, high mileage 300 being taken apart and main bearings disenegrating when the caps are removed.

Had a valvetrain failure at about 500K while on my way to pick up or 8K fifth wheel camper. No brakes on the camper and still got it home on 5 cylinders from halfway across the state. Just one of the rocker bolts loosened enough to not open a valve (could hear the miss but not feel it). All of then were loose and I dropped in rocker and head studs along with the aforementioned stuff and she'd pull like a scalded dog! 4500 rpm was about my safe/useful max speed. It would roll the camper attached to the 3 ton truck with barely a grunt, but the IDI pups much smoother and with slower engine speed. I relish getting to haul.

 

[Runningaford]

This thread reminds me of a Phoenix emissions testing center. They force all older vehicles, as well as all diesels to red line. The diesels they have you do it three times for about 4 seconds..... The gassers, well damn, they run them at redline for a couple, or more minutes.

State/City/EPA mandated destruction...

 

[Ruger_556]

He's actually not the first person to do it...someone who used to post on here did it with an otherwise stock engine and posted a video. You could hear the valve floating as the RPM's came up.

I figure this...that much rotating mass spinning that fast...even with upgraded valve springs, you'll get away with it for a while, but sooner or later things are going to scatter. There's a reason why big truck engines generally don't turn above 2500 RPM or so (and cruise closer to 1600 RPM IIRC), and the engines in large cargo ships barely crack 100 RPM. A person can do as he sees fit with his engine, but I strongly contend that it's taking a big gamble for not that much gain. Longevity's important enough to me that I wouldn't even think about doing it.

JMHO...

That'll set a permanent overspeed fault and possibly warranty cancellation on at least one major brand, most won't turn over 2200 rpm or so now...

 

[IDIoit]

This thread reminds me of a Phoenix emissions testing center. They force all older vehicles, as well as all diesels to red line. The diesels they have you do it three times for about 4 seconds..... The gassers, well damn, they run them at redline for a couple, or more minutes.

State/City/EPA mandated destruction...

setting the screw to half throttle would cure that

 

[The Warden]

That'll set a permanent overspeed fault and possibly warranty cancellation on at least one major brand, most won't turn over 2200 rpm or so now...

Forgive me; I didn't know the exact number so I made an estimate I actually had a feeling it was high, but I didn't want someone going off on me for giving a number too low...on the other hand, I think/hope I still made my point, as expanded on by a few others

 

[IDIoit]

update on this engine from FTE....
no bueno!
the guides wore more than a Taiwanese ***** @ port of call....
http://www.ford-trucks.com/forums/1438484-massive-valve-guide-wear-what-happened.html

 

[towcat]

we too have had one try convincing us it was a good idea too.
http://www.oilburners.net/forums/showthread.php?35822-HOW-TO&highlight=4500+rpm

 

[jwalterus]

Before to rockers loosened up on my 300 and I rebuilt the top end, I revved it to about 6K ONCE at a classmate (way back in high school) that was revving his '0somethingorother camero at me. I swear she yelled "ouch!" And to this day, even with cheb rockers, hardened pushrodes, guideplates and steel gears, I won't rev that high.

anyone else get a chuckle out of that one?

we too have had one try convincing us it was a good idea too.
http://www.oilburners.net/forums/showthread.php?35822-HOW-TO&highlight=4500+rpm

you mean the person who ended up ignoring everything and started getting answers like this?

..............or do like you have done in the past and ignore what I have to say and learn by grenading yet another motor. trust me... it's no skin off my balls.

 

[FordGuy100]

Haven't heard from that guy in awhile! (Dyoung). Wonder what ever happened to him (I do know he was going to build an alternator for RSDSL (whom I havent seen forever as well), and he totally screwed the pooch on that).

3300RPM's suits me good enough

 

[JLtoolman]

Free revving a 3 1/2 hp lawn mower engine is not a good Idea, and free revving a diesel is certainly a bad idea. We destroyed a race engine years ago when one of the mechanics wanted to make sure it would rev. Intake valve head made a mess when it broke off.