Predator Performance question

[outcrydrummer]

Dangit chancer where were you earlier lol.
It's snowing in NC tonight and this weekend......everything will be closed.
I didn't want to torture test the predator I just put all the nr racing stuff on but if there is enough interest in it I'll do it to my kart engine and just replace it when the weather clears lol.

 

[Kartorbust]

Tough call on how long. I'd say do it for an oil change interval. Something has to give by then.

 

[outcrydrummer]

But whats an oil change interval?
I change oil after every race on my engines so my interval isn't probably the best to go by at all haha.

 

[Kartorbust]

Whatever the manual says. Can't remember if it's every 25 or 50 hours.

 

[outcrydrummer]

If it's 25 hours that seems legitimate. It will take me several days to test for 25 hours run time but shouldn't be difficult. Definitely need to do that on a bone stock engine. With the intake and header that predator I have with governor modified is extremely loud.

 

[Kartorbust]

I do have a non hemi in the living room right now, but I'm waiting for a warm 20 F day to drop it on our snowblower. Otherwise I'd sacrifice it for this.

 

[outcrydrummer]

I appreciate the thought but it's all good. I honestly don't think its going to let go before a reasonable amount of time.
Any engine run at high rpm for a set amount of time is going to fail in some way.

I figured I'll get a new hemi, torture test it. If it lives (I believe it will) I'll put the test engine on my trike and its all good.
If it blows up then I'll replace what broke with better parts and start a build with it.
Win Win.

 

[Whitetrashrocker]

I'm gonna bet on the conrod spinning a bearing and galling at the crank before the gov let's go at 4800.

 

[Randy H]

Wow if your gonna put that many hrs. on it, how about before and after leakdown and or compression tests.

Hope you end up with a well broken in engine.

 

[outcrydrummer]

RPM Verification video of the governor mod is now posted.
https://www.youtube.com/watch?v=DL8212P0EI4

 

[outcrydrummer]

Here ya go chancer.
https://www.youtube.com/watch?v=aLwQ4T4TPMk

 

[chancer]

Thanks. That is what I had always guessed 5200 to maybe 5500. "5320ish"

Just gives a good number for throwing into gear ratio Speed Calculators.
But it is just not believable with out the Fireplace in the Background!
Thanks again

 

[OzFab]

I read halfway through to page two & I've seen enough...

Not quite the same animal but, same idea, I've had a stock[/i] B&S blow up a governor gear & another throw a rod; then I've had a Honda GX160 with stock internals, governor removed & some head work scare the pants off me which still runs hard it gets punished & asks for more...

In the case of the governor gear explosion, the reason was obvious, a poorly adjusted governor linkage caused overrevving which destroyed the engine; the rod failure? Who knows? The governor was intact & correctly adjusted & had been running as such for years without issue, the only possible explanations are low oil or wear & tear...

Here's the facts:
-stock conrods are only tested as safe to ~5500rpm
-governor gears are only tested as safe to ~4500rpm
-stock valve springs flutter/float/bounce at ~5200rpm

By adjusting/disabling the governor, you run the risk of destroying the engine but, here's another interesting fact: no matter what engine, whether it be a 212cc predator or a big block Chev, as soon as you modify it, you run the risk of destroying the engine; you will definitelyshorten its lifespan...

On a side note, replacing the stock, cast iron flywheel for a billet aluminium version has very little to do with the possibility of breakage at high RPM; if you notice, most kits including a billet flywheel advise keeping the governor intact, therefore, negating the high RPM risk; the main reason for replacing the governor is because the engine can spin up faster with the lighter flywheel, giving you more low end torque...

 

[chancer]

Thanks OZ.
Do you think some of the Broken Gov internals you have seen here may be due to Completely disconnecting all of the Gov linkages.
And that possibly Adjusting them is a better alternative.
I wonder now if Gov gears have broken due to not having ANYTHING attached as opposed to simply too many RPMs.
And... where did you get this Fact? "-governor gears are only tested as safe to ~4500rpm"

 

[Flyinhillbilly]

I've been thinking a lot about the why behind all of this and I think that Joe is right and the spring tension on the gov keeps it together. What if by disabling it the gears are free to throw the entire weight of the weights against the gear which causes it to deform and blow apart when and out of round gear is running to beat the band on another gear which is steel?
Just my simple hillbilly figuring, I have no substantiating evidence.

 

[chancer]

Thanks FHB. That was kinda what I asking about. You have asked it more eloquently.
I was asking OZ specifically cause I know (I think) he has a good knowledge of the inner working parts and movements of the Gov. system.
So he could maybe explain what should move where and when and why.
and answer that mystery.

 

[Flyinhillbilly]

Thank you. I'm not generally renowned for my eloquence, lol.

 

[outcrydrummer]

I read halfway through to page two & I've seen enough...

Not quite the same animal but, same idea, I've had a stock[/i] B&S blow up a governor gear & another throw a rod; then I've had a Honda GX160 with stock internals, governor removed & some head work scare the pants off me which still runs hard it gets punished & asks for more...

In the case of the governor gear explosion, the reason was obvious, a poorly adjusted governor linkage caused overrevving which destroyed the engine; the rod failure? Who knows? The governor was intact & correctly adjusted & had been running as such for years without issue, the only possible explanations are low oil or wear & tear...

Here's the facts:
-stock conrods are only tested as safe to ~5500rpm
-governor gears are only tested as safe to ~4500rpm
-stock valve springs flutter/float/bounce at ~5200rpm

By adjusting/disabling the governor, you run the risk of destroying the engine but, here's another interesting fact: no matter what engine, whether it be a 212cc predator or a big block Chev, as soon as you modify it, you run the risk of destroying the engine; you will definitelyshorten its lifespan...

On a side note, replacing the stock, cast iron flywheel for a billet aluminium version has very little to do with the possibility of breakage at high RPM; if you notice, most kits including a billet flywheel advise keeping the governor intact, therefore, negating the high RPM risk; the main reason for replacing the governor is because the engine can spin up faster with the lighter flywheel, giving you more low end torque...

Good info amd thanks for chiming in.
I still cant help but mention the hundreds of kart racers succesfully adjusting the governor and running all year with no governor failure.
Is it the end all be all??? No. I offered this as an tenporary gain of rpm before removing and installing a billet rod in one foul swipe.

Ive had great luck with it as well as all the racers i know.

 

[OzFab]

And... where did you get this Fact? "-governor gears are only tested as safe to ~4500rpm"

Dunno, read it somewhere

I still cant help but mention the hundreds of kart racers succesfully adjusting the governor and running all year with no governor failure.

As previously mentioned, the governor is safe to ~4500rpm so, running at ~4000rpm should be safe; my engine was running well beyond that when it disintegrated...

I also said modding any engine involves a risk, not necessarily that it will break...

Many years ago, I worked with a guy who built his everyday driver into a show car; at one point, he was changing blocks more often than engine oil until he backed off the mods; likewise, I've seen engines modded & run faultlessly for years...

 

[bob58o]

Here ya go chancer.
https://www.youtube.com/watch?v=aLwQ4T4TPMk

I still don't know what valve float sounds like. I was under the impression that you could hear it. I couldn't hear anything, or maybe I don't know what to listen for.