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# Waukesha VGF H24 GLD Bogging down under load

## Waukesha VGF H24 GLD Bogging down under load

(OP)
Hi guys,

Im running a couple VGF H24GLDs one of them was recently serviced, new head gaskets, wastegate, plugs, coils, oil ect.

but now I seem to have lost power in the engine. It bogs down and won't maintain speed at 500 amps while it it rated at 616 amps. (throttle fully open)

I have checked my O2, gas over air pressure, timing, firing, air intake and filters, compression and valve lash. I have checked for air leaks and exhaust leaks and I have little to no pressure drop from leaving the turbo to the Intake manifold and I am now out of ideas of what could be wrong

Compared to logs from before the service and last year, I seem to have about 5-6 psi lower intake manifold pressure at the same load.
I am suspecting maybe there is something wrong with the wastegate? despite it being new and not adjustable (like the old ones)

Any ideas?

Dan

### RE: Waukesha VGF H24 GLD Bogging down under load

Does the boost figure you measure at the manifold match the performance spec?

### RE: Waukesha VGF H24 GLD Bogging down under load

oh, and is the wastegate actuating when you load it up?

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
I do not know if the boost matches specs. I don't have them. But Boost is 5-7 psi less then previously.

hmm, I did not check the wastegate lever when I initially loaded the engine up, I'll check that. But I do not see any movement during load changes. Mind you, the changes are also not huge.

### RE: Waukesha VGF H24 GLD Bogging down under load

If the wastegate is not opening check wastegate valve is not leaking/stuck open. Check for exhaust or intake restriction. Was the timing drive disturbed/replaced - if so check valve timing.

je suis charlie

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
-(Update)-

The wastegate is not stuck open, just checked, it seems to open up when right after the heavy load has been applied and is evening out. But at around 10 PSI it opens (not fully) and at that point
too much exhaust is bypassed so I don't get sufficient boost in the intake to run at a higher load.

So I took out the new wastegate and had it laying next to my old wastegate, I hooked up some low pressure air, and I see that on the new wastegate it is very willing to open up, while on my Old
wastegate it takes about twice the psi before it moves. So I installed the old wastegate again and the engine runs just fine, even at almost max load, I have great boost and all is happy and dandy.

So seemingly the old wastegate works fine while the new one doesn't? they should be the same models.. unless there is a different wastegate for the G's, GL's or VHPs which is more sensitive?

### RE: Waukesha VGF H24 GLD Bogging down under load

is the wastegate tension adjustable? (I'm assuming there's a screw and spring on there somewhere)

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Nope, Not adjustable. There is, however, a limit screw that will limit the valve from opening. But I don't feel like playing around with that. I don't want my generator to overshoot the speed during load changes because the turbo don't react fast enough.

### RE: Waukesha VGF H24 GLD Bogging down under load

Wastegates are designed to control boost to a range of settings. This usually requires a spring change. Just swap the old spring into the new wastegate.

Wastegates with a seperate "muscle unit" and valve can sometimes be adjusted (slightly only - a few psi) by adjusting the push/pull rod length.

je suis charlie

### RE: Waukesha VGF H24 GLD Bogging down under load

Is it this type of wastegate?

If so, does the "old" and "new" have the same number of spacers?

If so, there were about 5 different internal spring groups for these, three single spring and two double spring. They all look similar, and ran into a number of problems with wastegates when customers used aftermarket suppliers that built both CAT and Waukesha wastegates, springs, internal shims and spacers would get mixed up.

There was a shop in Midland TX that used to rebuild and supply new assemblies and parts, can't find their info anymore (been quite a while since I directly dealt with that stuff).

I don't either CAT or Waukesha ever published actual bench testing specs for wastegates, we used to take a known good wastegate for an application, then apply air pressure to the inlet in 2 PSI increments and measure the valve position with a depth mic, then record it on a spreadsheet. A shop I worked with many years ago (now closed and everyone moved on) had built a test bench with a long reach dial indicator and built up their own test sheets.

Hope that helps, MikeL.

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Yes, The only problem is that Waukesha made a new model of the wastegates that cannot be opened without breaking the casing. I could break the old one open, but wouldn't get the old spring into the new
one and get it working again.

I asked my Rep that exact question and he told me that people had in the past messed around with the wastegates to get more power out of there engines and thus ruin their engines, even under warranty. So waukehsa, getting tired of having to pay for it over and over, made new wastegates that can't be opened or really done anything to.

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
No, doesn't look anywhere near those. I'll get a picture later on tonight. You'll know when you see it, nothing can really be done to ones I have.

Good idea about making that sheet with the measurements, no I just need a pressure regulator that is precise enough to actually read such small increments. I really only have centralized air in my shop.

(OP)

### RE: Waukesha VGF H24 GLD Bogging down under load

Waukesha should be able to give you a boost pressure spec for your engine. If it is only 10 psi, you are stuck with the lower power unless you are content to modify the boost setting. This is easily done without a spring change.

You can make small changes by adjusting the length of the muscle unit pushrod.

For larger changes you can fit a "bleed tee" in the pressure line to the WG. This involes a restriction in the line from the manifold followed by a branch bleeding air through a second restrictor back to the turbo inlet. The easy way is to mount both restrictors in the tee piece itself. Make the in-line restrictor about 0.80", 2mm diameter. The bleed will probably be smaller. Equal size bleed will roughly doulble the boost. Start small and incrase the bleed size until the boost is right.

je suis charlie

### RE: Waukesha VGF H24 GLD Bogging down under load

I think Turbonetics make these for Waukesha, probably an OEM product but you might get someone there to give you some ideas.

One thing to look at on this style is the rod adjustment. You can affect the opening pressure by stacking gaskets (not recommended) or readjusting the rod if you can.

The flapper looks like it is seating evenly, how does it mating surface look?

If it was me I'd get a small air regulator and a good gauge and see how much stroke you get for a given range of pressures and compare. If they have gone to a "fixed" wastegate then to meet differing power and emissions ratings and altitude they would need to offer more than one. I know the local Waukesha guys are griping because after being bought by GE they are going thru a number of pains with parts supplies, differing distribution paths and apparently lots of old documentation disappearing as systems are "updated".

Your best bet may be to find a shop in the patch that has a good turbo guy who may be able to get you some better help.

MikeL.

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Gruntguru; I'll have to get with the factory or something for the pressure spec. I don't find it in the manual nor does my rep know. I wouldn't necessarily want to modify the boost setting myself. I think i might then move into an area that's a bit over my head. I like your idea about the Bleed tee. I'll look into that, Thanks a bunch.

Catserveng (Mike) ; The rod is adjustable, according to the manual I have, Im only really "supposed" to change it because of altitude differences. and only by .04 of an inch per 1000 Meter elevation.

The mating surface is clean and smooth, the flapper sits fine. Yeah, I'll have to do the comparison over the weekend when the engine off.

Didn't know that there was a problem with parts and supplies. My distributor hasn't mentioned anything. But nice to know. :)

Thanks

### RE: Waukesha VGF H24 GLD Bogging down under load

Don't know if this the case for your situation, but if you run an engine above its designed power rating, among other things you may exceed thermal loading limits on the exhaust side: exhaust valves, turbocharger and exhaust manifolds; beyond that, maybe even the piston crown and top ring (to say nothing about knock, which I assume is being guarded against at any rate).

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

### RE: Waukesha VGF H24 GLD Bogging down under load

The engine you should be measuring, carefully, is the one that's _not_ bogging.

Mike Halloran
Pembroke Pines, FL, USA

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Hemi; No, Im not running at higher power rating than designed. In fact I always run at max 95% - equipment just seems to last longer that way.

Mike; Of course, it's the only one I know for a fact to be a good one. ;)

Thanks

### RE: Waukesha VGF H24 GLD Bogging down under load

Let this guy know that WED does have a BHP/INT Manifold pressure calculating spread sheet. He is not giving much information on the engine such as High (HCR) or Low (LCR) comp ratio. I would start with the parts replaced first. The VGF GL/GLD has 4 different turbos which could mount. It also has 2 different Wastegates, and there is the possibility of 3 different comp/ratio pistons which could fit. The wastegates are not like the VHP which we rebuild all the time and WED had released information on how to set them up for the different engines. He also needs to be correct in his stating the intake manifold pressure as Inches of HG and not PSI. The calculated Int/Man pressure for the VGF HCR is 31inches HG and for the LCR engine 33 inches HG. You could see that with a 6 PSI drop you would see approx. 12"HG loss so he is probably seeing a 6"HG loss of pressure.
1) Get his S/N and I can run a BOM of the engine how it left the factory so he can compare parts.
2) To prove it is not the wastegate, just remove the signal or pressure line and plug it so the wastegate cannot open.
3) The natural tracking curve of the AFR is to go from Rich to lean and if he is measuring O2 at 7.8% with a 6" HG loss he may be set lean. Verify the O2 sensor fuel cell is stable sampling open air and if it is good then make a small adjustment rich on the carburetor load screw and see if he get his power back. Only do this after making sure all the parts are correct.

Mike Halloran
Pembroke Pines, FL, USA

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Hi Mike. This is a little over my head, But I'll answer the best I can;

I dont know if I run HCR or LCR, the comp is 11:1

Serial: c-94371/1 on the engine (what is BOM an acronym for?) I was thinking I might have gotten a wrong wastegate - but I didn't know that there were several kinds etc. So I didn't pay much attention to it.

As for psi and Mercury, I have no data.. my gauge measures PSI, that's all I've ever used. But I can hook up a an HG probe if needed.

As for my O2, I did the test running the engine under load, but not overloaded and it was running at 60.00 hz, so the O2 readings should still be ok, right? I can see how the O2 getting off if I overload it.
It is a draw-through carb as well, so gas over air should be proportionate shouldn't it?

How do I get a hold on the BHP/INT calculating spread sheet?

Thanks to the both of you!

Dan

### RE: Waukesha VGF H24 GLD Bogging down under load

oh, and BOM is bill of materials (parts list)

### RE: Waukesha VGF H24 GLD Bogging down under load

From Mike's post your boost should be 31 or 33"hg ie 15.2 or 16.2 psi. If the wastegeate is cracking at 10 psi as you said earlier, that is your problem - wrong wastegate.

je suis charlie

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Yes, Wrong wastegate, I put the old one back in and it worked fine. My question is now, I dont see any other part numbers for other wastegates, and I cant adjust this type. so
how can i have ended up with a wrong one?

### RE: Waukesha VGF H24 GLD Bogging down under load

Your engine rating plate *should* be a guide to getting the correct wastegate. Failing that, by hook or crook you will have to find a way judiciously to increase the preload on the one you have. If the preload you end up with is higher than the spring in your wastegate is designed for, it may have a shortened life expectancy. Be wary too, of coil bind at full power, causing overboost, turbo overspeed & possibly other consequences.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

### RE: Waukesha VGF H24 GLD Bogging down under load

More response from my Waukesha expert:

{
Let’s answer his questions in order.

11.1 is a high comp ratio.

A BOM is a Bill of Material which shows how the engine was built (AS BUILT) when it left the factory. Based on the s/n of his engine here is the 3 main parts I pulled from the BOM.

Piston 300304K

Turbocharger 305866

Wastegate 305810

The gauge readings are only important when we know which scale we are using. We can convert PSI to HG and back. This way we are talking in the same language.

His O2 reading may be where the problem is. The AFR is being controlled by the adjustable orifice (Load Screw) at the higher loads. If you are not giving the engine enough fuel to reach the higher loads it won’t.

If you adjust the AFR to its lean setting before the engine has reached full Continuous Duty Load it will be too lean to reach full load. To normally adjust an AFR you need to run slightly rich (less than 7.8% O2) to make the BHP necessary for full Cont/Duty BHP. Once you are running at Full Rated load you then start leaning the unit out to the specific O2 readings. This is what I was saying earlier that the natural tracking of the carburetor goes from rich to lean. If you set up the O2 at a lesser BHP then when you need the Greater BHP you don’t have the proper air to fuel ratio to make the necessary BHP. The engine is set too lean. To see this happing all one has to do is start removing load and watch the O2 start to track rich (start dropping from 7.8% to say 6%).

If the parts are correct then the adjustment of the AFR is not correct based on his load and power demand.

}

Mike Halloran
Pembroke Pines, FL, USA

### RE: Waukesha VGF H24 GLD Bogging down under load

(OP)
Mike,

About the O2, I understand and it makes sense.

The wastegate Part Number your tech provided is correct, that is what I ordered, and that is on the invoice too. However, if you read ealier as well

I had the old wastegate out laying next to the new one I hooked up compressed air to them both, and I saw that the "new" wastegate would open at a significantly smaller psi then the "old" one - Obviously then bypassing exhaust at a lower load.

So I put the old one back in, and my problems stopped. Engine running at rated load with no problems.. O2 readings are perfect too.. So it must be the new wastegate. I just cant figure out why? as I said, it is new?

As far as I know, I cant adjust the wastegate aside for the few 0.001" on the power piston for altitude adjustments - which by the way is exactly like the old one.

Dont really know what to do about it. It feels like $1900 down the drain. ( I know, I know... spare parts.. but yeah..) ### RE: Waukesha VGF H24 GLD Bogging down under load I would pursue your warranty replacement options with the new wastegate. Evidently it is defective. "Schiefgehen wird, was schiefgehen kann" - das Murphygesetz ### RE: Waukesha VGF H24 GLD Bogging down under load As I said in an earlier post, changing the preload on the WG spring (by adjusting the pushrod or crushing the muscle unit housing) is not the way to go if more than 1 or 2 psi adjustment is required. The spring itself must be changed. je suis charlie ### RE: Waukesha VGF H24 GLD Bogging down under load So, did you receive the correct new wastegate, or did you receive the wrong new wastegate in the right box, or did you receive a correctly marked wrong part with some bullshit assurance, or what? Parts counter personnel have been known to swap parts and boxes in an effort to save their job after they screw up, and to keep doing that and similar evil until the inventory is irrevocably tangled. I'd say a$1900 screw-up justifies a polite call or ten to your parts supplier, and maybe a few less polite bonus calls.

Mike Halloran
Pembroke Pines, FL, USA

### RE: Waukesha VGF H24 GLD Bogging down under load

"Yes, Wrong wastegate, I put the old one back in and it worked fine. My question is now, I dont see any other part numbers for other wastegates, and I cant adjust this type. so how can i have ended up with a wrong one?"

============

Are there any identifying mumbers on the two, old, working OK wastegates?

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