Trailblazer 302 pulling down

[cruizer]

Idle frequency around the 43-48hz


Now as for engine, if its a 3600 rpm gasser use the 5-50, I don't care what model it is. I may never get to 50 wt as synthetic is temp sensitive, however at 100 deg F, its definately there. So since the engines are air and oil cooled, the oil also cools the engine Oil pumps have a dificuilt time pushing the standard 10-30 as it becomes basically hot water running out just as fast as its pumped in. The cooling becomes practically nil. Hech if I put 10-30 synthetic, in my big harley V-twin, The engine would bake itself pretty quickly and be sitting on the side of the road with overheat issues simular to what you guys are having.

We found years ago to use the 5-50 for all round protection and found Quaker to be the best hands down. Starts easy, and has the best protection. The engines simply doen't fail and run significantly cooler ar high temps.

The big diesels. even the high rev units, we use Guarol ECT (76 lubricants) 15-40 all rear round (stuff pours at -30C) zero engine problems

[cruizer]

Basically use what you want to use. I maintain and service around 2000 welders every year. The only problems I have are with the guys running the dinosour oils (high moisture content) and the guys sticking to what the manufacturer recommends. Alota rebuilds and pooched engines.

[HayFarmer]

Idle frequency around the 43-48hz


Now as for engine, if its a 3600 rpm gasser use the 5-50, I don't care what model it is. I may never get to 50 wt as synthetic is temp sensitive, however at 100 deg F, its definately there. So since the engines are air and oil cooled, the oil also cools the engine Oil pumps have a dificuilt time pushing the standard 10-30 as it becomes basically hot water running out just as fast as its pumped in. The cooling becomes practically nil. Hech if I put 10-30 synthetic, in my big harley V-twin, The engine would bake itself pretty quickly and be sitting on the side of the road with overheat issues simular to what you guys are having.

We found years ago to use the 5-50 for all round protection and found Quaker to be the best hands down. Starts easy, and has the best protection. The engines simply doen't fail and run significantly cooler ar high temps.

The big diesels. even the high rev units, we use Guarol ECT (76 lubricants) 15-40 all rear round (stuff pours at -30C) zero engine problems

Thx! That was pretty interesting and I had never considered an oil weight that heavy for a gas motor. Where I am this entire summer has been over the top HOT!

As for measuring engine temp how is that done? Are you talking about oil temp of engine body temp?

[cruizer]

Engine case temp, years ago we measured them with all sorts of oil combinations, and tested them to data plate specs via a load bank and used a infared fluke temp sensor.
With the 5-50 quaker we found that the engine was running 10 -18F cooler depending on how maxed out the welder was over an hour loaded running time.

No fluctuations/ surging, bogging down and pert near dieing compared with the 10-30 dinosaur and 10-30 synthetic

Now, synthetic is temp sensitive, sooooo, your not really running 50 wt unless the engine is freaking hot say on a hot day and the cooling air is too hot to adequately cool the engine. The hotter the engine gets the fuel evaprates to quickly as the intake air is equally as hot as the outside air. Keeping the engine cooler, the engine will run somewhat more effiecient.

OH, we used 2 Lincoln 305G units on the test

[Miller John]

Cruiser, we do love your experience and shared knowledge.

We test oil temps running these machines at max load for a minumum of 4 hours straight with an ambient temp of 104 F or 40C. The oil temps with recommended oil viscosity are fine. If running max. at high temps is done periodically, synthetic is no doubt the best. I've measured oil temps in the field and have never had them come even close to what the mfg's allow, and some of those measurements were in 100+ degree ambient with the customer using the machine pretty hard. We move a lot of air thru those engines to keep them cool.

I'm not bad mouthing the competition here, but their oil temps run considerably higher. in fact, they had to go to an electric fuel pump standard to prevent vapor locking (from extremely hot fuel temps). They have a quite different air management system.

[cruizer]

Hmmm, same engines same engine shrouding, other than the Onan/Onan subaru/Cummins, as for the fuel pump, there are 2 (on the Kohlers) And the electric fuel pump (which I find kinda silly) is for high altitudes. It was never ment for fuel vapour issues. It was simply cheaper to install it as apposed to it being an option. The electric pump fails once in a while and locks the fuel from reaching the mechanical pump but the mechanical pump is not known for vapour lock.

The onan with the vacum pump consistantly vapour locks at high temps

You Miller reps gotta realize that among other warranty contracts I have, I do have both Miller and Lincoln, so I kinda have to know these machines inside and out.

I suggested to the op to get a more exact engine rpm setting via using HZ as apposed to the engine rpm gage which I didn't suggest.

[cruizer]

Never the less, I suggested the 5-50 quaker for engine longevity as you don't suddenly need a rebuild at 3000hrs, I've got many engine drives in Miller and Lincoln surpassing that figure on up to 10K hours. Also had many on the Manf route crashing at 1800 hrs and some times less in both brands. Good$$ for me when that happens.

[cruizer]

I don't really get what all the hub is about anyways. Depending on how hot the engine is, the 5-50 may never get to 50 wt, and depending on how cold it is, it won't start out at 5wt either but that extra cooling and protection is there in case the engine warrants it.

The oil is what cools the engine. The fins are what removes that heat that the oil collects.
Wouldn't it be better for an oil that has at least some viscosity in high heat situations.

It's only less that 2 quarts on a change. Synthetic doesn't foam or blast crud against the crankcase walls for even more engine heat like the recommended dinosaur oil.

Actually I see that Onan prefers you use 15-40 synthetic in the p series engines up to 100 DegF

Oh, and when I said Quaker, I ment Quaker. It's the best, Mobil 1 and Penzoil are not so good for heat protection

Basically follow the manuf recommends if you feel unsure...... as we service techs need your hard earned money.

[white05gt]

A couple of hints from what I've seen:

1. Make sure you do not have too much oil in it. Too much oil will cause a problem blocking the fuel pump breather in the crankcase and it will act exactly as yours is.
2. I would use the oil that the mfg. recommends. That's what we test and the mfg's spend a lot of testing time to determine that. The only difference that I do in the colder climate is run synthetic once the engine is broken in.
3. The Trailblazer has an RPM guage built into it. The directions for reading RPM's are on the decal under the top door. Its real easy to do and you don't need a meter.

Good luck, but please check oil level.

Thanks for the suggestion, I did double check the oil and it's good.

[Finney]

Miller John,
I have the first of the 302 Trailblaser series and it does not have rpm readout.

cruizer,
The company I worked for bought 11 of these machines when they came out. When they got 100hrs on them we switched to Mobil One and noticed about a 12* drop in head temp.
My personal 302 has over 900hrs on it and I know the rpm's needs to be checked. When the linkages wear over time the rpm's will go down.
My biggest complaint with mine is when running the S32S VS feeder the rpm's are up and down when you are not welding. Welds fine just annoying.

[cruizer]

Unfortunatly thats a by product of having an Onan engine with a vacumn pump.

If you were to move the choke butterfly a few degrees closed, your problem will go away. It won't run any richer, just won't surge up and down in high idle. Works out to be 1/8" on the choke knob

[Finney]

cruizer,
We have the Kohler in these machines. Mine goes from idle to wide open and back to idle constantly when hooked to the feeder.

[cruizer]

Well, lets do some investigating shall we, first off that feeder is still drawing power from the power source when in idle, kind of in the threshhold from going from low to high idles.

I'd suggest that your low idle is too low and thats why its bouncing around, however, really your supposed to place the power source in high when running this feeder anyways