belt update on 500hp ISM

[racer0624]

While at Cummins South in Atlanta having my Onan fixed, J.J. Yelley's(sp) 2006 Essex, Nascar # 18 driver, coach was there to get a broken fan and turbo pipe replaced. Also I noticed that they were replacing the twin belt setup with the single unit. I thought this was just a recall on 2007 ISM's. Is it also on 2004, 05 & 06's?

Also, his golf cart was there and has a souped up two cylinder Honda engine in it that goes 55mph. SPEED...

John, 2005 4502 Essex

[racer0624]

While at Cummins South in Atlanta having my Onan fixed, J.J. Yelley's(sp) 2006 Essex, Nascar # 18 driver, coach was there to get a broken fan and turbo pipe replaced. Also I noticed that they were replacing the twin belt setup with the single unit. I thought this was just a recall on 2007 ISM's. Is it also on 2004, 05 & 06's?

Also, his golf cart was there and has a souped up two cylinder Honda engine in it that goes 55mph. SPEED...

John, 2005 4502 Essex

[Lug_Nut]

John, That seems to be the new replacement. It is similar to a supercharger belt. One of the heaviest wear in my opinion is when your Jake is engaged in high at speed. The ECM automatically calls in the full fan load at some speeds. This causes a sudden shock load and load demand on the belts. I had Spartan disable this feature as did Rebelsbeach. We feel the belt life is far more important than the slightly more braking aspect of this engaging.

[rebelsbeach]

Bill Thomas at Coach Care Cummins South is AWESOME!!

[footdoc]

I have not seen the ISM engine, but isnt the fan controlled by hydraulics and not a belt. On my I side radiator ISL I think it is...the belt runs AC and accessories I believe

[Ecker]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by footdoc:
I have not seen the ISM engine, but isnt the fan controlled by hydraulics and not a belt. On my I side radiator ISL I think it is...the belt runs AC and accessories I believe </div></BLOCKQUOTE>

No they are very different cooling methods and it uses a complex belt driven clutch which in turn passes power through drive shaft and gear box arrangement to drive the fans.

[footdoc]

Uh OH....complex as in COMPLE$$$ ?

[Lug_Nut]

Larry, Cummins uses hydraulic fans up to 400 HP. Both the ISM and the ISX use mechanical drive as the hydraulic system would have to be so large and may cause another issue of cooling the oil.
The mechanical drive used employs an electro magnetic slip clutch which also can electrically lock up one to one.

Here is how it works.

A series of electo magnets are within the clutch. As the hub rotates the field of magnetic energy causes the fan side to rotate at a much slower speed. As heat climbs the voltage increases causing the field of energy to increase which speeds up the fan slowly reducing the slippage. At 205 degrees F. the electic clutch slams in and direct drive sends the fan to top speed. This can take nearly 80 HP at top output and RPM. There are actually 5 functions that are measured and can engage the full fan drive power including intake temperature. One of the five includes engaging in Hi Jake for additional drag (I had mine de-programmed for this feature as did Bob Gregory).
I wish we could have hydraulic too but with this HP it is apparently not really practical.

[footdoc]

wow...clever engineering that is ALMOST perfect!! Thanks for the info

["007"]

Link to Spartan chassis forum.

[racer0624]

Lug-nut.
Great explaination on the clutch workings. According to Trip Tec mine engages at 203 instead of 205. Big woop. My out-of-spec clutch, which was replaced in Nappanee last summer, emited a "squeal" sound much like a slipping fan belt. It did this both at 205 degrees and hi-Jake when extra braking was needed.

I haven't had any belt trouble in 20,000 miles but will talk to Carl about a change when I'm there in Jan. or Feb. Maybe I'm borrowing trouble.

John, 2005 4502 Essex

[Lug_Nut]

John the squeal is acceptable as the clutch faces are both metalic surface. The '05 is not as critical as the '07. If you look at up to '06 at the rad grill and compare it to the '07, you will see the later is much taller. This is due to emmissions changes with the '07 requiring a little more cooling.
John, I may have met you at Outdoor Resorts in Hilton Head over a year ago. I had a DSDP and spoke with you and you showed me the inside of your coach. You had the antique white like glazed finish. Would that be you?

Peter

[racer0624]

Peter,

When Randy checked the clutch he said, the gist anyway, that the mateing surfaces were too far apart(measured in thousandth's) and caused the squeal as the metal surfaces weren't making hard, solid contact.

Wasn't me Peter as we've not been to Hilton Head in this coach. We do have the antique white looking cabinet finish.

You met and spent some time in Nappanee with friends of ours- John & Pam Hassell. Their house is about 3 miles from our RV park. We always have an empty lot with full hookup 50amp available if you're ever in the area.

John, 2005 4502 Essex, back in Fl

[Ecker]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Lug_Nut:
If you look at up to '06 at the rad grill and compare it to the '07, you will see the later is much taller. This is due to emmissions changes with the '07 requiring a little more cooling.
Peter </div></BLOCKQUOTE>

The engines are still 06 not 07 so what is this emmission change that requires a larger radiator?

BTW _EPA has issued a statement that for regulation of ULSD the engine configuration will apply not what a company calls its year. This was addresseed specifically to labels that are required in cab for ULSD.