Happy to Pass along the Following:
We have finally reached the end of our quest for an (almost) drop in Rocore floating bundle design replacement for the 3-1249T. The 50755B option in the previous drawing was not feasable for the expected volume of sales due to a $50K cost of tooling up for this unit.
Dave Wheatley continued to look at options and has been successful in making available a floating bundle cooler as a replacement for the 3-1249T. The number will be 5-7063E. It will have 3" ports for the coolant flow, the same threaded ports for oil flow as the existing 1249T but they are spaced at 14.5 inches instead of 12 inches apart. The overall length of the new cooler is 19.98 inches vs 19.6 for the original cooler. The U bolt leg spacing for the old cooler was 5.5 inches and the new one is 5 inches so the mounting plate may need to have a several holes drilled in it to match the U bolt spacing. From what I see this looks like a very usable design dimensionally for our current configuration. This design has been available for 5 years with a 2.5 inch coolant port. Our design change will just require a new version of end cap core assembly with larger coolant ports cutting the start up costs.
Knowing that this design had 5 years of history I asked about the floating bundle field performance regarding fatigue failures and he wrote:
Ed,
We have used this design on other major MH chassis for over 6 years plus refuse trucks for about same time with no issues with thermal fatigue failures. In that regard, it is truly superior to a fixed bundle design.
Let’s don’t get started on that book! I could add a few chapters myself.
Best regards,
Dave Wheatley
The 5-7063E Design:
The unit has an aluminum cast and machined outer shell. The shell has a groove for an O ring machined at each end as well as a groove for a retainer spring clip. The floating bundle is 16.3 inches long vs 14.1 inches in the 1249T so they have been more efficient with interior space getting higher heat transfer with longer fluid residence time in the tube. This offsets the smaller diameter bundle. The end caps are soldered to the bundle so that is a fully sealed assembly and the assembly then floats against the O ring as a seal. If there ever was an O ring seal issue there is no antifreeze to oil interface at an oring, it would just seep by the O ring to the exterior. I was concerned and wanted to be sure that we would not trade one issue for another. Dave also mentioned that the O rings to some extent offer a small amount of vibration isolation from the housing to the bundle which helps with fatigue issues. This looks like a good design, certainly elminating the main fatigue failure mode that we have now.
Cooling:
I had Dave run cooling models for the 1249T vs the 5-7063E design. He used a C13 525HP and a 4000 Allison given the C12 data was not redily available online from Cat any more regarding coolant flow. All things being equal the new cooler design should cool abot 4% better than the current design and passed the critical temperature limits set by Allison for the 525HP C13 version so I think cooling performance should be very similar to our current configuration. Dave was later able to get coolant flow information for the C12 from a Cat distributor and confirm the calculations are acceptable. From my perspective we had existing history of good cooling performance from the current 1249T cooler, the new version being as good, should be fine.
Cut and Pasted This Pricing and Availability Note From Dave:
Ed,
After much searching and complete inability of CAT Factory Tech service to supply coolant flow data (even with your engine SN),
I was able to find a CAT distributor that was willing to actually look for the data.
According to the data sheets referencing your SN, the coolant flow at “EVAL SPD” (assume that means rated speed of 1800rpm) is
101 gpm. The coolant flow at “PT + 100” (peak torque + 100, or 1300 rpm) is 72 gpm.
So, it would appear that you should have at least 100gpm at 85%CE, and my predicted temps should be valid.
Regarding current pricing, the following quantity breaks would apply to cover cost of new 3” end caps and tooling:
PN Min Qty Price
5-7063E 1-pc $2,025.00
5-7063E 5-pcs $ 920.00
5-7063E 10-pcs $ 775.00
Quoted prices do not cover freight. These parts would ship from our Burkesville, KY plant.
Best regards,
Dave Wheatley
In Conclusion...
Given an on the road failure would come without warning and cost in the $10,000 or more dollar range, each of us should do some personal soul searching here and decide what is right for you. If you have a 1249T cooler in your chassis with a C12 or a lower HP engine configuration that uses the 1249T this new design would be a far superior choice. If there are BAC members considering this preventative cooler change option it would be good to get together and form an order up given the pricing advantage. I know that anyone trying to go it alone here faces too high a cost.
If you do have a fail on the road as it stands now all that would be available would be the 1249T without some product stream being generated so now is the time to consider this option even if you wait to have it installed. If there is any interest let me know in this thread or by Email if not a BAC member (ednjillb@hotmail.com) and I will contact Dave at some point after we see where we stand....
Later Ed
