Keeping my 671 cool

[Gordie Allen]

I know this discussion has gone around before, but please just humor me. My bus is a 4104, 671 with 4 valve heads. Warm weather is attempting to move into Michigan and I can finally work on the outside of the bus again. We made an eventFULL trip to California and back in December, with a stop-over in Zuzax, NM for a new throwout bearing and clutch. Thanks to new found friends Larry and Judy it was an enjoyable ten day breakdown. Analysis of the trip – the bus runs great except for long climbs which cause the water temp to rise steadily in 70F or above weather. The bus came with a VERY oversized radiator, crank-driven fan and no shroud. Due to fan blade failure, I replaced the harmonic balancer and went to four electric fans sealed to the back side of the radiator. The fans are rated at 1200 cfm each. I now know that's not enough. I bought a parts bus last Fall which has a stock radiator (which looks to be in excellent condition), no shroud and a fan of questionable origin. My inclination is to have the stock radiator checked out (seemed to work fine on 60 mile drive home after purchase). Fabricate a proper shroud, and install a crank-driven fan. This is based mainly on Clifford's assertion that this can handle the 671 under all conditions. My other choice is to keep the big radiator (which may actually be part of the problem - flow direction, core configuration, etc.) and stay with electric fans, but upgrade to 10,000 cfm. If I return to a crank-driven fan, what are the OEM specs? Diameter, number of blades, pitch, etc. Is there a way to verify the fan I have on the parts bus? Any other advice?
Thanks to all who have helped in the past
Gordie

P.S. I'll fill you in on where I am with the electrical issues in another post. I sent my Victron in and it checked out, returned with no service charge. More on that issue later.

[Seangie]

Gordie -  would fabricating some kind of oil or tranny cooler help?  You could repurpose the electric fans for that.  

-Sean

Fulltiming somewhere in the USA
1984 Eagle 10S
www.herdofturtles.org

[shelled]

Gordie,

search around the archives.  There's a thread that talks about the requirements to make a working air scoop for the radiator on a 4104 with pix of final product.  At the time, the builder said it provided excellent cooling performance.  I haven't seen updates, but it might be what you need...

e3

[Utahclaimjumper]

A shroud is a must for a side radiator, it will maximize the effectiveness of the fan.>>>Dan

[luvrbus]

Gordie, on Devin's 4104 with a 330hp DDEC 6L71 I did a belt drive using pulleys,2 belts, shaft,pillar block bearing,the radiator was a standard size from a generator with a turbo 6L71,the core was 29x24x 6 cores without the tanks, a 22 in 10 blade plastic fan with a 3.5 pitch with a fan clutch. I found out the hard way a fan with a clutch will just spin full speed about 80% of the time,the shroud he made from fiberglass he has never had a heating problem since 

[gus]

It took me a while to catch on but I finally realized that I could climb any mountain all day long with no overheating if I chose a low enough gear.

Did just that one time in NM for seven miles - mostly in third and the last part in second.

This engine does not take kindly to lugging.

If it overheats always try the next lower gear and watch the temp gage needle drop no matter what the grade.

I'm not one of these guys who has to keep 60mph up serious mountains, just passing an occasional 18 wheeler keeps me happy:)

[Gordie Allen]

Clifford,
Did you use pulleys to change the ratio?

[gg04]

Used the stock drive on mine Clifford..Just went to a Flexilite pusher fan off of a off road truck..30" just built new shroud ...12 years ago... never overheats..still set at 330..Do still have a 2" Air dam in front of the radiator opening..rdw

[luvrbus]

Where are you at now GG haven't heard from you in a long time

[luvrbus]

Gordie,I have the 30 inch fan I also have the adjustable belt driven fan hub with the bottom 3 belt pulley if you can use the stuff you pay for shipping 

good luck

[Len Silva]

To the best of my knowledge, the stock 4104 never had a heating problem. If anything, they had a problem maintaining heat in cold weather. If you have an automatic trans, then you need to accommodate that, otherwise a well maintained stock system should serve you well.

[luvrbus]

 Up to 190 hp they do fine but people start installing the big injectors trying for the 238 hp then they have a  heating problem all the 4104's I have been around

[Gordie Allen]

Clifford, I'm going to look over my parts bus tomorrow and see exactly what it has. Will take you up on your offer if that looks like the best solution. Also I'm pretty sure when they did the rebuild, and added the four valve heads, they probably went to bigger injectors.

I've also been considering external oil, transmission and fuel coolers, but I just don't think I'd gain that much. Plus, unless I locate them in an air stream, I'd be adding three more fans!

[gg04]

Still in Falfurrias Clifford... Supposed to get doctors release in June..Then free again..lol ..Hope to get back to traveling by fall..rdw

[gus]

Len is correct, mine always ran cold until I got the rad shutters working.