Hi guys, been awhile since I've been on here and not sure I remember how to post but here goes. Fired up the ol 664 in- temps with no issues, ran about 50 yards to her death. The center cylinder wasn't get oil, not sure why But now it's junk. So I found a 3.9 Cummins. Does anyone know how much of a job it is to switch the Detriot out to A Cummins? Wondering about rotation. The screamer turned c. Clockwise. Does a Cummings turn the same? Thanks
Changing out the Detroit for a Cummins can be done but it is a fairly big project. Our 664 now has a 3.9 Cummins and in the end it was well worth it. Your throttle linkages, exhaust, engine mounts, bell housing, and flywheel will have to be changed. The Detroit is solid mounted to the frame, you will need to have good rubber mounts made up to take care of the vibration of the Cummins. Also finding the right flywheel/bell housing combination can be a challenge. We may still have some of the information around someplace about what the parts needed were but it was over 15 years ago now that the Cummins was put in our 664. Even though it was a big project in the end putting in the Cummins was a good move.
can you post about this project as you go? I might be in the same boat shortly.
The Cummins we bought came out of a bread truck I believe, and my father ended up buying it from our local diesel repair shop after they replaced the turbo on the engine. All of the parts needed for the project were bought there and not only do we have most of the parts numbers I believe the repair shop still has all of the part numbers used for the project stored in their computer. The detroits are a good reliable, simple engine but it is nice to hear yourself think when you are pulling logs. :)
sawdust, how is the performance? factory clarks with a cummins had a different converter than detroit machines, lower stall i think.
Right now my biggest concern is the the Detriot turns 3000+ rpm and the Cummins 2100. How will this effect the 2 speed hydrastic tranny n the hydraulic pumps that run the steering etc? A local Detriot guy is telling 5k to do a complete rebuild in the 353 which makes me lean towards a Cummins
My 3.9 Cummins turns 2500
Allaboutsawdust any #'s parts or telephone would be great. I'll keep asking around and trying to figure exactly what needs to change to fit the Cummins and I'll post what I find. The fact that the Cummins turns slower is the biggest concern anyone has mentioned to me. Rockwell the 3.9's I've found are also out of bread trucks/ ups trucks etc. 3 to 4 k for them depending on miles.
Our 3.9 turns about 2500 in the clark. There is a small and I mean small performance loss at super high rpms but is super super minimal. That being said there is also an improvement of performance at lower rpms with the cummins. With the sugaring the way it's been I have not been able to post but in the next couple days I will post some part numbers and phone numbers for this project.
Ah I understand that! Just coming in from our sugar house! Another 275 gallons made today! How's your season going?
It's been a good sugaring season for us so far hopefully we can get another good week out of the season before it turns off warm. If we had a little better sugar it probably would have ended up as a record crop for us but mother nature is in charge and is always sure to throw you some curveballs.
(https://forestryforum.com/gallery/albums/userpics/43318/20170326_200841.jpg?easyrotate_cache=1490573594) I am going to post some of the pages that pertained to our 4bt engine swap in the 664. A couple of the pages are from the company the parts came from with cummins part numbers. If anybody wants to pm me for phone numbers or more info feel free.
(https://forestryforum.com/gallery/albums/userpics/43318/20170326_200924.jpg?easyrotate_cache=1490573871)
(https://forestryforum.com/gallery/albums/userpics/43318/20170326_201004.jpg?easyrotate_cache=1490574093)
(https://forestryforum.com/gallery/albums/userpics/43318/20170326_201243.jpg?easyrotate_cache=1490574368)
(https://forestryforum.com/gallery/albums/userpics/43318/20170326_201323.jpg?easyrotate_cache=1490574412)
I don't have the info on the engine mounts used for the project but the shop where we bought our parts from should that information as well as this information I just posted on their computer under our names. Like I said in the earlier post if you pm me I can give the engine shops phone number and who to talk to.