Is the fluidamper worth it?
- Thread starter Pwnm30rdi3
- Start date
jeremiahmercier
Member
I should be able to report tomorrow, getting my belt in the morning
Sent from my VS985 4G using Tapatalk
Sent from my VS985 4G using Tapatalk
jeremiahmercier
Member
Will also be towing with it in the next week
Sent from my VS985 4G using Tapatalk
Sent from my VS985 4G using Tapatalk
Garbage_Mechanic
Member
Here is how I see this: Every higher horsepower Cummins, Caterpillar, or Detroit Diesel (2 or 4 stroke) has a viscuous vibration dampener. Development of the viscous dampener was part of a long list of items that opened the way for high horsepower diesels of today. Our 7.3 was first designed at 215 hp. That is 26.8 hp per cylinder. Say we go with a very mild build and go to 350 hp. Now we are at 43.75 hp per cylinder. How much harder is each power stroke twisting the crank?
The reason diesel engines need better vibration dampeners because the forces are so much more violent than any gasoline engine. The vibration being dampened is the twist on the crank in one direction of the compression stoke, followed by the twist the other direction of the power stroke. Since we have 20-1 or so, with the gas max of 13-1 or so you can see the force is higher to start out. Now we go over tdc and fire the cylinder, twisting the crank the opposite way. And we do it at lower RPM.
gnxtc2
Active member
No complaints here. Motor was running smooth towing 23k this past weekend.
Billy T.
[email protected]
Billy T.
[email protected]
Garbage_Mechanic
Member
To continue the thought:
What I see it comes down to is this: do you want the longest lived smoothest running engine?
Another comparison, you could build a 400+ hp engine with a stock turbo. You know it is going to fail, but do it anyway. You have a 400 hp engine, but with what level of longevity?
Fluidampers just make sense for anything much over stock performance wise.
I noticed a smoother running engine at all RPM especially low RPM.
gnxtc2
Active member
What did you do?
I was going to suggest to convert to a SD dual belt tensioner.
Billy T.
[email protected]
jeremiahmercier
Member
Only thing that I changed that affects the belt would be the damper and sd water pump pulley, the smaller pulley now make the stock obs belt too long
Sent from my VS985 4G using Tapatalk
Barnbuilder
Member
Not to muck up the thread but Jeremiah purchased the Fluidamper I had.
Garbage_Mechanic
Member
I have my new engine on the stand right now test fitting different set ups.
The Fluidamper by itself changes nothing as far as the belt length goes.
It does make it difficult to work with the belt if you use the stock OBS water pump pulley since there is not enough room between dampener ring and pulley.
This can be solved by running the smaller diameter 99-03 7.3 water pump pulley which gives clearance to R&R the belt with the added benefit of increasing the RPM of the water pump and fan.
However the snag is the smaller diameter of the pulley causes the stock belt to be too long and throws the tensioner out of it's range (a critical issue)
For my set up I have a 215 amp ambulance alternator which normally takes a longer belt when installed by itself, with the SD pulley the stock belt fits like stock.
The next issue with the Fluidamper is the stock fan hits the dampener ring. OBS Fluidamper kits cost more than 99-03 SD kits because a spacer is included with the OBS. If you run an 03-07 SD 6.0 fan the spacer is not needed and cooling is now improved 2 ways, one by faster fan speed and one by much more efficient fan.
The Fluidamper by itself changes nothing as far as the belt length goes.
It does make it difficult to work with the belt if you use the stock OBS water pump pulley since there is not enough room between dampener ring and pulley.
This can be solved by running the smaller diameter 99-03 7.3 water pump pulley which gives clearance to R&R the belt with the added benefit of increasing the RPM of the water pump and fan.
However the snag is the smaller diameter of the pulley causes the stock belt to be too long and throws the tensioner out of it's range (a critical issue)
For my set up I have a 215 amp ambulance alternator which normally takes a longer belt when installed by itself, with the SD pulley the stock belt fits like stock.
The next issue with the Fluidamper is the stock fan hits the dampener ring. OBS Fluidamper kits cost more than 99-03 SD kits because a spacer is included with the OBS. If you run an 03-07 SD 6.0 fan the spacer is not needed and cooling is now improved 2 ways, one by faster fan speed and one by much more efficient fan.
Garbage_Mechanic
Member
I have also learned we all sweat this too much as far as length goes.
Here is how to adjust the belt length.
First experiment by adding washers under the alternator mount feet until you get the tensioner into range. Then do something a little more permanent. However I would be comfortable with good quality washers. With only 3 mount feet flat bar shims don't help much over washers or nuts. Just be sure enough bolt thread is still engaged.
Of course throwing in the Motorcraft (NO aftermarket) dual pulley tensioner changes the belt length again. I'm not sure I'm going to run it, since it is Motorcraft only I would have to carry a spare one.
Here is how to adjust the belt length.
First experiment by adding washers under the alternator mount feet until you get the tensioner into range. Then do something a little more permanent. However I would be comfortable with good quality washers. With only 3 mount feet flat bar shims don't help much over washers or nuts. Just be sure enough bolt thread is still engaged.
Of course throwing in the Motorcraft (NO aftermarket) dual pulley tensioner changes the belt length again. I'm not sure I'm going to run it, since it is Motorcraft only I would have to carry a spare one.
