Performance Database

[trace elements]

All,

On another site, I saw a performance bulletin for the same hulls with different power and configurations. I thought it would be useful for all here.

If you would like to contribute, fill out the form at the link below, and I will compile all the data and share it with the group.

Open to Gas and Diesel owners. Let me know if anyone thinks any information should be added.

Fillable form: https://forms.gle/yHhhqns5zM6R1Jsf9

Results: https://docs.google.com/spreadsheets/d/ ... sp=sharing

[Ironworker]

I think its a great idea but not sure your Database is the best form to contain the data. Maybe an excel spreadsheet that everyone can add to and everyone can benefit from the data.

I will say that looking at performance data from other members helped me make my decision on which engines to use repowering.

[Amberjack]

I’m building a performance database after repropping, dumping weight, etc but like Rick I’d be more interested to see it in a forum spreadsheet rather than sent off to Googledocs. Perhaps I just don’t understand Googledocs. A spreadsheet would help me evaluate how my performance compares to others with similar equipment.

[trace elements]

If everyone fills out the form, the data automatically uploads to a spreadsheet where it is easily compared. I will attach the link to that below. But to all future respondents, it is easier to collect the information if you respond to the form. The Google products are useful because they are indefinitely hosted by google, cost-free.

Here's the link to the spreadsheet:

https://docs.google.com/spreadsheets/d/ ... sp=sharing

[trace elements]

Anyone else? So far, only 5.

[Tommy]

Trace,

Send me your email address and I will send you all my numbers from when I repowered Island Girl with 315 Yanmars. Some of us are so tech-challenged that it's just easier to email you info and let you fill out the doc online.

Email me at:

tdrake31 "at" gmail "dot" com

[John F.]

I filled it out buy a lot of unknowns for me, like boat weight, can't remember props, and don't know gph (she does really well). If it is too incomplete, feel free to delete. Plus, no one is going to repower with my motors--old and no parts and were just OK to begin with, but really good on fuel and have been great to me so far

[Carl]

Plus, no one is going to repower with my motors--old and no parts and were just OK to begin with, but really good on fuel and have been great to me so far

just ok to begin with???

old and no parts I get...

...but you just said they are great on fuel and have been great to you so far. Plus I believe they were pretty good to Doug too. Also mentioned they were old...how'd they get old if "just ok" to begin with.

Maybe alot of longevity has to do with the owners treating and maintaining the motors as they need to be treated. That may mean a little less wheel with a little less throttle.

The other part of the equation is knowing weight, how fast motor spins, gears, hp etc one can use the approximations to figure what the results may be for their boats.


I used Capys use of 6-53's as my benchmark of what would work for me. I needed aprox 216 hp like him, but preferably something lighter and newer with less tendency to leak oil. Then when Captain Walter chimed in with his 6Bt 210hp numbers I knew that was my 1st choice...followed by 6BTA at 250hp then Yanmars, Perkins, Cat's and...

[John F.]

Not to go into the whole DD 8.2 legacy, but while some had good luck, others had pretty miserable experiences. They were in Blackfin 32 combis among others. I run mine about 35% off the pins for a reason--the cooling system is between barely adequate and inadequate. The way the blocks are cast (open cylinders on top) DD 8.2s are very sensitive to overheat issues and the cylinders can "sink" and you can't get the head gaskets to seal. They also stretched head bolts and blew head gaskets that way. I talked to a guy that ran a local county motor pool (school busses, dump trucks, plows, etc) that had a real lot of 8.2s. He told me that as long as they were run easy and didn't overheat, they were pretty good. Overheat at all and they may be done, and that they didn't rebuild well at all. The marine exhaust manifolds were poorly designed, in that air pockets developed in the forward part of the manifold and caused the manifolds to crack. They had to have (and mine do) a work around fix. There's more (water pump bracket is a poor design) but I think you get the point. My "just OK" view is viewed as relatively positive by most and applies to DD 8.2s in general. Like I said, mine have been really good to me.

[Carl]

John, I fully understood what you meant initially and I am somewhat familiar with the 8.2 history. That is why I said it may have more to do with the owner (you) treating them like they need to be treated. Your knowing their inherent weakness you make it a point to run them "easy" instead of using them to what others might consider their potential.

Basically, you derating your motor to extend its life and that is how that motor needs to be treated to last. I guess I did the same with my ol gas 440's which were bought at what should have been the end of their life at 1200 hours since a rebuild, then I ran them for 25 years...well 3 or 4 after Sandy she sat. I know my first 4 years or so we logged over 150 hours a season but that dropped down as the kids came along, still had to be at least another 1200 hours. They ran well till the day they were pulled. Yes, they got a little tired, but I depitched the wheels to keep the right WOT and ran them at an easy 2850rpm most of the time.

[Carl]

Wonder if I goofed or...nah, I probably goofed. My cruise at 20knots is at 2300rpm.

Although till I clear up the high EGT's I am cruising 20mph at 2000rpm or 19 knts. Is there any way to edit my info on the spreadsheet, looks to be in view-only mode.

[trace elements]

Carl,

In the interest of making sure the spreadsheet is not accidentally corrupted, only I can make edits until the survey is closed. I will update for you, Carl. Thank you, and all, for participating.