Can someone verify some dp c and e gear ratios for me?

PickleRick

I am getting conflicting info,  im needing to be able to prop a 23 to 25 ft hull for approx 25 to 30 knots at 3400 to 3700 rpms.

The aq series (280 and 290) offered diesel gearing in both a 1.95 and 2.3. Ratios. These also fit on some gasser 4 bangers, v6 and even some v8s depending on applications.  

These were 80s to mid 90s vintage.   

For my application lower the rpms the better.

I know the vp site used to list this info but the page is dead now. Also, go pens  

Handymans342

Go Caps!

Handymans342

For what its worth, my outdrive was 1.67 and my Yanmar turned at 3600 max

PickleRick

Can you by chance give me your hull length and approx speed at 3600? 

Handymans342

34 feet and 34 mph

PickleRick

This is very good information. Thank you.  I know its a stretch but would you happen to know your prop pitch?  

Handymans342

19x21 4 blade. Dont ask me anything else cause I dont have the boat anymore lol

PickleRick

No great info!  That's really all i need.  Using a prop calculator the 2.3 ratios compared to what you gave me would be awful for a diesel set up.  I'm starting to gather some components of a diesel project.

I needed real world info not just paper calculations. Exactly what i needed

Handymans342

Yes, a diesel cannot over rev. Rick, have you heard that the EPA is going after the companies that make the tuners that get rid of the equipment that you delete in the factory computer??

PickleRick

Yes, a lot of tuners are not touching newer cars and trucks due to it being an EPA violation.  Inspection states are screwed. 

Im acually not allowed to open up a chainsaw or weedeater L or H fuel adjustment screws further than stock specs. It's an EPA fine if reported.  Been that way for years now. 

South Carolina has not done any inspections since the early 90s

Handymans342

None in Florida either

PickleRick

Luckily there is a loop hole for tuners and emissions mod manufacturers, an off road use only on the box.  Sled pulling, drag racing, mud bogging, circle track, road course are all big dollar sports.    

Handymans342

I dont know if you have looked at the new Mercury diesel or not but they top out at 4200 rpm I believe. Based on a VW motor. 

PickleRick

Any new or even used marine diesel is out of my budget.  I can get a complete mercedes or bmw car wrecked for sub 2k and another 3500 to 4k for adapters, retune for ecu and marinized exhaust.  In the 6k range i can't touch most marine diesels.  

With either engine 4000 or so rpms is safe for extended periods of time. The yanmar from the BMW also found in marine applications.  

Handymans342

I went 3500 rpm for 5 hours straight

PickleRick

Due to the much shorter stroke than what's found in the 4bt and 6bt engines the yanmar and vw/mercedes spin double the rpms and do it much more comfortably.  Just had a low mile bad tranny 95 mercedes 300D come across craiglist for 900 obo.  Sadly it ended up being a non turbo model.  I was hoping for a turbo.  Turbo models have oil squirters for the pistons for cooling and larger fueling capability from the injection pump

Handymans342

Diesels are fun

PickleRick

I agree. Being able to get parts at orileys in a Saturday is also a plus.