Dry Sumping Volvo DPR'S
 

Hi All,
We are in the process of installing higher powered engines and to enable the drives to cope with the extra power i have changed some of the bearings to minimise shaft deflection and also installed a PTFE hose into the lower unit this will be connected through the transom into a micro hydraulic pump through a filter and returned to the top bearing in the upper, this will allow me to run a much lower oil level this along with circulating the oil should keep the temperatures much lower.The drives have completed almost 1000 hours of use as wet sumps still on the original gears but the bearings have required changing every 250 hours and the oil every 50 hours.

Peter

You're blazing a new trail here. I have not seen these drives on any applications in the US other than D6 diesel engines on cruisers. I have DPX-A drives (no longer made) on my 38 Formula behind 600 hp per side, and have thought about converting to DPR's, but it seemed to be too big a job to be worthwhile.

Did you make your own shorty lower units, or are those standard ones with nosecones?

http://www.weismann.net
knows alot about them

Hi C_Spray,
The engines are modified D6'S running at around 400HP and 900 NM of torque, we are doing some further modifications to the engines which will increase their power to around 500HP with the torque deliberately kept below 1000 NM, we are also increasing the RPM to 3800. The lower units are Volvo castings which i have cut the skegs down and made nosecones for. Apart from running very hot the drives seem to be quite reliable unfortunately due to lack of demand Volvo will cease production in March and i don't think they have any plans to produce a replacement highspeed drive.

Peter

By "lack of demand", I assume that you are talking about the "-R" version, not the DP-H version that shares the samne gimbal and upper. There are lots of diesel stern drive packages being sold over here.

JJones - I saw Weismann's Hammerhead drive, but nothing about modified Volvos...

Hi C_Spray,
When volvo introduced their 400HP stern drive package in July last year they also re engineered the DPH outdrive it has stronger castings, uprated gears and bearings but it only has gear ratios and propellers suited to heavy boats with a top speed of around 45knotts. I think the DPR lower unit will still fit the new upper, i will be trying this in the future. The reason for discontinuing the DPR leg is because they only managed to sell around 20 worldwide in the whole of last year.

Peter

could you tell me what modifications you have done on your d6's i have the d6-350's in my formula 400ss and would like to get more hp out of them. my dealer wants me to swap out for the new d6-400 and drives. way to much money for what i want to do. would like to know what can be done and well the drives survive 400hp ?

From what I understand about the D6/400 versus the D6/350 and the old DPH's versus the new ones, the differences go beyond simple tuneups. Your best bet may be to look into trading up to a newer 400SS with the 400's.

i want to know what peterunwin did to "modify" his d6's to 400hp and what further mods he is doing to get them to 500hp. i'm going to run the current outdrives until they go boom then upgrade to the newer ones.

i've heard they run very hot on the top, wonder if a drive shower would help.

fixx
 

cone clutch drives converted to semi dry sumps ??
i dont think they will last long with out any oil keeping the cones from welding themselfs together..

Hi whatta life,
The first modification was to fabricate through transom exhausts this made around 15-20HP per engine, i then went on to remap the ECU'S taking the power up to around 400 at this point the standard cooling system was right on the edge so i modified it to flow more water by moving the water pickups from the nose cones on the drives to the bottom of the transom, these are much larger and flow much more water. My engines have done in excess of 800hrs in this modified format and have covered many hours at WOT... The 350HP injectors won't flow enough fuel to go much beyond 400HP but you can get them converted to 435 spec by a competent bosch service centre, this along with upping the common rail pressure gives the required flow to enable 500HP, along with the following parts
1. Heat exchanger from the 435 engine
2. Charge cooler from the 435 engine
3. Hybrid turbo charger
4. Inlet manifold from the 435 engine
5. Remap of the engines ECU
Obviously Volvo don't approve of people modifying their products so would probably steer you away from it, but it is much cheaper than buying a new package!!

Peter

Hi mrfixxall,
The standard drive relies mostly on splash to lubricate the bearings and cone clutches at the moment. The vertical shaft bearings are also shielded which furthur impedes oil circulation, on my semi dry sump convertion the oil is removed from the bottom of the lower unit through a hydraulic pump mounted inside the boat into a filter and returned to the top cap in the upper this has been modified along with the bearings to create a weir system flushing the top bearing and cone clutches plus the horizontal shaft taper roll bearings and gears before returning through the lower vertical shaft bearings back to the lower unit. I have also incorporated a breather which will drastically reduce shaft seal wear caused by pressure build up in the standard drive.

Peter

Nice to see a project with diesels again here ,good luck,and Habana Joe where are you ?
Since the word DIESEL has been wrote here ,his search function light must be flashing now .

These drives are pretty beefy monsters, almost the size of #6's. I'm glad to see someone working them over!

It just registered on my that you said you had 1000 hours on the gears in your drives. Holy crap...

There no reason you can't put a sprayer in the cone area.

Jeff

Hi All,
Final assembly of the drives, machined the oil transfer ports into the upper cap and set the backlash and bearing preload also changed the rear prop shaft as a precaution as i broke one at 450hrs it broke right on the friction weld between the stainless steel and carbon steel, they are now assembled and ready for paint.

Peter

Looks very interesting. I will be curiuos to hear your results.

Hi All,
Having finished the dry sump convertion i have now moved on to the fly-by-wire steering system, i have already built a system for the Ilmor engined boat and the system for the Volvo engined boat will be very similar. Because there is no creep in the system this allows the mounting of trim switches and throttles on the steering wheel as the central position always mantains the drives straight.

Peter

Here is what I had bookmarked online for when I ever buy a diesel 400ss.
http://www.chipexpress.com/products/2457/
http://www.chipexpress.com/products/2458/
http://www.chipexpress.com/assets/im...-thumbnail.jpg

peterunwin and the rest of the diesel guys, you think this can be reliable on current 350 and 370 D6 with DPH?

p.s. peterunwin your doing one hell of a conversion. Continue posting your updates.

Hi PhatboyC,
I think the guys at chipexpress may be living in a fantasy world because the standard 350/370 charge cooler and heat exchanger will not support powers any greater than 400hp even in England where our average water temperature does not exceed 12 degrees centigrade, we have found it necessary to modify the cooling system. Even with the mods exhaust gas temperature is on the high side. We also deliberately map out the torque to make the drives live.

Regards
Peter

Talk on another thread about adding vent tubes to a drive got me thinking about them on DPX/DPR applications. Did you ever consider or try that? I would think that in high torque applications it would take some of the load off the drive while trying to spool up the props?

Hi scarabman,
Whilst doing the dry sump convertion i have completely removed the cavitation plates with the idea it will vent at slow speed and reduce drag at high speed. During the boats refit i am also mounting the engines at 800mm centres they were originally at 950mm which will allow me to set them higher relative to the bottom, i am also reducing the boats weight by about 350kg. When the boat was standard with 350hp max speed was 52 knots after the engine and propeller modifications this rose to 62 knots with the reduction in weight and increase in power from the latest refit i am hoping to see better than 66 knots. Also made the manifolds for the steering system these power both sides of the cylinders , the standard volvo system only powers one side.

Regards
Peter

Thanks for your answer. I guess its a different world then all the turbo diesel trucks getting a simple remap boosting the turbos to get huge HP gains.

If I ever upgrade and buy a 400SS Formula I wanted to do 55mph with hardtop with a simple engine upgrade. I guess the marine world is a whole different ball game.

Peter - I heard from Ian Hawkins that you were going to be in Miami. Sorry that we couldn't meet. I spoke with Jay Koontz at the Volvo Penta booth about your project. He seemed intrigued. Keep up the good work.

Peterunwin, Awesome Project, I was looking into buying a new Formula with the Volvo D6-400 and was worried about spending the extra money for the Diesel's but from what you have said about the Volvo D6 and their drives (older ones), I feel much better about long gevity and being bullet proof. I was afraid that running a stock D6-400 at WOT or -10% I would have issues over time.

Rich

Hi C_Spray,
It would have been great to have met up with you.. however we decided to save up all our holiday for the year and come to Florida around mid October for around 6-8 weeks so we can have a tour round looking for real estate and also visiting the fantasy fest and world powerboat championship in Keywest perhaps we could catch up then?

All The Best
Peter

Thanks Rich, the D6-400 will be a very unstressed engine as it is identical to the 435 IPS engine the only diffference being the ECU programme.

All The Best
Peter

Hi All,
Mounted the trim and tab pumps to the carbon fibre plates along with the polarity changeover switches, this saves 8kg compared with the standard volvo brackets, also made some spreader washers for the transom shield bolts these save a further 2kg over the rather agricultural volvo standard issue they also spread the load into the transom much more effectively.
I am now making the tooling for the carbon fibre trim tabs.

Peter

Hi All,
Have finished off the preparation and then applied a couple of generous coats of two-pack to the drives, also made the jigs for the transom cut-outs as the engines and drives are being moved closer together with a higher X dimension.

Peter

So your boast will sit higher on the water for greater speed less drag?

Hi PhatboyC,
During the rebuild process i have been able to save a substantial amount of weight in the engine compartment, moving the engines closer together has allowed me to reduce the engines centre of gravity by 1.5" and at the same time decrease the X dimension by 1". I have also moved the engines forward by 5.2" as the engine and drive package weighs approximately 750 kg each this will move the longitudinal centre of gravity further forward as the boat previously was always a bit stern heavy.

Peter

Hi fatboyc

I tried those boxes on my 320hp cummins and they do absolute nothing not even in the higest setting we had added boost gauges to see what happend but it was nothing not even smoke increase . The told me that I would see a 50 hp gain for each motor , I tried it because they offered full funds return when not happy and the did .

Bor

Hi All,
I have finished the rebuild of the transom shields these have now been painted and the carbon cover plates fitted ready for installion to the boat, i have also decided to make some carbon fibre power steering oil coolers as the standard volvo units obstruct the water inlet flow and cause weed hangups. The electro-hydraulic pumps have also arrived for the dry sump system.

Peter

Some more pics

Thanks for sharing your experience. From what was said by you and peterunwin I am staying away.

Looking good peterunwin! Can I ask how much money you have invested so far in this project?

Thanks Very Much... as i do virtually all the labour myself i only have to buy the materials, i also sold the old engines which allowed me to buy two brand new 435 bobtails for less money than rebuilding the old ones to the new speck, so i reckon total cost will be in the region of £60000.00 and a hell of a lot of LABOUR!!!!! but i am hoping to market some of the special parts including the fly-by-wire steering system.

Peter

peter,

i'm ready to start upgrading my d6 350's . cant find anyone in the states that sells a plug in chip box or remaps ecu's. did you remap your own or can you recommend some one you trust ? i'd like a plug in box but haven't found anyone who has run a chip express ( or others ) that has had them work on the volvo d6's. looking for about the 400 hp mark with as little torque increase as possible.

then want to have the props worked on to get more top end out of them. i sure would appreciate any help .

p.s. let me know if your going to fantasy fest. we might take the boat down from naples, its only 3 hours.

I think 400HP is a little on the ambitious side bearing in mind your high ambient water temperatures so i would say 380HP is going to be top whack without changing the charge coolers. The 435 charge cooler will fit with some pipe work modifications and a new inlet manifold, the parts in England are not too expensive. You can also pick up a few horse power by removing the rubber bellows between the transom shield and the drive leg, not as good as through transom exhausts but it certainly helps. We can get your ECU'S remapped for you although i know we are a very long way away....
We are still contemplating coming out to fantasy fest and the world powerboat championships, we are also thinking of buying a boat to keep in Florida while we look for a house we just can't decide where we want to live there are just so many nice places...

All The Best
Peter