Parker 300 picture

**Father Nostalgia** · 11-03-2007

Had a great tiime this year the diesel ran exceptionally well, no problems, we only used 55 gallons of fuel. It has been and still is a learning experience. I would like to thank Ron Hill for his Propeller work. We ran last year and because of lack of test time with props and gear ratio's we only averaged 60mph. This year, we averaged 75 mph. and was limited by the size of our intercooler for more speed. At 75 we were turning 2800 rpm. We have a long way to go.

**Skoontz** · 11-03-2007

Father:

I know I'm talking truck vs boat, but that Dmax redlines at 33 at least ours do. Can you turn that bad boy up to 33 and have the motor last for prolonged periods of time as in running a boat?

I'm told that Dmax is one expensive engine, 14K or so, which is why we keep all our trucks stock... From the first time I saw pics of your boat last year I thought you had one bitch'in concept!

**mercmack** · 11-03-2007

I Was With Air Force Water Serviel School For The Last 8 Years Of My 22 Years I Served...we Ran Are Our Diesels 4 To 6 Hours Aday At Max Rpms And Never Had A Eng Let Go.. Course They Where Detroit Diesels 6v'ss And 8v's...

**Skoontz** · 11-03-2007

6v53-71 and 8v53-71 is a whole different animal than duramax. You ran heavy service truck engines, and those were still the old oil dripp'in change rattl'in scream'in Jimmy two stroke diesels. High RPM in design, I think you could redline one around 3700 or something like that. We used to run the 4-71's in Terex scrapers, one pusher one puller, on the pin all day, 12 hours except stopping for lunch...The Dmax HD engine for light to medium duty trucks, and the D'max 7.8 are two whole different animals. By far the best diesels in their load class, but when I saw that D'max in the boat last year I was intrgued!

**Mark75H** · 11-03-2007

I think 2,400 - 2,500 is about all you can reliably get out of a -71 Detroit. You might be able to get 3,300 or so out of a -53 ... definitly not 3,800; although it did sound like 3,800 on an 8-53

The original 2 stroke Gray/Detroits only ran 1,800 max

**Skoontz** · 11-03-2007

I think you mighr be right again, Sam. you got the two stroke thing going on...A hit every time the piston goes up...Sounds alot higher than every other time

**mercmack** · 11-03-2007

We Had Two 53's In Are Burtrims For Towing Par-asails, Since I Was The Engineer On The Boat, I Had To Set On One Of The Engine Hatches And Work The Towreel For The Pairasail..one Day After Years Of Doing It, Some Medial Person Came By With A Sound Meter Took A Few Reading And Said You All Need Ear Protection....so Now I Dont Hear So Good...
Are 36ft Boats Had The 8's And The Two Big 78 Ft Boats Had Two 8's...spent 3 Years On The Big Boats Once I Made Mastersargent

**Father Nostalgia** · 11-05-2007

I modified the engine for more rpm. The heads were ported and polished, bigger and better quality valves, heavy duty valve springs and a new higher lift cam. The intake was changed to a 2007 with 20% more intake area. A bigger garrett turbo was also added. The company that did the heads was So. Cal Diesel. I have noticed a big difference in the way the engine runs. It should run up to 4000 plus rpm. Gale banks has supposedly run his modified duramax engines at 5 grand. I only wanted a few more r's. We have had real good success with the v-drive. With 1:2.125 gear ratio, the cases had to be machined quite alot, however I engineered a water cooler that keeps the gear box at less than 140 degrees. Additionally, the gear box is only turning at the enigine speed which is under 4 grand. As I have mentioned, the props have been worked and I think I am getting close to what I want with performance. A little more tinkering and I'll be there.

**Skoontz** · 11-05-2007

Father;

The evolution of the duramax has always fascinated me...We worked for the senior engineer on that project out on Pala, CA, and originally, the D'max was supposed to run Nippondenso injection, which was/is bulletproof. GM played politics and ended up running the Bosch system which relies on a seal tight fuel system from the tank forward, which is why most of the early D'max injection issues occured....Then, after '05, they switched to Nippondenso, all our 05' trucks have Nipp, pre 05's run the Bosch. The Nippondenso is supposed to run high pressure common rail, which seems to be the way all light truck diesels are going....
Since we became Ford truck powerokelss after multitudes of problems I wondered when someone was going to put the D'max to a marine application test....Anyhow, I loved your boat from the forst picture I saw of it last year for the enduro
Are you running the Bosch injection system or is it the Nippondenso?

**MAXIMUS** · 11-06-2007

Originally Posted by Father Nostalgia

I modified the engine for more rpm. The heads were ported and polished, bigger and better quality valves, heavy duty valve springs and a new higher lift cam. The intake was changed to a 2007 with 20% more intake area. A bigger garrett turbo was also added. The company that did the heads was So. Cal Diesel. I have noticed a big difference in the way the engine runs. It should run up to 4000 plus rpm. Gale banks has supposedly run his modified duramax engines at 5 grand. I only wanted a few more r's. We have had real good success with the v-drive. With 1:2.125 gear ratio, the cases had to be machined quite alot, however I engineered a water cooler that keeps the gear box at less than 140 degrees. Additionally, the gear box is only turning at the enigine speed which is under 4 grand. As I have mentioned, the props have been worked and I think I am getting close to what I want with performance. A little more tinkering and I'll be there.

Really cool what you guys are doing there. Very admirable.