Ilmor 725/Indy build from the beginning

C_Spray

Charter Member
I've voted with my wallet when it came time to repower by 28' Batboat, and the nice guys at Ilmor (especially ILMORDude) have agreed to keep me updated. I thought that it would be kind of neat to see how one of these packages comes together step-by step.
Here's the first step - House of Kolor TruBlue Shimrin Pearl, one of the optional colors. By sheer coincidence, it's also the same exact paint used on my boat. Gotta love it.
More coming every day, I suspect. :sifone:
 

Attachments

  • IMG00028-20100305-0736.jpg
    IMG00028-20100305-0736.jpg
    98.1 KB · Views: 94
  • IMG00036-20100305-1338.jpg
    IMG00036-20100305-1338.jpg
    93.6 KB · Views: 87
Can you add a pic of the bat boat; so everyone can see what it's going in?

Should be an awesome combination!
 
That is going to be a sick ride Chuck! If you need a co-pilot for your Barnegat Bay Blackjack Run, let me know!
 
..If you need a co-pilot for the Barnegat Bay Blackjack Run, let me know!
DaveP's already got his cape ready. I'm not sure if we can fit BOTH you guys in!

Can you add a pic of the bat boat; so everyone can see what it's going in? Should be an awesome combination!
A variety of shots from between 1999 and 2003. She's been parked for 6+ years, but I got the urge to go trailer-boating again. We pull this with a Grand Cherokee, no problems. We plan to make the Smith Mountain Lake Poker Run on May 22, Jammin' on the James July 10, and the NJPPC Blackjack Run on September 4.
 

Attachments

  • 115_1523.jpg
    115_1523.jpg
    81.7 KB · Views: 122
  • IMTECOhd.jpg
    IMTECOhd.jpg
    62.3 KB · Views: 55
  • 12-5-2009_002.jpg
    12-5-2009_002.jpg
    145.1 KB · Views: 63
  • B58S6689.jpg
    B58S6689.jpg
    24.4 KB · Views: 64
  • B58S6669.jpg
    B58S6669.jpg
    22.8 KB · Views: 53
Great looking boat and holy hell is it going to fly with that engine/drive package. Any idea how fast it's going to go?
 
Great looking boat and holy hell is it going to fly with that engine/drive package. Any idea how fast it's going to go?
Thanks. We ran 92 with 630 hp in 2002, but that was with a DuoProp drive and the prop centerline 7" below the water. We're shooting for zero propshaft height with this package, plus another 100 hp, so it's hard to tell. The Rain-X raceboat ran 107 with 720 hp and a DuoProp, so 110 mph is probably not too far off. We're going with a 1.39:1 gear ratio to minimize prop torque and assuming 10% slip, so that works out to about a 28" or 29" pitch prop at 6400 rpm. We'll find out for sure in about five or six weeks.

I think that the engineering behind the Ilmor/Indy package is right-on; no blower and a 1,000 hp capable drive. I'm a great fan of reliability...
 
Last edited:
Great looking boat. I love those little hot rods! I'm with you....I like reliability. I'd rather be boating then working on it! This is a cool project...I'll be following it along. Thanks for sharing.
 
Very cool keep the pics rolling, Ilmor's motors turned out great in the Sunsation I hope to see more from that combo also in the future
 
What model Volvo is the drive?

Pretty sure C-Spray had a DPX on that boat, which is the same drive he has on his big boat. It was a performance variation of their standard Duoprop. Had integrated hydraulic steering and a much more hydro-dynamic lower section. I don't think many, if any, parts interchange.

The standard Duoprop drive runs into a wall around 60-65 mph. Its just too much drag in the water.

The DPX was a very reliable drive that enabled a performance engined boat to plane off like a runabout and still get great speeds out of it. Unfortunately they don't make it any more. Not sure how parts support is for the drives still out there.

I'm sure C_Spray will chime in and correct any misinformation I have here, but I think I am pretty close on most of it.
 
Last edited:
...I'm sure C_Spray will chime in and correct any misinformation I have here, but I think I am pretty close on most of it.
No need. You're right on the money. Here's the boat as delivered to me in July 1997, with a DPX-R, 1.59:1. It was later upgraded to a DPX-A 1.47:1 drive (see second photo). The DPX-A drive that was on it is now the spare for my 382 Formula.
 

Attachments

  • 12-5-2009_008.jpg
    12-5-2009_008.jpg
    130.6 KB · Views: 86
  • kh_dpx600.jpg
    kh_dpx600.jpg
    22.4 KB · Views: 51
Last edited:
Anyway, this badboy is the real focus of this thread. (Only in blue...)
 

Attachments

  • P1010611 (Large).jpg
    P1010611 (Large).jpg
    115.7 KB · Views: 53
  • P1010616 (Large).jpg
    P1010616 (Large).jpg
    144.3 KB · Views: 44
Awesome Chuck. I look forward to following the build and re-rig!!! Thanks for posting it!! :)

Nancy and I still talk on occaision about the hellride that you took us on in that thing !!!!:eek::eek::eek::sifone::cheers2:
 
Can't wait to see the rest of this build Chuck. See you at Jammin', if not before. Ride maybe? :D
 
Back
Top