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Beavertim
05-08-2002, 02:35 PM
Since I didn't get any response on the original board, I'll try again here.
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I ran my '78' 21 ft Eliminator (mini-day sport) on Saturday AM and clocked 63 MPH on GPS @ 5500 RPM's. Do those numbers seem reasonable for a Dominator B(?) cut with a stock loader grate? The boat was full of gas (40 gal), probably 100 lb of stuff in the bow and storage compartments (140 lb including my son (under the bow, not in the compartment) and my brother and I (350 lbs). The engine is a pretty much stock 460 BBF with twin turbo's. The jet has a bronze impellor, place diverter and 15 deg wedge. I am really interested in determining if the impellor is a B or A cut, and your opinions on what minor improvement options might be (custom grate, etc.) other than the obvious removing weight and gas or sinking lots of money into the engine. Also, does anyone know approximately what my boat weighs? Thanks in advance for your responses. Tim

rivercrazy
05-08-2002, 02:47 PM
Do you know how much HP your running?
I bet the hull and engine weight between 2,800-3,000lbs.
Depending on how much HP your running with that twin turbo motor, I think 63 might be a little on the slower side of what it should be going.
How many hours are on the pump? Is it tight and in good shape? Does it cavitate out of the hole?

Beavertim
05-08-2002, 10:00 PM
Rivercrazy,
I'm guessing the (based on the JPC curves) that I'm getting around 525 HP. Desktop dyno says it should be closer to 600 HP. The head porting and valve sizes make a big difference on DD results. I have DV3 heads with some porting on the exhaust side with stock valves. I've only had the boat for a year. The pump was blueprinted 5 yrs ago by ADM, and supposedly did't get much use over the five years. It takes off pretty well out of the whole for a big boat and doesn't seem to cavitate. Any idea what a typical speed for 5500 RPM on a Dom-B should be? I ordered a better grate from CP, and am anxious to see the results. Tim

greg shoemaker
05-09-2002, 05:08 AM
Is this boat blue and white and was it owned by woman who drove a 18 wheeler. I might know the boat Greg

HavasuDreamin'
05-09-2002, 06:26 AM
Greg:
Good to see you back on the boards!

rivercrazy
05-09-2002, 08:11 AM
An A impeller with 500hp would turn about 5,100-5,200 rpm. So 5,500 with a B sounds about right. You might be better off with an A or an AB impeller with a heavy 21 footer. However that depends on your peak HP/Torque curve. A B impeller with a heavy 21 footer will cruise at pretty high rpms.
I would still have your pump checked out. I have not heard one good thing about work done by ADM yet.
I would think with 500hp and a stait bottom, closed bow, and tight pump you should be more in the 65-67mph range.

Beavertim
05-09-2002, 08:48 AM
Greg,
How did you know? I'm not sure about the 18 wheeler part, but the boat is blue and white with a little good old 70's simulated wood grain mixed in. She lives in Hemet. What do you know about the boat? I found some oddities like a windshield washer H20 injection set-up, and a piece of the number 7 piston crown missing. Other than that I've been pretty happy with it. I have upgraded the pistons (forged vs cast) and cam(turbo grind vs stock), as well as cleaning up the exhaust ports. I'm thinking about possibly doing more head work next winter (larger exhaust valves + a little more porting) and possibly an impellor change/rebuild. Tim
RC,
Thanks for the inputs. I am going to get the pump looked at, just don't know when I'll get the chance. Is there anything (basic checks) a jet neophyte like myself can do in the meantime? Tim
P.S. What gas should I run in this engine (10 psi max boost)? I have been running 92 + octane boost.

greg shoemaker
05-09-2002, 08:17 PM
Tim The numbers you have posted are on the weak side. Sorry to be the bearer of bad news but Ithink your problem lies in the engine. With a turboed engine and 10 lbs. boost youd be making 360 hp on the engine normally asperated and with 40 hp per 1 lb of boost your in the 700 to 750 range on hp and with a B impeller you should be turning about 6000 rpm's. and running well into the 80's Greg

Beavertim
05-10-2002, 08:07 AM
Greg,
Thanks for the input. I know desk top dyno is not gospel, but with the DV3E-A2A heads with stock valves, it says I should be seeing around 600 HP, maybe 625. I believe the base HP for a 8:1 460 is around 335. The porting and valve size assumptions make a BIG difference in the predicted output. I had the engine apart last winter and all of the piston to bore clearences were within spec, the bearings were also in spec., so I think the bottom end is OK. I still believe I am missing some HP from the heads or the intake manifold/carb since the charts say 5500 on the B is about 525 HP. The carb is a single 780 Vac secondary Holley. Also, the jetting may not be optimum. I have 72/90's w/PV's in prim/sec. Will that carb support 650 HP? 750 HP?
BTW, Any history on the boat? feel free to email me Thanks Tim