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Discussion Starter #1 (Edited)
New Question post 29

Ok so i just ordered a 650 hp motor from M&R motors out of Glendale Ca.
an am putting it in my 2002 cobra open bow approx 2200 lb. boat with a Legand pump, Question is what impeller should i use and or how do i figure that out...Thanks in Advance


Existing motor is a stock 454 probably 400 or so HP. with i think an A impeller.
BWL Parker AZ.
Hoping for a big gain. please please please............
As of right now it goes 50 mph max. all day every day.
Yes will start out with the A impeller, Recieved new SS A/B last week Thanks Tom.
 

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I have on 02' ultra stealth with a 420 ish hp motor. Id be interested in seeing the gain you get from that motor. Where do you boat? I have a legend pump with I think an A impeller.
 

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Angry American
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Ok so i just ordered a 650 hp motor from M&R motors out of Glendale Ca.
an am putting it in my 2002 cobra open bow approx 2200 lb. boat with a Legand pump, Question is what impeller should i use and or how do i figure that out...Thanks in Advance


Existing motor is a stock 454 probably 330 or so HP. with i think an A impeller.
BWL Parker AZ.
Hoping for a big gain. please please please............
all depends on where it's making it's power. For example, if it's making the 650 at 6500 rpm but only 300 at 4500, it won't be much better than what you had. On the flip side of that, if it's making 650 at 6000 and 500 at 5K, it'll put a real big smile on your face.

In essence, you really need to know what the HP and TQ curves look like to be better able to choose an impeller.
 

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Cas gave you good info re power and torque , one things for sure your anticipated 650 hp will exceed all aluminum impeller limits making you a canidate for a bronze or stainless (OEMs and after mkt are rated @450 to 500) Motor info on your "M&R" mtr will be help full Tom
 

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Discussion Starter #5
New motor details for 2002 Cobra

Quantity Item Code Description Price Each Amount
Engine COMPLETE ENGINE BBC 489 MARINE PAN TO CARBURATOR 650
HP


1 3021 PC BBC ALUM CYL HEAD COMPLETE
1 DG3-454B 4340 NITRIDE BBC CRANK 4.250'
1 KB786-030 KB FORGED PISTON 489 GM -12CC DOME
1 9904-030 EXTREME RING SET 4.280
1 LG3-6385H 4340 H-BEAM ROD SET BBC 6.385
8 CB743H-000 BEARINGS
1 MS429H-000 PERF MAIN BEARING SET
1 CORES CORE PART BBC 4 BOLT
1 CLEAN BLOCK THERMAL CLEAN, SHOT PEEN, AND MAG CYL BLOCK
1 BORE8W/ BORE AND HONE V8 W/ TORQUE PLATE
1 SURBLKSQR SURFACE CYL BLOCK SQUARE ALL SIDES
1 135-3610 ARP HEAD BOLT KIT BBC W/ EDELBROCK HEADS
2 1047 PERF HEAD GASKET 1047
1 08-1110 BBC TRUE ROLLER .250' TIMING CHAIN SET
1 535-9701 BBC ACCESSORY BOLT KIT
1 01-461-8 COMP EXTREME MARINE 254 260,112 HYD ROLLER CAM
1 854-16 RETRO HYD ROLLER LIFTER SET BBC
1 2330 BBC STAINLESS ROLLER ROCKER ARM SET 1.7 7/16
8 3-8050-80 3/8 HARDENED PUSH ROD 8.050 W/ 210 RADIUS
8 MT8750 BBC PUSH ROD 8.750 X 3/8 HARDENED
1 Labor ASSEMBLE COMPLETE ENGINE BLOCK
CP209 BBC 8QT STREET PAN WITH BAFFLES AND SCRAPER, SPECIAL
STROKER CORE MARK 5-6

1 872005 NEW PERF. BALANCER BBC INTERNAL
1 2902 VICTOR JR BBC R PORT
2 7198 PUSH BREATHER W/ WASHABLE ELEMENT
1 M77HV HV OIL PUMP
1 IS-77 OIL PUMP DRIVE
1 77-S2 SCREEN
Page 1
Quantity Item Code Description Price Each Amount
1 S8430 BBC GEN 5/6 POLISHED ALUMINUM TIMING COVER
3303C BBC TALL FABRICATED ALUMINUM VALVE COVER SET
CHROMED
1 OS32121 1 PC OIL PAN GASKET BBC GEN 6
1 85551 SBC PRO BILLET DIST.
1 31239 MSD SUPER CONDUCTOR UNI. WIRE SET 180
8 3923 AUTOLITE SPARK PLUG
1 PARTS CUSTOM BUILT 4150 HOLLEY 850CFM CARB

1 Dyno Dyno test and BREAK IN
2 year warranty
 

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Cobra 2, once you get the dyno sheet from builder you will have the info needed to make your impeller choice.

I would also make sure that the oil pan(CP209 BBC 8QT STREET PAN WITH BAFFLES AND SCRAPER, SPECIAL STROKER CORE MARK 5-6) is no deeper than stock(7.8-8.0") at the flywheel end. If it is deeper it isn't going to fit a jet application.
 

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Ok so i just ordered a 650 hp motor from M&R motors out of Glendale Ca.
an am putting it in my 2002 cobra open bow approx 2200 lb. boat with a Legand pump, Question is what impeller should i use and or how do i figure that out...Thanks in Advance


Existing motor is a stock 454 probably 330 or so HP. with i think an A impeller.
BWL Parker AZ.
Hoping for a big gain. please please please............
How fast is your boat with your current 454.
 

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Discussion Starter #9 (Edited)
ok just recieved my new motor am very interested how the performance will change with the new motor, taking the existing one out this weekend.
Have a 454 with holley 750 DP, GM performance heads, carb to oil
pan approx:400 or so hp motor with 97 hrs on it for sell complete very reliable motor pushes my boat with people 3000 lb. 50 mph all day every day. $3000.00 or best o.b.o
 

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Resident Ford Nut
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Very clean.........did they ship you the dyno sheet ? I'm assuming you just kept the A to start with?

S CP :D
 

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all depends on where it's making it's power. For example, if it's making the 650 at 6500 rpm but only 300 at 4500, it won't be much better than what you had. On the flip side of that, if it's making 650 at 6000 and 500 at 5K, it'll put a real big smile on your face.

In essence, you really need to know what the HP and TQ curves look like to be better able to choose an impeller.
Cas been on way too many new boat run @ Mfg. on plane 3 sec's 52,53 Ship it... Your hull should run 62 whith addressing mfg. ship problems alone... Your "A" will work and get you thru test and set up, just don't hit it overly hard on take off and don't jump it....

9.99 out of 10 Your bottom has a hook, 3-5 MPH... then your set up or pump tune up will also pick you up.... Then your ready to start addressing your new power. the "A" with out getting stupid will survive.... to get you thru...

Get your boat to cut water at the rear... not at your elbow... Maybe a droop
to lift the tail....

When you get into the 60's see what your Rs are on what cut... Call some one and tell them... Its the first guide!!! Excluding us marketeers I have found the help given here to be good...so talk your way thru....
 

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You will get the best performance out of that boat by doing as Pops says.
You will get the best performance out of that motor with the pump spinning 6157 RPM. If you have any questions, call me 417-858-8616.
Duane HTP
 
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I did not. Now I do! with a MPD detailed A! If I were to do it all over. I would go No Inducer and a HH "B" But that would be a Guess cuz I am no guru like yourself. I am learning! BTW My boat is good out of the hole I just cant spin the A with an inducer as high as I should. Nor will he with that power. I will probably try the C again at some point with the inducer. I really like what I hear about HH impellers.
 
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