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Discussion Starter #1
Hi Jim

Lookin at this boat has a 502 .30 over victor jr intake 850 dp carb full roller valve train eddie marine exhaust. Individual selling it said it dynoed 643 hp @ 5500. But with a 26 four blade running in the boat he only gets 4800 rpm. Something seem to be off asked if it could be as simple as the tach seller says no. Am I wrong in thinking this motor should pull 5100 to 5300 rpm's with a 1.50 drive & 26 4 blade? please help. I like the boat just dont have the extra time and money to fix it if there is something wrong.


Thanks
Mark
 

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Discussion Starter #2
any body on here check these messages!!!!!!!!!!!!!!!!!!
Hi Jim

Lookin at this boat has a 502 .30 over victor jr intake 850 dp carb full roller valve train eddie marine exhaust. Individual selling it said it dynoed 643 hp @ 5500. But with a 26 four blade running in the boat he only gets 4800 rpm. Something seem to be off asked if it could be as simple as the tach seller says no. Am I wrong in thinking this motor should pull 5100 to 5300 rpm's with a 1.50 drive & 26 4 blade? please help. I like the boat just dont have the extra time and money to fix it if there is something wrong.


Thanks
Mark
 

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Your boat is working as designed. What outdrive is it? You don't want that hull over 80 mph from what the builder told me. I have a open-bow model.
 

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Discussion Starter #6
Bravo I was looking to buy this gem but I think I will move on to greener pastures to many great boats out there this just seem to have the wrong set up

Thanks for your Help

Mark (MR HLB)
Alpha or Bravo drive? With the motor you have you are really working the alpha if that is what you have.
 

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Boat Test GURU
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I think one big question is what camshaft is in that engine and what are the specs.

Sometimes just a small amount of adjustments and the RPM comes up.

JW
 

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Discussion Starter #9 (Edited)
Not sure, Per the owner there is a dyno sheet claiming 5500 rpm @643 hp do not have cam specks @50 nor peak torque just #'s thrown out by seller it is a 502 .30 not sure of the generation of block either it has low cmpression per owner 8.9 or 9.1 he says 87 is ok but he runs 91? That seems odd why pay more if you don't need it? confused on that one as well

I thought by using my old hot boat mags as my bibles they would give me a prespective on what were real test #'s with simular applications as his set up. I thought I could use his #'s to get a guestamation of an out of water test with 563hp 1.50 drive and a 26 4 blade I figured about about 5200 he is getting 4800 he also said he built the motor with reliability in mind not full race. The crusing #'s he gave me were 3300 @ 50mph I used bobs old formula to get max hull efficientcy at 100% than backed it down to 12 to 15 % slipage

Well I do know that drive ratios and props on boats act like rear ends on cars axles and ring & pinion. in relationship to RPM. Just seems the set up is not right . If it is more than that I will just pass on it too many others out ther to worry about this one boat. Your thoughts probably need cam prfile and dyno run sheet so it tells us it heart beat throughout the RPM range also any advance or retart for the cam set up right. Please let me know I will see if I can get it.

Also someone mentioned that going over 70mph in the 2450 caliber 1 is not recomended is that true? Is'nt the 2450, 240 hallet and now the 25 shockwave the same molds. Please educate me on this I am getting mixed info on the hull from different people I will trust your word.

Everything else is great on the boat to accomidate me and the family i am just not wanting to buy a boat with a hurt motor or with the wrong cam profile for a marine motor application

Thank you again jim for you time

Mark

I think one big question is what camshaft is in that engine and what are the specs.

Sometimes just a small amount of adjustments and the RPM comes up.

JW
 

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Discussion Starter #10
Hey

Jim

Is over 300 hours on a 454 mag 385hp that is serviced properly, too many hour and should be considered for rebuild when making a used boat puchase

Mark


I think one big question is what camshaft is in that engine and what are the specs.

Sometimes just a small amount of adjustments and the RPM comes up.

JW
 

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Discussion Starter #11
Jim can you help me out on this one please read my previous question regarding the 454 mag what hours are considered for a rebuild with proper maintenance I can only go by what the owner tells me and he says maintianed every year



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Mark
 

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Depends on how hard it has been run and its service. 800 hrs is not abnormal to rebuild.
 
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