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Bobby Daniels
I'm not sure what heads and cam he is running.
I do believe it was 10 to 1 compression, which I believe will be lowered now that he is getting a complete rebuild. It was dynoed at 550 hp pushing that 29' Power Quest 68 - 70 mph. The blower was set up for 5 lbs of boost, which the (mechanic) said would give him an additional 150 hp. Is that valid or not? Also if he turned it up to 6 lbs of boost as you suggested how much difference would that be to the 5 lbs? How much difference would 6lbs Vs. 5lbs make to the over all life of his engine? And drive? (bravo) I know boating is hard on engines, but he likes to boat alot, not work on them alot. He needs good power to get that big single engine moving. But also would like reliability, fast but not the fastest guy out there. Just nice balance. Cougarman |
10:1 and 5 lbs boost? Iron or Aluminum heads? The CR is probably too high unless you run REALLY high octane. Sounds like a combination of too much compression, you jetted too lean, and possibly too much advance on the timing.
Did he burn a valve or drop one, ie broken spring or retainer? Gary |
Gary Anderson
He has Iron heads, and he was burning premium fuel.
He was figuring it was jetted to rich by the way it smelled? And by turning his transome black? Cougarman |
IMHO, premium (93 octane) is needed for a 10:1 motor. Add 5 lbs of boost, and you're going to need higher octane than that.
Gary |
When blowers & high compression are together motors do not stay together long in a boat. If the motor had that much compression a blower should not have been put on that motor. The motor detonated itself apart. I bet on tear down that there is going to be way more damage that just a valve. Detonation is why it was building no more HP than what is was NA. Timing being off did not help but even if timing was righton the first time, motor had a very short fuse.
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110 octane may have detonated in that combo. All else aside that is the problem. Did he have any problems burning center and ground electrodes out of the spark plugs?
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I do alot of blower motors with aluim heads to disapate the heat and run 9 to 1 and 8 or so psi but I agree with turbo and vette it was a gernade with iron heads !! and it could not run as turbo said with that much detonation going on .
Get him to get some help on the board in rebuilding it and it will be a screamer ,,,,,:D :D :D |
It sounds to me that your mechanic is clueless on boat engines. Especially design.
Mine are weiand 256 with 2x700cfm running 8:1 with a very mild cam on 468CI engines. You should be running around 30 degrees of advance. I do not have a pyrometer on my engines but would like to have them. This is critical in knowing if your engines are running too lean or too rich. You could literally dyno in the water by tracking temperature. Makes carb set up much easier. Your engines were set up for high performance NON-blower use. You really need to change your pistons or heads to get the compression down. |
Cougarman-- It sounds like the same grade 8 auto class put hat motor together as the two 461's I bought from your buddy Rich !!
And those only had 10 hrs on them. Ya Right. Just tell your buddy to Break Out A couple more Thousand, that's what i had to do! Suck doesn't it! |
Del Sol
I don't know what you have going on, And I really don't
care to be in the middle of it. I'm simply trying to help a fellow that I feel was mislead for his own possible lack of knowledge. Obviously I don't have all the answers either or I wouldn't be on here asking questions to further my own knowledge aswell. Maybe you should take this up with whoever you feel is responsible. Those engines ran Strong when he sold them to you. And they were fresh! You emailed me awhile back and asked a few questions, but , never said a whole lot. You did say you had torn one down and found pin floated on you. Anways I also tried to help you a warned you about the place you were at. Because ( Kaama ) had some bad problems with them and I didn't want to see you get stung. Also I remember, in another thread you mentioned how great those engines were, and full fuel, empty, lots of people, or very few people the boat ran strong. And you said all your friends wanted to ride on yours all the time now. Instead of there own. Bottom line I still Believe Wolfie's Compition engines builds a great engine. Sorry for whatever went wrong with it. Sometimes things happen. Best of luck Cougarman |
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