What props and what hp??
06-19-2003, 09:30 PM
#1
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What props and what hp??
Hello just trying to get a little info on props on the 92 checkmate convincor 251. My boat has about 500hp at the prop and so far a 26 4 blade bravo works the best for speed and rpm, I want to be around 5200 rpm . I tryed a 26 hydromotive and it was very unstable it felt like the only thing in the water was the prop.I did call hydromotive and they told me to try a 24 they said there was to much tq for that prop, any body got some insite on this?
like what hp
year
hull
rpm
speed
and prop hydromotive,bravo,3or4 blades
Thanks alot
like what hp
year
hull
rpm
speed
and prop hydromotive,bravo,3or4 blades
Thanks alot
500 HP AT THE PROP
06-24-2003, 06:56 AM
#3
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I think we have determined that Checkmate used different x dimensions on various 25's. We am running a 23 Mirage and it works great. Others can't get on plane with a 3 blade. BTW, we have a stock 454.
06-24-2003, 03:31 PM
#4
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Hello,
I have a 251 Convincor, year 1997 with a 500 EFI (gear rotation: 1,5:1). It runs between 78 to 79 on speedometer and 73,4 on GPS with a 27 Mirage plus at between 5200 to 5300 rpm depending on the people and fuel on board and the water condition. Normally the boat runs on flat water and there are no waves. Does anybody got an idea how to get the boat run faster? Does anybody got any experience with a shorten Bravo One? Or does anybody of you ever changed the gear rotation from 1,5:1 to 1,36:1? In my opinion the engine got enough power, but it is very difficult to find the proper prop. In Germany only a few people using the pitch I would need.
In the past I have not written anything for quite a long time, but I had so much work and was not able to. But I promise to do better in the future.
I have a 251 Convincor, year 1997 with a 500 EFI (gear rotation: 1,5:1). It runs between 78 to 79 on speedometer and 73,4 on GPS with a 27 Mirage plus at between 5200 to 5300 rpm depending on the people and fuel on board and the water condition. Normally the boat runs on flat water and there are no waves. Does anybody got an idea how to get the boat run faster? Does anybody got any experience with a shorten Bravo One? Or does anybody of you ever changed the gear rotation from 1,5:1 to 1,36:1? In my opinion the engine got enough power, but it is very difficult to find the proper prop. In Germany only a few people using the pitch I would need.
In the past I have not written anything for quite a long time, but I had so much work and was not able to. But I promise to do better in the future.
06-26-2003, 02:28 PM
#5
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Hello Wild Willy,
well it seems that I do not have many options. But with a shorty drive you should have less water resistance, shouldn't you? There must a some possibility? Does anybody have experience with chip tuning on the 500 EFI? Perhaps, somebody else got any idea.
I am not at home this week-end, thus will answer as soon as I return. Take care.
well it seems that I do not have many options. But with a shorty drive you should have less water resistance, shouldn't you? There must a some possibility? Does anybody have experience with chip tuning on the 500 EFI? Perhaps, somebody else got any idea.
I am not at home this week-end, thus will answer as soon as I return. Take care.
07-03-2003, 01:20 PM
#6
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Hello,
There is said that Mercruiser got a new five blade prop. In Germany the information flow is very slow and I am not able to get any at all. Does anybody has tested it aleady and what kind of experience do you got?
By the way we had our first Poker Run on the Rhine River which was organized by my friend Mike and me. If you are interessted, you can have a look under www.Boote-Forum.de (its posted under the category offshore). There are really a lot of pics.
Greetings from Germany (todays weather: raining)
Liquidator
There is said that Mercruiser got a new five blade prop. In Germany the information flow is very slow and I am not able to get any at all. Does anybody has tested it aleady and what kind of experience do you got?
By the way we had our first Poker Run on the Rhine River which was organized by my friend Mike and me. If you are interessted, you can have a look under www.Boote-Forum.de (its posted under the category offshore). There are really a lot of pics.
Greetings from Germany (todays weather: raining)
Liquidator
07-08-2003, 07:59 PM
#7
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I also have that same question I have a 1991 251 GTX Convincer. I am running a 23 3 blade Mirage this is the new that came with the boat. About 2 years ago I needed to get it redone so I went to Marysille Prop West in the Grand Rapids area. I have them add cup and fix it and they cleaned it up. It was around $110.00. The last year we went though the motor. Nowthat prop doesn't work like it use to. I have tried a 25 mirage 3 blade it was OK but still not the same. I also tried Bravo 1 Lab 26 the boat was not the same no bow lift it ran nose in the water and no top end but the midrange was very nice. Any help would be nice.
07-10-2003, 02:00 AM
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Hello All Trimed Up,
in order to give you any advise, I need more information on your engine (what type, what year, hp, rpm, etc.). Regarding your 26, I have borrowed a 26 four blade from a friend of mine and I found out that it is a good midrange prop without any problems with the bow lift. Check your trimtapes.
Greetings from Germany.
Liquidator
in order to give you any advise, I need more information on your engine (what type, what year, hp, rpm, etc.). Regarding your 26, I have borrowed a 26 four blade from a friend of mine and I found out that it is a good midrange prop without any problems with the bow lift. Check your trimtapes.
Greetings from Germany.
Liquidator
07-10-2003, 04:52 PM
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Hey Liquidator
The new motor is only slightly changed 454 BB it's a Mag. Older 1991 it's still stock on the outside. It had over 650 hard hours on it so it was needed. All new stuff inside rings,cam,all the bearings and a head job. The work was done by a friend Valako Race Heads. (Jim and BJ are great) After all this we sent it to the dyno at Earhart Engineering in Gun lake. It made 440 hp at 5500 rpms with 36 degrees of timing. Now I have to burn 93 gas. The good stuff or they say I can burn a valve. I hope this helps.
The new motor is only slightly changed 454 BB it's a Mag. Older 1991 it's still stock on the outside. It had over 650 hard hours on it so it was needed. All new stuff inside rings,cam,all the bearings and a head job. The work was done by a friend Valako Race Heads. (Jim and BJ are great) After all this we sent it to the dyno at Earhart Engineering in Gun lake. It made 440 hp at 5500 rpms with 36 degrees of timing. Now I have to burn 93 gas. The good stuff or they say I can burn a valve. I hope this helps.
07-11-2003, 02:30 PM
#10
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Hello All Trimed Up,
It is very difficult to discuss your problem via the forum, because I cannot look inside your engine. If it would be my engine and it would loose performance, I would do the following things:
1.) Check the compression, but be present.
2.) Check the ignition timing.
3.) Check the carborator.
There must be a problem somewhere. Further, I would ask the person who had redone your engine, if he had drilled 0,25 over on all eight pistons. Because, if you change only the pistons rings on an engine which got over 650 hours, then it got only for next 15 to 20 hours a good compression, but afterwards it is gone. I suggest you to not run over 5500 rpms. Keepan eye on your valve springs.
It is sometimes a bit difficult to understand each bit of your technical vocabulary, especially the abbreviations. If I understand correctly, your engine runs at 5500 rpms with the 23 3 blade and then you should run at approximately 5200 rpms with a 25 3 blade. I hope, I was able to help you in some way. Good luck to you. If you have any further questions, do not hesitate to contact me.
Greetings,
Liquidator
It is very difficult to discuss your problem via the forum, because I cannot look inside your engine. If it would be my engine and it would loose performance, I would do the following things:
1.) Check the compression, but be present.
2.) Check the ignition timing.
3.) Check the carborator.
There must be a problem somewhere. Further, I would ask the person who had redone your engine, if he had drilled 0,25 over on all eight pistons. Because, if you change only the pistons rings on an engine which got over 650 hours, then it got only for next 15 to 20 hours a good compression, but afterwards it is gone. I suggest you to not run over 5500 rpms. Keepan eye on your valve springs.
It is sometimes a bit difficult to understand each bit of your technical vocabulary, especially the abbreviations. If I understand correctly, your engine runs at 5500 rpms with the 23 3 blade and then you should run at approximately 5200 rpms with a 25 3 blade. I hope, I was able to help you in some way. Good luck to you. If you have any further questions, do not hesitate to contact me.
Greetings,
Liquidator
