seansmp8

How much should I trim her up. I stop trim just before i get a little roster tail.

chaparral 2550sx

Hey Iggy, he is not even close to what that small block should be running RPM wise, you really think he can pull a 21?

seansmp8

From what I have read, Mirage props are mostly made for big block boats. This one is 15 1/2" big. Most 19 or 21p props are around 14". So maybe I just need to go with a smaller diameter prop like a 19p 14" Laser. Does this sound right?

AIR TIME

CALL BBLADES they have a prop swap you give them your info they send you a prop for testing its a little extra say 25 bucks I would start with a laser 21 and if you pick up speed but are a little low on rpms you can have it labbed to get them back if the 21 is right at 4800 I would go to a 23 and lab it that should get you back to 4800 and you might pick up 5mph. a friend of mine is putting in a 350 325hp he had a 220hp merc before its a 17ft runabout we are hoping to turn a 24 3 blade turbo prop I have which will have it running in the 60plus range . if not he will buy a 21. art

chaparral 2550sx

who is BBlades???? you have there contact info?

QWKRN U

Bret at BBlades will take care of you.
BBLADES Professional Propellers, LLC
N5007 Highway 73
Princeton WI, 54968
Phone: 920-295-4435
Fax: 920-295-4436

Iggy

I never said he could run a 21" pitch. I used that size as an example.
A 21" isn't all that big. My 1988 F-206 LS Formula has the original 260hp 350 MAG and it came from the factory with a 21" Mirage (which I still have) on a Alpha drive. Top end is 58 mph @ 4800.


I trim till the engine increases rpm without an increase in speed. At this point the prop is slipping. Then I lower the drive till it stops slipping. Some day I'll get the trim indicator fixed and I'll know exactly where it's at.

seansmp8

My trim indicator is broke too. Its just kinda frustrating because I see all these people with stock 5.7 260hp hitting 55-60 and here I am with a Vortec 350, comp cam and a 750 carb and I can't get anything decent. My boat is only 20.6' so its not like I am pushing a 24' with a 350.

seansmp8

does anyone Know of any "lend a prop" dealers on the easter shore near Kent Island?

seansmp8

Ok, I tried a 19pitch cleaver prop. yesterday and got the rpms at 5200 but still only got 53mph. Do you think I should go to a 21 or 23? I was thinking a 21p laser would get the rpm down and maybe a few more mPH.