38 Special prop questions

[FunHome]

I have a 1993 38 Special with Carb. 502 Mags running through bravo 1 drives with 1.36 gears. Right now I running 19pitch 3 blade mirages, spinning inward, at 4700rpm and the best to date is 60.5mph on GPS.

Question is if I want to get more RPM's out of the motors I would drop down in pitch, but running 17 or 18 pitch prop's sounds crazy. Should I measure the diameter of my props and maybe drop down in size?? If so how much? I've only dealt with going up and down in pitch, not size. Idealy I would like to run at 5000rpm which would be closer to it's redline.

[FunHome]

HELLO, Hello, hello,........

Is there anyone in here????

[Wilks]

The 1.36 drives are hurting you some. 1.50 would be better with a 23 mirage plus.

[BigDaddy]

I think Julie is out of town right now, but I'm sure she'll respond when she sees the question [smilie=042.gif]

[Throttle Up]

I agree you need to go to 1.5 drive ratio. When going to a 17 or 19 pitch prop the diameter is typically larger because the props are designed for heavier slower boats. There really are not any "performance" props out there in the 17 -19 pitch range.

If you didn't want to change gear ratio you still have a couple choices. One option would be to go with the lower pitches and then we could cut the diameter down, The Rev 4 prop is available in a 17 pitch but I don't think it will work well on your boat.

Matt

[BigDaddy]

Any idea what ASH is running? I know he has 4 blades..

[Bajapit]

02 .38 Special.
I have 496 Mag HO's, 1.50 to 1 and I have 24 Pitch 4 Blade Marage .

[FunHome]

02 .38 Special.
I have 496 Mag HO's, 1.50 to 1 and I have 24 Pitch 4 Blade Marage .

What HP are those??

[FunHome]

I agree you need to go to 1.5 drive ratio. When going to a 17 or 19 pitch prop the diameter is typically larger because the props are designed for heavier slower boats. There really are not any "performance" props out there in the 17 -19 pitch range.

If you didn't want to change gear ratio you still have a couple choices. One option would be to go with the lower pitches and then we could cut the diameter down, The Rev 4 prop is available in a 17 pitch but I don't think it will work well on your boat.

Matt

I've been told that they use the 1.36 gears so it's easier on the bravo drives on heavy boats. I'd like to change to 1.50 gears but I don't see that happening anytime in the near future unless I come into a large sum of disposable money (baby due in Feb.!) :roll: So what about cutting the diameter down on my 19pitch?? Or would it be cheaper to go to 1.50 gears and use a set 23pitch mirages that I already have. I have no idea how much it is to change gears, but I would assume it would expensive since they have to get into the drives.....

Also, I have an old set of 21 pitch cleavers that came off one of my old boats, could they be worked into something???

[Bajapit]

HO's are 425 HP each.
PIT

[FunHome]

Pit, What kind of speed are you getting??

[Throttle Up]

There are a few different ways that we can increase the RPM. Pitch change, diameter reduction, lab finishing. It is determining which is going to give you desirable results.

Julie

[FunHome]

Well of coarse I want more speed and I feel I have a little more RPM to gain, Out of the hole performance is not important to me, because I usually just bury the tabs and bring it slowly up on plane. (it still blows out a little as it comes up)

[Throttle Up]

Then Lab Finishing is one option. This will produce a 200-300 RPM increase and should net you 2 more on top. If you want through inhanced performance in there then I would recommend you take a look at the Mercury Rev 4 possibly.

Julie

[FunHome]

If I went to a Mercury Rev 4 (4 blade I assume) what pitch would you think I should go with??

How much??

[Throttle Up]

Possibly a 17P Rev 4 or even a 17P Mirage Plus to attain the RPM of 4900-5000.

Julie