Can I spin a 30P prop???
 

Boat: '02 PowerQuest 34 w/ twin 496HO's

Prop(s):
std Bravo1 28P will get 4900 to 4950 RPM
Labbed (by York) will get 5100 to 5200 RPM occasionally hits rev limiter.

I was thinking I could get a set of labbed 30P props and increase cruise and maybe gain a little on top end.
Do you think I can acheive this, or will the 30P be tto much????

Thanks in advance?


BTW: Need a set of York labbed 28P props in greaat condition?? I have a set for sale or trade.

I would think that you're there. Your numbers look great, what more could you ask for? Maybe add CMI, air filter, computer retune and then the 30" would do.

BillR,
Sounds like you are ready for 30p. I changed the flame arresters to K&N and the exhaust to Gil Big Guns on my 33AVS Scarab. Started hitting the rev limiter so went to 30p stock Bravos. 72mph to 80mph.

Stock 30 will be too much, Possible if you go wth lab 30. You will never know until you try. It's only money.

BillR,
What was your speed at 3000 or 3500 rpm with standard 28 then after labbing.
Also, what was top speed before and after labbing.

Rick

You could probably send them back to York and have them change the pitch to 28.5's or 29's.

BILLR, i dont think your ready for no friggin 30's yet. big big dif between a 28 and 30 b1.

rv, let me answer your question and ask one back. I have exact same setup as Bill. Yes we bought the same boats, dealer's offer was just too good post 9/11. Anyway, I just got my props labbed at York. Before labbing I was runnin 50 at 3500, 60 at 4000, and 76-77 at 4900. After labbing I am runnin 45 at 3500, 55 at 4000 and 77-78 at 5150.

I told John how unhappy I was with the loss of cruise speed. He says its normal, he built me a great set, and I should live with it. Basically, I must pay more for some tweaking if I feel the need.

I ran Bill's props and only saw 2 mph reduction at cruise. I could live with that. Is it normal to loose 5 mph off cruise speed with labbing?

wms,
I am no expert on labbed props but from listening to some people that have had labbing done and talking with some lab shops it seems like mid range cruise speed suffers. Yours seems to be another case in point.

It seems these shops thin the heck out of the blades and do other tweeks to get that top end increase that everyone asks for. They don't seem to mention anything about mid range cruise effects though do they. And I don't think alot of people taking the prop to be labbed think about this or care. It is top speed that seems to be discussed. I am not sure but from what I have heard it seems like it must be difficult to get both, WOT increase AND mid range cruise incease (or hold your own). Maybe some real prop experts can respond to this with some facts!

Rick

p.s. that sucks York has that kind of customer support. I always thought that at least 1 or 2 tweaks were part of the labbing. It is difficult to know exactly each persons boat/setup/handling to get it right the 1st time. I am sure it happens but seems like tweaks are required and should be covered.

Exactly!! I went with York because all of the good things I have heard about them. Why John chose to be the hard ass with me is beyond me? :(

I was aware that my mid range would suffer with labbing, but was not prepared for 5 mph. And my top end was not markedly improved either. Anybody else seen this much loss of speed (at cruise) after labbing?

I talked personally with John at York about labbing my props, He was extremely helpful. although I have yet to send them in.
he did tell me cruise might suffer. depends on what you want.

if thinning the props lets the motors turn more R's, thus gaining top speed, great, but in my application, I was at my bone stock peak rpm already(4600, 330's) so I told him when I do it , I will spec the lab to gain the typical 200 rpm, then cup to pull 100-200 back into increased pitch. I will specifically tell him I want to maintain 40mph at 3000 where i am at. He told me wow,most don't go into that much detail or thought. ( ie most are looking to rev a little to dial in to thier peak power output) but just tell him what i want out of the service.
This should give me the most speed possible out of my engines at their peak of 4600.

keep in mind his fees are on the order of $175 - $200 per prop, compare that with the (increase service?) of merc lab at $600+?
(just remembering mercs pricing from other posts......)


I would send what you have back to be cupped to gain some pitch. that must still be less than selling used, and buying new, and labbing the new ones........ and it seems you are very close.

good luck.

Rambunctious, I too went into such detail with John. I told him what my cruise speeds and rpms were and requested that he try to maintain them as best he could. However, he claims I told him my top speed was 72 and that I now have a 5 mph increase at top end. (Don't know where that came from, but he is convinced that I am off my rocker, I think.) I do remember something about him getting me close to the 80 mark to match the other 340's in our club.

wishful thinking.

NO...stay with the 28's

no prop is going to do it all...i have a lot of props...but for the poker run boat i use cruising props most of the time...not top ender's. Figure out what you want to do and go from there...and EVERYTHING is not really an option.


ps...keep in mind that B1's are not made to lab...they are cast ready to go...unlike the race props they build...they must be labbed after they come out.


watch out you heavy boat owners....thined props can make ya go slower!!!!

What! :eek: Have not heard that one before. Care to ellaborate?

oops...did i say that :rolleyes:

never said a word...wazn't me!

If you can hit the rev limiter on the 28's you can run 30's. The down side is your engine will turn less RPM's and may live longer. It might be faster depending on how much torque you have.

we bang the rev limiters with 32's...can we run 34's:rolleyes: ...NO

call the guys (and gal) at throttle up props...they know what's up!...They ARE NOT going to take an off the shelf prop that is thined and send it to you!

www.throttle-up.com

your best bet is to have 2 sets of props...remember the 30's are going to stress the drives more!!!