switching from XR to HT B-max - Page 2

tomcei · 11-30-2007, 07:10 AM

I thought the "new" HT series had a better lower than the original or it was different. If it is a merc lower gear why wouldn't Dean use the
gear to give it the 1.5 ratio (let me guess, not as strong ,as you stated)
I thought I heard the Imco lowers bolt on to the Bmax with a slight water jacket mod.
Does the Imco lower use merc gears?

bonecrusher · 11-30-2007, 07:44 PM

Has anyone tried these on a larger cat? Im putting on a 36 Spectre with apprx 800hp...keeping my fingers crossed on more reliability.

articfriends · 12-01-2007, 02:53 AM

Quote:

Originally Posted by tomcei

I thought the "new" HT series had a better lower than the original or it was different. If it is a merc lower gear why wouldn't Dean use the
gear to give it the 1.5 ratio (let me guess, not as strong ,as you stated)
I thought I heard the Imco lowers bolt on to the Bmax with a slight water jacket mod.
Does the Imco lower use merc gears?

The Imco sc uses stock merc lower gears,the new 35,000$ Imco 1000 uses something extra hd/special. As far as the B-max, I am not a expert but the second hand info I have is that the "HT" still uses merc lower gears but has been re-fined in other ways,Smitty

monstaaa · 12-01-2007, 07:52 AM

i have done the install a few times. it is a bolt on, simple install. in all cases they slowed the boat down between 2.5 and 6 mph. a-the gear drag is greater and b- the foot print and dynamics are off.
the biggest draw back is sue to the xtra weight of the drive itself and the fact that you now move the weak link from drive to gimbal. on 1 boat the drives no longer blew , he ended up breaking two gimbals . which tore up the transom, props, rams, and almost killed everyone in the boat.

tomcei · 12-01-2007, 10:47 AM

Quote:

Originally Posted by monstaaa

i have done the install a few times. it is a bolt on, simple install. in all cases they slowed the boat down between 2.5 and 6 mph. a-the gear drag is greater and b- the foot print and dynamics are off.
the biggest draw back is sue to the xtra weight of the drive itself and the fact that you now move the weak link from drive to gimbal. on 1 boat the drives no longer blew , he ended up breaking two gimbals . which tore up the transom, props, rams, and almost killed everyone in the boat.

My thoughts were a new Imco gimble (I've heard it's much stronger than the merc HD)
Then throwing on the HT-Bmax

monstaaa · 12-01-2007, 05:01 PM

i would strongly suggest that as well as the helmut they offer

RBeyer · 12-01-2007, 07:38 PM

Quote:

Originally Posted by articfriends

I'm under the impression that B-max only sells there drive with merc 1.36 lower gears or the other steep lower gears because the 1.36 gears have poven to be slightly more durable. I do know they are using merc lower gears,not some extra strong aftermarket version or anything. Has anyone tried re-gearing the drive with merc 15/19 1.50 lower gears? By cryoing then giving the lower gears a multi-step surface treatment that ends with them having a very smooth finish I have gotten the 15/19 1.50 gears to last much longer then they ever did in stock form on my boat with a bravo drive. My understanding is that most boats go slower when switching to a B-max because of the extra friction of the larger upper gears and bearings but what I'm wodering is if some guys are losing speed from the overall gearing and re-propping why not try going back to 15/19 lower gears once the warranty is up,Smitty

Smtty,
I totally agree the majority of my speed loss is a result of the gearing and not so much the weight.
Maybe after the warranty I may.
Bob

RBeyer · 12-01-2007, 07:41 PM

Quote:

Originally Posted by monstaaa

i have done the install a few times. it is a bolt on, simple install. in all cases they slowed the boat down between 2.5 and 6 mph. a-the gear drag is greater and b- the foot print and dynamics are off.
the biggest draw back is sue to the xtra weight of the drive itself and the fact that you now move the weak link from drive to gimbal. on 1 boat the drives no longer blew , he ended up breaking two gimbals . which tore up the transom, props, rams, and almost killed everyone in the boat.

If I recall that thread there was alot more to that story.

monstaaa · 12-02-2007, 08:36 AM

Quote:

Originally Posted by RBeyer

If I recall that thread there was alot more to that story.

of course. but from a mechanical or engineering standpoint the weak link is moved and that is fact. same issues on a high powered single engine, busted gimbal.

not blaming or trying to disuade anyone from b-max, just offering info. in my findings the stronger gears, heavier weight hanging from a pivotal point not enginered for, and larger surface area, there is an effect to the overall performance of the vessel and its attributes.

tomcei · 12-02-2007, 08:46 AM

As I understand it Dean offeres a gimble assmy for his drives. I believe it requires mods to the transom. Is this correct?
I'm looking for options as well and I would prefer to go with a gimble and helmet assy that is a merc cut out in case the boat is changed back to bravo stuff.

Monstaaa, Do you believe the Imco complete transom assmy w/ helmet, gimble, and trim rams is up to the challenge?

Sorry for jumping in the middle of this Bonecrusher