Cattitude

My season was cut short two months by a siezed blower with 143 kind, well maintained engine hours. The sealed bearings in the rear got tired and allowed the rotors and housing to engage in a little foreplay, luckily seizing quickly before the rotors became end mills.

As best I can tell, the long block is good, though I'll be taking a closer look.

I know of a Hybrid kit from Dustin, and for conversation sake, let's say I'm confident I can get a kit in time for next yr. His kit is the only known option that will allow me to go intercooled as a scoop or insert is not going to happen.

I know of a kit the blowershop offers, tweaking pieces of my blower and using them with a 250 blower that has a better bearing design etc. (Shame on Merc). Polished (If you like that) and keeping the conventional roots look, no IC for reasons above. More affordable, but a lot less to the system too.

I'm not a centrifugul fan for reasons I won't go into.

So what else is out there for options?? I would not mind a bit of extra powerbut want to stay sane as it's an XR with a 28 Pantera and it would take a lot of power to get appreciable gains only to grenade drives (My 25' Daytona ruined me)

plums

hi cattitude. What hybrid kit are you talking about. I have 575sci's and would like to know more about dustins kit.

Cattitude

It's an "unadvertised" kit using the 3.3L blower and a mix of other 500/525 kit components, intercooled, custom computer map etc. With a cam and valvetrain pieces said to be good for 800 reliable ponies on pump gas.

If I pull that trigger, I'll skip the cam change for now and do it when I freshen the engine. The 575 long block is a good base to start with IMHO, not too impressed with what I've been learning about the blower design- or Merc's willingness to stand behind it. "It's perfectly acceptable that your 3 year old, 143 hour, fresh water, computer confirmed 95% cruise speed operation sealed bearings failed and seized your blower" "Yes, you can tell people we said that" I've got their service manuals, I must have missed the chapter about changing sealed blower bearings at 100 hour intervals

Steve Zuckerman

Catitude:
Sounds like you have late model hybrid Weiand/Holley/B&M blower. I don't know why Merc chose to use the B&M end bearing caps with the Weiand housing. It does have the sealed back bearings, which I think is a bad idea. I have an earlier model Weiand (only) 256 on my 575. It has an oil reservoir in the rear bearing plate.
I had a problem with my 575, which ate a screw that fell out of the rear throttle body. Check yours and locktite them all!
It dinged up my rotors. I had the Blower Shop repair my rotors and put in fresh bearings. I now change the oil (RP synthetic 50W90) every 25 hrs. or so.
I also installed the Whipple lowpro intercooler, and it really woke the motor up. I am now running a 3" blower pulley (stock 4"), AZSM ECU, MSD box, intercooler, and the motor is really doing it's thing.
To make a long story short, I would have the Blower Shop rebuild your Merc blower or use their 250, which I understand is very nice, with your throttle bodies and the Whipple 575 intercooler. I think you'll be dollars ahead, and have a nice running, reliable motor.
Regards,
Steve

Cattitude

Steve,
I appreciate the input, a good friend has two 575's in his tiger, so he's trying to learn form this too. I'll talk to the BS again- I'd consider rebuilding my blower IF the bearings could be upgraded to a wet or roller design.

Unfortunately, I can't IC in the conventional sense without an insert or scoop which I'm not willing to due, the hatch has/gets plenty of hours logged on it too

Von Bongo

You blew up my boat!!!

Sorry to hear it KB, I feel your pain of lost time on the water.

I was going to suggest blower shop 250s but I see you already have it covered. That would be my choice.

plums

Thanks catitude. Did you price out that kit that dustin is selling? Why is it not advertised?

Steve Zuckerman

Cattitude,
I hear you about cutting into the bunny hatch. I did not want to do that either and didn't. The Whipple unit is only 1 5/8"s taller than stock. As you probably know, it is an intercooler core down inside a new intake manifold, that replaces the stocker. Looks stock to the untrained eye ("yeah it's a 575, guess I got a good one" ). I'm now running 7 PSI with Fel Pro head gaskets.
Regards,
Steve

Cattitude

Did you go with Felpro as a precautionary measureor cause you lost a stocker?

I hope to start turning wrenches in about 4 weeks, prefer not to pull heads at this time but will do that when i freshen along with a roller cam upgrade

Steve Zuckerman

Cattitude:
When the screw fell out of my rear injector/throttle body, the blower rotors cut it in two. Half fell into #5 and half into #8.
It had real bad knock . Fortunately I was idling out of a no wake zone and caught it before it did even more damge.
I ended up having to replace 2 pistons, clean up the heads,
and get the Blower Shop to fix my rotors. I had them do the bearings too on their recommendation, and I'm glad I did.
Since the motor was out and apart, it made good sense to replace the factory gaskets with high quality Fel-pros. We also replaced all the bearings and ring sets. By the way, the factory head gaskets didn't look good and are not much IMHO.
This past winter I added the Whipple IC and went to a 3" blower pulley for 7PSI intercooled boost. The motor has given me excellent service since then.
I estimate current horsepower @ 750 bobtail/725 PSHP.
Regards,
Steve