575Sci Owners
 

As most of us know the weak link are the 256 Weiand blowers on these motors. If something goes wrong with the blower there are no hard parts available. I found a company that takes the time to get their blowers to work with the 575Sci setup. Dyers Blowers makes their own cases and rotors. They took my TBI plates and resized the holes to fit their 8-71’s They also took my thermostat housing and machined an adaptor so it also could be used. They also machined a new lower pulley so I could use the serpentine belt setup. I will be running the 8-71’s 5% over for 6-7pounds of boost. I will start the installation tomorrow and I will post photos. So glad to find someone so helpful as Gary and his son Bill.

http://www.dyersblowers.com/

heard some good things about them, had i not found the deal i did on the 420 megablowers i did they were my next call

What throttle bodies does that use? Two Two-barrel TBI's?

Yes

How much $ ?
What is your HP gain?

I paid $3300. per motor + shipping

As for HP gains...I'm sure there will be some but I have no idea.

The lower Pulley (like the one they machined for you) is available from The Blower Shop (steel). Tstat adapter is available from whipple and the Throttle body adapter was a direct bolt on for me. I am about where you are at as far as over-driving and am at about 9.5psi on my stripped littlefield 871.

Knot trying to jack up your thread ... Looks like you have a killer set up going. I have the Blower shop set up. 6-7 pounds of boost. And the support has been great. I have the Arizona Speed set up and I really like it. The stock merc fuel injection has been awesume so far.
Chad

You have the 250 blowers correct? What are your HP #s? And did you do the aluminum heads as well? I've got a 29 fountain with a 575. And my name is Chad as well lol. Would like to talk to u more about it. Can u please PM me ur phone # if that's cool?

Thanks Chad

looks good!

It was this way when I bought it. Arizona Speed and Marine did the work. I have super chillers and the 250 blowers. I am guessing that I now have 675's? Sorry I am knot more help..
Chad

troper, what speeds are you running with the 575s in the 40 Outlaw?


WwW

I was going to go with the Blower Shop 250's but they needed the front snouts and I had 1 bad one. If I gave them the other snout the 256 would have been hard to sell. They quoted me 2800. ea using my old snouts. For another 500. I got all new 8-71 blower and intake.

It would run 78-79 full fuel and 4 people. Had it 81 a few times when just me and almost empty

Just did mine. We upped compression. Added roller cams. Cleaned up stock heads. Reprogram ECM. Added super chillers with mid size pulley. Made 715 @ 5100 and still climbing.

Yep, and you have a lot more potential w your new set up as well. You wouldn't by chance have a stock 575 tentioner pulley laying around would you :D

Call Brian at DMPE, he has my old one and I'm sure he will sell it.

:lolhit: you gotta be luvin this lol. Do you have a contact or web site. DMPE??

Install was pretty straight forward. No major problems, just had to re-bend the fuel lines. Need to get some new TBI gaskets and she will be ready to fire. I knew it was going to be a close fit under the hatch but I have 2" to spare

Mine only has 125 hours so i just left in insides alone. Next winter I should have close to 300hrs. then i want to refresh with roller cams and some head work. I'm going to call Mark at Precision and see if he has a tune for my setup.

2" is just enough room for whipple Low Pro intercoolers. I also have a way to plumb them without have to add thru hull pickups and not starving the motor of any of its cooling.

When I do the refresh I might add intercoolers at that time. How did you plumb yours?

I Tee'd off the water pump inlet hose and added a check valve just off the tee. The check valve opens when hose pressurizes (at about 40mph) force feeding the cooler. Also I Tee'd off the pump outlet hose and installed a pressure relief valve, which Tee's into the intercoolers feed line downstream from the check valve. This feeds the innercooler right when you put the sticks forward and pump pressure builds. It will take some of the engines cooling water at lower speeds then the inlet check valve opens at high speed when the motor needs all the pumps cooling capacity.

This is my 4th rendition of plumbing on the chiller. I fed it directly teed off the pump outlet hose...idled like a cold carbed motor with no choke and temp would climb on motor at high speed. I then added the pressure relief valve to in the feed line. This worked OK but I did not feel it supplied enough water to the cooler (and that was stolen from the motor). Not wanting to add a transom pickup, I teed off the water pump inlet hose and added a check valve in the chillers feed line. This worked good at higher speeds when it opened but opened a little too late for my liking. When the water started flowing it was pretty damn hot! So with a little thought I have a combination of pump feed for low speed and force feed for high speed.

BTW...I have a imco lower with very large intake slot so I can not speak for how it would work on a merc lower.

Without chillers your pistons will get hot in a hurry. Better safe. I think the stock pistons are set up for 4-6 psi boost if I am not mistaken. Heat could get high w those large blowers. I'm sure you are all over this , but just be carefull !!


Chad

I'd bet that 8-71 is making less heat at 6 psi than his stock 256's made at 4.5 psi

I have thought about switching to a no chiller 8-71 setup myself, to save the hassle of the chiller plumbing and issues

Mine feed off the stock waterpump the entire time.I have sepaeratre dumps out the side and run about 10 psi water at w o t. The merc fuel injection seems to have all the ideling gremlins covered.I can send you a pic when you are ready. But I do like Jrider's check valve set up. Hope this helps

ahh.. Lean something new every day. If I had no chillers I would have not have to have scoops in my sun deck :D Leads me to think. Next refresh . Better rods.. JE pistons.... New blowers with the chillers.. Maybe I could be running 850's.. But then I'd need new drives .. lol :D

From what I've learned from Dyers the 8-71's are more efficient and will produce less heat running at 5% over than the 256's. At 5% over it 5-6 pounds of boost. Waiting on Fedex to get here with the lower pullies so i can fire this up. Funny thing my wife was asking question about the Blowers and I was telling here that these would whin more than the old ones. She said she like the wining sound and was wonder would go faster.......:lolhit:

The 575 already has crower H-beam rods, crower crank and JE pistons stock. Although you will make even less heat if you change the pistons and raise the compression to 8.75:1 and turn the boost down. The flat tappet cam is the thing that needs the upgrade in a 575.

I thought for the blower noise on our boat was going to be the death of me my with future wife, figured it would be a tell tale sign that I was on it and she would ask me to slow down.....go figure, she is just like yours, she loves it and I feel as if the noise excites her more than I ever could :lolhit:

Never fails...FedEx lost the package with my lower pulleys.....

Hurry up. I'll take your blowers.
Rob

You had to cut scoops in the deck or your fountain? Mine seems to have pleanty of room, 2002. My close friend has the same boat 2004 with super chillers on the stock blowers and did not need to cut, semi staggered.

The blower shop blowers you have are 250s right? Are they that much taller than the stock 256's or do you have giant chillers? My arresters have got to be almost a ft below the deck stock

I put the Super Chillers on mine. On the rear engine I drilled one 1" hole up to the second layer of plywood in the hatch to clear one of the arrestor studs. On the forward engine I cut out an oval in the hatch on the first layer of plywood. The hatches are double layered plywood and I didn't need to touch the second layer. I covered the bare wood with vinyl, sanded the cut and painted it white with something really thick. It looks like white plastic. Then I put white piping where the two pieces of plywood join.

My motors are high. Headers are 5/8 from the gunnel in the rear

:lolhit:

Finish the install and took it out yesterday afternoon. She ran great with no problems. 97degrees and I did 1 WOT run, boost was right at 5 lbs spinning Lab 30P and hitting the rev limiter. solid 85 MPH. Did not think I would be that fast with a non step 12000lbs boat. I am a happy camper. If anyone is thinking about doing this upgrade to the 575, don't hesitate it's well worth it. Let me know if you have any questions.

Looks great. I'll be upgrading blowers also this winter. Can't decide weather to get the TBS 575 replacement or go bigger with hatch mods.

-My Weiand 256's were refreshed by TBS about 100 hrs ago. Still make all the boost but rattle at idle. (just off idle they sound fine) It's a bit unnerving. Is this normal? How sloppy can the gear drive get before the rotors start to bump?

Kurt

Here's a link to our 575sci conversions to 871s.

Polished 871s are $3750.00 per engine.

http://www.dyersblowers.com/187/1676.html

Bill Dyer