575 SCI rebuild
 

change the heads and cam,lower the compression a bit.

Roller cam, Intercooler, freshen blowers, and pulley for max boost.

Currently running Whipple Inner Coolers and smaller pulleys. I am thinking about 871's. Trying to decide if its time pull the engines and go for the complete rebuild.

i did mine at 15X

refreshed bottom end rings and bearings, stock merc components,
525EFI cam
AFR CNC 305 heads - big chambers dropped compression even lower then stock
.040MLS head gaskets,
dyers 8-71 kit
eddie young EFI ontop
Holley HP as the mefi **** the bed on the dyno -
made 775hp on 4psi at 5900 un cooler

with the whipple cooler im sure you can do a super easy 8XX

At 410 hours, I think I'd just do complete refresh.

Eddie Young did good (top end only) on some 575's we had. Heads, roller cam, tuning, etc.

https://cimg5.ibsrv.net/gimg/www.off...f175c128ad.jpg
https://cimg6.ibsrv.net/gimg/www.off...9087bc9f54.jpg
https://cimg7.ibsrv.net/gimg/www.off...1e3ff5147d.jpg

I went .030, cleaned head and deck, 525 roller cam(I think), Super Chiller w/slightly smaller pully, stock fuel system, stock MEFI
Cam I .610/298* E .632/306*
Press fit pins and cast iron heads
Stock oil cooler
703HP@5372 740TQ@4100
4# boost
92 octane
Ed Trihey @ Ed's Automotive assembled/dynod them
310 hours and still run the same based on top speed of boat hasn't lessened.
WOT oil pressure 38PSI@170F@5350RPM for 10 minutes+ freaked me out but 310 hours later I guess it works and it's easier on the distributor gear.

Starting to get into the details, complete rebuild this winter.

Thanks for all the insight.

@ 7.5 to 1 you must mean raise compression...

that oil pressure never scared you? Mines like that and I getting a HF/HV oil pump put in and a new 10 qt pan with a crank scrapper with a built in windage screen.

It freaked me out too. I put another gauge on, same thing. Pulled engine and checked pump, good. Ran a quart low and a quart over, same. 300 hours later, many of them at 5K+RPM, still the same. Hot oil after running WOT for an extended time and returning to idle, 32PSI. Both engines.
Kendall 20-50, Wix and/or Quicksilver filters, 160-170max oil temp w/stock cooler.
Water pressure is 12-18# on one engine and 16-22# on the other.
What kind of temps are created just by pumping oil at higher pressure? Not to mention heat created at the cam/dis gears from the extra work load.
Low pressures and temps, and high hours must mean good flow.
Hey, whatever works.

Id do the EFI Whipples if its in the budget should fit under the hatch with no mods. I did this this last winter

Build in process, hopefully done by May 1.

What combo did you go with?

Dyer's 871 conversion kit, Eddie Young Fuel Delivery system, AFR heads

pair of 3.3 L

for the Eddie young EFI to clear the dyer kit i had to have a 5/16( i think, not sure off the top of my head) spacer made for the injection plate to sit on so the throttle linkage would clear the blower something to watch for if you have limited space

what are you going to use to run it?

https://cimg2.ibsrv.net/gimg/www.off...5fb7644bf.jpeg
Coming soon

https://cimg1.ibsrv.net/gimg/www.off...efc222350f.jpg
Getting close

https://cimg9.ibsrv.net/gimg/www.off...2acfd5299.jpeg
Going to Young Performance for final tuning

Made 759 hp @ 5psi boost

What compression did you end up with? Also, did you end up .030 over? Original crank or stroked?

Short list: Used OEM crankshaft, Callies H beam rods, JE pistons, Comp custom roller 241/251 [email protected] .648 lift on a 113, Johnson BBR lifters, Manley pushrods, Crane gold rockers, Cloyes timing, Total Seal AP rings, Comp Springs, AFR 345 CNC chambers and bowls, Manley severe duty intake valves, Manley inconel exhaust valves, melling performance HV pump, Clevite bearings. 515 cu.in. and compression ratio ended up at 8.4.

We do understand this has gone from a 575 rebuild to a custom build. lol Those dyers are great blowers for the price.

Those dyers are great blowers for the price.[/QUOTE]

Gary Dyer is great to work with.

Young Performance Marine - dyno clip

https://www.facebook.com/watch/?v=896146457532960

https://cimg3.ibsrv.net/gimg/www.off...116964b97.jpeg

How are the engines doing? I did the young performance injection and I'm thinking about doing the dyers kit. So you had to build a spacer so the linkage would clear??

Ended up at 750hp per motor. Runs strong, great midrange power. Linkage was eliminated, throttle cable only. If you blow up the above picture, you can probably tell what was done. No plates attached to the headers.

I see you have a larger fuel filter head. Did you still use the factory mechanical lift pump? Just curious about the fuel delivery. I have a big weldon pump i can use.

I have Eddies complete fuel delivery system. Factory pump won’t work. My pump in a Weldon.

Sorry for the quick interruption, but hot damn,
Now that’s s shop ! :) :)

Ordering the dyers kit Monday. This will get bolted on my afr 357 headed 565. Sucker is going to rip. Honestly just want a mild 800hp. This will be a very reliable combination with 1000hp potential easy. Next is drive, boat has a new xr. I never do hole shots or ramp up throttle fast. Things tend to last when you drive easy.

Add a drive guardian and you'll be glad you did later on.

I'm newer in the boat performance world, what is a drive guardian?

Definitely some square footage there.