The motor is almost back together I am waiting on 1 piston and one ex valve. Manely had the .100 long 1.900 valve on back order and know one around had one. As far as the heads being studded we are making 8 pounds of boost. When the 525's were in there the last 4 years they were making 9 pounds of boost with head bolts with no problems. Then all of a sudden last year they burned 7 pistons on the back motor after running the same tune forever. So the first thing I did was pull all the injectors and flowed them and guess what they were all good so now I pulled the whole fuel system and cheched all the filters and had SX flow the pump and it was all good. Now I checked the whole cooling system and coolers for a overheat and check the ECU for any codes of a over heat NO Problems there either. Now I pressure test the headers to see if they are cracked and letting water back in. NO Leaks there either. So I pumped all the gas out of both tanks just in case for some reason he got some bad gas in that tank because it seemed to have the problem after Gavin filled it up. When I took the front motor apart to get the heads and blower off the head gaskets and pistons looked great in that motor. So I wrote A couple est of what it was going to take to fix the one motor and then wrote a est to make them 540's so they could go to a Dart block and have a thicker cylinder wall so we could controll the blow by with the blower. After talking with both Seely brothers they did not want to spend a lot of money and they have been a good customer for years and seeing why we could not find a reason it burnt the pistons I worked with them and took alot of their old parts in on trade for the labor to build them these 975 HP 540's. No where in this project did we cut any corners because it's name on the project when it's done. I built the new motors and tuned them on the dyno and whatched the air fuel and cylinder temps real close looking for any problems and the cylinder temps were 1275- 1300 and the air fuel was 11.0 at 8 pounds of boost plenty safe to ship the motors to RF. After the engines were installed I flew down myself and fired up both motors and went on the first test ride with my laptop and 0/2 meter hooked to the engine. We warmed the engine up and rode at 3000 rpm to heat the oil up and the air fuel was 11.6 11.8 making about 3-4 pounds of boost up 4800 rpm we made 8 pounds then to 5400 and still 8 pounds the air fuel was 10.8 the boat was running about 111mph we then stoped and turned around and ran it up again then I noticed the blow by out of the motor and I went right up to the dash and the water was 110 degrees the oil was 190 and we had 25 pounds water pressure so we came back in on one motor and I pulled all the spark plugs and they were all black accept # 4 it was clean. I pulled the motor and disassembled the engine right there and found the piston torched right by the intake valve so I had the engine shipped back to my shop in Michigan and when I took the head off the other side it started burning 2 pistons on the other side. Ok the Air fuel was 10.8 the spark plugs were black and the piston tops are all black from burnt fuel. I tested the innercooler and it is not leaking and sent the headers back to CMI and they tested good. The front motor is ok it is just this back motor and after all I have done to check everything you all think it was just because there were no head studs.

Sorry ,we just assumed yes assumed it would have head studs , again sorry for upsetting anybody .

Tyler, its good to hear what it takes to get high HP out of these engines -- its not just a bolt-together-and-go proposition!

It wouldn't have anything to do with less exhaust back pressure from shorter tailpipes, would it?

Update....I spoke with Tyler this morning and he has consulted with some of his peers (Richie Zuhl, Keith Eickert) and there seems to be a consensus, based upon the burn pattern on the tops of the pistons, that the issue is related to a timing issue. Long story short, we are installing new Billet MSD distributers, and replacing the PCM on the Stbd motor just to eliminate any goofy computer glitches. Tyler is sending down a leak down gauge to Lil R and he will do a leak down test on port motor. IF all is good then we will move forward. If not..then I will probably send port motor back for Tyler to look at.

CMI tested the headers and they held 60PSI with no leaks. However, they are 7 yrs old and we are going to replace the Stbd headers with the new Gen X style. We will then send the old Stbd headers to Tyler and he is going to weld AF bungs into each tube so he can read AF on each cylinder..as opposed to a left bank/right bank average taken @ the Tailpipe when he re-dynos the Stbd motor.

Shooting for another visit to RF at the end of this month. Do any of you guys wanna loan me some money?? Or maybe let me live with you?....WE ARE TAPPED!!!

IDK?? Someone smarter than me might answer this one...lol.

It burned the pistons with the other ones. and it is just the back motor. I still want to pull all the water restictors out of the tailpipes to get all the volume thru them now we got plenty of water flow. Mercury put those in there to keep water pressure in the 525's.

Everytime I think about having a big motor put in my boat, I read all this and decide tame power is for me.

huh? uhm....there was nothing talking about how to build high HP engines in that post? What I read was: Motors keep blowing up and we don't know why, it has 10.8 AFR, and no head studs are fine" nothing about bolt and go operations? and no high HP engine specs...

I feel for you guys, this sounds really frusterating... and expensive!!!

Tyler, it really appears you will have covered the basics well. I'm sure this is a stupid question, but are you 100% sure the head(s) and block are straight?

And FWIW, regardless if the lack of studs is associated with this reoccurring issue or not, I'm shocked they weren't in there in the first place!