refresh 500 hps
 

im at 340 hrs on hp 500s carb year 2000 and want to refreshin up in the spring. any ideas what all to replace and would like to build up about 50 hp. brand of parts to use and
hp build up ideas. currently have 1" spacers under carbs and carbs been re drilled and run msd boxes. i replaced the valve springs at 200 hrs.

thanks for any help

Re: refresh 500 hps
 

Only 50 hp?? You know I'd love to get my hands under those valve covers. I have a die grinder that loves to remove cast iron. :D With a good port job, 10.5 pistons and the right cam, how about 600 hp a peice? 90 mph and he want's more :rolleyes: I knew I liked you!!!

Re: refresh 500 hps
 

keep everything the same...good valve job, a bit more compression, and maybe a cam change...shoot for 580ish. that's about what a 525 conversion is.

ps...i have known race 500hp's to have that many hours on them and still go'n.

Re: refresh 500 hps
 

With a good intake, carb and our head work you will see 700+. Call or email me. Thanks Mike
[email protected]
570-956-2840

Re: refresh 500 hps
 

How much does a 200 hp head job and intake cost and what intake comes with it?

Re: refresh 500 hps
 

HEY MONKEY WHATS UP, NEED TO RULE THE RIVER( LOL)
YOU KNOW HOW IT IS NEVER FAST ENOUGH. :drink:


HEY JOE GOOD TO HEAR FROM YOU BOAT STILL WORKS GREAT ILL GIVE YOU A RING SOMETIME THIS SPRING WHEN IM READY TO REBUILD AND ALSO MAYBE WE CAN TALK ABOUT A LITTLE BOTTOM WORK ON THE HULL AS WELL.

THANKS RICK :drink:


THANKS TO ALL FOR THE INPUT

Re: refresh 500 hps
 

A 700+ hp, 500 ci engine will not be very user friendly.

Re: refresh 500 hps
 

Top End:
Have heads throughly gone through. Check and replace any gaulded valves. Retainers and locks are cheap and would just put new in. Have bowl work (porting) done on the intakes and exhaust. This is the best bang for the buck. Have shop do a nice 3 angle valve job. Keep intakes and carbs. I would check springs and replace if seat pressure is down more then 15%.

Middle:
Cam change with the bowl work will get you the power increase you want easily. New timing sets, double roller would be good, I would change the lifters out.. . .especially if the springs were real bad when changed at 200hrs.

Bottom:
Marine engines don't see much cylinder wear. If the P/W clearance is within factory specs I would hone and re ring. Polish crank and use new bearings.. Use stock Melling M77 and shim pressure spring .125".

Assemble with cometic head gaskets. Should give you a reliable 560HP

Re: refresh 500 hps
 

My advice."START NOW" don't wait.

Re: refresh 500 hps
 

In response to your question 800xcr how much $$. Our fully ported head jobs are 1200/ set, plus what ever hardware and valve components alond with machine work if any are needed. Intake of choice is a Merlin sing plane.

PatriYacht Our 700 hp engines are very user friendly. Due to the fact that they have a hydraulic roller valve train which is very reliable and requires minimal maintence.