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-   -   HP500efi Cylinder Heads (https://www.offshoreonly.com/forums/general-q/344546-hp500efi-cylinder-heads.html)

Satisfaction 03-01-2017 07:23 AM

So castings were good and spent about $650- at marine machine shop with me providing springs / locks and retainers

did run into a glitch with springs - planned to go with isky 8005-a spring and 10degree locks and retainers per info in other posts but the installed height of those and most suggested HP500efi replacements are 1.875" w/ 135# seat pressure

My heads (casting..934) are set up at closer to 2" so shop said find a longer spring or machine in seat pockets -- and get to 1.875

I talked to Isky and they suggested ISKY 8205-SP which would have about 135# seat pressure at installed height of 1.950 and similar spring rate

Anyone else run into this? My engines are 2003 - both engines had same dimensions (one still had factory engine seals on it-so guessing it is original - at least no machining etc)

Not opposed to PAC or other spring either just looking to stay in bounds with what others have had success with!

Thanks, Tom

((glad I started early - need significant time to complete these projects!!!))

adk61 03-01-2017 08:42 AM

I have nextek endurance spring available... its a bit heavier duty comes in at 170# @ 2.050 these are the GO TO spring for upgrade


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