The 502 that I was running in my Kona bent some pushrods and tore the head off of one of the valves which then went through the head. So now I am trying to figure out what to do next. I am going to have to bore it to at least a 509. Since I am going to have to get new pistons anyhow, I was thinking of just making it into a 540. So I have a couple of questions that I hope that you guys can help me with.
1. Is this too much motor for my boat? It's a 1978 Kona Makai.
2. I spent a little time looking around on the internet and found some 540 kits for around $2000 give or take a few hundred dollars. The motor is a Gen 5 502 that is stock except for it has been converted to solid rollers with a 670 lift cam and a gear drive. Can anyone suggest a good kit to use?
3. If I do run a 540 will my SS A/B impeller be the best to use? I have a JG with a droop, place diverter, and loader grate
I know that this is going to be real expensive but I want something that is as bullet proof as I can make it. This is the second time that this thing has blown up this season and replacement JE pistons are pretty expensive at $160.00 a pop. Thanks for the help I don't really know that much about boats but, I figured that you guys would be able to help me out here.
Thanks,
Doug
You are right in the price range at around$1800-$2000 for a kit.You can get a nice eagle crank and h beam rods(250 or 400 long)and a set of J/E pistons.Some people will say eagle is junk.I have ran it and not had a problem.I have had good luck buying stuff from shafiroff racing.You could always use your crank and rods and build a 509 and save some money.What heads do you have?
[ October 07, 2003, 01:34 AM: Message edited by: 565edge ]
Think about what you want the boat to run, the determine how much HP is required and build accordingly. BTW if the replacement 502 pistons are 160 a pop, I would spring for a new set of off the shelf SRPs at around 500with pins and locks. I know GM pulled some crap with JE where JE is locked in on the retail pricing of that piston, so perhaps you would want to get away from the cost associated with that exact forging.
The 2k you're going to spend on a new crank and rods could go a long way in replacing that head which was desroyed with valvetrain debris. Do you know why the pushrods bent and the valve failed? If not, I wouldn't spend another dime on parts because you could end up right back in the same situation. Determine what went wrong, and make sure that issues is corrected 1st and foremost. I think you'll make more power with a 509 with better efficiency (spend your 2k on the top end) than you would with a 540 with lower overall effeciency.
Good luck,
Chris
If you got the funds go for it. No replacement for displacement.
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