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-   -   Converting A 502 (https://www.offshoreonly.com/forums/general-q/19643-converting-502-a.html)

Drew 03-08-2002 01:58 AM

Dave F has a goodlist but I would not put this much work in with out changing to one piece valves. You could go with good stainless valves for this application and they would flow better than Inconel in my opinion. There is more HP to be had if you change heads. Cam choice would depend on heads used and or how much flow work is put in to stock heads. You could use stock valve covers if you break or grind off the drippers. You may need to double gasket valve covers or take about .060 off of adjusters for roller rockers but it can be done. New covers look cool though. Sounds like a fun project. Are starting with a base 502 or 502 mag motor.

obnoxus 03-08-2002 04:59 PM

UM Paul,,,, you can't make a HP500 out of a 4.3 V-6.:D :D :D

1Boatnut 03-08-2002 05:32 PM

I was wondering how long it would take before I would see you post some crap, and its a 3.0 Study this well,cause your gonna help>

Dave F 03-08-2002 05:41 PM

I don't know if he has two piece valves or not. I was under the impression that all Chevy intake valves were 1 piece, and Merc uses the Inconel one piece exhaust valve. But hey, what do I know? If so, I agree, 1 piece is the way to go.

Yes, I absolutley agree with bigger power gains with different heads, but that's another 2g's.

Glad I could help. It was pretty easy though, I just had to pull out my receipts from the last time I built one.

DAVE

obnoxus 03-08-2002 05:43 PM

Help,,,, **** I end up doing all the work so you don't screw it up, and then I have to tow your ASS back !!!! HEHEHE Almost spring !!!!:D :D :D

1Boatnut 03-09-2002 09:24 AM

How many times have you towed me? You are usually so far out in front of me you dont even realize I am dead in the water> But if you insist on doing all the work,you know where the boat is,so what the hell are you waiting for?

rpm 03-09-2002 09:37 AM

500 longblock
 
Rod

I have two 1997 500 HP longblocks with approximately 50 hours each since rebuild for sale - intake to pan $5500 each.

920-236-4220

obnoxus 03-09-2002 10:59 AM

I already told him about your motors Rod,,, but see,,, my buddie Paul here squeeks when he walks he's so cheap !!!! We could go through his for under 3k,,, including heads, but there is no need because he is so much faster the me now !!!! ( anyone noticing a trend here LOL !!! ):D :D :D

B.R.S. 03-09-2002 11:53 AM

1 boatnut if you already have the block and exaust to start why do you only want to duplicate the HP 500. I started with this combo used stock GM heads and flat tappet cam, Weind intake and Lightening headers an made 547 HP at 5100. I have Dyno sheets to back it up. This winter changing to Dart intakes and a little carb work and are expecting 600. The block is stock and the heads have had no portting just a good valve job with inconel valves, the correct springs for the cam and Harland Sharp roller rockers. The motors are totally reliable!

1Boatnut 03-09-2002 12:55 PM

B.R.S ,that is certainly something to consider.I just dont want to get too radical,because as you stated I really want something that is totally reliable.Did you use the stock 502 Carb? What year is your block? I believe mine is a Gen V ,and I was told it already uses roller rockers and cam. Anyone know this to be true ? Not that I am not going to change them,just interested.


Rod,the longblocks you have might be a option ,but I also was kind of looking forward to this project. Thanks,and I might be calling you either way,for the parts too!


obnoxus(Dennis) as far as sqeeking when I walk,I learned from the best. YOU!!! I also like to refer to it as currency conscious. Also if I already were so much faster than you now I would save the 3-5 grand for fuel,since I burn twice as much as you do. DONT make me start posting picture ( with you always in front ) cause you know I have them.

Guys,again thanks for all the imput. It has helped me alot. Any more input would still be apreciated. EXCEPT from you Dennis.

Sorry guys just having a little fun with a ex buddy. :D :p ;)


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