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-   -   Refreshing a 502 (https://www.offshoreonly.com/forums/do-yourself-boating-budget/318546-refreshing-502-a.html)

inspector747 09-29-2014 05:07 PM

Refreshing a 502
 
Hello all,
So I am in the process of "Freshening/ rebuilding" my 502 and now that it's torn down I have a few questions, the heads are GM (#14097088) that are ported and polished, running an ISKY Race cam.

Style: Hydraulic roller tappet
Basic Operating RPM Range: 3,000-7,000
Intake Duration at 050 inch Lift: 238
Exhaust Duration at 050 inch Lift: 248
Duration at 050 inch Lift: 238 int./248 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 294
Advertised Duration: 284 int./294 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.578 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.608 in.
Valve Lift with Factory Rocker Arm Ratio: 0.578 int./0.608 exh.
Lobe Separation (degrees): 110
Computer-Controlled Compatible: No

With the basics above would changing to aluminum heads be a benefit? Any other recommendations?

I am going to Morel Lifters with Scorpion 1.7 Marine Endurance Roller Rockers

Thanks

SB 09-29-2014 05:17 PM

2 things from me:

The words ported and polished mean nothing to me. Who did the port work and do they know what the helll they are doing ?

What exhaust are you running and are they dry ?

Ooops: a third thing - what compression are we aiming for ?

inspector747 09-29-2014 05:25 PM


Originally Posted by SB (Post 4194770)
2 things from me:

The words ported and polished mean nothing to me. Who did the port work and do they know what the helll they are doing ?

What exhaust are you running and are they dry ?

Ooops: a third thing - what compression are we aiming for ?


No idea who did the port/ polish and right now I'm running wet exhaust but will be changing to dry either with headers or fab the Gil's I have. The boat ran great this summer with what I have, just looking to make sure I don't have any or introduce any problems

inspector747 10-08-2014 11:32 AM

Well after debating (Not really) and talking with Bob (Marine Kinetics) decided to go with a custom cam, AFR Aluminum heads, Holley EFI, Morel Lifters, Scorpion 1.7 Endurance Rockers, DUI Distributor and Moton Rods.... I'm still out on whether replacing the pistons or going to CP Carrillo bullet.

1st thing is getting the block in for hot tanking and cylinder wall check and Crank in for magna flux.... Will keep posting on the build

Forgot to add Borgie's help.. Thank you

AllDodge 10-08-2014 04:27 PM


Originally Posted by inspector747 (Post 4199536)
Well after debating (Not really) and talking with Bob (Marine Kinetics) decided to go with a custom cam, AFR Aluminum heads, Holley EFI, Morel Lifters, Scorpion 1.7 Endurance Rockers, DUI Distributor and Moton Rods.... I'm still out on whether replacing the pistons or going to CP Carrillo bullet.

1st thing is getting the block in for hot tanking and cylinder wall check and Crank in for magna flux.... Will keep posting on the build

Forgot to add Borgie's help.. Thank you

Looks like you to are getting info from one of the best here. With your build what is the HP and TQ numbers Bob is coming up with?

Cole2534 10-08-2014 04:56 PM

I'm betting the 650 range.

Borgie 10-08-2014 06:34 PM

I

Originally Posted by inspector747 (Post 4199536)
Well after debating (Not really) and talking with Bob (Marine Kinetics) decided to go with a custom cam, AFR Aluminum heads, Holley EFI, Morel Lifters, Scorpion 1.7 Endurance Rockers, DUI Distributor and Moton Rods.... I'm still out on whether replacing the pistons or going to CP Carrillo bullet.

1st thing is getting the block in for hot tanking and cylinder wall check and Crank in for magna flux.... Will keep posting on the build

Forgot to add Borgie's help.. Thank you

Gonna be a sweet motor man! Bob is a true gentleman and his knowledge on what works is truly amazing! Take this and add some of Alex Haxbys , (holley efi) and you have a perfect recipe. I'm looking forward to your results!

Budman II 10-08-2014 08:36 PM

What size AFR heads are you going to run? Cometic MLS gaskets? Head studs? Make sure you have the proper RA finish on your block with the MLS gaskets - heads should come with proper finish already. You have mostly blind head bold holes in the 502 block, so shouldn't be any major concerns with sealing the threads. Follow Bob's advice and run a good, stout set of pushrods too. You're gonna be a happy boy.

MILD THUNDER 10-08-2014 09:13 PM

Good job ditching the GM 088 iron heads. They suck.

sutphen 30 10-08-2014 09:55 PM

do you boat in fresh or salt water?


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