Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   575sci 502 to 540 (https://www.offshoreonly.com/forums/general-q/288545-575sci-502-540-a.html)

JRider 12-06-2012 09:25 AM

575sci 502 to 540
 
What is the best way to get to the 540 displacement? I dont think my cylinders have any ridge so should I use a stroker crank, go with shorter rods and use my pistons? Or should I keep the rods and go with different pin height pistons? The pistons are JE and the rods are Hbeam Manley (what merc used stock in the 575). Not up on BBC internals like I used to be on SBCs.

F-2 Speedy 12-06-2012 09:34 AM

Im going from 502' to 540's, the route Im taking is to reuse my gen 6 blocks, bore them around .030 to 4.500, 6.385 H beam rods and 4.25 stroker cranks, pistons will be 4cc to 10cc dome and should put me around 9.5 9.8 compression with a 118 cc chamber. AFR 305 as cast with CNC'd chambers is what Im going to run.

good luck

4bus 12-06-2012 10:02 AM

:food-smiley-007:

Need4SpeedGTCS 12-06-2012 11:17 AM


Originally Posted by 33outlawsst (Post 3827357)
Im going from 502' to 540's, the route Im taking is to reuse my gen 6 blocks, bore them around .030 to 4.500, 6.385 H beam rods and 4.25 stroker cranks, pistons will be 4cc to 10cc dome and should put me around 9.5 9.8 compression with a 118 cc chamber. AFR 305 as cast with CNC'd chambers is what Im going to run.

good luck

Nice!

the deep 12-06-2012 11:35 AM


Originally Posted by JRider (Post 3827355)
What is the best way to get to the 540 displacement? I dont think my cylinders have any ridge so should I use a stroker crank, go with shorter rods and use my pistons? Or should I keep the rods and go with different pin height pistons? The pistons are JE and the rods are Hbeam Manley (what merc used stock in the 575). Not up on BBC internals like I used to be on SBCs.

Without boring your block to 4.5" you will not achieve 540ci . You need the proper combo of bore and stroke .

JRider 12-06-2012 01:02 PM


Originally Posted by the deep (Post 3827455)
Without boring your block to 4.5" you will not achieve 540ci . You need the proper combo of bore and stroke .

Not looking to hit that exact displacement. Going for bang for buck i guess you could say. I am limited on how big I can go due to the dual throttle body setup.

Rookie 12-06-2012 03:46 PM

Is there a way to do it and keep you pistons? You would need to change your crank and rods but wouldn't you have to change pin height on the piston or can this be made up by a different rod length? I am also curious

Young Performance 12-06-2012 04:25 PM

Depending on how the pistons and crank counterweight are cut, they may or may not clear the crank counterweights with a stock (6.135) length rod. Usually, they won't clear, so you need to go to a 6.385 or 6.535 rod with a 4.25" crank. You would also have a less than desirable rod angle(1.44) with a 6.135 rod and 4.25 crank. If you use the longer rod, then you will have to change the pistons because the compression height will not be correct. Most would use a 6.385 rod with the 4.25" crank.
Eddie

tunertech 12-06-2012 06:48 PM


Originally Posted by 33outlawsst (Post 3827357)
Im going from 502' to 540's, the route Im taking is to reuse my gen 6 blocks, bore them around .030 to 4.500, 6.385 H beam rods and 4.25 stroker cranks, pistons will be 4cc to 10cc dome and should put me around 9.5 9.8 compression with a 118 cc chamber. AFR 305 as cast with CNC'd chambers is what Im going to run.

good luck

pow :lolhit:

drivrswntd 12-06-2012 06:55 PM


Originally Posted by 33outlawsst (Post 3827357)
Im going from 502' to 540's, the route Im taking is to reuse my gen 6 blocks, bore them around .030 to 4.500, 6.385 H beam rods and 4.25 stroker cranks, pistons will be 4cc to 10cc dome and should put me around 9.5 9.8 compression with a 118 cc chamber. AFR 305 as cast with CNC'd chambers is what Im going to run.

good luck


Dead on and sounds like a Bob M build up. He did the 548 tall deck I got and cant wait for spring to get it in the boat and on the water


All times are GMT -5. The time now is 07:25 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.