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-   -   454 vs 489 (https://www.offshoreonly.com/forums/general-q/224022-454-vs-489-a.html)

Rookie 02-06-2010 12:41 PM


Originally Posted by crapr6 (Post 3039851)
Ok iam sure this question will be hard to answer but iam just trying to get an idea if I should just rebuild my 454 or build a stroked/bored 454 to a 489..

What HP and TQ numbers are gained from going from say a 454 built with good heads, cam, intake to a bored/stroked 489 also with good heads, cam, intake..
Any numbers guys? Just want to see if its worth it? Any advice?
Erik

I was almost in the same boat as you, but I had Merc 420's. Instead of going with a stroker kit cause I already had forged internals I spent my money on good heads and pistons. I put a set of fully ported and Wedged JimV Merlin heads on and made 590HP and 561TQ @ 9.5:1. If you already have good heads and need forged internals I would definitely go stroker.

Use Scat I know where you can get some Twisted EAGLE cranks from a lot of torque and the load of a boat.
I plan on going to a 540-565 later so I will just take my stuff from my 470's and use it on them.

"?" can you take a stroker kit from the same GEN 454 and put it in the same GEN 502????? and just replace the pistons?

endeavour32 02-06-2010 12:44 PM

[QUOTE=
"?" can you take a stroker kit from the same GEN 454 and put it in the same GEN 502????? and just replace the pistons?[/QUOTE]

As long as it's a 1 piece main seal I don't see why not!! 454 and 502 cranks are the same.

Rookie 02-06-2010 12:45 PM


Originally Posted by crapr6 (Post 3040243)
All great info guys,
So now iam looking at Eagle and Scat rotating assemblies. I have used Scat stuff before with no problems. Just wondering if the Eagle stuff is as good if not better then Scat?
Erik

Scat, there are a few people that have had luck with Eagle, but I know more people that have twisted Eagle cranks when they started to make a lot of torque.

getrdunn 02-06-2010 12:52 PM


Originally Posted by Rookie (Post 3040245)
I was almost in the same boat as you, but I had Merc 420's. Instead of going with a stroker kit cause I already had forged internals I spent my money on good heads and pistons. I put a set of fully ported and Wedged JimV Merlin heads on and made 590HP and 561TQ @ 9.5:1. If you already have good heads and need forged internals I would definitely go stroker.

Use Scat I know where you can get some Twisted EAGLE cranks from a lot of torque and the load of a boat.
I plan on going to a 540-565 later so I will just take my stuff from my 470's and use it on them.

"?" can you take a stroker kit from the same GEN 454 and put it in the same GEN 502????? and just replace the pistons?

I was looking to do my home work regarding my build as well. Currently I have a fresh 496's but wondered if in the near distant future if I would be able to get 502 blks and use the old rotating assm. with the exception of having to get new pistons. I have Mark 1V currently so what 502 blks would I need?

endeavour32 02-06-2010 12:57 PM


Originally Posted by getrdunn (Post 3040252)
I was looking to do my home work regarding my build as well. Currently I have a fresh 496's but wondered if in the near distant future if I would be able to get 502 blks and use the old rotating assm. with the exception of having to get new pistons. I have Mark 1V currently so what 502 blks would I need?

I don't think they made a MK IV 502. The mark V+ block's are a 1 piece rear seal... I think you would have to go with either a bow-tie block or a dart or merlin. All of those you can take out to 4.6" bore

tx911 02-06-2010 01:34 PM

They make mk4 502's but they are very rare. All after market blocks use a two piece rear main, so your mk 4 rotating assembly will work good with a dart or merlin block. You can also get a adapter to run a mk4 rotating assembly in a gen5/6 GM block, it worked fine for me.

getrdunn 02-06-2010 01:42 PM

What years did they have Mark 1V 502 blocks? It's amazing how much of this you forget when you get out of the loop for a short period.

Thanks,
John

crapr6 02-06-2010 02:01 PM


Originally Posted by Rookie (Post 3040249)
Scat, there are a few people that have had luck with Eagle, but I know more people that have twisted Eagle cranks when they started to make a lot of torque.

Ok sounds good! I have seen Eagle stroker kits much lower in price compared to Scat strokers kits. Iam looking for the best deal since money dosn't grow on trees around here but I also know YOU GET WHAT YOU PAY FOR..Scat it is
Erik

Ms PatriYacht 02-06-2010 04:20 PM

Scat has a better reputation for accuracy. Still needs to be checked carefully.
Oops, used the wifes computer without changing the log in.

tx911 02-06-2010 04:35 PM

I dont know what year they made the mk 4, 502 blocks. There was a set of motors built with them on sale here not that long ago. I think they are very few and far between, because they went to the 1 piece rear main seal very soon into producing the 502. I am sure they would cost you more then a set of dart or merlin blocks anyway. Using the adapters to put a two piece rear main crank in a one piece rear main block is a good alternative. The oiling setup on the gen6 blocks is improved over the mk4 blocks from what I understand. The aftermarket blocks also take advantage or the oiling upgrades too.


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