454 vs 489
 

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 in your same shoes about a year ago. Needless to say I went with 496's. I have had several built 454/468's in boats over the years. Your torque will undoubtably be much greater in the stroker. I will be posting a thread here soon on the dyno numbers for my 496's. I think if you compare pretty much the same components such as heads, intakes, carbs etc you'll probably see around 75 + HP with the stroker. I am pretty certain I will be at around 600 HP. It's not easy to get over 500-525 HP with a 454 and stay under 9.5 to 1 Comp. I know there are people who claim they do however not that often. I have forged int. Dart Pro 1's 310, Dart intake, Custom comp grind hyd. roller. 10 to 1 comp. Carb - N/A.

Let me know if you have any questions. I think though if you stroke it now you'll never regret it. If you don't you'll always wished you had. Just the way it goes. There are also some pretty good kits available at affordable prices.

Fixx
 

I know this boat http://www.offshoreonly.com/classifi...o30340-en.html
made a little over 600 hp,engines built by powersorce in forlake il..started out as 420's bored .060 over,custom hyd roller cams,merlin big oval port heads,lightening headers. and the list go's on.. im not a sales man but if someone were to buy this boat and swap the power and sell it,they would have a nice package:D BYW the trs trannys were just done too!20k will take the boat..like i said im not the sales man i knew the old owner tommy wgo passed away and his widow is trying to get rid of it..

Seems like a decent deal for somebody. What kind of speed did the previous owner get out of it? I wish her well.
John

Fixx
 

the boat runs according to tommy 82 mph..engines dont look pretty but i know its a strong runner..

Let me start by saying this.
Years ago I built a ford 8.2 deck 302cid based motor to a bored and stroked 347cid (aftermarket block, heads, etc,etc). It was a turbo motor and ran it in a fox body mustang 1987-1993 body. It made just over 800hp with a csu blow thru carb that needed to be sent back since we had jet sizes up to 98 and it still ran lean..Anyway I always wonder if I had built a 9.2 deck 351W based stroker motor what this thing would have made...so like you said I always wonder why I didnt go with the bigger block to start with from the get go.

Now this is what I have.
I have a stock 330hp motor, 4 bolt block .030 over already and of course stock 330 cast crank and rods.
I have a set of World Grumpy Jenkins 320cc rec port iron heads. If I do a .060 over 454 and try to use these heads it will be to much head for a 468cid. I was told that these heads will work better with a stroked 454, and I really need to upgrade to a better forged crank and rods.
Iam guessing these heads on a 489cid 10 to 1 comp, RMbuilder hyd roller cam, good valvetrain, good intake w/850 carb and Lighting headers it should make good power.

You pretty much said exactly what I would have. The 320 cc intake runners are for sure going to be on the sloppy side so to speak on a 454/468. On a 454 I personally wouldn't want any more than about 280 cc at least for a marine engine anyway. I went with my 310's because it kind of went with the package, cam selection etc. I plan on running around 5800 at WOT. Dean Gellner helped me out the build and cam grind. That ***** sounds wicked. I have the cam specs if you want them. Otherwise your option with Bob would be great also. Jeffsaw on the board here did a very similar thing as you however he had the gm oval port heads. 820's I think, There pretty much like the 049's. He picked up like 5 mph from his previous build when he stoked it and did the Bob M. cam thing. You are on the right track and it sounds like you know what's up so I'm sure you'll be fine.

Funny you menition the 351W stroker. I have one sitting here on the shop floor ready to go in my 69 Mach. Need a bell housing for it and it's good to go.

PM sent..
I have a few bellhousing one for a T5 trans, one for a TKO trans and another for stock C4 trans.
What trans you running a top loader 4 speed?

I've been in your shoes for the last 2-3 months. I was almost going to sell my 439 rotating assembly and go the 496 route. But I was then assured I wasn't going to "regret" what I was doing with the big bore short stroke. So here is what I was told by two really good engine builders/engineers. First thing I was told is that cubes are cubes. A longer stroke will build no more torque than a short stroke- cubes being equal. However the short stroke will have a wider flatter power curve, according to one of the guys and short stroke will be much easier on the rods and crank. If a 496 lets say can make 625 hp which is 1.26 hp per cube. Then my 439 is capable of the same 439 x 1.26 = 553 hp. The same formula goes for torque. So a bigger motor will build more power, but it won't build more power per cubic inch all else being equal . So the difference between your 468 and the 496 would- be 589 hp vs 625 hp so about 2 mph. I think my next engine build is going to be a 4.6 bore merlin block with my little 3.76 crank which will be a 499. The thing will rev to the moon and make awesome power from 3300-6100+ rpms. I'm sure I'm going to get some flack from this post, lol.

I agree with getrdunn on the heads. Check out the new AFR 265 oval port. It comes with a cnc chamber, fully cnc intake port and cnc bowl port in the exhaust. It was designed to fill the void in the 427-468 range. It would be a killer head on your package and the price is great for what you get.

I agree that thoses AFR heads would be perfect for what I want to build, but I kinda got stuck with these World heads after buying them and have spent some money in them already. I can't sell them and break even so Iam going to try to use them and work around these heads.
Iam sure people will say just sell them and start with a better head but I will lose money if I sell these world heads.. :party-smiley-004:
Erik

When we had them on a flow bench , they are a brawdband head ,,so to speak.....they make good power in a 454 and up to 540 Ci ,,,on an other note ,,,i would only go 9.6-7:1 in a boat....TO MUCH LOAD THRU OUT THE RPM BAND,,,not a car witha tranny u know ?!
I would definatly go with a forged crank anyways,,,i believe the 330 had a cast crank ,,unless u already upgraded it !

The Merlin Ovals are good, is that what you have? You'll make good power with those. The afr's are better but they also cost more.

No I have the World Merlin Bill Grumpy Jenkins port design rec port cast iron heads. Cast number 1-043B
Intake runner is 320cc
intake valve is a 2.250
exhaust valve is a 1.88
118cc combustion chamber
They are to big for a 454 I was told but work best on 500+ cid motors. Another reason to build a stroker 454..
Erik

with those big heads you may need to build a stroker. Good luck with the build, soon its going to be time to be on the water again.

Thanks and I agree, before you know it its going to be spring/summer. All this snow today isn't helping thought!!!
Erik

Yea, thats correct. I picked up 4-5 MPH just from the bore and stroke. Same heads, intake, exhaust, cam, ect.. The only thing I changed was the forged stroker assembly. At that point I had a crane cam, stock exhaust, penut port heads and the Holley MPI. This setup is not advised, it did not last very long with the stock exhaust.

I agree with you premise that a bigger motor will not make more hp per ci than a smaller motor. A decent build will make abot 1.1 hp per ci. So a 454 will make about 500 hp and a 489 will make about 538. In this case however, the bigger motor is a better match for the heads. I would guess that the difference when it is finished will be about 50 hp.

As far as the longer stroke being harder on the rods and crank etc., at the rpm's we run, there is no real difference between the two. Drag racers are turning 4.5 stroke engines 8000rpm's with Scat and Eagle rods all of the time now and they only break if something else is wrong with the motor. If you build that small stroke motor like you saying and only turn it 6100, it will only make about 600 hp, 650 with really good heads. Supercat 750's are 510 ci and turn up to 7800 rpm to make 750-800hp. Why not put a 4.5 stroke crank in your new talldeck block and spin that 6100rpm and make 800 hp and have along operating life.

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

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?

[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.

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.

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

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.

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

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

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

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.

You pretty much nailed it. The seal adapters to put a Mk IV crank in a Gen V/VI block is only about $80. They work well.
You are correct that the newer blocks have better oiling.
Eddie

So if I find a couple of Gen V/VI's go a head and get them???
What's the going rate for 502 blk needing to be machined, etc.?

Yes. Get em. They aren't that easy to find used. They are available new for somewhere around $1500. I may be able to find a few a little cheaper. Had a line on a few a while back, but I really didn't need them. Let me see what I can come up with. I'll let you know.
Eddie

Fixx
 

The biggest issue with the mark 502 was cooling issues.the newer gen v was revised for better cooling then they did another revision on the gen6 to make it better and also decided to add the roller cam set up..

Hey Guy's, fwiw, it took me two years to find a genV 502 block. Few and far between. The good news, I got it for $750.00. On my way to a blown 540ci, chiller on the way. The rear seal adapter worked fine for me also.
And for its worth again, my last build was 454 to 489 and picked up 6-7 mph in my 23.5 Arriva