280's With 800+hp
 

Anyone that has a 280 with 800+hp, how does it handle, what props are you using, any pointers on anything....

Wear a helmet, lifeline jacket and hook up the lanyard.

LOL, I think your right, but I don't think that is what he is looking for. :drink:

mine has well over 800 i run a 32 bravo lab prop and turn it 6000 plus

oh and you will need full hyd steering , mine has 280 tabs on it also

1482 Hp X Powerdrive 5 Blade Herring Cleaver 120 Plus Mph Straight As An Arrow.

Wow!
Any picts?

I don't think they make film that fast.:lolhit:

had 26/280 1050 hp 32 b1 labbed hydro steering. Setting up a 280????? ask MikeS he hooked me up
-Mike

All this talk and the fact my boat didn't sell makes me want to build another engine. I've got the heads, valve train, and fuel injection from a 500EFI. I could either rebuild my 454 to make 450-475 or the 502 that's in the boat to make 500-525.
How much do you guys think I'd gain upgrading from my 415HP/502?
It's probably a $3000 investment and time away from boating this spring so I'm not so sure it make sence for this year...

Pat, Sell both and build a 540 making 700hp. normally carb aspirated and you will have a near 90 mph boat.

Hi Rick, how are things down in PA?

You know I've tried to sell the 1999 454 I have a couple of times and it does not seen to be worth enough to bother. I did sell the L-29 heads off from it and use the $$ to buy the HP500 heads I have.
For an extra $1500 or so I could buy a stroker kit for the 502 and build a 540, which has crossed my mind. I would also have to buy a new cam and lifters for the 540cube so add that to the bill. There are proven combos with the 500EFI intake, heads, and such that will make 600+HP with a 540 cube, but I think a build like this will put me over budget.
I'm thinking with all the EFI stuff I have in stock the next engine I build will not have a carb but I could go either way.
I did some research today and rebuilding the 502 vs. the 454 is far more expensive. The pistons are more than double for the 502 and the 502 block I have needs to be bored out the 454 only a honing. I could almost buy a stroker kit for the 454 with the cost difference.
At this point I'm thinking that I just leave the 502 in the boat and build a 500+HP stroker out of my 454. This way I have no time pressure and won't miss any boating until the new engine is ready to swap with the 502.
The boat will top out in the high 60s now with the 415HP/502 so I'm guessing she'll run 75+ with a 500HP/488.
We’ll see how much $$ I have after doing taxes next month…:eek:

Pat get the 502 prepped i have rods pistons and a base pan gill 12qts with pick up you will have a sweet combo. just a nice 4.25 crank and your set. I say do it up
-Mike

you can get 600 hp out of a 496 been there done that

Guys I think what it comes down to for me is that I have a lot of parts in stock to build a 500HP EFI engine.
To build a higher HP engine the price tag is going to rise way beyond my budget because a lot of the part I have already invested in will not be used.
I need to deside if the extra 7-8mph the boat would gain going for 415HP to 500HP is worth the $$ and effort. If it is, then do I rebuild the 502 or build a stroker from my 454?

Pat just to give you a ballpark mph, I get on a GPS between79-82 mph depending on wave conditions and how full on gas and wt on the boat with with 635hp. I also have the bus windsheild which scrubs a little mphs off.

with the non gps speedo it was showing 88-90

Thanks for the info Meatman.
The privious owner of my boat, VelocityRick, had a 650HP/540 in her and she ran 82+.
I've seen 68 on my GPS at 4600rpm with a stock 26p B1. People tell me the boat should run 70+ with the 415HP/502 and that I could gain that 2mph by labbing the prop. I will do that when I ding it up and we'll see.
If I can go from 68 to 75+ by building a 500HP engine utilizing the parts I have in stock, I believe it's worth it. If all the $$ and effort are only going to buy be 3-4mph then it's not worth it.
Other reasons to stay with a 500HP upgrade are the stock B1 drive and the insurance I have. I'm not buying another or upgrading the drive and my insurance company will only go for a 500HP max in this boat.
Anyone have an HP500 in a 280?

Pat,

I think you're mixing crankshaft and prop shaft HP ratings. The HP500EFI/HP500 is 470 HP at the prop (not 500 HP) so you're looking at +55 HP which is more like +4 MPH gain - not 7 MPH to 8 MPH. The 500EFI set up will cost you a lot more then HP500 as you'll need belt drive fuel pump/water pump set up(to feed the EFI pump) and CMI headers ($$) to match the ECU mapping.

Pat, I've got a good recipe for a 502/MPI upgrade, I went from 5100 rpm to 5800 without a prop change. CMI sport tubes were a huge factor with performance and my credit card, both were sizzling.

Yes, I know how Merc rated the engines. In real world testing though, the 502 MagMPI dynos right at about 400CSHP with the stock cast exhaust and the 500EFI around 510CSHP with headers. So I believe the engine I'm planning for will make close to 100HP more than what I have in the boat now.
So do you think an extra 85-90HP gets me running over 75mph?
It would be nice to here from someone that has a 280 with a 500HP.
I have Stainless Marine manifolds which should flow plenty for a 500HP; they flow not much less than the small CMIs. As for the EFI system, I have an AZ Speed intake, the TB, and fuel injectors from a 500EFI. I also have the Crane/Merc 500EFI roller cam, roller lifters, and roller rockers. The heads I have are from a HP500 carb engine so I'll need to change the valve springs. The wiring harness and MEFI III ECM I also have in stock, but the ECU will need to be remapped. I have a water cooled double electric fuel pump setup that should flow plenty and I have an adjustable fuel regulater. I even have a K&N spark arester/filter for the the system.
What I need is the parts to build a good quality stroker short block out of my Gen VI 454.

I have a 1996 28 with a hp500 all stock with cmi headers. Runs 77-78 all day in the heat. One guy low fuel and the wind on my back 79.5 I run a labbed 28 bravo.

Thanks Kevin, That's what I needed to hear...:drink:
Now I just hope I'll have the $$ after doing our taxes...:eek:

Hey kev is it ever a problem having your boat in heat. Seems it would be a pain in the a$$. Pat go for it i want to see that thing on the ct.,cladios and at block for the boys weekend wish i could have made it but shooting for this year. Take care
-Mike

Hi Mike,
I plan to do Block at least twice this summer; once with the wife and kids and once with the big boyz.
Same with Claudio's, that a great day trip for us.
As for the engine, the next step will be to find a stroker kit for my gen VI 454; most seem to be for gen IV engines.
later all,

Sounds good pat good luck.
-Mike