Who's got a desk top dyno?
 

Now that I have all the major pieces bought, can you plug it in and see what it says,, or anybody have any good guestimates?

454 8.5 compression, 731 cam, promaxx 320's, ( Intake .200 = 155cfm, .300 = 228, .400 = 289, .500 = 336, .600 = 368, .700 = 388 .800 = 392 exh .200 = 117, .300 = 158, .400 = 205, .500 = 228, .600 = 258 (w pipe 277) .700 = 260, (280) .800 = 261 (283)... 1050 dom on a 177 blower, 5psi.

No desktop dyno, but I would guesstimate around 580hp @5400 rpms.

put it together bring it up to michigan, 30 min north of detroit this time of the year my "real" dyno is looking for jobs to run

567.3

I modeled a 525 SC then changed the heads to your flow numbers, swapped cams and raised the compression. It shows 617 HP.

Oh boy.... I think Im going to need a bigger prop.... :party-smiley-004:

and that thing just before the prop.

yeah, that too... when I replaced the lower 2 years ago, the propshaft and the vertical shaft both had twisted splines

What you have in it for power now and what kind of speeds are you running ?

If I throw the little pulley on and a 2" shorty, the bam speed calculator thing predicts top speed somewhere between the mortuary and the crematorium....

A worn out 310hp 7.4 mpi.. I saw 62 once and that was with an ugly 3 blade

You should have said "AFR" heads. The HP guesses would have been 650+. lol

Seriously though. Those heads are flowing as good if not better than a set of afr 305's. Those are real flow numbers, not "advertised". I gotta do some stuff around the house right now, but I'll try and run it in my program for you as well.

The 731 cam is gonna be a bit on the small side to get in the upper 5000's for peak power. I'd probably would have gone with the 525EFI or 741 cam. I could compare the two , and see how they stack up power wise.

Shooting from the hip, I think you'll easily get over 600 without a problem. Wayne272 build a set of those engines, but had a 236/245 114 crane Flat tappet, 177 blower, dominator, stock Merc heads, and made 575ish around 5500, with around 4.5lbs of boost. Torque was 600ish ft lbs.

well do you remember the 454s that made 690,yes i know that was with dyno headers.i like flow numbers,i love dyno results.i would also love to make the same power with a set of heads that cost 25%less.i hope phragle does some dyno tuning and posts results.imo the 731 will be on the small size.

^^^ isn`t it basically the same motor that made 690hp as Phragles? Why is your guess is 130hp less?

My guess: 688hp

Should be interesting to see how the promaxx heads work out. Could be a nice option.

Phragly, you gonna dyno it ?

not the same,different heads,cam and compression ratio.basically a different build.

how did you arrive at that number,my number was achieved using the SWAG method.

The plan is to dyno it....and get a good solid base tune. I would also like to see if the tune stays consistent if I swap to the glory pulley....

I told her last night I wanted to swap "Glory pulleys" I have 2 black eyes this morning!!! :hijack::evilb::lolhit::thankyouthankyou:

That can also be achieved by letting the wife see the boat receipts.

That will be a nice build regardless but I'd say griff would pretty close estimate.

I got 630hp with that combo, and 612HP, with the stock 525sc camshaft in it.

Stock 525sc cam, was 228/236 114 LSA .530/.551

731 cam, is 226/236 112 LSA. .587/.610

That would make sense to me. If I recall, griff replaced his stock flat tappet cam in his 525sc, for the 731, and picked up about 100rpm. Thats probably around 20-25hp gain. Cams are fairly similar duration wise, a bit more lift /lifter acceleration with the roller design. Thats about what I think should be expected when going from a flat tappet to hyd roller cam. Its certainly not 50+HP like some may suggest.

Thats figured with small headers and right about 5lbs boost. I am sure if its dynoed with big tube dyno headers , those numbers will be higher. Prob 650 plus with the 731 cam, dyno headers, etc.

Correct on the 731 swap.
I was running the stock bottom end with 7.5 CR pistons and about 7.5# of boost. I estimated I was around 560-570hp.
I figure the extra boost I had and his 1 point higher CR are pretty much a wash for HP.
I'm not sure how much the promaxx heads will gain hp wise. Maybe 20-30hp???

so what kind of speed you thinking?

TRS right? set deep?

77mph

Bravo, set in the middle......

Thanks MT..... Im now in the catagory of making more than I planned. Original plan was a legit 525 at the prop or so.........

Rob what exhaust you have on there?

I have a set of stainless marines, with regular risers and a set thats dry to the tip. I would like to get by with the standard risers if possible so I dont become that guy with the noisy azz boat.

My fully jacketed stellings , with gaffrig superflo series mufflers, switched to closed , sounds as quiet as a set of stock 330s.

So maybe 80?

if ALL the stars align... but I am pretty much counting on mid 70's

Going to need to Wear your Special helmet.

It will do that with 450 at the prop.

Uh-ohhhhh....

Time to update the life insurance...

You have full hydraulic steering, so no big deal; I saw your video, LOL.