Dyno Results: 502 w/ AFRs
 

502 ci
AFR 305S CNC Chambered, Anodized Heads w/Matching Cam (from Marine Kinetics/Bob Madara)
850 cfm QuickFuel Carb (91P, 96S)
Timing: 34 deg
TARGET: Reliability

http://www.youtube.com/watch?v=ALq5WAt-cPA&feature=youtube_gdata_player Link: http://www.youtube.com/watch?v=ALq5W...e_gdata_player

[ATTACH=CONFIG]523158[/ATTACH]

[ATTACH=CONFIG]523157[/ATTACH]

peak hp at 5900 rpm,nice.what is the compression ratio?my guess is around 8.8.

Correct - I think it was calculated at 8.9.

91p 96s with 3.5 Pv in primary only

So you have a stock 502 and added heads, cam, and new carb and that is it? Were the heads fully dressed or did you piece them together? What intake are you running?

Great numbers by the way.

Missed that - there were a lot of jets flying around. :angry-smiley-038:



Yep. Heads came with upgraded valves and springs from AFR via Bob.
Dart intakes (HP500)

That's allot of added power for not allot of money. Thanks for sharing!!

GReat VE's. Inductive Supercharging going on!!!

thanks for sharing the info and your jetting as well....

Is the VE of 106 correct? Just wondering awesome for NA.

How big did you guys go on the cam? You going to run dry or wet exhaust? Great numbers! Bet you are excited.

Perfect peak, then drops off.. beautiful ! Thats where a custom cam makes all the difference.
Wish I had some $$ left in the budget at the time of my engine fun for new cams from BOB but it was not to be.
Good luck with it!

All of the data is as accurate as it can be from the super flow. So yes peak ve is 106

It has wet exhaust, mixes just inside the transom.

How many hp is added by dynoing with the motor stripped down? As in no accessories and dyno headers vs. CMI or Stainless Marine exhaust. Awesome numbers for mild upgrades.

Less than 10 hp for accessories, dyno exhaust vs marine not sure. I'm welding a bung in the tails for my a/f meter today. May be able to get an idea from how far off the jetting is in the boat

We found from fully stripped with dyno headers to fully dressed pulling water thru seawater pump boat headers running boat cooling, wet exhast, flame arrester, alt, powerstering pump. It was just about 50 hp.

i think the wet exhaust vs dry is app 25 hp loss on a n/a engine.

You would be correct its not so much being wet as it is the up turn. Kills the flow of those nicely cnc ported heads!

Not sure of the number. ...but I am sure it won't be the same as the dyne (I'm also not going to reach 5900 RPM). All I care about is that it is #1: Reliable and #2: Relatively more power than their former life as HP500s.

More data (can't find the cam card!) attached.

[ATTACH=CONFIG]523207[/ATTACH]

You will be surprised, they seem to have a real good torque band and hold it nicely!

Nice number for a low compression 502. Those are the as cast heads with the CNC program run in the chamber only correct?

Totally depends on the motor build up.

Also camshaft vs exhaust sizing/wave tuning has a large effect.

I did a few million tests on a basic small cam low compression 502cid/540hp with wet marine / dry dyno headers/ undoing each belt accessory (including belt driven sea pump) one at a time / etc /etc / etc. 15hp max difference no matter what was done / added / or taken off.

The more actual overlap a cam has, in a NA motor, exhaust can be a big deal !

What size carb spacer? Material? Is it 4 hole or wide open?

Open, 1" wood. Consistently worth 10hp on the last 3 engines I've tried it on and all the ones the dyno operator has tried. 4 hole typically worth a couple more ft lbs, couple less hp

So 1 guy is saying 50hp and another guy is saying 15...? That's a bit of a difference. Just curious cause my 500efi dynoed at 522hp and 591ft/lbs of torque fully dressed with all accessories wet exhaust and pulling water through the sea pump. I guess I'm pretty darn happy with that.

Found the cam card. .645 lift 234 dur intake/ .640, 240 exhaust. 112 lobe seperation

Different motors. Different rpms, heads, cam, compression, etc,etc.

Read what I said about cam overlap vs exhaust.

Also, I've been a part of 100's of non marine engine dyno tests and I'll tell you accesory hp loss not only depends on what you are turning but how hard (rpm) you are turning them. It'd usually not as much hp loss though as magazine ads make it look like.

Anyway, so yeh....had a chance to run that 502 full wet....exactly how engine would go in boat. It was low compression (8.8:1) with mild cam and good heads. Ran 3 different intake manifolds and different spacers also.

Nothing really phased that engine. I think I could have pissed in the carb and it would have ran the same. LOL.

So I'm assuming the rotating assembly is stock 502 mag?

I look at CFM #'s a lot. Of course I do. Ooops, forgot I'm SB here. Normal name is CFM.

Anyway - anyone notice this Motor could have used more carb ? Also, it looks like the carb had difficulties keep a half way linear A/F ratio.

The A/F ratio on the sheet appears not be to a wideband, but thru the fuel meter vs Air meter. So , the ratio is not what was actually used by engine but you can look at it to see peaks and valleys. Seems to flutter. Could be the carb itself, but I see the same sort of trends on carb's that aren't sized the way the motor wants.

Seems to be some power left in the carb dept. Not just WOT.

Just letting out some thoughts from my own couch / armchair on the internet. LOL.

Those at not the babblings of a mad man.... Bob Madara told me I'd need more carb. He suggested 950-1000 CFM. They were new last summer, so I didn't want to spend more money on a new set.

I had brought my 1000 cfm pro systems carb but since we made the power we were looking for and even if it picked up 30 hp new carbs aren't in the budget, we left it as is. Those are calculated air fuel numbers from the air and fuel flow data.
Rotating assembly is hp500.

I would say you hit your goals perfectly..... Any more power might work against you if you are using a Bravo 1! Decent dock manners, 600HP/TQ, I would say this is pretty much the default 502 upgrade!

Yep. I'm happy with the results. I was hoping to keep it "Bravo 1 friendly"!!

Nice !

I by no means am an expert at reading dyno paperwork. But isn't the low (lean) 0.39-0.42 BSFC in the heart of the torque curve making anyone else a little nervous? Not an expert, but that is where I was told to be concerned.

I think alot of guys today are still going off the carb sizing thought process from 1985. The modern high performance marine engine is a far cry from a 400hp mercury 454 cyclone or a hopped up 330. We are now seeing N/A engines making 600, 700, 800hp. A 465hp HP500 ran just fine with a 800 holley. That's 465hp at 5200rpm. A far cry from 600hp at 6000rpm.

Or there are guys running N/A 540's hoping to make 700hp but want to keep a stock 800 holley on it. I think it goes back to the days when everyone threw a dominator on a 400hp engine and wondered why is was a turd.

did he say TURD,lol.

Was not insinuating this engine is undercarbed, just a statement regarding a trend I See on oso

I wonder if the the factory EFI from a '96 502 mag would support that HP?