raeburn

I know there are previous posts on this, but I just wanted to clarify before making changes to my motor. I have a 2002 496HO with Raylar's 103kit and Whipple's Stage 2 PCM Calibrations. Engine runs strong, but has serious transom soot, black oil, and strong fuel odor from exhaust. I run a low temp thermostat (runs 140-150 on guage) and use 91/92 octane. I heard to use 89 or less, tried that didn't help. I'm going to put the stock themostat back in this weekend to see if that helps. Is there any type of re-flash that can be done to the PCM that might also help? I know some degree of soot is common with 496's, but mine is terrible!
Ray, Dustin - help please!!

Canada Jeff

A "re-flash" for the computer is the only way you can help it. You can send the computer back to Whipple and tell them the syntoms so they can make a change in the fuel calibration.

Once you have Whipple calibrate your computer they put a password in it so only they can axcess it to change it. So you have to deal with Whipple now. Not a bad thing, just telling you. It may take a few tries but you need to do it!

Wild Card 09

That sounds like a cool motor (particularly for a 25OL). How many hours do you have so far?
What drive and prop are you running?

Take it easy until you get the PCM right. Unburnt fuel in the exhaust means you are taking the lube off the exhaust valves, and that isnīt good for them and is a sure sign that the settup isnīt right yet. Whipple will get that sorted, Iīm sure, but talk to Ray about it, too!

Whipple Charged

Our stage cal is for stock motors. Raylar tested these cals with his packages and confirmed they do in fact work together. You might want to contact Ray because he has more data with the computers and his engines. For a custom tune, we'll need air fuel, rpm and manifold pressure data, no other way to do it. Our stage program already runs 14:1 at part throttle and 12.5:1 @ WOT on stock engines, not to mention a ton more timing everywhere, so not much can be done on stock engines, but with your engine, it might be possible to tweak.

raeburn

Thanks for the reply, Dustin. I don't have the set-up to measure A/F ratios (wish I did). I read on another post that "Hot 4 Teacher" was having the same issues with an identical set-up (496, Raylar103, and whipple stage 2). He has all the gear to read his Air/Fuel, pressures etc and relayed the #'s back to you. He said it took a couple tries, but his engine is now running great and soot free. I guess every engine is different, so what works on one may not work on another? Do you think the CMI Sport Tubes I'm running could have any affect?.
I heard Raylar recommends keeping the stock thermstat when using his aluminum heads with the Stage 2 calibrations, I thought I would give that a try this weekend and see if it makes a difference. I pulled a few spark plugs and they looked good, not loaded up at all.
Any input is greatly appreciated.
Thanks,
Bruce

raeburn

Thanks, Wild Card. I have 134 hours on the motor (about 80 hours since the Raylar kit was put on). It also has CMI Sport Tube headers - looks and sounds awesome. The previous owner had the modifications done over the last couple seasons (I bought the boat in March). He was very meticulous and took amazing care of it - it looks like brand new inside and out!
Right now I'm running a labbed 28p Bravo on a Bravo X leg. Best speed so far is 74.4 on GPS at 5100 rpm. I think there's a little more there - need to get this fuel/soot issue figured out first (don't want to hurt a good motor!)
Your 25OL is something else - how's the 600 treating you? Looks awesome in the bilge (seen pic's of it on other posts). My brother-in law has a 25OL with a blown 540. He's been hitting 88 with a Sportmaster and Stock 28p Bravo. I think he picked up a labbed 30p to try - tons of fun!!

Hot 4 Teacher

Bruce, the only way you can get a custom tune is to provide the #'s Dustin mentioned. IMO, it's a good idea to monitor the A/F in an aftermarket motor and FASS makes it really simple. Your CMI's have O2 bungs, right? I wouldn't run 91, nor would I run 87...89 is where you need to be with a stock stat. I guess it matters how aggravating your soot problem really is. Mine was bad enough to get the right #'s and send it to Dustin a few times.

Good luck!!

raeburn

Hi Hot 4 Teacher, I didn't notice any bungs on the headers - I'll check again. What rpm's did your motor produce the most soot at? It seems like mine is worst at idle and low rpm (under 3000), but maybe it just sticks to the transom easier at lower speeds. I ran a tank of 89 from Chevron (no Sunoco up here), on the long weekend but it didn't seem to help compared to Shell's 91. Hey, were you also seeing your oil turn black after only a few hours?
Your Crownline must haul a$$ with the Raylar 496 in it! I met a guy last summer that had a stock 496HO in a 22 foot Regal with the Fastrac hull - he was hitting 70+ no problem! Took a lot of bigger boats by surprise!
Bruce.

raeburn

Just checked the headers and there are bungs on them (in the collector part of the headers - before where the water enters the exhaust) They already have something connected to them - Mercury's Smartcraft doesn't use O2 senors do they? There are two wires coming from them, looks like a pinkish beige wire and and dark brownish wire with a light stripe. They go up over the valve covers into a wire connector and then kind of disappear under the manifold cover.
Anyone have any ideas?
Thanks,
Bruce,

Hot 4 Teacher

Sounds like you're already measuring A/F somewhere and I'm not familiar with smartcraft.

I produced the most soot @ idle & cruise speeds. (750 - 3,000rpm) I haven't really notice the oil turning dark either, I'd say the two problems are directly related though. I run Amsoil 20/50 racing oil, if it matters.

Believe it or not, my boat is a 550hp turd. I don't have dyno #'s, but it's been bored 30 over with all forged goodies too. The best I've seen is 68 mph with a light load. However, I've beaten a few "70+" boats with it. I keep it only because of all the room it has. I had 4 adults and 6 kids in it last weekend and it's still small enough to yank a skiier out of the water and plane @ less than 20mph for the youngin's watersports.