Anyone converted one of these to a carb and distributor? Got a dart intake and looking for the rest of the parts. Ignition, cooling and such. Any advice appreciated!
Here we go again. I dont think hes wanting to put the 496 in the wifes SUV.You're actually wanting to go BACKWARDS? Are you also going to take the EFI off of the PU, SUV, or sedan you drive daily?
Yet as great as you think efi is, they still give fits that even some of the guru's cant figure out. On my 502 MPI for instance. If you rev it up in neutral it will stay @ 1100 rpms and if you kill it and refire it idles back down just fine. Have put a new IAC or what ever you call the pos and checked everything they PROS could come up with but still does it.496mag/HO Pros vs. Cons of converting backward from EFI to carb.
1. "Anyone" can wrench on a carb.
1. No more ECM to tell what sensor has gone bad. No sensors to go bad
2. No more ECM to save the motor if there is low oil, low oil pressure, low fuel pressure, high water temp, low water pressure. Never had any of those problems
3. No more knock sensor to keep the motor from detonation. Never had my stuff that far out of tune, guess i must be good , huh?
4. Now have to pump throttle for cold starts.Lazy
5. Now have rich warm starts. Not with the C&S
6. No more compensation for altitude / density altitude. I dont fly my boat that high
7. Lack of precise fuel distribution. Wrong
8. Possibility of fuel puddling in the intake. Never had a problem with that, must be lucky.
9. Have to run the blower EVERY time you start. should be doing that anyway
10. Lack of RPM compensation when in-gear / out-of-gear.
11. Power valve(s) to blow out / leak. No worse than all the sensor to go bad
12. Possibility of vapor-lock. That can happen with some efi systems too
13. Fuel available when key is off (run-on / dieseling / hydro-lock) Must just be me but you seem to have alot of trouble with something so simple.
I'm sure I left some out.
Beer I'm also aware that you are an intelligent fellow , so dont tell me that you believe that your friend with the 600" deal has to live with those problems he's experiencing. You know just as well as I do that with a tiny bit of tinkering that those problems would be gone forever. If you just buy a stock carb, pull it from the box, plop it on there and expect it to operate perfectly in every way, then yes, you will be disappointed.OK, so the original poster now says he only has a long-block. While carb STILL is going backwards, at least he is not contemplating pulling off a MPFI intake and all of it's efficient hardware. He just looking to COMPLETE a motor. And in that respect, I would suggest you just look at a complete Gen IV, V, or VI motor instead of mess with a Gen VII. Not being familiar with it, you will be hunting for the pieces and parts to make it what you want - and that won't be easy.
Hass, you are going to the wrong people on that hanging-at-1100-deal. If you had a laptop connected, you could watch either the TPS being hung-up just long enough for you to shut it off, or you would be able to see the marker hanging around either a map reading or IAC follower reading that it shouldn't. Someone is missing something, and it's not THAT hard. I tune EFIs all the time and you can watch ANYTHING YOU WANT - you just have to know which screen to watch. Rinda makes laptop software to view all of the tables. There are others too that make software to adjust and follow the MEFI ECMs. Cool, so now all I need is a new laptop, software, cables and some geek on the phone to tell me how to use it.
The 140-degree thing is probably as simple as MOVING the CTS to somewhere more stable? REAR water runner of the intake where flow is not as prominent AND cold water is not present? That being said - a carb is blind to temp and CAN'T ADJUST for cold/hot motor/water temps. So, you WILL have an un-correctable in-efficiency at some point in the temp spectrum. Be it rough cold-start or rich hot starts/idling. Jetting is FIXED on carbs, whereas it's constantly variable on EFI. Yes, the motor will PULL what it wants throught the venturies, but what's on the other side is STILL LIMITED and fixed. The EFI will adjust for altitude, heat, loaded boat / empty boat. EFI adjusts HUNDREDS of times per minute / if not per SECOND (some systems), a carb just sits there with a dunce cap on.
I thought about moving the CTS but was told that Merc has an untold amount of $$ in designing this sytem that I'm getting ready to modify. And to leave it factory. Moving that CTS 6" from the path of the incoming water coming from the seawater pump that is heading directly to the thermostat outlet and putting it in the intake, under the thermostat would stop the cold problem but might go the other way and make it read to hot at times and set off the buzzer. What BS. Love my carbs.I rode on a friend's Magic deck a month ago. 604" BBC, carbureted. It runs nice. Calm cam, 750hp, nothing outrageous. But without a choke, he fires it cold and it idles at about 500, just chugging. Not smooth at all. HAS to let it warm up a bit before going for fwd/rev on the outdrive. THEN, even when warmed up, that 30" prop drops it 300-400 rpm. So it dips and then recovers - with a bit of a brown "puff" from the tips. A bitchen carb just can't do the multitude of adjustments necessary to make in/out of gear transitions NEAR as smooth as even a HALF-ASS EFI tune can. Plus, he complains of a bit of fuel puddling on real cold mornings - where MPFI has the fuel being shot right at the intake valve. DO THAT with a carb.
What SUPER car or SUPER boat COMES WITH A CARB THESE DAYS??? You can't tell me Alexi is really worried about EMISSIONS on his 800ci, 2000hp super motor! I don't see any carbs NEAR that thing. If carbs were ALL THAT, they would have a place there as well.
You couldnt get it past Big Brother. That 800" deal is a beatiful engine and powerful, but many are making that much power with half the CID today with turbos.
You're a smart guy, Hass. You can't tell me otherwise. So, I know YOU know that all of the drivability and efficiency you get in your daily driver is JUST AS GOOD for a boat. Do we still play RECORDS and TAPES? Still ride on BIAS tires?? Do we not POWDER COAT more stuff than paint?? I have every bit of belief that you have your blow-through dialed in just as you want it. To be perfectly honest, you probably COULDN'T improve on your particular setup with EFI - aside from a few touches to under-the-curve (cold / high altitude) areas of the fuel curve. BUT, we're not talking specifically about blow-through turbo setups here. We're talking modest HP, ANYONE behind the wheel, turn-key drivability.
So, touching on emissions - we all know that is why all mfgs have gone to EFI for their package engines. So that poises the question to you - - why CAN'T they make just as much HP/TQ and maintain their emissions with carbs??? If carbs are the end-all-be-all of fuel-mixers.......why are they so obsolete in the air - on land - and sea???
Again on the CTS issue - I wholeheartedly believe ALL boats should have closed-cooling! Heat-exchangers are so prominent now, I don't see why someone would want to run WITHOUT one. Mine sits at 150-160 (160 therm) no matter what. WOT, idling, cruise. So, the motor doesn't get shocked with cold water. Every time you fire your 502 up, it gets a shot of cold water through it from the lake. No bueno.
I can see where you would desire this , since you love efi. I personally dont have any problems with the lake cooling, been using it for yrs on many many boats without issues(except the efi BS)
How much experience do you have with this engine? How much experience do you have with the Raylar cylinder heads for this engine? Just curious.I imagine you got a SMOK'N deal on this thing because anything the marine sealer got over scrap was a blessing.
to my knowledge, you can use a stock standard deck dizzy with the Dart manifold.
As much of a loser this motor is, the single best thing that you could do to the long block you have is drop a carb on it. If cammed correctly, it has the potential to bury a Merc 496 HO without mercy.
It will, and never can be what a MKIV thru Gen 6 is. But your on the right track to making it better than you could ever hope for with the stock Merc/GM EFI without breaking the bank.
I have to laugh at the guys that buy into Raylar's BS, and dump tons of cash into these things when Dart has now come to their rescue for a lot le$$ and alot more potential.
Some good qualified head work and the right camshaft, thing can crush a Merc/GM EFI 8.1 and for alot less ca$h.
Enough to know the engine is a dead end performance wise, or ther block and heads would highly sought after pieces. Performance guys aren't morons. If there was ANYTHING desirable there, they would be getting snatched up right and left. They are infact being ignored. TOTALLY.How much experience do you have with this engine? How much experience do you have with the Raylar cylinder heads for this engine? Just curious.
I agree - a 496 with a carb should totally be obsolete and not used at all. Same for a 500 inch carb'd Caddy. I have a restored 75 ElDorado with the 500 in it. Planning on TBI for it to get rid of the obsolete carb. So, I agree that the carbureted motors should be obsolete.Enough to know the engine is a dead end performance wise, or ther block and heads would highly sought after pieces. Performance guys aren't morons. If there was ANYTHING desirable there, they would be getting snatched up right and left. They are infact being ignored. TOTALLY.
As for the Raylar stuff, again, a huge seller in the performance worldsphss Gigantic HP gains for the cash outlaysphss You take your Raylar equiped 496, and I will spend the same cash on a MKIV stroker 496 and we'll meet up and you show me what you got. Bring lots of cash!!!!!!!!
I don't have need to have ANY experience with a 500 inch Caddy to know they are next to worthless. I don't need to eat a shit sandwich to know I don't want one.