A/f 540ci n/a
 

OK, so far I have 3.5 hours on new engines gotta look more at tuning, so far my A/F has been around 13:1 at idle, and nboth engines run hight 11's to low 12's across the board.... cruising at 4000 it is pretty solid at 12.2:1.... so far at 5300 was most I pushed it was at 11.8:1 and a tad richer, I do know I need to add vents to hatch as I KNOW it is looking for more air, that's is tomorrows project... just to be sure I have enough....I think as rpm increases its gonna go more rich due to airflow, I would rather rich then lean LOL

what is a good target for N/A engines? no dyno..... on water under loads....

to me the low 12's are real good and safe.... whats the input?

Tim, I think you are going to find lots of opinions on this topic.

Textbook says, gasoline engines make maximum power at a 12.5:1 air fuel ratio. Thats assuming non ethanol gasoline. Throw some ethanol in the mix, and now you have to go richer to make maximum power.

I put a wideband on my GM big block gas dually before. The setup from GM was to pretty much be at 14.7, until you get over 80% throttle if I recall, then goes to 12.6 ish. 14.7 was best for emissions, and gave good economy, but not the best power, nor safe.

I think the word "cruise" is often thought of in the marine world, as "cruise" like in a car/truck. But, imo, it isnt the same. Take my gas dually for example. "cruising" down the freeway at 55mph, I might be at 10% throttle opening, and requiring maybe 60HP to maintain that speed (just a guess). Now, look at your engine, "cruising" across the lake at 55mph. You might be at 50% throttle opening. It may require 375HP to "cruise" at 55mph.

More load, more throttle input = more heat produced.

Back to your setup, I would like to see around 12.7ish at cruise, and around 12.0-12.2 at wot if you run E10 gasoline. I would look for those numbers on a cool day. Hot days it will richen up a bit. But you dont wanna melt stuff on that cool fall night coming back from the island.

Theres more to this tuning thing, as timing advance can play a role, fuel distribution, etc. More timing advance may work better with a richer fuel mixture, less timing advance may work better with a leaner fuel mixture, and so on. A 454 making 650HP, may not need the same settings as a 540 making 650HP. Larger bores may want more timing advance, than a smaller bore, and so on. Piston design, chamber design, quench, all play a part. This is where dyno tuning an engine is worth its weight in gold. The dyno should not be looked at as a tool to tell you how much power your engine makes, but a tool to let you know what the engine likes, or doesnt like.

Cool so I would think I'm close so far, timing is locked at 32, for now anyway... We discussed that and over winter that may change as I can't do anymore changes now just wanna enjoy it...

I was just thinking of getting it safe for the summer, maybe you need a trip up here next weekend lol

A good example of basic dyno tuning, and the results, are what Mike Tkach and I recently witnessed on the dyno. A friend has some blown 522ci engines that Mike built for him. I designed a custom timing map for it, with the daytona ignition box. For years, we ran locked timing on our blower stuff. The idea of going with these boxes that would allow custom timing map, really opened up a tuning window for us. Playing on the dyno with it, proved its value.

We set the engine up and did some preliminary pulls, the old fashioned way. Timing was locked at 34*, and away we went. We had our air fuel ratio where we wanted it, and had our results from that setup. We then installed my custom timing map to the ignition. Traditional thinking, told us we would lose power in the midrange, by backing the timing down. The main goal of this custom map, was for safety, but my research told me, we just may see no loss, or even an increase in midrange power, from the fact the spark timing was simply too far advanced with locked timing.

SO, we upload the map and do a pull. We were shocked. The engine lost NOTHING in torque. It actually gained a small amount of torque, and the EGT temps in the midrange, cooled down a bit. My map, had 25-26 degrees of advance in the peak torque area. What did this tell me? Well, that if I removed 8-9 degrees of spark advance there, and the engine didnt lose anything, is that we were simply firing the plug waaaay to early at that point in the RPM band. We all know what happens with too much spark timing. So, IMO, this ignition box and map, has opened up the safety margin of this engine, by a huge amount.

Now, I took it one step further. At 34* locked, at 6500RPM, the engine made 1018HP. My map, gave the engine 1 more degree at 6500RPM, bringing the timing to 35. The engine responded with 1036HP. An 18hp gain from 1 degree of timing. It liked that extra degree, but only at 6500RPM.

My thoughts are, this custom program feature, not only added a safety margin, but also netted a engine that will simply be more efficient with a 3d map, and is making more power, from 3500-6500RPM, and idle/start better, with some great features like idle stabilization, and start retard.

What I've learned about locked timing, which is what I believe you run Tim, is that it sucks. There is no way around the fact, that with locked timing, there is some point in the engines powerband, where you either have too much, or not enough timing. As charge density increases, the need for advance decreases. As rpm increases, the need for advance increases. At 3000RPM cruise, your engine may want 36* of timing. AT 3000RPM wot acceleration, it may want 22 degrees of timing.

This is not new info to the pro's, but to a do it yourself guy like me, this data is priceless.

Nice to hear your back on the water. Glad to see your project is all coming together! Good luck and enjoy.

Joe if that kind of gains can be had on a N/A engine inwould probably look into that system over winter possibly, I would love to see that dynoed on a setup like mine, hoping indont have to have engines out to do it though as I wanna not pull for a few years lol

I have the bungs to add EGT and plan to over winter I can't do anymore right now I am tapped out big time!!

Full Force
Your idle could be cleaned up more , you and I have very similar engines. Low 12 across the board is very good and extremely safe. I run 14-14.5 at idle runs clean and crisp. Mine is also fuel injected. What power did end up making?

12.2 at wot for your application would be golden.

Don't know power and honestly I don't even care lol I just want it to run every weekend..

Yes I know idle is rich I just last night found out was the starboard o2 wasn't working so before I kept swapping sides now I can monitor both engines this weekend coming...last weekend was not a timing weekend it was for getting some time on the engines now it's time to make sure they live...

He'll never be able to shift without stalling, at a air fuel ratio of 14.5 on a carb'ed engine. EFI, different ball game.

I figure 13-13.5:1 is good idle with car to go after no?

Idle AFR all depends on what makes it idle best and not load up.

It also greatly effects the transition into your primary metering, and the primary metering itself a tad.

Single plane intakes, big cams, tunnel rams, superchargers, exhaust system, etc,etc can all vary what it wants.
These are not your stock cam heated dual plane intake set-ups.

As I quote all the time, Darrin Morgan says "Your engine is telling you what it wants. Are you listening ?"

Try to go leaner than where you are now, and see how it shifts for you. Every engine is different. A mild cammed stocker might idle all day at leaner afr's. I'd shoot for the leanest idle you can get, without stalling when shifting around the dock, or sneezing trying to get on plane. The number there, is gonna be what its gonna be.

what carbs ? you may be able to change idle air bleeds or idle feed restrictions(if changeable) and lean it down and see what it likes, but I think mid 13's may be to lean

Cool that's kinda what I was gonna work on this weekend...

1050 quickfuels

and very safe,,no need for the lean is mean thinking w/ a boat.your still gonna get 1gpm at wot.:)

exactly,strap it to a dock,put a vacuum gauge on it w/ o2 sensors and have it it till it shifts nice.

Locked timing is great for a lawn mower, for everything else it blows goats.

Playing with boosted 4 cylinder applications where you are pulling 500-750WHP out of 2.0 liters of displacement timing becomes VERY important. So 32 degrees of timing may work great for peak torque at, say, 4500RPM's, but as RPM picks up, piston speed increases but the speed of the flame in the combustion chamber stays relatively constant. Therefore to get the most efficient and powerful combustion starting the combustion activity earlier by advancing timing will improve power. My timing maps usually work out to be something similar to an inverse of the torque curve of the engine. By monitoring knock sensor activity as well as AFR I know what works well and what doesn't, as well as monitoring trap speed. My next theory is just a theory, and I don't know it to be true, but I believe by reducing your EGT with proper timing you are reducing exhaust valve temperature, valve spring temperature, and the end result is reduced oil temperature. There really is no downside here.

As far as distributors locked I just run what has worked for years, of course there are more ways especially these days... I am gonna have a divorce if I do t stop wrenchin and use the boat, I can change all that over winter....

All my buddy's have locked timing we been doing it forever, for now that's what I gotta do at least for a bit I can't wrench daily all my other things in life been on hold.... Gotta focus

She'll probably kick you to the curb anyway. LOL.

Oh I know your tapped this season Tim, I wasn't saying rush right out and change your ignition, my point is that when you can do it the results are impressive and well worth the investment.

Movie for sure something I will look into over the winter I would like to look at the system Joe was talking about

the quickfuels are very adjustable, you can go .004-6 smaller on idle feed restrictions, or a couple larger on the idle air bleeds and see how it does..just went thru this on my blow thru

Most likely haha

HaHaHa - I know exactly what you mean! Things have been getting hot in the kitchen for me as well. ;)

I agree with ya :D

http://33outlaw.zenfolio.com/img/s5/...57349102-3.jpg


http://33outlaw.zenfolio.com/img/s7/...32343279-3.jpg



Wanted to experiment with a 3D timing map and EGTS this summer.

Like the Kevlar and spring oilers. EGT and timing you will need more than one in the same header tube to see if you need more or less,

just remember EGT's can be misleading...nothing compaired to 02's

Hopefully they no longer get wet with new exhaust.

http://33outlaw.zenfolio.com/img/s8/...69127011-3.jpg

Apache , figured taking the reading from just one might be useless but figured its better info than nothing, I will take it with a grain of salt.

Yes egt plays a huge role not bad to monitor I plan to add later when I make more $$

Those came out sweet!!! Maybe I can have your guy dip my manifolds this winter?

You ended up using the tails? Cool, spent some coin getting those polished, glad you could use them.

So why would you lock the timing? This is new to me so I truly don't understand the benefits of it, if any. It seems like total advance is what you're looking for and the curve to retard it at idle was to protect the motor/help idle, to be simple about it.

Takes out the crap idling when you have a distributor that gets hung up, its not a must but it's easier to not have the issues, I never had issue having it locked out

Do u run the start/retard timing boxes? Mine are locked at 34 and pull 20deg out for starting.

No boxes I never had issues starting them

I guess in my case I never messed with what works

really cleans up the idle with more aggresive cams and carbs, allows lower idle speed and your drive will love you long time for it....

looks nice...is that the water dump across from 02 ? if so 02's not going to last long..

Still jacketed there