As my 385 build progresses slowly but surely, I think it's time that I start looking toward the tuning portion of the build.

I'll be running the ARAP .bin, code $6E MAF on the '165 ecm. I have Craig Moates' tuning equipment, as well as an ALDL cable for datalogging. I tuned my 305 TPI last year, so I'm not walking into this blind.

However, there are a few things I'm iffy on. First off, any suggestions for a break-in tune? For the half hour cam break-in period, I would prefer my new motor not be a lean, mean, knocking machine. What about timing and fuel? Am I better off to start up the car to find timing and AFRs, then turn it off and burn a new chip to complete the break-in? Or should I just get it to fire, and run it for the full half hour without fully setting the timing. I can change AFRs while the car is running via adjustable fuel pressure regulator too.

Next, what about a knock sensor/esc? I had asked this question previously, but details in the build have changed since then, and things were cloudy then anyway. It's known that there are different knock sensors, one for the 305, and one for the 350. However, I'm running a 385, 4.040 in. bore, 3.75 in. stroke. Does that change the working of the knock sensor, being different dimensions? Which knock sensor should I use? Now the second half of that, the esc. I'm not familiar enough with the workings of knock sensors/esc, so bear with me. The 385 is a flat-tappet cam. Any difference in the sound picked up by the knock sensor between roller and flat-tappet? I would imagine the esc's are different too. I could go with an 85 flat-tappet 350 knock sensor/esc combination, but how does that work with a newer (165) ecm? Is an older esc compatible with a newer ecm?

Finally, the cam is a 110 LSA. I've heard of the tuning woes people have had with that tight of an LSA with MAF. Rumor is, it's a challenge, but not impossible. Suggestions, hitns, tips, or tricks on this? This isn't a daily driver, mainly a track car, but it is street driven. I don't need (or want) a perfect smooth idle, but I do need (and want) it to run. Preferably without stalling when I drop it into gear lol.

Thanks, happy tuning!

 

Bump for ya. I know someone has been in this situation before.

One thing though Id like to add. Dont just start up the car and think you need to tune it before you break in that cam. That first few minuets is the most important time in its life. I cant say what you need to do specifically for the tune before hand, exspecialy since you've changed the whole engine system but just look arround and hopefully someone will chime in with a starter bin for you.

https://www.thirdgen.org/forums/tbi/...-350-swap.html

From what I always was told. A knock sensor is dialed into the bore of the engine along with other properties. My thoughts would be that you would need a 350 knock sensor at the very least.... even one off a flat topped 350 it at all possible. Some one has had to of run into this situation before.

I will say though, andrew, do not ever attempt to go floor that car until you get the knock sensor stuff down pat. Dont go blow that engine up. Running as much compression as you are, will really hurt a engine as much as if I just blindly floored my car with incorrect KR command and feedback. You might not have boost or n20, but you've got alot of compression.

 

Try arap as is but with few basic changes. Change the timing table to something less agressive. Arap sees 40-45 deg at cruise. Id change to 35-37 or so in the 2000-2800 rpm range. Idle timing around 26-28 deg total.

Set idle rpm to 900 for now or so. Cam should idle lower once tuned. 110 lsa wont be an issue.

Everything fueling wise i'd leave stock for now. Arap should be close on idle and part throttle. Once you start motor i'd let it run full break in. Just have a big electric fan running to keep airflow up so it doesnt over heat. Need to work the coolant bubbles out at the same time.

This is why i like hyd rollers!

Arap ran my buds heads cam 360" motor with mainly stock maf tables and just adjusted for commanded idle speed. I also used a mild modded AUJL for my big cam 383 for initial start and it worked good enough. Air fuel was close, it idled but abit rough, but not bad for stock tune

 

Thanks Orr! I was hoping you would chime in, I know you really know your MAF stuff. 40-45 degrees in ARAP? Wow, that's crazy aggressive lol. How do you feel about the timing between iron and aluminum heads? Calculations show about 11:1 static compression, but I'll know for sure once the heads are milled for cleanup. Thoughts on what octane fuel? Thanks a bunch!

 

Are you still going 93 or going to mix the gas with some VP100 or ld110? If your staying 93 you better prove that the knock sensor will work correctly. Any such luck on figuring that area out??

 

Thats an issue. Iron generally requires less static compression to run on pump gas. 11 to 1 with right camshaft is generally ok with aluminum. Iron usually needs a point less, but can depend.
I'd be alittle concerned with irons with that cam but could try. I would cut back on timing for sure. Run a cold spark plug, maybe even 1 colder than what you would run with aluminums. Aluminums i try 2 steps colder than stock. Using NGK's thats a 6 heat range. Boost or spray i run 7-8's. With high compression, 7 may work with irons. Run a tad richer. Trying to keep chamber temps low to fight detonation and preignition

Timing for aluminum or iron i dont think requires anything different. It depends on the chamber combustion characteristics and compression. Like afr heads like lower timing compared to rhs aluminums, for similar applications. Just the way the heads work. I usually find the limit by relying on the knock sensor and work back from there to find sweet spot

 

Andrew your so close to places that sell unleaded and leaded race gas that it wouldnt hurt to just mix your fuel for piece of mind while your tuning and dialing in the car. Some 50/50 mix with unleaded vp100 for 6.00 a gal and 93 for...well say 4 bucks a gal will get you in the middle roughly. I would think that you should be ok with high 90's octane levels.

Nate ran 10.5:1 with those iron heads and mixed 110 leaded with 87. He never had a issue with KR or at least bad plugs. When he tore the engine apart the bearings where in good shape along with everything else but bad scaring on the thrust side of the pistons(150K mile racing engine..lol). So I feel that if you have 11:1 compession that you will really need to cut back on the timing, get your colder plugs like Orr said and even run a air intake track to gather the outside air so that you can run close to ambient air intake temps as possible.

I remember last year you were seeing like 30-40 degrees higher temps for the IAT compared to ambient. Were you going to fab up something to help that temp number??

 

With no load on the engine during cam break-in detonation shouldn't be a huge concern as long as the timing isn't crazy or the fueling isn't so lean that you're going to overheat it... That said - I'd do what Orr89RocZ said - reduce the timing in the tables (or just pull the timing out all around via setting the distributor retarded) and add a little fuel to it around the range you're going to run it for cam break-in (1800-2200 usually)

Once it's broke in then you can get back to the job of burning a good tune to it.

 

Yeah Mark, I'm thinking I'm going to have to mix it. Or maybe just run straight 100. As for the IAT temps, I'm going to fight that a few different ways (a few are just in theory). First off, I'll be running an electric water pump, which will help cool off the car between rounds tremendously. Second, I'm cleaning up almost everything around the intake. This should allow more airflow around it, hopefully cooling it off better. Third, considering running a 160 thermostat. Fourth (this is a real longshot), porting of the runners and base make for less material there, thus being less dense, and should not be quite as heatsoaked. Again, longshot lol.

As far as the break-in, I think I've got a pretty good idea what I'm going to run for the tune. As long as it's not lean, I think I'll be alright. As said, once the break-in is out of the way, I can tune it much better.

 

What do those chambers of the heads look like? Are they cast heads? You could always polish them really quick. Mine look sorta like mirrors to help prevent detination a tad.

I deshrouded mine too but heres a shot of when I was in the middle of working on them working on them. It probly took 8 hours to do both heads. If you just polish them your really not taking much meterial out, your just smoothing the casting to get rid of the hot spots as much as you can.




The thermostat should help and so does the water pump. But if you can run some piping out of the engne bay to collect the air that should dramatically lower the intake air. Ambient air is always going to be a ton cooler then whats under that hood.

 

That flat-tappet block is scary. I would only run one if it were free, as you will gain more with the roller block. Not sure if you have this block and it is machined already, but I would try and trade it for a roller block. Not trying to jinx you or anything. I went through many cams in the early 90's when they switched the oil formulations to less and less zinc. I wiped many lobes, from comp to crane cams. I would run a bottle of STP oil treatment or GM engine oil supplement (and I think comp sells one also with zinc) in with every oil change. Get a case now.

The 110 lsa cam won't be an issue.

You will need the 350 knock sensor. Install it with teflon tape and do not crank down on it, only install it to book specs. I suffered false knock when over-tightening mine.

 

I wouldn't toss the block and cam if that's what you've got to work with - I've broken in a LOT of flat tappet engines and have never lost a lobe in one yet. Just research your oil and get one that's got plenty of ZDDP for break-in and break it in right and you'll be fine. I used to use the Castrol HD30 until a couple of years ago when they reduced the level of zinc (it's still great for daily use - just not enough for break-in IMHO), then I ran the Castrol with a bottle of the Comp Cams break-in lube additive, and now I run straight Valvoline racing oil now for break-in. I've also had a friend I built an engine for and he tried the Comp Cams oil and hasn't wiped a lobe yet either.

However that said - if I were starting with nothing I would absolutely look for a late model roller engine and run it over an older block for the simple reason that you can reduce a little bit of friction and gain the ability to run a much more aggressive lobe profile with a roller tappet.

 

I will agree with the above but hes got what hes got and im sure as long as he breaks it in well and uses the break in additive i told him about many months ago, chooses his oil wisely, he will be ok. Im not sure why andrews really not responding to this thread, but as a friend I know that he was just trying to get some details on the tuning aspect more then anything. Hes got another page for the mechanical areas of the build.

 

I think I've got a pretty good idea of what I'm going to run, for the breakin at least. TPI-FORMULA350 was very kind to send me his .bin, for his 11:1 aluminum headed 385 Superram. Very similar specs on our builds. Also huge thanks to RBob for setting me on the right path for the knock sensor.

As far as the motor itself, the machine work is already done on it. It was free, so I used what I had. In the future I may just retrofit a roller cam into it, but not this year. Should have the motor back this week actually. Any other tips you guys have would be much appreciated. One thing I'm looking at is that PE mode doesn't activate until a certain RPM, around 3000 if I remember correctly. Should I lower the enable in that parameter to say 2000, for when I'm on the converter as the tree is coming down, to bring in the spark and fuel before I break the beams? Just a thought.

 

I would only mess with PE if you notice its overly lean or rich under your 0-xx% tps pulls.

Try to tune that PE so that it doesnt flood out the car when going into 100% TPS. I say 100tps because I know you mainly going for 0-100% tps pulls since shes a drag car now. Look for a smooth transition, so much so that you cant see the difference when PE is activated via afr's.

Did you get your modded xdf and adx for the wideband??

Just remember only change one thing at a time. Never change spark and fueling on one chip burning session.

 

Pe mode is lv8 based and tps based i believe. I have to look back at the maf stuff but i do recall lv8 being a parameter.

 

Auto Zone carries the Lucas zinc oil additive. I use it in my car(flat tappet). about $16 a bottle.

 

Napa has the also. Just ask for a break in additive by lucas oil and theyll get it for ya. 15 bucks sounds about right.