New 345 SV engine data

Craig

Active member
Ok after what seems like an eternity I got the rebuilt 345 engine fired up.. 30 over pistons and stock cam, light porting on the heads(air injection hump removed) 2 barrel manifold. 2 1/4" exhaust going back to a y pipe with a 3" dynomax muffler.
This is both a fuel and timing controlled system.

I followed the setup procedures. Turned the key on and set the tps to .57 volts, followed by setting the iac, and setting the timing to 0. Fuel pressure 13 psi. I log data the whole time the engine was running, but once I got all the setup stuff done, I log some data for a couple minutes. The engine is brand new and tight, so I am only running it a few minutes at a time. Letting it cool down a bit. I used an ir gun to check temp and everything is looking good so far.

Here is the data after doing bills initial setup procedures.

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Data looks pretty good.
The tps is still high at 2.6%.
You also have a tps and an est error.
Recommend you clear the faults before the next log run. Also uncheck the raw box.

Then when done save the blm table too.

Install looks good.
Looks alot like mine but with a pretty alum intake.
What chip are you running?
 

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Thats is Jeff's red paint job on the engine, the flash makes it look a lot like yours.:icon_eh: its killing Jeff that I had him install a faux aluminum intake. ( just painted with silver hammerite) but I like the 2 barrel design for adding a TBI unit.
Using a stock TBI off a 92 caprice, and the ECM from a truck with the stock chip.

What should the tps be at? (edit.. 0 ) I also noticed that at wot (engine off) the voltage was 2.5v vs 4.5-5 v I have about 5 tps sensors ( new style) that I have collected and they all read about the same. (edit.. will double check to make sure TBI is opening up all the way doh, as I was in the cab using the pedal)

will save the blm table tonight. Current display setting is latest narrow. And I uncheck the raw data.

802d1191428462-Scout-II-build-up-saga-Scout-motor-Jeff.jpg
 
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A faux finish on an intake......that's just wrong. Stay off the diy network while working on the Scout.

The blm table saves all of them. I normally view the wide avg when logging.

Looks like you answered most of the others.
Make sure the throttle is going full open and full closed.

For the ECM to set the idle mode it looks for the tps to be below 1.2%.
The iac numbers didn't look bad so it should be more of a tps adjustment then the min idle screw.
 
a faux finish on an intake......that's just wrong. Stay off the diy network while working on the Scout.

No not a faux finish, just a "fake" aluminun manifold (painted silver ) I just tossed in the french word for fake/faux lol

does it make any difference what size the holes are in the manifold? Meaning there are spread bores, vs 2 barrel, vs bored out to 2" two barrel manifolds?
 
Ok I warmed up the motor for a couple minutes and here is the log file after warming up the motor.
 
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To be efficient the holes should blend in.
I ran my first one just bolted on to the stock 2 barrel.
I now run the 2 barrel with the holes bored to match the adapter.
I did it when the manifold was off duri ng the rebuild.

Data looks fine.
I need to look up the code to check idle speed. Seems a little high.
 
Forgot to list my injectors, it's what came with the TBI unit when I pulled it. GM part # 17084327 for the 5.7l cop car flow lbs/hr @ 13psi 65

I have a second TBI as a spare (untested at this point)and it has GM part # 5235279 for the 5.0l flow lbs/hr @ 13psi 40

so next step is a test drive if the data looks good.:winky:
when the iac was disconnected, I set the rpm to 500.

Edit.. So much for a road test, I just finished installing the rear driveline and a new hub on the rear 14 bolt axle. Still need to add oil.
Now for the bummer part, tomorrow I teach a night class, Thursday is valentines day, need to take the wife out and Friday I fly out of town for work, so there won't be much progress until I fly back next Wednesday . I will have access to the internet.
 
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Back in town, and got more data. I drove around the neighborhood for about a mile and then let it cool a bit and then back out for more drive time. Varied the speed a lot and everything seems to be running fine. Still being easy on it.

I cleared the table at the start of the day, but just keep hititng save after that.
 
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Just to clarify, being easy to me means not a lot of drive time before letting the rings cool down a bit. I got an auto so I gas it in first and shift to second manually. Sunday I got in some more drive time, but noticed the blm's vary a lot now that I'm gasing it a lot more. I'm doing short burst to seat the rings. Stop sign to stop sign. I plan on driving to work Tuesday once the mud flaps are installed.
 
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I drove the Scout to work, about 20 miles on the hwy. I'm trying to understand what all the numbers mean. Bill I know you been doing this a long time and I have a big learning curve.
I know that a blm of 128 is the correct air fuel ratio.

Can you post one of your blm table and log data? Trying to see how the data varies as you drive. Maybe I'm barking up the wrong tree here.
 
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Your wide average blms look ok for now. Read up on bill's FAQ for tuning notes. It's easy to do. 128 is 14.7:1 air/fuel ratio.

Here is what I do. Get it below 128 (a tiny bit Rich). Go tune timing at this point. Once you have timing dialed in ( you can spend eternity doing this) . Go back to correct the fuel. Again, I try to stay a little bit below 128. I feel the motor runs better a bit below 128.

By the way, during the timing tune, you will notice your motor will sound "different". Quieter, smoother but it will roar like a race motor. This is a sign of timing dialed in. Use the 80/20 rule and don't pull your hair out trying for an absolute perfect tune. Remember that the tune should be robust in all conditions (air temp, fuel quality, elevation, towing a load etc....) if you tune it too perfect for a certain condition, you will be tuning again and again and again...
 
Cool stuff bill:winky: once the hollister trip in two weeks is over I will dig deeper into this. ( lot of other junk to get ready) I still have a question on how the timing affects the engine blm's. If I advance the timing 5 degrees I would expect the engine to run leaner, and if I retarded the timing it would run richer. Writing this and reading it now I question my self as to how spark timing would affect the mixture:icon_eek: I noticed the tail pipe has some black soot from running a tad Rich.

I drove the Scout to work again today, so I'm getting some miles on the motor.
 
You are Rich on the higher rpms.
The low speed idle areas look pretty good.

The mixture will lean some as you optimize the timing/cylinder pressure.
You will get more power out of each combustion thereby burning more of the fuel and have less dumping out the tail pipe...so the o2 will read leaner.
To a point!!!! Then bad things happen to your pistons.:nono:

I would probably turn the pressure down 1-2 lbs until you can program a chip for your engine.
 
I have made no timing changes, but now that the engine has about 200 hundred miles on it, the blm is leaning out?

I drove it up hill from 50' to about 2000' ( 30 miles ) and the blm is higher. I'll do a startup procedure test in the morning, to make sure everything is still the same. Even coming back down the blm were staying high. I would have to gas it to make them come down. Any advice is greatly appreciated.
 
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Wecraig...
Blm's do not get leaner while driving without a reason...and your went way lean.
I would start by checking all your fuel line clamps and replacing the fuel filters.
It looks pretty typical of a new FI install, as the system pumps more fuel out the tank it starts to clean it out.
Most systems need the fuel filter changed about 3 times before it is fairly clean.

Recheck your fuel pressure before and after changing the filter.

You are now way too lean.

Ans attach the unmodded file for me to look at.:smilewinkgrin:
it's easier for me to convert then then redo one already done.
 

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  • 20080229_122731_LOG.xls
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Here's an unmodified version.

I was unable to get the setup double check.
I took my son to the northern CA. / Nevada derby car race. This was the final level and he got 9th place and a trophy, not bad:gringrin: to even get to this level. As this was his 4th event. I thought we would be home earlier, but ended up taking all day.

Edit... I pulled and cleaned the tank out, the only other difference would be old gas vs new gas?

Sunday update. I double checked the timing, it was about 2 degrees btdc, so I turned it up to 0 zero. I also noticed that the line does not move when I give it gas, with the timing wire reconnected?
I double checked every hose connection and they were tight, I did find the base plate was a tad loose and tighten it up, the manifold was tight. I check the psi while driving around and it stays right at 13 psi with no needle fluctuations. I picked up a fuel filter 10 minutes ago, but have not put it on yet.

Looking back at the other days data ( I attached the data from the 27th) and noticed that it's about the same. When driving to work last Tuesday and wed. I see some blm in the 150's right now I notice that cruisin along at about 2000-2200 rpm the blm like to sit around 150 or so. If I give it some gas it comes down. Duh. At idle its running fine at 128, take off and it drops to maybe 122, but once up to speed 45-50 and just motoring along that's when its higher at 150

I don't want to mess up the motor with the blm being to high, so this could mean no hollister trip :( still have 4 days to fix it!! I was using a stock map sensor hose and replaced it as the connections seemed to have a loose fit, no change in blm.

More updates. I been going over everything with a fine tooth comb. I did notice that when I first start out the engine is Rich blm 120. As I drove down the freeway for 7-8 miles and no change, even with changing the rpm from 2300-2900. I got off and back on to come home and floored it up the on ramp and then once on the freeway and up to speed 2500rpm and the blm had jump to 150. So I removed the TBI and used gasgacinch on the gaskets and reinstalled. This was to for sure eliminate any air leakage.
 
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