New to TBI Tuning SBC 327 TBI

[kidsandjeep]

Hello All,

Hoping for some advice, I have a SBC 327 TBI'ed motor and it runs good, idles a bit high and the timing may need some help Currently a stock 1227747 ASDU ECM. The motor is in my 1951 Modified M38 (CJ3A) flat fender and it runs all over Moab in the heat but living in Colorado Springs when I run it up old Stage Rd, on some steep climbs up the mountain she overheats really bad, not sure if it is the the climbing, the drastic change in altitude, timing or the engine bay holding too much heat. I did add hood louvers and the engine doesn't overheat normal driving. I would like to try some different tunes in the ECM. I have the larger PIN Flash Proms and the Moates G2 adapter as well as a stock ECM once I get the tune right. Any "Bins" you all would suggest trying. Hope I got all that right, as I said totally new to tuning. I did delete the EGR on my TBI unit but as I said no other tuning changes.

Thanks all!

--Scott

[kidsandjeep]

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[MO LS Noobie]

Have you added any electric fans to get air flow across radiator at rock crawling speeds? I do OBDII stuff, but there are some basic physics that apply.

[In-Tech]

Hiya,
This might help as a starting file :)

[kidsandjeep]

Hi, yes, I have an electric fan. Purchased with the most CFM I could get given the room I had. I should have pushed the motor further into the firewall but I didn't.

[kidsandjeep]

Thank you! I have a buddy helping me this week with soldering the chip parts from moates. Then I will see about programming chips. I have been reading here quite a bit about that process.

[MO LS Noobie]

I have a customer with a 383 SBC in a 80s model CJ. Had to try several different fans to get proper airflow. Worst-case scenario you could fog the front of the radiator with a water mist if you're only having problems at a certain point in the trail.

[kidsandjeep]

Thanks MO LS Noobie, that is a good tip on fogging the radiator, the steep climbs and rapid altitude change seem to be the biggest issue. I drove it last year all over Moab in July and never overheated or saw engine temps above 200. I stop before I boil over on Old Stage (last run I forgot my IR Temp Gauge so I couldn't check actual temp but gauge hit 245) and usually wait a few minutes to cool down then climb some more, repeat. I can try the misting next time if tuning doesn't work I am also going to raise the rear of my engine hood slightly to maybe remove trapped heat. I have hood louvers but maybe not enough. I can try different fans too but need a very thin fan due to space issues between the radiator and water pump. I would take a recommendation on a real good electric fan if anyone has one.

[Fast355]

Thanks MO LS Noobie, that is a good tip on fogging the radiator, the steep climbs and rapid altitude change seem to be the biggest issue. I drove it last year all over Moab in July and never overheated or saw engine temps above 200. I stop before I boil over on Old Stage (last run I forgot my IR Temp Gauge so I couldn't check actual temp but gauge hit 245) and usually wait a few minutes to cool down then climb some more, repeat. I can try the misting next time if tuning doesn't work I am also going to raise the rear of my engine hood slightly to maybe remove trapped heat. I have hood louvers but maybe not enough. I can try different fans too but need a very thin fan due to space issues between the radiator and water pump. I would take a recommendation on a real good electric fan if anyone has one.

Ditch the electric fan and use a mechanical fan with a universal shroud. Electrics will never cool in that kind of environment. I had a massive 34x17" dual core radiator and dual electric fans on my Express van and it still overheated. Put a clutch fan on it and it runs cool. I converted my 1980 Corvette to a TBI B-car accessory setup and only had room for a thin flex fan on a 3/4" spacer, but I had zero cooling issues with that car running the AC.

[Fast355]

For something working hard at higher engine speeds and lower vehicle speeds you want a fairly agressively pitched fan, not a flex fan or some kind of thing bladed race fan. I worked on a L31 350 in a Kohler generator that had a fan about 18" in diameter but similar construction. It ran full load at 1,800 rpm and never ran over 210F on a 115F day with a very modestly sized radiator and matching shroud. Radiator was 20" x 20" and 1" thick core.

https://www.amazon.com/Mechanical-St...RoCzJAQAvD_BwE

[MO LS Noobie]

I can try different fans too but need a very thin fan due to space issues between the radiator and water pump. I would take a recommendation on a real good electric fan if anyone has one.[/QUOTE]
If the tune doesn't take care of it, I have used a 2 gallon garden sprayer with the nozzle set on mist. As far as electric fans, what is your radiator core dimensions, and do you have room in front for a pusher fan also? I run a 6.7 L LS and the stock dual electric fan set up keeps it around 200° with the air conditioning running in the ambient temperature over 100°.
Remember there are many ways to skin a cat, but a cup of gasoline and a match are by far the safest and quickest.

[Sledhead2]

Ok I am going to ask some questions in trying to learn some stuff.

1) have you always ran TBI on this build?
2) Did you ever just run a carb and HEI? Did you ever take it climbing in Colorado with just carb set up? did it get hot?
3) Did you ever make a data log when climbing and it gets hot? I would be curious to see the timing and A/F Ratio when climbing

I only ask because like you, I am trying to figure out if your running into a timing and fuel mix issue or an air flow thru the radiator or both. But which one do you start looking at first

You say it does not get hot at Moab, this has me thinking your driving at say 30mph or more and thus have air flow, plus your at a lower altitude. So everything in the tune might be in harmony.

I know nothing about climbing, but it sounds like your in lower gears, higher rpms, and barely moving (thus no air flow) and climbing in altitude (which is going to play heck with timing and a/f ratios.

I wonder if you are going to need to burn a custom chip and swap them out depending on the fun trip you have planned.

Maybe make a climbing chip that has a completely different fuel table and timing table set up for thin air, and a daily driver chip for playing in Moab.

[kidsandjeep]

Hi,
1) I have always had TBI on this build.
2) Never took it climbing Old Stage Rd with any other setup
3)I haven't data logged while climbing but that is next.

I just got an ECM setup to start programming different tunes, the stock chip in the current ECM (ASDU) may not be optimal for the SBC 327 and TH350 Trans (4.56 gears, 35" tires, thinking about a 5.13 regear). So I am going to play around with tunes any input any recommendations on what to start with would be appreciated! The trails I ran in the summer at Moab were slow speeds, high outdoor temperatures. If anything on Old Stage Road here in Colorado I am running much faster (25MPH average I could go faster) then when I am rock crawling (under 5mph) so air should be moving better. I am curious on whether custom tuning fixes my climbing issues. I am totally a newb to programming. Altitude may be a factor also, the road is pretty steep running next to Pikes Peak a 14ner, climbing into the mountains. I have tried shutting down and maybe that resets the ECM? Do I have to disconnect the battery to reset the ECM? I haven't done that. I also think my current electric fan may be under powered for this climbing (odd that it cools in other situations) and as you say the A/F and timing are also problematic. I have been looking at a Perma Cool Hi Performance Electric fan as an option. It's a tight fit in the engine bay but I maybe an offset 14in Perma Cool (vs a 17" that even at 3.75" width won't fit with the water pump) and custom fan shroud. The 14" permacool is rated at 3300 CFM. I hope to start programming custom chips in the next few weeks. Thanks for the comments.

[kidsandjeep]

Ditch the electric fan and use a mechanical fan with a universal shroud. Electrics will never cool in that kind of environment. I had a massive 34x17" dual core radiator and dual electric fans on my Express van and it still overheated. Put a clutch fan on it and it runs cool. I converted my 1980 Corvette to a TBI B-car accessory setup and only had room for a thin flex fan on a 3/4" spacer, but I had zero cooling issues with that car running the AC.

Dumb question but can I run the flex fan without a clutch? If I remember right the clutch plus fan sent me down the electric fan route in the first place.

[kidsandjeep]

I can try different fans too but need a very thin fan due to space issues between the radiator and water pump. I would take a recommendation on a real good electric fan if anyone has one.

If the tune doesn't take care of it, I have used a 2 gallon garden sprayer with the nozzle set on mist. As far as electric fans, what is your radiator core dimensions, and do you have room in front for a pusher fan also? I run a 6.7 L LS and the stock dual electric fan set up keeps it around 200° with the air conditioning running in the ambient temperature over 100°.
Remember there are many ways to skin a cat, but a cup of gasoline and a match are by far the safest and quickest.[/QUOTE] The radiator is like 22" X 20" aluminum, it was all I could fit and no room for a pusher. In those moments I am waiting for it to cool so I can keep going I ponder the cup of gasoline and match. HA!