Big Block C4s
#61
Burning Brakes
#62
I’m working on that too. Its hard. Stock sbc or lt1 China wall of block to hood is 10.75 in the reAr, approximately 9.75 in the front. I figure 10.25-10.5 in the middle.
a Bbc bolted with the stock sbc mounts is exactly 1” taller.
holley bbc efi oval port intake and the edelbrock vic jr efi oval port are both 6” tall (5.96) from china wall to 4150 carb pad.
the edelbrock 4150 tb i sam using is right at 3” tall. Itll fit, i have to be creative with air cleaner options.
accufab makes one that is exactly 2.5” tall that is a really nice piece, but its also exactly double the price of the edelbrock unit.
with standard length injectors, the fuel rails interfere with a 2” drop base intake base, but a 1” drop 14”round fits.
with ls3 height/style injectors a 2-2.5” drop base will fit because the fuel rails sit lower. So you could run a 2-3” tall 14” round air cleaner with a k&n style 14” filtered lid, and it would probably feed enough air. It would probably be extremely warm (HOT) C4 corvette underhood air. It can be done, but theres some engineering to be done.
if you run a 4bbl efi system like the holley sniper efi, or the ez-efi alot of people are running, an oval port torquer 2 intake with the 4 bbl unit on top will work just fine.
plan on at least home porting a torker 2. They are a little rough.
a Bbc bolted with the stock sbc mounts is exactly 1” taller.
holley bbc efi oval port intake and the edelbrock vic jr efi oval port are both 6” tall (5.96) from china wall to 4150 carb pad.
the edelbrock 4150 tb i sam using is right at 3” tall. Itll fit, i have to be creative with air cleaner options.
accufab makes one that is exactly 2.5” tall that is a really nice piece, but its also exactly double the price of the edelbrock unit.
with standard length injectors, the fuel rails interfere with a 2” drop base intake base, but a 1” drop 14”round fits.
with ls3 height/style injectors a 2-2.5” drop base will fit because the fuel rails sit lower. So you could run a 2-3” tall 14” round air cleaner with a k&n style 14” filtered lid, and it would probably feed enough air. It would probably be extremely warm (HOT) C4 corvette underhood air. It can be done, but theres some engineering to be done.
if you run a 4bbl efi system like the holley sniper efi, or the ez-efi alot of people are running, an oval port torquer 2 intake with the 4 bbl unit on top will work just fine.
plan on at least home porting a torker 2. They are a little rough.
or 4bbl rect-port flat-as-a-pancake GM LS6 intake manifold?
Last edited by rpoL98; 01-04-2021 at 04:26 PM.
#64
Advanced
#65
Advanced
kwik performance makes an adapter that will bolt the stock c4 L98 crank pulley onto the gen vi bbc balancer. I already have their sbc to bbc adapter mounts that I was going to use on another project, but when I reached out to them, they told me that although they designed their original kit to adapt specifically the truck sbc brackets, with their crank pulley adapter, it will adapt any sbc bracket setup.
if I have the room, then I basically already have a solution without spending what realistically amounts to $2000 on brackets, pulleys, and accessories
#66
Le Mans Master
..... My tow vehicle ... 2001 GMC Yukon XL 2500 4x4 has the big block that you need ... 8.1L 496 cubics with a MPFI system including cam and crank sensors and distributorless ignition ... this powerplant was used in 3/4 ton and 1 ton trucks from 2000 to 2005 and maybe 2006 ... I'll try to get a crank to throttle body measurement (this might be a tall deck block) .....
#67
Advanced
..... My tow vehicle ... 2001 GMC Yukon XL 2500 4x4 has the big block that you need ... 8.1L 496 cubics with a MPFI system including cam and crank sensors and distributorless ignition ... this powerplant was used in 3/4 ton and 1 ton trucks from 2000 to 2005 and maybe 2006 ... I'll try to get a crank to throttle body measurement (this might be a tall deck block) .....
if you’re a millionaire you can get the raylar stuff, and 0 backwards compatibility.
the gen vi was not quite as advanced as the gen vii, but factory roller cam, full 4 bolt mains, priority main oiling, 1pc rms, and the ability to run any aftermarket oval port or rectangle port head makes up for the incremental improvement that was made by adding ls tech.
also, my engine has a cam amd crank sensor, and they actually offered tue gen vi with 24x efi and coil near plug ignition, which I will actually be running on my 84 monte carlo. Gm still makes the gen vi valve covers with the coil mounts on them
#68
Computer??
Guys.... I am going to put a big block in my 1987 Corvette. I'll use aftermarket stand alone EFI on it. What does it take to keep the digital gauges working?? Will I need to keep the original ECM computer to run the digital dash?
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
#69
Burning Brakes
No reason a stock ecm can't run a big block. If you want aftermarket, the only setup I've found that retains full dash functionality is the ebl (www.dynamicefi.com). The drivers dash (temp, oil pressure, etc) don't get their signals from the ecm, but the center dash (mpg) does. Either would work for both your bbc transplant and your tpi swap.
#70
Pro
Guys.... I am going to put a big block in my 1987 Corvette. I'll use aftermarket stand alone EFI on it. What does it take to keep the digital gauges working?? Will I need to keep the original ECM computer to run the digital dash?
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
http://www.gearhead-efi.com/Fuel-Inj...7-pcm-Possible
'87 uses MAF but my understanding is the '7427 PCM can do either. Be advised the '87 uses a 100k ohm knock sensor whereas your stock truck PCM uses a 4k ohm sensor.
#71
Drifting
Guys.... I am going to put a big block in my 1987 Corvette. I'll use aftermarket stand alone EFI on it. What does it take to keep the digital gauges working?? Will I need to keep the original ECM computer to run the digital dash?
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
Second question. I want to put the TPI 350 out of the Vette into my 1994 GMC truck. Should I just buy a replacement Vette ECM, (90 bucks), and a HyperTech chip, (150 bucks) and wire it all up in the truck??
Thanks for ANY help on this!!
Vetterobert
Actually I am in the process of reverse engineering the MPG mileage data to the digital dash to get the functionality back with in my 1984 with MaxxECU. I will use an Arduino to get data required data from Maxxecu, probably using CAN-bus, and then convert and forward data in 160 baud ALDL format used by the dash.
#72
there's a parameter in the stock ECM program for engine size, IIRC, it's actually cylinder volume. then multiplied by # of cylinders.
#73
The big block going into the Vette is heavily modified, so I'm going with aftermarket EFI for that.
That's really good news that I don't need the factory ECM to keep the digital dash going. I WILL miss the "trip computer" function, but pretty much figured I was going to lose that in this project. Oh well....
Those trip computers are handy and convenient, and definitely help me save fuel on long trips. It seems like there would be a market for a stand alone unit to retrofit cars. With today's electronics and microprocessors, it doesn't seem like it would be too tough for some "techie" to come up with, but it's beyond my capabilities. There's two approaches that could be used. Either using fuel consumption info from the injector pulses and vehicle speed/miles covered data, (or even GPS), or using a flowmeter for fuel use, (minus fuel return), and again, computing that against miles covered via VSS or GPS data. Fuel flow gauges have been used on injected aircraft engines for many years. (We use gallon per hour data to calculate range, etc.)
On to the GMC pickup. I didn't get a chance to check which trans it has today, but I will ASAP. With the info you guys have so kindly provided, the plan now will be to hand wire the Vette computer to the Vette TPI engine in the truck. The "64 dollar question" will be handling the trans.
Thanks a bunch for the info thus far!!! You guys are great!!
VetteRobert
That's really good news that I don't need the factory ECM to keep the digital dash going. I WILL miss the "trip computer" function, but pretty much figured I was going to lose that in this project. Oh well....
Those trip computers are handy and convenient, and definitely help me save fuel on long trips. It seems like there would be a market for a stand alone unit to retrofit cars. With today's electronics and microprocessors, it doesn't seem like it would be too tough for some "techie" to come up with, but it's beyond my capabilities. There's two approaches that could be used. Either using fuel consumption info from the injector pulses and vehicle speed/miles covered data, (or even GPS), or using a flowmeter for fuel use, (minus fuel return), and again, computing that against miles covered via VSS or GPS data. Fuel flow gauges have been used on injected aircraft engines for many years. (We use gallon per hour data to calculate range, etc.)
On to the GMC pickup. I didn't get a chance to check which trans it has today, but I will ASAP. With the info you guys have so kindly provided, the plan now will be to hand wire the Vette computer to the Vette TPI engine in the truck. The "64 dollar question" will be handling the trans.
Thanks a bunch for the info thus far!!! You guys are great!!
VetteRobert
#74
Drifting
#75
Burning Brakes
The big block going into the Vette is heavily modified, so I'm going with aftermarket EFI for that.
That's really good news that I don't need the factory ECM to keep the digital dash going. I WILL miss the "trip computer" function, but pretty much figured I was going to lose that in this project. Oh well....
That's really good news that I don't need the factory ECM to keep the digital dash going. I WILL miss the "trip computer" function, but pretty much figured I was going to lose that in this project. Oh well....
#76
Again, take a look at the dynamicefi EBL flash II setup (http://dynamicefi.com/EBL_Flash.php). I call it quasi-aftermarket, but it should do exactly what you want and not lose the trip computer! It's a factory ECM modified with flash-tuning capability, 8 analog/digital inputs (including self-learning wideband o2), greatly expanded tuning parameters, etc. It uses your current wiring harness with a few wires moved in the ECM connector, and, the best part, will be way cheaper in the end than any other aftermarket EFI that fits the bill. Unless you need to control pwm solenoids or are going distributor-less (requiring crank/cam position sensors), I can't fathom spending 3x the money plus a much more difficult install to get the job done.
#77
Burning Brakes
1) modified ECM hardware (piggyback board installed) that gives you:
a) flash tuning (with the ability to store multiple tunes at once)
b) 8 channels of analog-to-digital 0-5v inputs for additional sensors (like wideband o2, fuel pressure, etc.)
c) usb interface
2) extensively rewritten ECM software that:
a) eliminates the limitations in the various GM code (pulse width cap, 255 gms/sec airflow calcs, etc.)
b) extends the range of the spark/fuel tables to much higher RPM and gives the tuner much more control over things
c) supports things like boost and the items in #1 above
3) PC logging/tuning software that:
a) utilizes the USB for much faster logging (though ALDL is still supplied to the car's diagnostic connector and trip computer)
b) brings those 8 a/d channels into the datalog data stream
c) does VE auto-learn with either a narrow-band (not so effective) or wide-band o2 sensor and updates the VE tables accordingly (you still have to flash it back to the ECM)
You still use TunerPro (or similar) to read and modify your bin's. If you go to the update section on the dynamicefi site, you can download the pc software (what's up display) and tunerpro definitions to poke around with it - gives a good idea what you can do with the system.
#78
Well, I did look at that, and it is interesting. I would still need a high flow throttle body injector to mount on the Performer Rpm Air Gap intake on my big block. (And some serious schooling on EFI flash tuning!)
Ok, so using the Vette TPI in the 94 GMC 4x4. The truck has the 4L60(E) trans.
Thanks!
VetteRobert
Ok, so using the Vette TPI in the 94 GMC 4x4. The truck has the 4L60(E) trans.
Thanks!
VetteRobert
#79
Does your truck have a 4L60E/4L80E??? I would consider this but of course it would involve PROM tuning:
http://www.gearhead-efi.com/Fuel-Inj...7-pcm-Possible
'87 uses MAF but my understanding is the '7427 PCM can do either. Be advised the '87 uses a 100k ohm knock sensor whereas your stock truck PCM uses a 4k ohm sensor.
http://www.gearhead-efi.com/Fuel-Inj...7-pcm-Possible
'87 uses MAF but my understanding is the '7427 PCM can do either. Be advised the '87 uses a 100k ohm knock sensor whereas your stock truck PCM uses a 4k ohm sensor.
Thanks for any help!!!!
VetteRobert