Yup. I have a super nice Line-X coating in my whole interior so I really dread the thought of cutting into it. But I should think about it again.
CK5
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Back to carb?
- Thread starter Mastiff
- Start date
This is what a lot of guys are running. Shouldn't mess up the lining too bad.
You have a link to a thread about that?
I think, look up marine access panels.
DPI Marine: All Hatches
low profile access hatch, deck lid, storage solution, tackle center, first-aid storage, glove box, fire extinguisher storage, live well hatch, anchor hatch, flush series, hidden fastener series
www.amazon.com
Fuel Pump Access hatch
mods, please delete if this is not ok. I added a fuel hatch to my blazer build during the rear links and frame install and thought I would throw up a video and blog post on it over on my website. Secure, functional, strong and big enough to provide adequate access. Should have done this years...
ck5.com
The only real reason to downgrade from EFI to carb is the threat of EMP - Electromagnetic pulse. In that scenario, you need a points ignition, not an electronic module, but an alternate scenario is to keep your spare ECU/alternator in some kind of Faraday cage so they still work after the nukes go off. Then, the question becomes one of finding continual sources of fuel, but maybe all you need is a couple hundred miles to bug out then park/scrap it. Keep in mind the roads will be full of disabled vehicles, so that living in any large town/city is not an option. Pretty big rabbit hole...
Anyway, there is ALWAYS something that can disable ANY vehicle. Maybe a 1-wire 80's GM diesel has the least scenarios if you pack an old-school Onan generator. Of course it can always crack the heads or block or you can just lose all gears in the transmission...
Anyway, there is ALWAYS something that can disable ANY vehicle. Maybe a 1-wire 80's GM diesel has the least scenarios if you pack an old-school Onan generator. Of course it can always crack the heads or block or you can just lose all gears in the transmission...
Have ya considered running a propane system ?
They’re not for everyone but the are reliable.
Any system will eventually fail - injector pumps, lift pumps, fuel pumps, sensors, ECM’s and carbs will all eventually fail to deliver.
I’m a big fan of diesels, certain carbs, GM TBI’s ( including Howell’s stuff ) and propane set ups. All have their advantages and drawbacks - just depends on what’s important to you.
They’re not for everyone but the are reliable.
Any system will eventually fail - injector pumps, lift pumps, fuel pumps, sensors, ECM’s and carbs will all eventually fail to deliver.
I’m a big fan of diesels, certain carbs, GM TBI’s ( including Howell’s stuff ) and propane set ups. All have their advantages and drawbacks - just depends on what’s important to you.
I can honestly say in all the years I’ve driven old junk (that’s all of them), I’ve carried every part I thought could fail and leave me stranded. You know what parts have left me stranded….the ones I didn’t carry, every damn time. I say carry some tools, a few spare parts and don’t worry about the what ifs because inevitably the one that gets ya will be the one you never thought of anyway.
I would stay with what you've got. I have had both mechanical and efi fuel pumps go out, stranding me both times. Adding an access hatch for the electric pump is worth the time. I did convert a 67 Camaro to a sniper that came with the blueprint 427 I added.
Added an access door in the trunk and installed a in tank fuel pump (Holley). It ran well but I eventually switched back to a carb and a mechanical fuel pump. An access door and an extra pump would make me fill pretty good driving a stock gm efi anywhere.
Added an access door in the trunk and installed a in tank fuel pump (Holley). It ran well but I eventually switched back to a carb and a mechanical fuel pump. An access door and an extra pump would make me fill pretty good driving a stock gm efi anywhere.
Aegis43
Registered Member
I don't want to jack Mastiff's thread, but I also really need input on factory TBI and my '88 K5. I want to swap the pretty seriously built 385" sbc from my Camaro into the Blazer (396 going in the Camaro) as the 5.7 now in it is tired (read: weak, very low on power) and blows smoke on start up. I have no idea how old that engine is, meaning if it's ever been rebuilt (block stamp matches VIN).
Why would I want to do this? Well, this is what I've got. I want the Blazer to have 350+ lbs/ft torque and I don't need a pretty, virtually new small block on an engine stand as garage art. I'd LIKE that, but wifey not so much.
My questions are:
(A) Can factory TBI be reprogrammed to run on a 400hp, aluminum headed, substantial roller cam engine? I absolutely am going to install an O2 sensor in the collector of the header. It has one now in the Camaro.
(B) If no (the 750 Q-Jet and HEI would be transitioning with the engine into the Blazer), what do I do with all the OBD I bits? The original 700R4 (I assume) was rebuilt 5 years ago and is very sweet. Does OBD I have any control over that?
Thanks for any help you guys are willing to give.
And I apologize to Mastiff if I'm out of line here. I've just been a lurker a bit here since joining. Kind of been busy with a certain yellow Camaro.
EDIT: I realize the factory TBI intake manifold is not going to flow enough air for the thing to make 400hp at 6000 rpm. That's not my intent here.
Why would I want to do this? Well, this is what I've got. I want the Blazer to have 350+ lbs/ft torque and I don't need a pretty, virtually new small block on an engine stand as garage art. I'd LIKE that, but wifey not so much.
My questions are:
(A) Can factory TBI be reprogrammed to run on a 400hp, aluminum headed, substantial roller cam engine? I absolutely am going to install an O2 sensor in the collector of the header. It has one now in the Camaro.
(B) If no (the 750 Q-Jet and HEI would be transitioning with the engine into the Blazer), what do I do with all the OBD I bits? The original 700R4 (I assume) was rebuilt 5 years ago and is very sweet. Does OBD I have any control over that?
Thanks for any help you guys are willing to give.
And I apologize to Mastiff if I'm out of line here. I've just been a lurker a bit here since joining. Kind of been busy with a certain yellow Camaro.
EDIT: I realize the factory TBI intake manifold is not going to flow enough air for the thing to make 400hp at 6000 rpm. That's not my intent here.
Last edited:
The first question is whether or not it's a good idea. If it is 400HP (has it been dyno tested?), that's probably a high-revving engine, as you might want in a Camaro. Putting that into a truck, won't you need a higher-stall torque converter and lower gears to make it work right? That could be nice for some applications, but not great for DD streetability. Will you need to upgrade the transmission and rear end?
As for the question, I think a roller cam 385 is pushing the limits of what the factory TBI can be programmed correctly for. The key will be finding someone willing and able to write the new PROM(s) for it. The BBC TBI unit would be better suited, as it has larger throttles and larger injectors, although it may be hard to get a good idle if those injectors are too big. Probably an adjustable FPR is in order and put a good exhaust system on it. In the end, the high-end flow might limit the engine power.
However, it might take several iterations of burning to get it to run right in all regions. You would want one of those TBI scan cables to take datalogs. It would probably be better to get another ECU in there. If you step away from GM TBI, at least you already have the in-tank fuel pump and EFI fuel lines already in place. I would be tempted to go DIY with a Megasquirt and the GM TBI to Megasquirt adapter board, but you need someone to set it up and tune it or jump into the learning curve yourself.
Probably the TBI intake is compatible if the 385 has standard (pre-Vortec) SBC heads, but you should at least look at an aftermarket intake. Maybe take a look here: https://www.gmt400.com/threads/is-300-hp-possible-from-a-tbi.48003/
If a mod wants to make this a new thread, please jut move this post along with it.
Aegis43
Registered Member
@Blue85 The Camaro did get tested on a Mustang chassis dyno. With zero tuning and an old rebuilt Holley 3310, through PS, AC, alt, WP accessories, Tremec TKX, it made 353 ft/lbs at 3800 rpm and 321 hp at 5400 rpm at the tire. It was making over 290 ft/lbs at 2500. AFR 195 heads, AirGap (not an RPM) intake. This is with 1.75" long tube headers and 2.5" exhaust. This wasn't a test & tune. It was just a let's see what I've got ($290 for three runs). I think swapping a better intake on it, a new, better carburetor, and tuning that, would have gotten me another 25 hp/tq. The roller cam, heads & headers are all designed for easy peak power at 6000 rpm. So I put a new Q-Jet on it now.
I realize this is in no way an ideal engine for the Blazer. It's just what I've got. I don't have an unlimited checkbook. I don't have the skills, tools, patience, and frankly the intellect, required to make factory TBI work with this engine by doing it myself. I assume it would be upwards of $2000 (maybe more) for a competent guy to do all the programming and time spent dialing in, even if I spend the extra (another $300-ish) money to put a milder cam in it. I wish I did. I'd like to be able to afford some other aftermarket FI too, but I just can't justify pouring money into something I just need to run reliably. I don't expect to be able to just turn the key and go in all types of weather like a modern vehicle. I didn't grow up that way. In 1980 I was 16 years-old. Another initial expense I'd have to incur is having my TBI unit completely rebuilt, as mine is all worn out. Currently, a good friend and shop owner has his own '89 K5 and he swapped his unit onto my engine to get me going again. He's not encouraging me to put the Camaro engine in the Blazer, btw. He's neutral.
I'm not a hardcore off-roader. I'm blessed to have a company vehicle to drive for work, and the Blazer and Camaro are the only two "cars" I own. So the Blazer is my "daily driver," as it were, for after work and weekends. I don't rock climb, bounce, or do difficult hardcore off-roading. I like camping and forest service roads. If I have to cross big mud puddles, or slick muddy inclines, then I like having that 3-wheel drive, as it's got a 10-bolt open rear, 3.42 gear, Warn manual hubs and 33x12.50 KO2s. It regularly sees 75 mph on the freeway.
So back to my question, is the transmission controlled in any way by the OBD I? If I decided to go carb, do I remove all the electronics under the dash? I understand swapping the fuel pump out for a sending unit, rerouting/changing fuel lines.
Thanks ... to any and all who are willing to chime in
I realize this is in no way an ideal engine for the Blazer. It's just what I've got. I don't have an unlimited checkbook. I don't have the skills, tools, patience, and frankly the intellect, required to make factory TBI work with this engine by doing it myself. I assume it would be upwards of $2000 (maybe more) for a competent guy to do all the programming and time spent dialing in, even if I spend the extra (another $300-ish) money to put a milder cam in it. I wish I did. I'd like to be able to afford some other aftermarket FI too, but I just can't justify pouring money into something I just need to run reliably. I don't expect to be able to just turn the key and go in all types of weather like a modern vehicle. I didn't grow up that way. In 1980 I was 16 years-old. Another initial expense I'd have to incur is having my TBI unit completely rebuilt, as mine is all worn out. Currently, a good friend and shop owner has his own '89 K5 and he swapped his unit onto my engine to get me going again. He's not encouraging me to put the Camaro engine in the Blazer, btw. He's neutral.
I'm not a hardcore off-roader. I'm blessed to have a company vehicle to drive for work, and the Blazer and Camaro are the only two "cars" I own. So the Blazer is my "daily driver," as it were, for after work and weekends. I don't rock climb, bounce, or do difficult hardcore off-roading. I like camping and forest service roads. If I have to cross big mud puddles, or slick muddy inclines, then I like having that 3-wheel drive, as it's got a 10-bolt open rear, 3.42 gear, Warn manual hubs and 33x12.50 KO2s. It regularly sees 75 mph on the freeway.
So back to my question, is the transmission controlled in any way by the OBD I? If I decided to go carb, do I remove all the electronics under the dash? I understand swapping the fuel pump out for a sending unit, rerouting/changing fuel lines.
Thanks ... to any and all who are willing to chime in
