Headers question w/pics

[sgtusmc]

Hey guy's I have a question about Blackjack headers for the 2.8. Long story short, I'm a retired Marine. Over the last couple of years my 9 year old son and I built this '53 GMC. We did a frame swap with a 1988 s10. We kept all the s10 running gear. I found a cheap set of brand new headers on eBay for the 2.8 (I'm not expecting hugh H/P gains it's my 9 year olds truck and he wanted headers). Well my question is, The 2.8 is TBI and there is a welded bung for the EGT sending unit. The pipe itself is not drilled through. What would happen if I did not use the sensor? Would it make the computer get funky on us? It's not a big deal to drill through the pipe. I was just wondering if I could bypass it with no effects.

[The_Raven]

That would be an O2 sensor, not EGT.

Drill the hole and install it, your ECM and fuel milage will thank you for it.

BTW, cool looking truck.

[sgtusmc]

Raven- Thanks for the quick reply. As per the instructions it states. If your vehicle is equipped with the exhaust gas temperature sending unit (part #AC-AFC-4P), It will be necessary to drill a hole in the header where the adapter is welded on #3 tube.
In the pic of the headers, look at how high on the tube the bung is. The stock bung on the y pipe is very low. I'd have to cut and extend the o2 wiring to get it up that high.

[The_Raven]

These trucks, nor any GM vehicle ever came with an EGT sensor.

The only things ever attached to the exhaust are O2 and EGR, but EGR path is within the heads on the gen1 2.8L design.

The bung for the O2 is probably moved there, so that it can get heated sufficantly. Header equipped vehcilces have a hard time with single wire O2 sensors getting up to operating temperature.

You could swap to a heated O2 sensor, and leave it in the Y-pipe (Which will need to be custom anyway).

[KJF95S-10]

I think you would be ok if you didn't use it. Truck looks awesome btw.

[lee-mill]

that truck is so cool

[neo71665]

There should be 2 kinds of fittings (depending on how factory you kept the 2.8). On the pass side there should be fittings for the A.I.R. pump and the drivers side should have the O2 sensor. The A.I.R. can easily be deleted. If you want to keep the TBI the O2 sensor has to remain.


I just put my O2 in the drivers side collector but I also upgraded to a heated sensor.

[layinlow88]

Quote: Originally Posted by KJF95S-10

I think you would be ok if you didn't use it. Truck looks awesome btw.

read post #2


anyways...nice lookin truck man...i'm digging it

[neo71665]

Quote: Originally Posted by KJF95S-10

I think you would be ok if you didn't use it. Truck looks awesome btw.

I find it amazing you done a fuel injected v8 swap and yet don't know the need of a O2 sensor.

[bobditts]

that looks like a big heavy truck for the tiny 2.8L. Is that the engine that came stock in that vehicle?

[neo71665]

Quote: Originally Posted by sgtusmc

<cut> Over the last couple of years my 9 year old son and I built this '53 GMC. We did a frame swap with a 1988 s10. We kept all the s10 running gear. <cut>

Quote: Originally Posted by bobditts

that looks like a big heavy truck for the tiny 2.8L. Is that the engine that came stock in that vehicle?

Please tell me you didn't just ask that

[sgtusmc]

Hey thanks for the help guy's and thanks for the kind words. My son and I just finished doing the drivers side. I will drill out the tube. I'll do a search for the heated o2 for the 2.8. If by chance you have the part # that would be cool. Either way, thanks a bunch guy's. The 2.8 is not as fast as I'd like. I thought about a v8 swap. But, since it's going to be my son's first ride. I'd like to keep as slow as possible. It does help out a little since it's a 5 speed. Once again thanks for your inputs.

[neo71665]

http://members.shaw.ca/betterthanyou...gen_sensor.htm

[sgtusmc]

Neo- Thanks for the link. You guy's were right about the o2 sensor. I emailed the guy I bought the headers from. His action said they would fit all the way up to 1990. He just got back to me and said he had mad a mistake. The headers are for 1982-1984. I told him I had mounted the drivers side and was unsure about the pass side. The guy said for me to keep the headers and refunded the money back to my PayPal. I'll have to get back to him about the refund. It just doesn't seem right to get a free set. I'll try and meet him in the middle. So now, I'm not sure on what to do. The only thing I really know about the 2.8 is they went from carb to TBI. From what I've read the block stayed the same right? I haven't drilled through the tube yet. The funny thing is, the rubber hose that comes off the smog pump lines up right to the bung on the header. It's just not the same size. I removed the o2 from the Y-pipe and it's the same size for the bung. If it's there for the smog pump I'm not going to run it. Should I drill out the pipe and extend the o2 to fit that bung or mount the o2 close to the factory location. I'm going to fab up an new Y-pipe for the headers so I can always weld in a bung. Sorry if the questions sound stupid. It's my first header install and I don't want to disappoint the little guy.

[neo71665]

Quote: Originally Posted by sgtusmc

Neo- Thanks for the link. No prob, what we here for

So now, I'm not sure on what to do. The only thing I really know about the 2.8 is they went from carb to TBI. From what I've read the block stayed the same right? 1986 was the first year of fuel injection. There of a number of minor differences with the RWD blocks as GM reworked them. Around the 84/85 time frame GM went from a lever type clutch to a hydro setup. 86 has a combo serp v belt accessory drive. In 86 they increased the main bearing size and the heads were given larger valves. 87 and on had a total serp belt setup. GM over the years also upped the displacement from 2.8 to 3.1, and finally with a redesigned (thicker cylinder walls) block a 3.4. Sadly the s-series only seen the 2.8 from the factory.

I haven't drilled through the tube yet. The funny thing is, the rubber hose that comes off the smog pump lines up right to the bung on the header. It's just not the same size. I removed the o2 from the Y-pipe and it's the same size for the bung. If it's there for the smog pump I'm not going to run it.
Bung on the pass side? if so that is indeed for the smog (A.I.R.) pump. just plug it and don't run it cause its not gonna hurt anything. If you have emissions testing in your area and they run it as a s-10 you just might have to hook it up.The 82-85 used a different A.I.R pump setup and you might have to make an adaptor for it if you do.

Should I drill out the pipe and extend the o2 to fit that bung or mount the o2 close to the factory location. I'm going to fab up an new Y-pipe for the headers so I can always weld in a bung. Sorry if the questions sound stupid. It's my first header install and I don't want to disappoint the little guy. When I done mine I just extended the wire and run the O2 in the collector at the end of the header on the drivers side. The factory spot is really not the best spot and with headers you do not want it in a single primary tube. Truth be told it should be in the y pipe right after the 2 banks merge so it gets a true reading of both cylinder banks. The factory put it up by the manifold because of the cold issue mentioned earlier.

Good luck and if you wanna learn any more about 60 degree engines I can shoot you some links or just ask. Raven Is a very well source of info also as he knows tons more than I.


I'm currently building a 3.4 60degree to replace my worn out 2.8 in my blazer. I'm hoping to push the 200 HP mark with a cam, 1.6 roller rockers, headers, 2.5 inch exhaust, ported and polished heads, bored intake with a 4.3 TBI, and a few other secret old hot rodder mods. There are all kinds of stuff to do to these motors and still have something that reliable. They are more often over looked but personally I would take something that was designed to be a v6 over an afterthought V8 with 2 cylinders chopped off.

[bobditts]

Quote: Originally Posted by neo71665

Please tell me you didn't just ask that

I read that and understand that. Still doesnt tell me what the original engine was. Just because he swapped out for an s-10 frame and drivetrain, doesnt mean that truck didnt originally come with a 2.8L. Please dont tell me you never thought of that!

[neo71665]

Nope cause the first 60 degree v6 was a 2.8 and didn't make its debut until the early 80s as a totally new design with the banks spaced closer together for smaller engine compartments.


Besides in 1953 the motor woulda been most likely been a inline six rated at less HP than a 2.8. Chevy didn't come out with their famous smallblock v8 till 55. Working on those old vehicles were where I started out tinkering. Granted most of it was swapping in bigger motors and such but you still tend to learn about what your working on.

[bobditts]

I did not know any of that. That is why I asked. Thanks!

[sgtusmc]

The 1953 GMC came with a inline 6 248 engine that was frozen (under 80 horsepower). Gas tank behind the seat and a badly rusted frame with a straight front axle. A lot of guys who build these old trucks put in Mustang 2 front clips, box the frame rails, new gas tanks under the bed, and new engines. It ends up costing an a$$ load of cash. With the s10 swap (reg cab long bed) we got updated everything along with reliability. For my son and I it was easier to make the brackets to mount the old tin to the s10 frame than to Frankenstein the old running gear. Also, if we ever decide to V8 the truck s10 mount can be had almost anywhere. I appreciate all the help guy's.

[neo71665]

Quote: Originally Posted by bobditts

I did not know any of that. That is why I asked. Thanks!

No prob, I know sometimes I come across as a smartass but I don't mean it all the time.

Quote: Originally Posted by sgtusmc

The 1953 GMC came with a inline 6 248 engine that was frozen (under 80 horsepower). Gas tank behind the seat and a badly rusted frame with a straight front axle. A lot of guys who build these old trucks put in Mustang 2 front clips, box the frame rails, new gas tanks under the bed, and new engines. It ends up costing an a$$ load of cash. With the s10 swap (reg cab long bed) we got updated everything along with reliability. For my son and I it was easier to make the brackets to mount the old tin to the s10 frame than to Frankenstein the old running gear. Also, if we ever decide to V8 the truck s10 mount can be had almost anywhere. I appreciate all the help guy's.

Pretty common thing to do. Even way back when in hot rodding people put old model a bodies and such on the 32 fords cause of the upgrade to better stuff and more options.

[KJF95S-10]

Quote: Originally Posted by neo71665

I find it amazing you done a fuel injected v8 swap and yet don't know the need of a O2 sensor.

I do know the need, I was referring to the EGT sensor. I didnt read post #2 Chill.

[83 S-10 owner]

You can go without the sensor but you will need a bypass for the sensor. It plugs into the harness and will give good output to computer.

[The_Raven]

Quote: Originally Posted by 83 S-10 owner

You can go without the sensor but you will need a bypass for the sensor. It plugs into the harness and will give good output to computer.

That only applies to OBD2 systems, and only for the post cat O2 sensor, OBD1 uses only pre-cat O2 sensors.

[Hazardous]

seeing that truck makes me miss my old 50 chevy p/u

[sgtusmc]

Quote: Originally Posted by Hazardous

seeing that truck makes me miss my old 50 chevy p/u

That's reason enough to build another one. Why not save one from the tin crusher?

[Hazardous]

i would but have to get my 94 and my 87 harley done first