6.2 exhaust manifold down between 6 and 8?

[BadDog]

Does anyone know of a 6.2 exhaust manifold that with down pipe shooting down between 6 and 8? That would normally put the down pipe right into the starter, so I doubt such a thing exists, but thought I would ask just in case there might be such a thing on some van or something.

 

[tRustyK5]

Hummer H1 headers maybe. Passenger side points right at the firewall on our trucks though...

 

[BadDog]

If it were the other side, that would be great. I've got a passenger side header, and I was kicking around making a few mods to get what I want, but I'm not fond of steel tube headers, much rather have a cast iron solution. But you can't always have what you want...

 

[tRustyK5]

Yeah, 6.2 exhaust is pretty limited from what I've seen too. I had a set of the H1 headers, and abandoned using them due to the re-work needed. As much as they're not ideal for what you are looking for, being steel tube they're a lot easier to re-work to your needs.

 

[campfire]

My suburban has something similar to what you're describing, but it's on the driver side. The pipe comes down about 6" ahead of its stock location. No idea why. As already said, if the passenger side manifold did that it would come down into the starter motor.

Side question...at the end of this funny manifold manifold (dropping straight down rather than angling back) is a 3" tall block with what looks like a vacuum-actuated valve between the manifold and the exhaust pipe. I can't imagine valving off the main exhaust stream. Does anyone know of such a valve? Is there some other manifold with an EGR valve in that spot?

I'll try to get pictures up...

 

[BadDog]

Older gassers had a heat riser restrictor there, never seen one that I recall on a diesel.

For any future searchers, I found on another forum that the 6.5 NA in P30 Vans ("Grummans") has a passenger manifold that points down instead of back to the firewall.

My thought is to use this passenger manifold on the drivers side. That (hopefully) puts it dumping downward behind the power steering and ahead of the motor mount. If this pans out, that lets me hook up the BAE turbo cross over without the complete mess that they normally have. In my case it's even worse because cross over and long travel would interfere with anything remotely resembling the OEM BAE cross over. Of course with my luck whatever I find will be a little to close one way or the other and prove impractical anyway.

 

[BadDog]

Eh, I must have inhaled to much diesel fumes. I just took another look, and dumping between 1&3 puts it right into the mount. To work, I need something dumping down at 45* or so on the front side of 1. Basically like a stock passenger exhaust, but pointed down 45* with center line crossing the bottom of the #1 exhaust port.

More and more this is sounding like I will have to modify the passenger header I have to fit exactly the space available.

Rene, you mentioned having looked into modifying these. Do you recall what the alloy is, and process required? I don't imagine it's anything tool complex, probably could be done with TIG using standard ER70S, or maybe a high nickel filler to reduce corrosion?

 

[campfire]

Older gassers had a heat riser restrictor there, never seen one that I recall on a diesel.

Hmm...quick image search turns up things that do resemble what I have. So...what does a heat riser restrictor do? Why would it actually choke off the exhaust flow?

I'd also be interested in knowing what non-6.2 manifold was swapped onto my engine. Not to mention why...
Do sbc manifolds fit on 6.2 blocks?

 

[campfire]

Eh, I must have inhaled to much diesel fumes. I just took another look, and dumping between 1&3 puts it right into the mount. To work, I need something dumping down at 45* or so on the front side of 1. Basically like a stock passenger exhaust, but pointed down 45* with center line crossing the bottom of the #1 exhaust port.

More and more this is sounding like I will have to modify the passenger header I have to fit exactly the space available.

If you want something coming off the front end of the passenger side manifold, can you simply take a drivers' side manifold and install it (backwards) on the pass side? Do they easily swap sides like that?

Or is that what you're suggesting?

 

[BadDog]

SBC manifold won't fit 6.2 heads, no idea on where your riser came from (factory or otherwise, snow-plow/cold-weather option?), but temporarily restricting exhaust flow (short of killing it) will heat up the engine faster, diesel or otherwise.

And you've got it reversed. My passenger manifold is a BAE part, complete with turbo mount flange. For my plans, that is a done deal and not optional.

What I want is a way to get the cross over from the driver's side to the passenger side to feed the turbo without something that looks like a contrast x-ray of the small intestine (I would settle for large intestine ).

Since the heads swap from side to side, the manifolds can mount either side, simply reversing the front/rear orientation. So since the passenger side exhaust exits to the left as you face that side of the engine, if mounted on the driver's side, it would exit to the front (still left) side. I was investigating whether there might exist a cast iron passenger side manifold that I could install on the driver side to feed the cross over forward of the mount and cross-member instead of going down the back and snaking back through/around.

 

[campfire]

SBC manifold won't fit 6.2 heads, no idea on where your riser came from (factory or otherwise, snow-plow/cold-weather option?), but temporarily restricting exhaust flow (short of killing it) will heat up the engine faster, diesel or otherwise.

And you've got it reversed. My passenger manifold is a BAE part, complete with turbo mount flange. For my plans, that is a done deal and not optional.

What I want is a way to get the cross over from the driver's side to the passenger side to feed the turbo without something that looks like a contrast x-ray of the small intestine (I would settle for large intestine ).

Since the heads swap from side to side, the manifolds can mount either side, simply reversing the front/rear orientation. So since the passenger side exhaust exits to the left as you face that side of the engine, if mounted on the driver's side, it would exit to the front (still left) side. I was investigating whether there might exist a cast iron passenger side manifold that I could install on the driver side to feed the cross over forward of the mount and cross-member instead of going down the back and snaking back through/around.

Ah. That makes much more sense. In that case, what I have (whatever it may be) would make your life a little bit easier, but not as much as if you dropped out in front of that engine mount.

Would a 6.5 passenger-side manifold moved to the driver side (with turbo port blocked off) put your forward-facing exhaust where you want it?

Hmm...On second thought that sounds bulky. Unless you want twin turbos.

 

[BadDog]

Twin turbos, yummm... but not on a 6.2...

And yeah, a bit bulky. I think the header may be my best bet, but would like to at least find a late 6.2 or NA 6.5 (which apparently has the exit where I want) to see if it might fit.

 

[campfire]

Twin turbos, yummm... but not on a 6.2...

 

[BadDog]

Heh, just stumbled onto this post. First pic shows almost exactly what I'm wanting to do, but they welded a down tube to the stock cast manifold.

Look at the first pic.

 

[tRustyK5]

The H1 header is mild steel, might have a bit of a zinc coating. Should be easily weldable with just the basics. If you're gonna weld to a cast manifold, lemme know and I'll pm you.

 

[diesel4me]

My suburban has something similar to what you're describing, but it's on the driver side. The pipe comes down about 6" ahead of its stock location. No idea why. As already said, if the passenger side manifold did that it would come down into the starter motor.

Side question...at the end of this funny manifold manifold (dropping straight down rather than angling back) is a 3" tall block with what looks like a vacuum-actuated valve between the manifold and the exhaust pipe. I can't imagine valving off the main exhaust stream. Does anyone know of such a valve? Is there some other manifold with an EGR valve in that spot?

I'll try to get pictures up...

My 82 has that valve,its called an "EPR" (exhaust pressure regulator" ) valve..its purpose is tied in with the EGR valve,from what I read about it in one of my service manuals,it has a butterfly like a EFE or heat riser like a gas engine,that stays closed and directs more exhaust up to the EGR valve,which is open most of the time unlike the one on a gas engine would be,at idle and lower rpms...the EGR valve and the EPR are controlled by the EGR solenoid on the rear of the engine on the drivers side..

On my 6.2 someone just unplugged the EGR solenoid and dissconnected the vacuum supply to it from the vacuum pump,and that EPR valve is spring loaded ,so it'll stay open if it gets no vacuum to its little vacuum canister...
If you had a J code intake,there is no EGR crap or EPR to deal with...

 

[campfire]

My 82 has that valve,its called an "EPR" (exhaust pressure regulator" ) valve..its purpose is tied in with the EGR valve,from what I read about it in one of my service manuals,it has a butterfly like a EFE or heat riser like a gas engine,that stays closed and directs more exhaust up to the EGR valve,which is open most of the time unlike the one on a gas engine would be,at idle and lower rpms...the EGR valve and the EPR are controlled by the EGR solenoid on the rear of the engine on the drivers side..

On my 6.2 someone just unplugged the EGR solenoid and dissconnected the vacuum supply to it from the vacuum pump,and that EPR valve is spring loaded ,so it'll stay open if it gets no vacuum to its little vacuum canister...
If you had a J code intake,there is no EGR crap or EPR to deal with...

That makes sense. The engine is an '82 red-block. It just sounds so screwy to induce high back-pressure in the exhaust pipe. So opposite of what I'd like to have in the exhaust...

That prolly also explains why my '83 has 2 vacuum solenoids (one running EGR and one disconnected). I've wondered what that extra solenoid is for...

diesel4me, does your EPR-equipped manifold (driver side, I assume) drop the exhaust vertically down through the EPR valve instead of running back at an angle like the other 6.2 manifolds do?

 

[diesel4me]

Yes,the drivers side exhaust manifold dumps straight down,near the oil filter--in fact,I think the gas small block exhaust manifolds are so similar,that the same exhaust pipes could bolt right up if you decided to go with a gas engine..the passenger side manifold on my '82 has the usual 45 degree angle tilt that kind of hugs the firewall,just like the gas exhaust manifolds do..

I've read a few posts on other diesel forums saying the EGR system is a poor idea on a diesel,that it soots up the intake valves under their heads,also coats the intake with oily slime..some claim the valves were so caked up the engine couldn't breathe well,they ended up having to pull the heads,remove the valves,and use a wire brush on a bench grinder to get the carbon build up off the valve stems...I know my intake looks like a stove pipe under the EGR valve,so I dont doubt its true!..

From what I read I guess Fel-Pro has steel block off plates like the ones on a small block you can install to cork off the EGR passages in the heads,I guess engines with J-code intakes have the ports blocked off with those..

 

[campfire]

Yes,the drivers side exhaust manifold dumps straight down,near the oil filter--in fact,I think the gas small block exhaust manifolds are so similar,that the same exhaust pipes could bolt right up if you decided to go with a gas engine..the passenger side manifold on my '82 has the usual 45 degree angle tilt that kind of hugs the firewall,just like the gas exhaust manifolds do..

I've read a few posts on other diesel forums saying the EGR system is a poor idea on a diesel,that it soots up the intake valves under their heads,also coats the intake with oily slime..some claim the valves were so caked up the engine couldn't breathe well,they ended up having to pull the heads,remove the valves,and use a wire brush on a bench grinder to get the carbon build up off the valve stems...I know my intake looks like a stove pipe under the EGR valve,so I dont doubt its true!..

From what I read I guess Fel-Pro has steel block off plates like the ones on a small block you can install to cork off the EGR passages in the heads,I guess engines with J-code intakes have the ports blocked off with those..

Ok, then. I'll assume the P.O. kept the '82 manifold when he swapped the engine. Mystery solved (thanks for allowing the hijack).

diesel4me, a J-code or 6.5 intake will have a solid surface where the manifold meets the EGR ports in the head. So installing one (with gasket) effectively blocks EGR off without needing a separate block-off plate.