GM 5.3/4L60E/Klune/Stak 300

[Jeff 98XJ WI]

I really don't understand the theory behind the construction of these manifolds. Let me try to explain the construction. It seems like they have a plate that bolts to the head, four short tubes welded to this, then the two halves of the inner piece installed over the short tubes and welded to the tubes. Then the two halves of the outer installed over the inner and the short tubes and welded around the tubes. There is a ring of fiber material between the inner and outer pieces where they join at the collector. Finally, the curved tube is welded to the junction of the inner and outer at the collector. The inner has two open slots per exhaust outlet that allow at least some gas to pass between the inner and the outer and two open slots where the inner and outer meet back at the collector. Here are a couple pics of the slots by the exhaust outlets.

I think I'm just going to tack the inner to the outer at my cut line, reinstall the outer at an angle for frame clearance and then weld the tube to the outer collector at an angle that works. Jeff

 

[Jeff 98XJ WI]

Changed plans again. I welded the whole mess back together and instead cut the flange almost all the way off with a cutoff wheel. I then bent the saw cut together and did it twice more. In the end the exhaust manifold tucks closer to the block and clears the frame. The motor mount is going to be tricky, but I'll figure something out.

Jeff

 

[Root Moose]

Looks good.

Those are strange manifolds.

The only thing I can think it would be for is acoustics (reducing or modifying) or heat shielding. I'm not terribly confident the heat dissipation is worth the effort they put into these unless it is some kind of software designed thing that was easy to theory out for big results.

Regardless, very strange.

 

[Jeff 98XJ WI]

Here is the drivers side with the manifold modified right by the ports. I'm happy with the fitment.

I've got to do some magic with tubing to swing the output close to the block, down, forward and around the front of the oil pan now. Man, mandrel bent SS tubing sure isn't cheap! Jeff

 

[Jeff 98XJ WI]

Back to the intake manifold, I decided to copy what I saw another person do and drill and tap a hole in the side of the manifold to duplicate the truck manifold for one of the valve cover vents. Here's my pictorial:

Here's the truck manifold and it's port:

I layed out a hole and drilled it before realizing that it passed right though part of the throttle body seal. Oh well, I just dealt with it and finished the hole and tapped it to 1/8" pipe thread.

Here's the setup on the engine:

Jeff

 

[Jeff 98XJ WI]

A little progress today. I pressed the harmonic balancer on the engine using an electrician's hydro hole punch kit! I adapted the kit to the engine by welding a 7/16" fine thread coupling nut to a M16 x 100 bolt with the head cut off and then threading the reducing stud on to the bolt/nut and pumping away. Worked slick! BTW, the LS engines use a press on balancer with a stretch to torque bolt instead of a keyed crankshaft. I don't know why, but this is the way they are.

One source told me I needed to install a special spacer on the crank first but another source told me I did NOT need to use the spacer. After pressing the balancer on, it looks a little tight to me. I think I need the spacer. Oh well.

Jeff

 

[Sponge Bob]

I agree from your photo it looks like it needs to come out. Possible belt killer!!

 

[Jeff 98XJ WI]

Well, I ordered a bunch of small parts that added up to a good chunk of change from GMPartsdirect and now I'm waiting and hoping they send the stuff in a decent time frame. They did NOT answer two emails asking about part numbers and time was wasting, so I just went ahead and ordered, but now they haven't accepted the paypal payment nor have they responded. They are so much cheaper than a GM dealer though that I had to try. In the mean time, I am trying to plan the exhaust. So far, my plan is to use part of the stock Vette manifold downpipe on the drivers side to kick the tubing closer to the block, fit in a 90 degree to point it down to another 90 pointing forward then to another 90 wrapping around the oil pan to another 90 pointing it out the back of the jeep just above the bottom of the frame rail. The passengers side will get the stock down pipe welded back on at the correct angle to swing down and into the 90 coming from the other side. So, I have it envisioned, but how do I actually make it happen?! I guess I'm going to purchase some mandrel bent 90's in stainless steel and weld them together after cutting and grinding to fit. That's how I made the exhaust route for the 3 link front in the old xj. I used a Borla pipe and cut and fit numerous pieces together. I think the vette downpipes are 2.5" OD. I would actually like to use something smaller for routing around the oil pan, but I think I can make 2.5" stuff work. Can I run the passengers side 2.5" pipe into the other 2.5" pipe from the top and just weld it in like cage tubing with a hole cut in the bottom tube? Do I have to step up in size after I combine the two downpipes? If so, to what size? For fitment purposes, staying 2.5" would be easier than trying to fit 3" tube. Do I need to put some sort of flange in places for ease of disassmbly? Can I use a swaged end in place of a flange? For instance, under the oil pan, maybe I could use a slip fit with a clamp to separate the drivers manifold from the rest of the system. I'm not sure how to put a joint in the passengers side between the manifold and the junction where it comes into the pipe from the drivers side. Suggestions? Jeff

 

[UNCC_99XJ]

I'll be interested to see how this turns out in the end. What year did you get the 5.3 from? I ask because the 5.3 we've got has been giving us a lot of problems in the last couple of years...just curious as to what the mileage is and what not on this motor.

 

[Sponge Bob]

yes weld the pass side to the top like a rollcage just make the hole as exact as possible to keep from causing any turbulance. This is how my stock y pipe is on my impala. The joint had some angle to it so i would not make it a 90 connection. Then i would have a ball flange for flex. You need to install the 2 oxygen sensors also some where after both manifolds.

 

[xjbubba]

Project is looking good, Jeff. You have certainly have perseverance!

Your exhaust plan sounds good--after all, you're building a "crawler", not a street rod.
I'd try to use smooth bends, and pipe as big as will fit. Of course you need to know where your control arms and other required rock crawling assets will be placed before building the exhaust.

The following shots are my 5.7, so not "real" applicable, accept it gives you an idea about routing arround the front of the pan, from the driver's side to the passenger side.
I merged the two pipes with a home made Y-pipe. Took two 2.25 pipes into a 3.5 inch, the necked it down to 3 in back to my Cat. Works fine, as long as you keep it off of the dyno.

 

[Jeff 98XJ WI]

Thanks for the input guys. Xjbubba, do you have any better shots of the Y joint? Do you recommend 3" pipe beyond the Y then? Jeff

 

[xjbubba]

Jeff;
I don't have any clearer shots because it's all wrapped for heat reduction; however, the following shots are the stock '94 cross over after which I modeled my fabrication.
I used an exhaust pipe reducer from Summitracing.com (part # wlk-41973) to fab the collector. I "massaged" the 3" ID end to accept the two 2"OD down pipes from the manifolds (my prior numbers were wrong! looked at my notes, and realized my memory was bad). I then run a 2.5" pipe all the way back--the Cat and muffler are 2.5 in. Running a 3" pipe back, over the tranny cross-member was not doable because of clearance issues.
I don't notice any "penalties" in power using the smaller pipe, but again, it's a "crawler", not a street rod.

 

[Jeff 98XJ WI]

More Vette manifold mysteries! I cut what remained of the downpipe in half only to find another inner/outer tube!

When one looks into the end of the tube I don't even find a joint!

It really doesn't matter as I'm just going to weld 2.5" tube to the cut portion of this, but it sure is weird. Jeff

 

[Jeff 98XJ WI]

Well, I bought 14 items from GMPartsdirect.com for a grand total of over $300! OUCH. Oh well. I got:
Two water pump gaskets-5.32
Two exhaust manifold gaskets-16.52
One short oil fill tube-4.52
One new harmonic balancer bolt-2.97
One Corvette alternator/power steering pump bracket-51.37
One idler pulley-30.41
One tensioner-55.40
Two power steering pump bolts-4.78
One intake manifold bolt...turns out to be nothing special, so I'll pick up the rest locally-2.52
One starter bolt as I needed one-3.11
One power steering pulley (Caddy CTS-V)-23.97
One LS2 steam crossover tube-28.51
One smooth idler pulley for if I use a KWiK system for the York-31.23
One power steering pump brace-5.20
Total-265.83
S&H-58.45
Total-324.28!

I bolted the alternator bracket on and snapped a couple pics:

A closeup view of the power steering pump mount shows that it places the pump about 1/8" off the end of the head and offset just to the outside of the head. There is a thicker boss there for the two bolts that hold the power steering pump in place.

Here are a couple with the pump bolted in place:

Here's a shot of the truck alternator in the Corvette bracket. Notice that the truck alternator fits and lines up fine, but the bolt spacing is off.

I came up with a real slick way around that:

I decided to use a LS2 steam crossover tube to keep the steam traveling up on it's path from the heads back to the radiator. The truck crossover would have put a pocket in the rubber hose connecting to the throttle body.

Jeff

 

[Jeff 98XJ WI]

I purchased a shorter oil fill tube since the tall truck unit hit the hood.

There is a little plastic clip that holds the unit in the right position and I broke the one for the truck fill tube when trying to twist it to the removal position. I had to reach into the valve cover area and pluck it out.

Here is the single intake manifold bolt I purchased:

Looks simple enough. I'll source a complete set through fastenal locally.

Jeff

 

[Jeff 98XJ WI]

After mounting up the alternator and power steering pump with pulley, I jostled the engine around a bit till I finally settled on it being offset to the passengers side by 1/2". The power steering pulley is very close to the steering gear, but I think has enough clearance. The belt might get too close to the gear though on it's way to the alternator and I might install another idler just below the alternator to hold the belt away from the steering gear, but I think I'll see how it goes first. I also pushed it back pretty much as far as it can go while the steering gear is pretty much as far forward as it can go.

I sliced a sliver off the seam on the firewall to make enough clearance on the drivers side:

Passengers side is 10" off the frame

Drivers side is 10.5" off the frame

Drivers side exhaust manifold

Passengers side exhaust manifold

Drivers side firewall clearance

Passengers side firewall clearance

Here's the power steering pump pulley clearance

Here's a shot of the belt route up to the alternator

Front view of engine and accessories:

Jeff

 

[XJEEPER]

Looking better than it ever has.......keep after it, Jeff!

 

[Root Moose]

x2!

They always say that it's the "nickel and diming" that makes engine swaps expensive. Great to see some costs associated with getting the details right.

 

[Jeff 98XJ WI]

I've not made much progress on the rig in the last few weeks. I've got a hair brained idea to make Air Conditioning work on the rig and don't want to finalize the motor mounts till I decide on a compressor and mount it. The original GM Truck compressor would work, but it needs a different mount to push it back in line with the LS2 crank pulley. It MAY fit in an LS2 bracket, but I'm not sure. However, it is of a Variable Displacement type and needs the GM body computer to make it run correctly. So, I tried a number of other compressors and lines in the tight confines I have. The '93 XJ compressor lines exit out the back which won't clear the motor mount. A '88 XJ compressor has lines that exit perpendicular to the back, but I still didn't think they would clear things. A Dodge Durango compressor looked like it would fit, but the lines ended up obscurring the motor mount bolt and was kind of deep. I found out that a number of aftermarket A/C companies use a Sanden 7176 compressor that is tiny and the lines exit out the side. They are readily available for $250, but I couldn't find any existing cars that used them. However, Geo Metro's used a variation that I think will work, so I now have an ebay score on its way.

I did mock up a set of motor mounts on the engine side. I sunk the tubing for the XJ Lower Control Arm Bushings into a plate to tuck it as tight to the motor as possible. This might give me room enough to slip a bolt in past the compressor and get a wrench on both ends. I plan to replace the front two bolts with Allen Head units to make getting a wrench on them possible. They do fit as is now though! I plan to build a boxed in section that extends out from the frame rails and cradles the bushing. I also plan to make that section bolt on to the frame with through the frame sleeves and bolts so it can be removed if necessary during engine removal.

I set the hood back in place to check for clearances after getting the vette LS2 accessories mounted up and adjusting the engine placement. Looks good! I am a bit concerned about an air intake system with the MAF sensor and a radiator with fans fitting in there, but I imagine I'll come up with something to make it work.

The alternator clears the hood fine as does the oil fill tube. The fuel crossover tube on top also just clears the hood! It may look funny, but if it works and doesn't cost me anything, it's staying for now. The tranny dipstick and tube also fit after massaging the tube a little.

Until the Compressor is in, Jeff