The Stovebolt Site Forums The Shop Area General Truck Talk Jim G’s SLURP Project – Posting 31: Steering box & exhaust issues! Ideas?

This posting is one in a series. If you have not yet read the earlier postings in the series, you’ll need to, as this posting won’t make much sense without having done so! Just do a search using the word “SLURP”.

In my last posting I hinted that there was some not so good news coming next. Here it is.

Randy and I ran into a couple of problems last night that I hope maybe one or more of you can “steer” us to solutions on.

When trial fitting the engine and tranny for the first time, we discovered:

Good news:

- By setting the engine back about 1.5 inches from the position that Street & performance thought would work, we gain a bit more width clearance between the chassis rails, as the rails diverge as they go from the front of the chassis to the rear

- With the 2 inch setback in the firewall, the engine cylinder heads will clear the firewall even in this more rearward position

- The engine mounts and tranny crossmember work well (although we may need to put a spacer between the transmission and the crossmember to raise it a bit, depending on how the chassis actually sits once the new leaf spring mounts arrive next week

- We picked up a lot of fore-aft clearance in front of the engine, to give us more room for FEAD and for the sandwich condenser/radiator/trans cooler/shroud/electric fan assembly

Bad news:

- The stock LQ9 driver’s side exhaust manifold cannot quite fit, even once we ground off a nub on it – you cannot get the gasket surface flush with the engine before the bottom end of the manifold hits the driver’s side frame rail

- The stock LQ9 passenger side exhaust manifold is even worse – cannot get even CLOSE to a fit before the bottom end of it hits the passenger side frame rail

- Any replacement exhaust (different manifold, tubular huggers, etc) MUST come down either at the rear or centered – definitely not forward, as coming down in the forward area would run right into the engine mounts

- The factory steering box blocks access to one sparkplug, and also makes it impossible to get either an exhaust manifold or a tube header pipe to one of the exhaust ports. Although Street & Performance said that the steering box does have to be moved outward about one inch if using a smallblock engine, with the LS series engine that does NOT solve the problem.

Here are some photos:

Grinding down the nub on the left manifold did not help:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem001.jpg


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem002.jpg


Look at the sparkplug and exhaust port clearance problem here:


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem003.jpg


Here’s a couple of shots showing how the driver’s side exhaust runs into the frame flange before it could be bolted tight to the exhaust port flange surface on the engine:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem004.jpg


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem005.jpg

Here’s a side profile view of the engine and trans in the frame:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem006.jpg

Here’s a view from the rear, with the driver’s side exhaust manifold as close as we could get it to where it actually needs to be:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem007.jpg

Here’s a frontal view, without the exhaust manifold obscuring it:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem008.jpg

And here is a view from the rear, without the exhaust manifold in the way:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem009.jpg

Yes, I know that Street and Performance said this would all work with only the steering box being moved outward about an inch or less, but that was with a smallblock, not an LS series engine, and they neglected to mention any other mods being required for an LS engine!

It looks like we need two things:

1. A different steering box: one that mounts on the OUTSIDE of the rail (versus on top), and that supports drag link operation versus cross steer. The factory ratio on the manual steering box on Red is 26.24 (Red has an 18” wheel), and I very strongly prefer to stay manual steering versus power, unless there is a COMPELLINGLY simpler power-equipped solution.

2. Different exhaust manifolds, OR hugger type headers, OR Randy suggested we could hand make headers (parts kits are easy to get and Randy can weld) that go straight OUT through the inner fenders, and then down and back.


We could do the “out, down, and back” exhaust by horizontally slotting the inner fenders above the chassis rails, and after everything is done and we KNOW everything works, replace the slotted inner fenders with new inner fenders that have fitted slightly oversize holes for each pipe versus one long horizontal slot, or aesthetically pleasing cover plates over the slots. One reason I warmed to this idea is that the exhaust path out the exhaust ports is then VERY unrestrictive in the first critical inches, plus we could keep the individual pipes LONG and also REASONABLY close to equal in length. Neither cast manifolds nor hugger headers would provide either of those benefits. Plus, this approach would LOOK really trick. (About as trick as we could hope for – this shape of body does not go well with zoomies!)


We need a steering box that has the following characteristics:

- Manual, not power

- Can mount easily to the outside of the driver's side frame rail (so for example, one that has vertical flange or flanges that enable bolting horizontally from outside of driver's side frame rail to the rail)

- output shaft sweeps a Pitman arm vertically fore and aft (the Pitman arm connects to a drag link on the driver's side axle spindle, and steers by pulling the drag link forward or rearward)

- Ideally, as near to the 26 to 1 ratio of the stock steering box as possible, since we have manual steering (no 16 to 1 "quick steering" boxes!)

- Not too large in physical size

- Suitable to handle 3000 lb vehicle

Potential examples of type that would work: a mid 1960's GM van, or a GM 4-wheel drive.


Unless we go the custom “out, down, and back” route, we also need a set of exhaust manifolds or headers with the following features:

- Designed for any LS series engine (LS1, LS2, Ls6, LQ9, LM4, etc), NOT for a smallblock

- Center or rear downward dump

- Hug the block

In the case of the exhaust, we’d really like to get temporary access to a few manifolds or headers that we could trail fit, because we KNOW from the computer modeling I did earlier that the exhaust will have a significant effect on the power we can expect to get from the cammed LQ9 engine.

Randy does not regard this as a serious problem – just a temporary delay while we find the best solution – and that makes ME feel less concerned.

Any ideas guys and gals?

Jim G

Postscript!

Randy and I must have stumbled onto just about the only exhaust manifold that would NOT work!

I say this based on what happened this morning.

I made a very early morning run down to Colvin Automotive, where my friend Daniel Denton, the dyno operator and tuner, had said he would leave a couple pairs of exhaust manifolds for me to pick up and trial fit. One pair was from his personal C5 Corvette, while another was of “forgotten” origin! This latter one is referred to below as the “other” manifold!

I brought them home and quickly trial fitted them. They BOTH fit just fine!

Here is what the Corvette manifolds look like uninstalled, and then from the front and from the rear views when (loosely only) installed:


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem010.jpg


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem012.jpg


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem013.jpg

Here is the “other” manifold set:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem011.jpg




http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem014.jpg


http://i252.photobucket.com/albums/hh16/JimGnitecki/Exhaust-steeringclearanceproblem015.jpg

I still cannot get the factory steering box into its stock position, but either of the manifolds clears everything else.

Randy now has TWO surplus steering boxes for us to try next session . . .

Jim G

The more that Randy and I find out about that Flaming River T-Bucket Reversed Corvair steering box, and the more measurements we take, the better it sounds.

Here is a photo of it from the Flaming River website:

http://i252.photobucket.com/albums/hh16/JimGnitecki/Steeringbox-FlamingRiverT-Bucket.jpg

This box is a funny 3D shape of course, but the baseplate is only a little over 4 inches long, and the maximum width anywhere is 4 inches. It uses needle bearings and is made of steel, not alloy. The ratio is 20-1, which is acceptably close to Red's stock 26 to 1, and very workable thanks to both the needle bearing action of this box and the aftermarket tapered needle bearings in Red's front end.

The box could sit in almost exactly the same spot as the stock one, but would need a piece of simple angle iron bolted to the left side of the frame rail (no welding into the frame), so that it can sit just a bit further left than the stock box, to clear the exhaust manifold. Two of its mounting bolts would go into the angle iron, and one into the original truck frame.

Because the box is so small, we could actually move the engine a tad forward or backward (engine mount holes not yet drilled), so that the box's rightmost projection goes into an area where the exhaust manifold is "recessed" a bit.

The box is actually small enough that it would be entirely BELOW the sparkplugs.

Randy pointed out that the Pitman arm shaft would be at almost precisely the same point in 3D space as the factory box, and of course Flaming River offers Pitman arms too.

Randy thinks this solution is way nicer than the 60s-70s GM van box.

On the strength of all this, I ordered one of these Flaming River boxes to trial fit. I can return it if it does not fit well.

Jim G

Jim,

It looks like you might have found a fairly simple solution to what I was afraid was going to have drastic implications on either the LQ4 install, or at least have serious implications on the results. I would be curious to see a few A to B pictures of the old vs. new steering setup. Thanks.

I'll post photos and text descirbing what happens, regardless of the outcome!

Jim G