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:
Look at the sparkplug and exhaust port clearance problem here:
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:
Here’s a side profile view of the engine and trans in the frame:
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:
Here’s a frontal view, without the exhaust manifold obscuring it:
And here is a view from the rear, without the exhaust manifold in the way:
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
hmm...
), and was TAIL heavy versus frontend heavy like Red is. It IS a really tiny box, only about 4" long and 4" wide at its extremities, so would limit the translational and angular displacements of both the steering column and the Pitman arm. The ratio of the box is 20 to 1, which would stiffen the steering a bit (factory ratio on Red was 26 to 1), but then I'm sure the Flaming River version is MUCH smoother and more friction-free than EITHER the GM Corvair or GM AD box.