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I have been reading BBC install threads and was wondering if anyone has tried moving the engine and transmission a little to the right away from the steering box. The reason I ask is when Chevrolet put a BBC in the first generation Camaro the left exhaust manifold interfered with the steering box just like it does in a Tri-five. To solve this problem the engineers used asymmetric frame brackets and an offset transmission cross member to move the engine (and transmission) a good half inch to the right of the center line of the car.

I have read many posts about moving the engine forward for clearance but haven't seen anything about moving the engine and transmission to the right. I figure if it was good enough for the 396 Camaro it's good enough for a Tri-five Chevy. A little extra space between the steering box and the hot exhaust is worth a slightly off center engine.

Here's what the Camaro Research Group says about it:
http://www.camaros.org/engine.shtml#EngineMounting
In order to gain engine compartment clearance, big block (BB) engines were offset 1/2 inch to the right (towards the passenger side) by means of asymmetric brackets. 1967-68 BB frame mount brackets are 2-1/2 inches wide (but not the same as SB) and use the same engine mounts as 67-68 302ci and 350ci. For 69, BB frame mount brackets were redesigned to use the new thicker, narrower, engine mount also used by 302ci and 350ci. BBC bracket pairs are easily spotted because the left bracket is noticeably taller than the right in order to achieve the engine offset.
 

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offsetting the motor is not a problem as long as the trans mount is offset by the same amount so crank is parallel to pinion shaft in the diff.
i have done it up to three quarters of an inch in cases due to starter motor/ steering rack issues with right hand drive cars here in australia.
 

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I have been reading BBC install threads and was wondering if anyone has tried moving the engine and transmission a little to the right away from the steering box. The reason I ask is when Chevrolet put a BBC in the first generation Camaro the left exhaust manifold interfered with the steering box just like it does in a Tri-five. To solve this problem the engineers used asymmetric frame brackets and an offset transmission cross member to move the engine (and transmission) a good half inch to the right of the center line of the car.

I have read many posts about moving the engine forward for clearance but haven't seen anything about moving the engine and transmission to the right. I figure if it was good enough for the 396 Camaro it's good enough for a Tri-five Chevy. A little extra space between the steering box and the hot exhaust is worth a slightly off center engine.
No issue with the driveline as stated above.

Check the pass side header clearance though, mine is fairly tight on that side also. No interference on the steering box with a stock box, no interferences either side.
 

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Pushing the engine sideways, you also need to consider the K Frame positioning, the engine height may also be affected, the radiator set up with the fan positioned to one side may affect cooling, and you`ll need to consider getting the pinion angle/transmission tail shaft all lined up.
 

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Pushing the engine sideways, you also need to consider the K Frame positioning, the engine height may also be affected, the radiator set up with the fan positioned to one side may affect cooling, and you`ll need to consider getting the pinion angle/transmission tail shaft all lined up.
the only thing that happens when you shift the engine sideways some is the pass header gets real tight. there is no affect to the cooling system and no affect on the frame.
 

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Doesn't Earl Williams have a nice mount that allows for side to side?
 

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Yes to all the above. It's okay to move the engine over as long as you move the transmission mount the same distance.

And yes, the latest style Earle Williams mounts give you a bit of potential movement to the passenger side. I don't know the amount but it's not much.
 

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Discussion Starter #8
Doesn't Earl Williams have a nice mount that allows for side to side?
Those Earle Williams motor mounts look really good. The new style mounts have the option of mounting the engine in the standard position or ¾ inch forward and also has slots to shift the engine side to side.

Another thing to consider on a big block installation is crossmember sag. Crossmember sag is common in Tri-five Chevy's. Not only does it cause wheel alignment issues but it also causes the top of steering box to tilt inward toward the center of the car. This is exactly what you don't want when installing a big block. This inward tilt is worse at the top because the frame where the box bolts up is no longer plumb. I believe frame sag is why some cars have more of a problem with steering box clearance than others.

The weight of the car is constantly trying to push the frame rails together. Think of the control arms as levers and the narrow stock engine mounts as the fulcrum. The strength of the front crossmember is all there is keeping everything in position. When you hit a pothole these forces on the crossmember are amplified. The weight of the engine is pushing down and the upper control arms are pushing in. Over the years the front crossmember bends and the top of the frame rails move closer together. On my car my frame rails had moved 3/8 of an inch closer together (3/16" per side). I had a body shop pull my frame back into specs. Actually they pulled it an additional 1/4 inch wider which is 1/8 inch per side.

I wonder if side motor mounts will brace the frame rails and help prevent the crossmember from bending. What do you think?
 

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Considering the "stout" design of Earl's mounts, I'd think they would help
 

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I think they might help because the forces due to the engine weight are moved outboard.

But, I'm a bigger believer in collision damage causing frame sag as opposed to wear and tear. Potholes and curbs are in the collision damage category too.
 

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Just my opinion but, I don't think the trouble of moving the engine over away from the steering box is worth it, just to lower the temps by several degrees. I haven't had any problems from heat from the exhaust on the steering, and I haven't heard of anyone else. I think its a waste of time and money, if your moving it over just for heat on the steering box.
 

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Discussion Starter #12
I think its a waste of time and money, if your moving it over just for heat on the steering box.
On a small block engine you are correct, but when installing a big block in a Tri-five the #5 exhaust port is very close to the steering box. I have seen several big block cars with only 1/8 inch of clearance between a dented in header tube and the steering box. Gaining an additional 1/2 inch by shifting the engine and transmission to the passenger side can make the difference between fitting and not.
 

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On a small block engine you are correct, but when installing a big block in a Tri-five the #5 exhaust port is very close to the steering box. I have seen several big block cars with only 1/8 inch of clearance between a dented in header tube and the steering box. Gaining an additional 1/2 inch by shifting the engine and transmission to the passenger side can make the difference between fitting and not.
I understand that, I have had a big block in my 56 before I know all about the # 5 exhaust port. Heat was never a problem on the box. For me or anyone else I have known with a big block in their trifive. Just sayin, don't think it's worth all the trouble. What makes you think you have a problem?
 

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a very slight dent, yes, then grind a little off the box. i had a leaking steering box, tried to fix to no prevail. pulled all the fluid out, packed it with wheel bearing grease. no problems, just over 10 years now.:shakehands:
 

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Mine is off center about 1/2".

As far as frame sag. Most of it was built in. It was already in 56 that GM showed us how to bend the frame to give it more caster. They didn't "sag" in 1 year. Even after that I don't think they gave the new ones much tweaking from the original specs.
 

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Am mocking up the Williams LS mounts, in the rust bucket.
I have them tacked in, for now.
I had to use the grinder on the edges, to get them to fit the contour of the frame.
The pictures on Earl's site shows just about what I've done.
The engine is shifted to the pass side about 1/2"+.
I have the Borgeson box, and at 1/2", I can almost get my finger between the box, and the 2010 Camaro header.
The box has not been milled down. One could get another 1/8", if that was done.
As it is now, I can use the alum heat shields that come w/ the headers.
The header will be ceramic coated, and the exh system will be s/s, Pypes 2.5" out the back. That also goes in, b4 the body is swapped over.
I also have Earl's trans x member. The frame tabs are slotted like the engine mounts, so alignment to the diff is not an issue.
Everything is tack welded, until I'm sure it all fits. Still have to finish up the 8.8.

Back under my rock..:D
 

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Yours is now a fingers width further away from the box than mine. I need to address that some day, it vibrates the whole car. Some time ago I pumped it full of high temp wheel bearing grease.
 

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I ground the corner of my CPP box significantly with no adverse affects. I didn’t want to ding my coated headers. Plenty of clearance now.

72CEAF30-A9A6-4531-B5AD-8BAF5AD4A545.jpg
 
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