5.3 INSTALLATION IN 72' CHEVELLE 'help'
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Staging Lane
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5.3 INSTALLATION IN 72' CHEVELLE 'help' Got the 5.3 vortec and 4l60e sitting in my 72' but the trans angle is about 7 degrees. The trans is about as high as it can go and the engine cannot be lowered any more, only have about a quater inch of clearance between the holley pan and cross member. I have read about other 5.3/1971/1972 installations without having to cut on the tunnel so trying to figure out how to solve my problem. I removed the entire front clip for the installation so the front end is a little higher than the back but don't think it would add that much to the angle of the motor/trans. Any ideas would be appreciated.
72' Chevelle
05' 5.3 vortec / 4l60e
Holley pan
Chevelle narrow frame mounts with Energy Suspension engine mounts.
72' Chevelle
05' 5.3 vortec / 4l60e
Holley pan
Chevelle narrow frame mounts with Energy Suspension engine mounts.
I've got my 5.3 set back about an inch in mine. No accessories, no rad, no fluids, no batt...I'm at about 5 degrees...
Got the 5.3 vortec and 4l60e sitting in my 72' but the trans angle is about 7 degrees. The trans is about as high as it can go and the engine cannot be lowered any more, only have about a quater inch of clearance between the holley pan and cross member. I have read about other 5.3/1971/1972 installations without having to cut on the tunnel so trying to figure out how to solve my problem. I removed the entire front clip for the installation so the front end is a little higher than the back but don't think it would add that much to the angle of the motor/trans. Any ideas would be appreciated.
72' Chevelle
05' 5.3 vortec / 4l60e
Holley pan
Chevelle narrow frame mounts with Energy Suspension engine mounts.
72' Chevelle
05' 5.3 vortec / 4l60e
Holley pan
Chevelle narrow frame mounts with Energy Suspension engine mounts.
What conversion mounts are you using? Holley? 1in back? You also need to keep an eye on tie rod clearance.
Kerry
Last edited by analyte; May 3, 2013 at 11:09 PM. Reason: typo
Thread Starter
Staging Lane
Joined: Mar 2012
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Using stock narrow frame mounts and poly motor mounts with an adaptor plate.
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You'll never get to 2-3 degrees on a Chevelle LS swap with stock steering as even the oil pan with the lowest profile in the front (F-body pan) needs to ride over the top of the tie rod ends during full turns. The components on these cars were designed for compatibility with the old motors, which had much narrower oil pans (6 1/4" compared to almost 8" for LS pans) and allowed the engine to be dropped down between the tie rod ends instead of having to ride above them like an LS engine has to.That issue could be overcome by just raising the rear of the transmission, but the small/low tunnel height on A-bodies works to kill that idea right off the bat. Both of the fixes for this problem are expensive...go to a rack and pinion set-up up front to allow you to lower the engine, or rebuild the tunnel sheet metal to allow you to raise the rear of the transmission. Obviously, there are many Chevelles that have been swapped with the 5 degree inclination angle you are experiencing, but the working U-joint angles that acheives are not something I would feel good about when putting together a moderate to serious performance machine. There's at least one build I found on this site that understood all this and took the time and effort to reform his tunnel to get it right.
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There you go, bczee is another swapper who is all too aware of what is required to "get in right", A-bodies are just not a good choice for LS swaps for someone on a budget that wants a well-engineered final result. If you have the financial, technical and physical means to see your way through the details then they can be swapped well like any other car, but it's a bag of compromises when done in a bolt-together fashion.
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Thread Starter
Staging Lane
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I checked a flat place on the frame under the door and the frame is sitting at about 3 degrees up. My garage floor also has about a 1 or 2 degree slope.
I checked the engine angle again and it is right on 6 degrees so I hope that the weight of the front clip, exhaust maifolds, alternator, oil and water along with sitting on a flat surface will result in somewhere around a 4 degree angle.
I checked the engine angle again and it is right on 6 degrees so I hope that the weight of the front clip, exhaust maifolds, alternator, oil and water along with sitting on a flat surface will result in somewhere around a 4 degree angle.
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You need to verify your U-joint working angles with your car at your decided ride height with your chosen wheel and tire package installed. The engine inclination angle is not set for the benefit of the engine or transmission, it's to ensure you will have adequately minimal U-joint working angles for long U-joint life and vibration-free operation. It's stange how these LS swaps have turned into the backward-step process that they are for most people instead of resembling the process that's used by vehicle manufacturers and custom car builders...ride height/stance are determined first and then the engine and rear end pinion are set as needed to acheive proper U-joint working angles. If you disregard these steps you are not properly engineering the swap but instead just assembling parts for the sake of doing so.
Yes 5+ degree or more is a bit much.... What is really important is the the angle of both the Diff pinion angle and the engine/trans angle..in regard to the Driveshaft. Depending on what you have.. 5 degree might be what is needed!.. (see below).
Suggest you reseach Drive Line Angle or Setup..here are a few articals to start with..
http://www.4x4wire.com/toyota/tech/driveline/
http://www.4xshaft.com/driveline101.html
Oh, BTW.. the Floor pan support/cross brace can also be in the way of the Yoke/U-Joint. I had to use a BFH on it to flatten it some. Others have had to cut it out and make a new one that is higher and re-enforced.
BC
Suggest you reseach Drive Line Angle or Setup..here are a few articals to start with..
http://www.4x4wire.com/toyota/tech/driveline/
http://www.4xshaft.com/driveline101.html
Oh, BTW.. the Floor pan support/cross brace can also be in the way of the Yoke/U-Joint. I had to use a BFH on it to flatten it some. Others have had to cut it out and make a new one that is higher and re-enforced.
BC
I am sorry, but what most of you are describing as the "angle" is completely irrelevant. What if the car was jacked up in the rear? What is the car is lowered in the rear and high in the front? The angle of the engine with respect to the earth is completely irrelevant.
In order to set the driveline angles, you need to be paying attention not to the angle of the engine with respect to gravity, but the front and rear operating angles. The front operating angle is the angle between the output shaft of the transmission and the driveshaft. The rear operating angle is the angle between the pinion gear and the driveshaft. The front and rear operating angles need to be equal, but opposite and also as small as possible without being zero.
On a GM a-body with a LS engine, you essentially need to raise the back of the transmission as high as it will go. If your car will be lowered, you may still run into a situation where the front operating angle is too large. This happens because when these cars are lowered, the rear axle rides higher inside the body. This causes the front operating angle to increase. By adding adjustable rear upper control arms, you will be able to make the operating angles equal, but you will not be able to reduce them. This will likely result in operating angles that are more than 3 degrees, which I guarantee will cause a high speed vibration. This is one of the dirty little secrets of a-bodies that are lowered.
Andrew
In order to set the driveline angles, you need to be paying attention not to the angle of the engine with respect to gravity, but the front and rear operating angles. The front operating angle is the angle between the output shaft of the transmission and the driveshaft. The rear operating angle is the angle between the pinion gear and the driveshaft. The front and rear operating angles need to be equal, but opposite and also as small as possible without being zero.
On a GM a-body with a LS engine, you essentially need to raise the back of the transmission as high as it will go. If your car will be lowered, you may still run into a situation where the front operating angle is too large. This happens because when these cars are lowered, the rear axle rides higher inside the body. This causes the front operating angle to increase. By adding adjustable rear upper control arms, you will be able to make the operating angles equal, but you will not be able to reduce them. This will likely result in operating angles that are more than 3 degrees, which I guarantee will cause a high speed vibration. This is one of the dirty little secrets of a-bodies that are lowered.
Andrew
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Your description is valid Andrew and is the same thing I'm trying to convey to the OP, which is that the actual measured engine inclination angle is only relevant to the point of how it affects the U-joint working angles; what it is in relation to the frame, ground or any other reference point is irrelevant. That's why the ride height, rake and wheel and tire package needs to be decided before the inclination angle of the engine is fooled with. At that point it is set to get the same but opposite angles you mention while shooting for a maximum of 3 degress of working angle in each joint. The smaller the working angle the better as long as it's at least 1/2 a degree.
I can tell you with confidence, that if you plan on lowering the rear of the car at all, you would be best off to raise the back of the transmission as high as it can go. You will be limited by the slip yoke making contact with the floor boards.
Andrew
Thread Starter
Staging Lane
Joined: Mar 2012
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The car sat fairly level before the 5.3/4l60e swap and I have no plans to change it. The front is a little high because of no front clip but I hope it will drop back to level. It sounds like I am going to have to get the drive shaft cut and installed to be able to get the correct angle, just hope I will not have to cut up the tunnel.
