Engine/header install
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The brake line will be a problem. Even Pontiac had a different brake line route when using the RA/HO cast iron manifolds to avoid heating the brake line. Most brake fluid boils around 450° and the header tube will be above that temp with the pedal to the metal. I would want an inch of clearance.
The rag joint has plenty of clearance. We have a few cars in the club that the pins on the rag joint almost touch the header tube and they haven't had a problem.
As stated above, solid mounts are asking for trouble. First look it would seem that the engine wouldn't pull against the solid mounts any harder than the rubber mounts, but the problem is the nasty flexing the frame and cross member exerts through the mounts. Our old frames are really mushy. Look at it like a large lever twisting and pulling on the side of your engine block. The rubber or poly mounts absorb the twisting while the solid mounts put the stress right into the cast iron block.
The poly mounts have a low melting point. We ordered out one of the first sets that Butler had available and watched the polyurethane drip off the mounts on the test stand. Granted, temps are a little worse on the stand since there is little air movement, but it was still pretty strange to see.
Not a big fan of engine mount spacers unless the pan itself is sitting on the crossmember, but that is just my preference. There is a cure for the drag link touching but I'm a little hesitant to post it since getting carried away can lead to a big headache. When engine is in position and drag link is lightly touching the bottom of the pan, simply whack the drag link itself towards the pan. All you need is an 1/8" and you are totally safe putting a 1/4" dimple into the pan. Aftermarket pans are fatter in the bottom front and are down farther. Go 1/2" and you will have the crank counterweight skimming the pan. Clearancing works great but you can get carried away. We've probably clearanced over two dozen pans without a problem.
The rag joint has plenty of clearance. We have a few cars in the club that the pins on the rag joint almost touch the header tube and they haven't had a problem.
As stated above, solid mounts are asking for trouble. First look it would seem that the engine wouldn't pull against the solid mounts any harder than the rubber mounts, but the problem is the nasty flexing the frame and cross member exerts through the mounts. Our old frames are really mushy. Look at it like a large lever twisting and pulling on the side of your engine block. The rubber or poly mounts absorb the twisting while the solid mounts put the stress right into the cast iron block.
The poly mounts have a low melting point. We ordered out one of the first sets that Butler had available and watched the polyurethane drip off the mounts on the test stand. Granted, temps are a little worse on the stand since there is little air movement, but it was still pretty strange to see.
Not a big fan of engine mount spacers unless the pan itself is sitting on the crossmember, but that is just my preference. There is a cure for the drag link touching but I'm a little hesitant to post it since getting carried away can lead to a big headache. When engine is in position and drag link is lightly touching the bottom of the pan, simply whack the drag link itself towards the pan. All you need is an 1/8" and you are totally safe putting a 1/4" dimple into the pan. Aftermarket pans are fatter in the bottom front and are down farther. Go 1/2" and you will have the crank counterweight skimming the pan. Clearancing works great but you can get carried away. We've probably clearanced over two dozen pans without a problem.
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So what's wrong with motor mount spacers in your opinion? My grease zerks were hitting the pan also on lock to lock, so hitting the drag link and bending it slightly is ok?
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I'll reiterate my statement "but that is just my preference". So no earth shattering reason not to use shims, and just a small handful of reasons why there may be better solutions. The front crossmember where the engine mounts bolt to is at about a 30° angle sloping to the middle and mounting shim plates underneath the mounts brings the frame portion of the mount where the bolt slides through not only higher but also more towards the centerline of the frame. Higher you go the more the mounting bolt hole come in and produces consistent stress on the flexible part of the engine mount. Much better to keep any side loading off the rubber for the longest life.
Raising the front mounts produces more angle on the engine centerline running through crankshaft and transmission. If it was correct before, it is now off. If it was off before then it would still be better to investigate why it was off instead of applying a band-aid fix with shims.
Raising the engine up decreases the room above the engine and if running an aftermarket manifold might get things a little tight on clearance between air cleaner and hood. Also, the frame and the crossmember are probably the most solid part of the car and everything bolts to the frame and if something is off it is probably the bolted on stuff and not the frame or crossmember. The most logical point of change is the trans crossmember and/or the transmission mount. I've seen three different heights for the 400 transmission mount and they have varied over a half inch in height. This height change in the rear changes the fan height in front and also tilts the engine down on the drag link. Many transmission crossmembers have been damaged in the past by someone jacking up the car on the crossmember. So the front problem is probably either the various height aftermarket transmission mounts or bent transmission crossmembers.
I also gave myself some weasel room for using spacers if the pan is sitting on the crossmember, and I guess we could also add if the zerk fittings are hitting the pan at full lock. We know that most aftermarket pans are made fatter than original pans and this increase is pretty equal in both depth and width. So I would agree that the band-aid fix of adding spacers is much less work than removing and locating a proper size stock pan. Still a band-aid repair in my book, but one I would submit to. We had a similar problem on the '65 Cat Safari wagon with the pan almost touching the crossmember and the zerk fittings slightly hitting the pan. We could slip a piece of cardboard under the pan and called the clearance good enough and we took a round punch and put small dimples in each side of the pan for the draglink zerks to clear. Guess I can't get away from calling the dimpling also a band-aid repair
. Our problem is the 16"x4" diameter air cleaner sitting above the RPM manifold already touches the hood on acceleration and raising the engine would make matters worse. We picked keeping the engine low so we could run the biggest air cleaner possible.
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Raising the front mounts produces more angle on the engine centerline running through crankshaft and transmission. If it was correct before, it is now off. If it was off before then it would still be better to investigate why it was off instead of applying a band-aid fix with shims.
Raising the engine up decreases the room above the engine and if running an aftermarket manifold might get things a little tight on clearance between air cleaner and hood. Also, the frame and the crossmember are probably the most solid part of the car and everything bolts to the frame and if something is off it is probably the bolted on stuff and not the frame or crossmember. The most logical point of change is the trans crossmember and/or the transmission mount. I've seen three different heights for the 400 transmission mount and they have varied over a half inch in height. This height change in the rear changes the fan height in front and also tilts the engine down on the drag link. Many transmission crossmembers have been damaged in the past by someone jacking up the car on the crossmember. So the front problem is probably either the various height aftermarket transmission mounts or bent transmission crossmembers.
I also gave myself some weasel room for using spacers if the pan is sitting on the crossmember, and I guess we could also add if the zerk fittings are hitting the pan at full lock. We know that most aftermarket pans are made fatter than original pans and this increase is pretty equal in both depth and width. So I would agree that the band-aid fix of adding spacers is much less work than removing and locating a proper size stock pan. Still a band-aid repair in my book, but one I would submit to. We had a similar problem on the '65 Cat Safari wagon with the pan almost touching the crossmember and the zerk fittings slightly hitting the pan. We could slip a piece of cardboard under the pan and called the clearance good enough and we took a round punch and put small dimples in each side of the pan for the draglink zerks to clear. Guess I can't get away from calling the dimpling also a band-aid repair
. Our problem is the 16"x4" diameter air cleaner sitting above the RPM manifold already touches the hood on acceleration and raising the engine would make matters worse. We picked keeping the engine low so we could run the biggest air cleaner possible.
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I don't want to hijack this anymore so I'll state this and then it's back to your regularly scheduled program. Butler used a Pontiac stock unplated 6 qt. pan and I never caught that it was rubbing but the hot rod shop that did an alignment for me did because they also had to replace a ball joint. I had put a Transdapt poly trans mount in for my 4spd with the stock crossmember and the directions said to use the spacer but he said I didn't need it and was trying to tilt the motor up but it didn't help. So I did the spacers not knowing all the info you shared but it's staying and I have an Eddy rpm with a 1/2" spacer a different air cleaner then a taller billet hold down nut and I have about a 1/4"-3/8" clearance still on my '65 hood luckily. Like I stated in the broken motor mount bolt thread the new passenger side mount was a bear to beat down into place and I had to grind a point on the bolt to get it to thread in and the motor is still tilted up on that side. I have the through bolts and trans bolts slightly loose and I am going to take it for a light drive to see if it settles in.
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All information is helpful. I'll have to wait until Monday to speak with Butler/Ames.
I realized my last video displaying my concern was 9 seconds.
Below I attached a longer version for all to see for theirs an mine future mods.
I realized my last video displaying my concern was 9 seconds.
Below I attached a longer version for all to see for theirs an mine future mods.
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I think the rubber mounts will do that and maybe it will have more clearance once the trans is bolted on top the crossmember. I think the motor mounts are more towards the front of the motor causing it to sag backwards, I would probably block the motor up taking the stress of the mounts if it's going to sit for an extended period....might be worried about nothing I hope. I see the supervisor is camera shy 😉
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I believe I'm taking @PontiacJim advice on staying away from solid mounts.
Between the advice here and those of Ames techs I may purchase one of their upgraded kits for peace of mind. I'm holding up my resto with this decision, but I refuse to ever remove these headers once the body is on.
The jury is still out, but I will be taking @PontiacJim advice on staying away from solid mounts.
Between the advice here and that from Ames i may uograde now because these headers will not be coming off after the body is on.
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Ya I think that's a good idea, it's not an all out race car right? I bought the torque lock mounts the one side is bolted through then surrounded by rubber.
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@Baaad65 ...I'm going to be staring at the car in the garage with a beer in hand more than driving--#never mind racing!
The engine is moderately "built"--forged internals, port/polished heads, bored .30, 274H comp cams. I believe the builder said it should produce ~485hp at the crank
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I'm sure a lot of guys here are jealous that you're getting to install headers with the body off 😉
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Well--im happy my internet friends cautioned me before I slapped the body on first.
My coworker keeps me in check when I screw things up.
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Nice, ya I wouldn't want to screw up and have him/her after me 😉
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Install the bellshousing, trans, mount, and crossmember. You don't have to install clutch, linkage, shifter, etc.- just the basics. Then see if the pipe hits. With only the engine mounts, you won't have any idea of clearances as the engine will drop back when it hangs. Mock up the needed items and then you will also know if shimming will be needed or do anything for you.
If you want to check the angle of the engine, get the frame level front to back first. The AMA spec for the 1967 GTO engine installation angle is 4 degrees 42 minutes, or according to an online calculator = 4.7 degrees.
If you want to check the angle of the engine, get the frame level front to back first. The AMA spec for the 1967 GTO engine installation angle is 4 degrees 42 minutes, or according to an online calculator = 4.7 degrees.
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I remember seeing this same information somewhere...now where could that have been...oh ya way back in post #47 🤣
The engine will hang down without a trans hooked up. I would mock that up before doing and clearancing work
When I did my TKX install, my engine sat unsupported for two weeks and it didnt move. When shimming my trans mount for the drive angle, I hit the extremes of the range of motion.
In the end, it was only the rag joint that hits, and only when the steering is in one position, and the cam's rough idle is making the motor bounce.
In the end, it was only the rag joint that hits, and only when the steering is in one position, and the cam's rough idle is making the motor bounce.
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144 Posts
This was actually mentioned back in post #39.
The purpose of the mock up is to give you some clear guidance on the true angle of you engine and how the driveline to engine setup may or may not interfere with brake lines and vice versa (before you start ordering parts and wasting time and money.) Doubt you'll have pinion angle issues but, the purpose of the procedure is to know. Some of these could be non-issues and I wouldn't want to see you chasing your tail. You have the perfect opportunity to put your GOAT together right with nothing in the way. It could wind up that you just need to do controlled denting on some of your header tubes and be done. They're so beautiful, it almost seems like sacrilege but, that's what most a lot of us with headers have to do not to mention, another reason to mock it all up. Take your time, step by step and you'll have good results with the power team and you can move on to the next. There are some of us here that envy your position. Glad to see the solid mounts are not really a consideration especially given the probable power & torque output of your build. Must be the motor mounts used mine drops towards the rear significantly when trans is out
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If even needed, one other option may be to safely use a small spreader or the like below or even a brake piston spreader with rubber shims to prevent marring can work to nudge the pipes a 1/4" or so.
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