The intake should be level...........That being said, I like the looks of a Nailhead when the valve covers are level. I 'm running a log intake on my 401 so with the intake level the motor is level also. Not much help am I?
The engine should have a bit of inclination. I can't remember the degrees, you'll have to look it up. An intake usually compensates for that inclination, making the carb sit level. I'm going to go out on a limb and say that just about anything attached to the engine would have the same inclination as the engine.
The bottom line is the carbs SHOULD be level............As you can see in the picture, the carbs are level, the valve covers are level and the motor is level.......................Most other intakes will be high in the back but there are ways to work around that.
so could my intake be raised slightly in the back? Could it be on backward? Posted using the Full Custom H.A.M.B. App!
"Could it be on backward?" Sure it could. Lots of fabbing, but anything is possible. Here's some info from a 15 second GOOGLE search: "Engine, pinion angle and ride height are all relative to the ground. Most engines are set at 3 degrees, when you look at the side of the intake manifold on a carburetor engine you will notice the manifold has a wedge in it. This wedge is to allow the carburetor to sit level. The main purpose of having an engine angle is to allow for more room in the passenger compartment by having a smaller tunnel. That is why the car manufacturers build front engine cars with the engine at an angle. Drag race cars have a 2 to 3 degree negative engine angle, the engine will tip down in front. Having this negative angle allow for better weight transfer to the rear of the chassis. The 3 degrees you keep hearing about is the recommended angle for carburetor cars with intake manifolds set at 3 degrees. With the engine and pinion set at 3 degrees they do not line up directly and requires you to make them parallel. This misalignment allow the u-joints to rotate on a street car." Read more: Determining Engine and Pinion Angle http://www.roadkillcustoms.com/hot-rods-rat-rods/hot-rod-engine-pinion-angle.asp#ixzz3AhMYjlQz So, what angle did you set your engine at? I'm sure there's a thread about it some where.
From your link though I gather that the engine does not have to be level and should have some rearward drop to it.
That was just something that I found that may apply to your situation. I didn't even look at the link. But one of the things I learned a while back is engine placement and setting the carb level. It made sense, so I keep it in mind. Do ALL cars require the carb base to be 3 degrees? Maybe not. But those engineers did a few things for a good reason.
something a long time Hotrod builder taught me was that with an angle finder sat on the carb pad, reading level that is where the engine needs to be mounted if that makes sence, as this helps set up the engines "fall back" angle "incase of any engine mount failure", so from the side as said above the intake rear will usually be sitting higher than the front, and the valve covers/engine leaning back, but this could be different with Nailheads though I believe it depends on the intake setup too hope this helps Charlie
Don't forget to check both directions as indicated, lengthwise and across the engine. It's all about float levels, when both directions are level the engine should be then roughly 3 degrees down at rear. Engineers spent $M on R&R, I take advantage of their experience and try not to reinvent the wheel. Differential will be then 3 degrees up otherwise you'll suffer strange driveshaft harmonics. One thing follows another.
I have a 401 nailhead in my model A R.P.U. The back of the engine is 3/4 " lower than the front when measured to the frame. I think I put the angle at 3 degrees. Anyway everything works fine.
Thanks I figured it out lol. I think that's another thing that is different on these than the sbc haha. Posted using the Full Custom H.A.M.B. App!
My level-angle isn't the most accurate, but from my own experience it is 4 or 5 degrees for a 401 or 425 with the stock 4 barrel carb manifold.
Got a 54 Buick Roadmaster, 322, .030 over, 350TH tranny w/ a 3.08 rear end, a really great set up for the highway!! finished this build August, this year, 2014. http://www.jalopyjournal.com/forum/threads/31-model-a-hot-rod-restoration.847790/
Picked up a radiator shell today and figured I would set it up really quickly to see how much I am going to have to Bend my headlight mounts and get an idea on upper shock mount position. Posted using the Full Custom H.A.M.B. App!
Got the top insert tacked in place ran out of welding wire so had to stop for the night Posted using the Full Custom H.A.M.B. App!
I don't usually like the gallery of critical comments, but I'll have to agree, this time. Please re-engineer those pipes. After you instruct every passenger & every kid "don't burn yourself" You'll stick your leg to it too. Good luck Posted using the Full Custom H.A.M.B. App!
Having fried my leg on the side pipe exhaust of a friends plastic cobra,,I hate them,,if they stick out as sure as the sun comes up in the morning somebody's kid is gonna grab hold of one of those pipes ad get severely burnt. HRP
I've got the same issue actually. I'm putting a Nailhead in a '27 roadster. The Nailhead is a very tall engine. I don't want the carb sitting up above the cowl. It actually limits how low I can go with the car. If I could level the engine it would lower it and the entire car. Maybe I can have the intake machined level?
As stated, you're going to need 3-4% down for driveline phasing. If the intake is higher in the back that should get it pretty close to level, I would think. I always measure the angle at the transmission tail shaft but I would think you could also measure it at the starter.
The carbs will work with a little off angle, or you could machine it level weld up the stud holes and retap at new level. As for drive shaft angle most hot rods have the opposite problem than the oem's have, the drive shaft is usually going uphill to the rear increasing u-joint included angle. The engine and rear end should have the same angle within a degree dependent on your suspension design. The key to drive shaft angle is that it needs to be the same on both ends and the included angle of the u-joint should not be more than 5 degrees. I have had to use a double cardon joint at the front and tilt the rear end down to within 1/2 degree of inline with the drive shaft to make the drive shaft not vibrate and the rear u-joint to work and lubricate itself. The reason for the u-joint angle to be the same on both ends is that as the joint goes through its rotation angle the drive shaft speeds up and slows down twice per revolution. Having the angles the same means that the rear joint is canceling out the front joint and all the speed changes are in the drive shaft. When you are greater than 5 degrees included angle on the u-joints the speed changes start to be felt as vibration because they become more violent as angle increases. A double cardon joint cancels it self out letting the drive shaft run at a constant speed. Isn't it funny how when you are building hot rods one change can affect so many other things and one needs to think like an automotive engineer. Jim Ford
Well we are Automotive engineers. Only difference is we're not on OEM wages with pensions built in In the Model-T roadster, the engine and transmission centerline will be an inch or so lower than the axle centerline. (16" wheels) so I can run the Nailhead level and have the driveshaft run uphill to the axle. BTW. This lightweight car has over 300hp. I'll want it to launch well. It doesn't want to embarrass itself on the 1/8th. I'm having to balance a build here which runs a competitive 1/8th, looks 100% mid-fifties authentic and fulfills my aesthetic requirements too. Anyway I'm hijacking this guys thread here. I'll start my own build thread soon.
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