Hello everyone, Just need a measurement to confirm what would be my set-up on my rear end. When you place a 350 sbc at level (O degree at the intake manifold), what is the angle i should find on the th350 tailshaft ? Hope my question is clear enough... Thanks Jeff
Thank you gimpyshotrods ! I can read 5° on my model A SBC setup but was not sure if it is a usual set up angle. I'm working on another chassis so i'm trying to avoid any mistakes...
And That image is still wrong. The text for drive shaft up is still doesn’t match illustrating media. Yep still wrong
Well i know the basic rules of pinion angle...just wanted to know what is the angle i'm expected to find at the tailshaft housing of a th350 transmission bolt on a 350 sbc, when you position the top of the engine intake manifold level (at 0°).
Doesn't that depend on the angle of the carburettor mounting relative to the centerline of the engine / trans? And are they all the same? I know 3 degrees is mentioned commonly but wouldn't wish to guess / assume, or presume that somethings not been tampered with. You could get an angle from somewhere that's 90 degrees from the engine centerline though, eg block face, front of cylinder head which would confirm the angle with the carb level. Probably 3 degrees! Chris
Pinion 3decrees down from Centerline (s) ! First both lines , engine line and pinion line, to same way. Second drop pinion 3decrees down. If racing combination, You can do more with pinion angle. aulis
You're right Chris it should depend on the angle of the carburetor mounting wich i think should be at level. For what i know and what i've seen the carb mounting needs to be level if you want the carb working correctly but if i'm wrong let me know...it's always a good thing to learn new things !
Carb base level = ideal. Transmission shaft and pinion should be parallel. From there it doesn't matter if the driveshaft runs uphill, downhill or sideways. As long as the u-joint angles (not some crazy 30 or 45 degrees though) are equal and in opposite directions the U-joints will live a long and happy life. Lynn
I always found modern engines (post WW II OHVs) to be 4 deg. Level the carb, check the pan rail, 4 degrees. I set hgt to make the rest of the hook ups easy, i.e. shift linkage, steering, plumbing, blah, blah, blah. From there set up pinion angles and driveshaft mysteries. Where did I get this 4 degree number? Setting up too many drag racers to remember. Whether digital or the trusty 'swing gauge' angle finder that's the number. I something hot I might tend to take a couple degrees out or put simply the carbs might lean fwd just a wee bit. Why? Those cars ran the majority of their lives at WFO. Where's that bowl fuel going when the long skinny pedal is trying to break through the floor? Stops that Holley from spilling fuel out the bowl vents too. Understand, I'm talking extremes here not the usual weekender with some added excess. At the end of it all make it easy to finish and keep angle mojo in mind, but there's no hard and fast rules. If the carb leans fwd just 1 degree it won't know the difference on the road.
Like some have mentioned, it depends on the intake you're using. Put a level on the carb mounting base, and then lay it along the oil pan rail or on the top edge of a rocker arm cover. The diffeence in the two is the angle of the carb base relative to the crankshaft centerline. A Super Victor manifold doesn't have any carb angle built into it, as do many of the aftermarket intakes. OEM stuff will usually have some angle built in. You can get angled wedges to correct any carburetor leveling if you think it needs to be absolutely level with the earth. Keep in mind that under acceleration, braking, turning, going up a hill, wheelstands, etc. the fuel in the carb will adhere to Newtons first law, the law of inertia and not remain level in the carbs bowls.
Again? Seriously? We have beaten this horse to death, hung it up and are beating it some more? Has anyone remembered the hoomerhingie equation? That also can complicate things.
The crank should be @ 3 degrees. it should be close to perpendicular (within a second or two) to the crank or you can measure off if the crank flange or . . . If you are looking for something to match just thiMk
Ok now what?????? You’re not ever going to hold these rules, the BS self inflicted 3* level rules . It’s better to really understand driveline angles that work instead of trying to make the arbitrary some sort of rule.
Tremec has a good app in their tool box. https://www.tremec.com Sent from my SM-G950U using The H.A.M.B. mobile app
I don't measure off the carburetor pad, Usually go off the oil pan rail if possible (where it bolts to block) to get parallel with the crankshaft
Well some subjects on here only get beaten within an inch of their life ,so you need a few more wacks to make sure .
Basic outline: No radical angles. Crank centerline and pinion centerlines parallel with the chassis centerline, and thus each other, not necessarily coincident, when viewed from above. Carburetor pad set level, with the car on the ground, some deviation, but not radical, is fine. Crankshaft plane, and pinion plane parallel, when viewed from the side. Angles are most often read with tools that reference gravity. The stated expected angles in many of these diagrams assume that the chassis is level. If you use the complimentary -3º/+3º diagrams, and you have a 1.5º down-in-front chassis rake, neither angle will be read as 3º, with an angle finder. In that case, your measured shaft angle would be 1.5º for the crank/trans, and 4.5º for the pinion. It sounds off, but that is because your tool is referencing the ground. The angles need to match each other*. No harsh u-joint angles. No steep driveshaft slope. If either seems required, a 2-joint shaft is not for this application. *Configuration of the rear suspension can have an effect on axle wrap, on acceleration. Leaf springs are the worst offender. Links with soft bushings are somewhere in the middle. Heim joints allow little-to-none, but have drawbacks. It is not uncommon to have the pinion plane out of parallel with the crank plane, to compensate for axle wrap. Imagine that the u-joint on the pinion will want to rise when you hit the gas. The idea is to build it with that point a little below where it wants to go, when it is at rest, so it ends up in the correct location under load. I have never observed this to be an issue on a conventional street-going vehicle, except for when the power levels were in the 500lb.ft.+ range, and/or the incorrect leaf springs were being used.
Appears to be a nice car for sale. However ,,, If you bought it, my condolences If you built it, don’t do this again Here’s the body line rake Protractor on bodyline Here’s the results of this stupid 3* so called rule in action Protractor on engine The more observant viewers might notice the scoop lines up pretty well with the mortar joint that one can be more than reasonably certain the mortar joints are level Like my buddy says- “I can explain it to you but I can’t understand it for you.”
We had one of those demonstrators at each of our training centers. You can really see the speed up/slow down when the angles get real large.
I don't get your point. The U-joints don't care in the least what the rake of the body or chassis is. And the body and chassis can have a radically different rake relative to each other, except it may look goofy. The U-joints will be happy if the crank centerline and pinion centerline are close to parallel under load, the joints are properly phased, and the individual working angles are reasonable. Joint mfrs. would like to see this limited to around 3 degrees, which is an appropriate goal, but in my opinion, can be exceeded substantially during transient conditions. (I estimate that the same Hooke type U-joints on a Jaguar IRS axle might be at around an 8 degree angle at full bump, and since it is beyond the differential, could see 3 or 4 times the torque in the drive shaft.) Some means to limit axle wind-up is prudent, especially with strong engines. As to the proper carburetor angle, I'll defer to those that claim to have relevant experience and knowledge. IMO, they are not as sensitive as others seem to believe. If accelerating or cornering at .5 Gs, the carburetor thinks it is leaning back or outwards at a 27 degree angle, but still works fine. SU and Weber side-draft carburetors are generally mounted level, but in several cars, at an approximate 15 degree slope.
Are you referring to this illustration? 1 drive shaft level Text says “rear end 3 degrees up” Protractor clearly shows rear end at zero #2 drive shaft down Text says “rear end 3 degrees up” Protractor clearly shows rear end at zero #3 driveshaft up Text says rear end 3 degrees up Protractor clearly shows rear end at zero Again drive shaft up Text says “Engine 3 degrees down” Protractor clearly shows engine at zero Indecently most hot rods with just a little bit of lowering or some rubber rake will wind up in the “driveshaft up”’situation. Do the math because they got that all fucked up too. Engine 0 rear 0 and drive shaft at 2 The way it’s drawn is the correct way to set it up in your hot rod. Just ignore the text. Much like one should ignore that 3* level carb horseshit. Oh and BTW The general and most common way is to set the engine and pinion parallel. So for God’s sake speak it that way. If The trans goes down then the rear goes down = parallel. If the trans goes up then the rear goes up = parallel. If the trans goes down toward the rear and then you turn your confused ass around taking your goofy gravity angle machine with you there by completely changing the point of reference now the pinion goes up towards the front = parallel, maybe.
Yeah that’s just one of my points. Mega buck hot rod, blower and related jewelry, open hood. Yeah so it looks goofy, it’s got to be that way because 3* down rules say so- what’s your point ?
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