700R4 positioning

[Zandoz]

I'm planning to position the engine so it sits level. I know that typically engines, and the attached transmissions, have been mounted with around a 5 degree tilt to the rear. Will mounting a 700R4 level cause problems? If so, what is the minimum mounting angle I can get by with?

 

[bobs66440]

From what I understand, rear drive cars are set up from the factory with a 3 degree angle down in rear to provide more interior room (smaller trans tunnel). As a result, carb intakes are wedge shaped (taller in back) to compensate and keep the carb level, which is ideal. So keep in mind that you will need to find a level intake if you want to mount the engine level, otherwise your carb will always be on an angle. If you are using fuel injection, I don't think it matters.

Also, you need to have some angle to the drive shaft. In other words you don't want the trans and pinion yoke lined up exactly.

 

[bobs66440]

I can't think of any reason why the engine & trans can't be level, except maybe the oil pickups may be designed to scavenge from the rear because of the tilt.

 

[Screaming Metal]

What Bob said....the only reason not do its because you want it that way. Just be sure to take into consideration your pinion angle or lack there of. there are no tech reasons why a motor can't be level. And if the carb is sitting at a angle, the solution is as close as the nearest Bridgeport....

{Taking a trip, I looking forward to seeing if they have internet on the planes yet}....

 

[Hotrod46]

I leveled my headers to the ground and have not had any issues. I'm nowhere near 3-5 degrees down. I do jack up the frontend when checking the trans fluid (700R4). Your carb float level may need to be adjusted.

 

[EX JUNK]

My engine sits level and I've experienced no problems. The reason that I set it up that way was so the header outlets were parallel with the bottom edge of the body and not hanging down like a lot of set ups.

Jim

 

[Zandoz]

It looks like I'll be running a carburetor set up (if the deal I've made goes as planned). My intent was to run a 5 degree wedge plate to level the carb. If when I get the manifold it turns out to be other than 5 degrees, I may have to rethink the whole thing. On the pinion issue, I'm under the impression that as long as the pinion and transmission angles were the same and parallel, but not in direct line, it would be OK. Am I wrong on this point?

 

[fluidfloyd]

It looks like I'll be running a carburetor set up (if the deal I've made goes as planned). My intent was to run a 5 degree wedge plate to level the carb. If when I get the manifold it turns out to be other than 5 degrees, I may have to rethink the whole thing. On the pinion issue, I'm under the impression that as long as the pinion and transmission angles were the same and parallel, but not in direct line, it would be OK. Am I wrong on this point?

You're right on the money Bill. Here is a ink that gives you a lot of information on the phasing of drive shafts.

George

http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html

 

[Zandoz]

You're right on the money Bill. Here is a ink that gives you a lot of information on the phasing of drive shafts.

George

http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html

Excellent link....the most common terms explanation I've seen.

 

[bobs66440]

You're right on the money Bill. Here is a ink that gives you a lot of information on the phasing of drive shafts.

George

http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html

Yup

 

[409T]

For my money, it is far more important to make the components of your car to be aligned or relative to themselves, not to the planet. It doesn't make sense to me to obsess over making a carb or engine or trans or whatever level when most of us have garage floors that aren't level, driveways that aren't level, and we drive on streets that may be flat but probably aren't level either.

 

[Zandoz]

For my money, it is far more important to make the components of your car to be aligned or relative to themselves, not to the planet. It doesn't make sense to me to obsess over making a carb or engine or trans or whatever level when most of us have garage floors that aren't level, driveways that aren't level, and we drive on streets that may be flat but probably aren't level either.

Definitely the mechanical necessities take precedence...I just don't know if there is a mechanical necessity involved with the 700R4.

There are a few reasons for my wanting to run the engine and transmission level. To me it looks better. It allows a lower center of gravity and if I go with a hood, a lower hood line. On the other end tilting the engine requires tilting up the pinion, raising the drive shaft, and subsequently the already too high bench seat I'm planning on.

 

[baddawgcustoms]

Definitely the mechanical necessities take precedence...I just don't know if there is a mechanical necessity involved with the 700R4.

There are a few reasons for my wanting to run the engine and transmission level. To me it looks better. It allows a lower center of gravity and if I go with a hood, a lower hood line. On the other end tilting the engine requires tilting up the pinion, raising the drive shaft, and subsequently the already too high bench seat I'm planning on.

Take a look at ExJunks seat in his car. Beautiful bench seat with a driveshaft tunnel built in and keeps your butt real low in the car so you sit IN it. It's a fairly easy construction process. Hopefully I'll be attempting it one day soon myself.

 

[Zandoz]

Take a look at ExJunks seat in his car. Beautiful bench seat with a driveshaft tunnel built in and keeps your butt real low in the car so you sit IN it. It's a fairly easy construction process. Hopefully I'll be attempting it one day soon myself.

Unfortunately I'm a REALLY big guy...there will be no getting my fat butt below the top of the tunnel...even with the slightly widened body I'll be using. Anything I can do to lower the tunnel....or avoid raising it ...will be a good thing.

 

[Zandoz]

I figured an illustration might help...

 

[Screaming Metal]

How about incorporating the tunnel into the seats, ie, the top of the seat sitting even with the top of the tunnel, whatever much of one is there.
Yes, you can sit the motor/trans low in the frame, going wide with the oilpan, to get the drivetrane away from the floor, to keep the necessity of a tunnel down.

I've sat in T's that make you feel if you lean too far, you'll fall out. I hate that. I like to sit into the car not on top of it....

 

[fluidfloyd]

How about incorporating the tunnel into the seats, ie, the top of the seat sitting even with the top of the tunnel, whatever much of one is there.
Yes, you can sit the motor/trans low in the frame, going wide with the oilpan, to get the drivetrane away from the floor, to keep the necessity of a tunnel down.

I've sat in T's that make you feel if you lean too far, you'll fall out. I hate that. I like to sit into the car not on top of it....

That's good thinking Screaming. If you have the room you could also build a trussed drive shaft cover that tied into the firewall and the rear body kick up. This would add a lot of torsional stiffness to your frame rails with very little effort. Just a thought.

George

 

[Zandoz]

How about incorporating the tunnel into the seats, ie, the top of the seat sitting even with the top of the tunnel, whatever much of one is there.
Yes, you can sit the motor/trans low in the frame, going wide with the oilpan, to get the drivetrane away from the floor, to keep the necessity of a tunnel down.

I've sat in T's that make you feel if you lean too far, you'll fall out. I hate that. I like to sit into the car not on top of it....

The motor and transmission height is not the determining factor for the seat height. The pinion height at full suspension compression is. I'm planning this as a "bobtail" layout...think Tweedy Pie, but lower. The low point of the seat is almost directly over the pinion U-Joint. As the plan stands now, the lowest part of the seat will be notched to fit over the the tunnel, and will be about 6-3/4" above the floor...in an unchanneled body.

 

[Zandoz]

That's good thinking Screaming. If you have the room you could also build a trussed drive shaft cover that tied into the firewall and the rear body kick up. This would add a lot of torsional stiffness to your frame rails with very little effort. Just a thought.

George

I already planned on an 1-1/2" square tube K-member angling out from a cross member under either side of the rear end of the tunnel, to the frame rails, just under the firewall. Also, I've toyed with the idea of using extruded aluminum beams for sides of the tunnel.

 

[fluidfloyd]

Bill,

I was thinking of a small sized tubular skeleton that would be a stressed backbone. Then just a lite gauge aluminum or glass tunnel that hugged it. If the drive shaft is above the floor level you will have to put a tunnel in it anyway so why not make it serve two purposes?

Something else to think about for anyone building these types of cars. Having fairly short drive shafts can sometimes cause clearance issues. You might consider a Independent Rear Suspension system. The differential housing is permanently fixed letting you build a very close (as in low) floor tunnel. While I know the the cost can sometimes be a factor there are a number of factory cars using IRS units and plenty of crashed ones in the bone yards. They really aren't that hard to adapt to your use. Plus they do draw people's attention. Just something to think about. We're building one based on the small Winters V8 center case. While they now do offer that case in an IRS configuration it was actually to narrow for our purpose so we designed our own side bells to fit our needs. The unit is at Mark William now getting the stub axles and drive plates machined. Once we get it assembled with the inboard brakes I'll see about posting it for you to see. This will not be an ad to sell them as they are targeted for a specialty car we are building. Just giving you something to think about. I'll be in touch.

George