Taller hood/dash lower rear, how you deal with it?

[tibimakai]

I'm building a 442E chassis, and I don't like the big difference between the hood/dash height compared to the rear of the car, there is a 6" difference.
Dash is around 10-11", that is normal, right?
How you guys are dealing with that?

[RoyzMG]

I'm not really sure what your concern is. If you look at the McSorley 442E sketches, the rear height is 21" and the height at the bottom of the scuttle mount point is 15" or a difference of 6". You can make your scuttle height anything you desire (within reason). Did you want the total scuttle height (from the car bottom) to be higher or lower than the back of the car or what? The total scuttle height will be highly dependent upon which engine you will be using and how much clearance to the underside of the hood you want. One of the main reasons for the 442E design was the newer, taller twin overhead cam engines that could be used. Ground clearance and hood clearance are somewhat related. But I'm sure I'm not telling you something you don't already know. What do you plan to do for a scuttle, make your own or purchase one?

[tibimakai]

The 442E chassis height is 15" and if I add a 10-11" scuttle, it will be 25-26". So the back is 5-6" lower.

[SkinnyG]

It offends me, too.

So I started building another frame.

(grin)

Seriously.

I'll get back on it once my current project (not a 7) is done.

There is actually a LOT about the "book" chassis (and derivatives) that offend me.

[RTz]

Me neither. So I raised the back.

[tibimakai]

How did you do it? Extended the angled tube?

[RTz]

The frame is my own recipe. Comparison between mine (blue) and "Book" (yellow)...

[tibimakai]

It looks good, thanks.
Since my rear firewall is done, I'm looking to modify it in an easier way.

[Driven5]

The 'book' frame was designed for engines like the Ford Crossflow, which is only like 17 inches tall. Modern DOHC I4's are more like 25 inches tall. With a frame that's only 2 inches taller, there's your 6 inch mismatch.

I'd look at it as an exercise in hiding the excess with a blended approach, rather than driving all of the variation from one place to another. The easiest trick to gain an inch or two, as even used by Caterham, is to hang the oil pan below the frame. That reduces the amount that you need to raise the rear to make it a better match. And you don't necessarily need the height to be a perfect match, just 'close enough' to not be obvious. Speaking of which, if there is any chance you might go with more modern (larger) diameter tires, you might also want the rear of the frame a little taller anyway.

[tibimakai]

I have a Duratec 2.5L(Fusion) engine and I placed it an 1" under the chassis. I did not want to stick out at all, but this way is a good compromise. Only the VVT valve connector may touch the hood. I may have to add a small scoop. We will see, I don't have a nose yet to properly see how things are aligning.
Surprisingly, this engine's oil pan is very flat, it only leans 6* toward the passenger side. I thought that it should be 10*, but is not.
I may make a fiberglass lid(I hope not because I hate working with fiberglass) for the rear that could be a a bit taller and could compensate for some of the height.
I'm trying to attach some pictures with a car, but for some reason the pictures never load up.
Budget is tight, wife is not working, mortgage, car payment, ....
The nose has a 3.5" radius at the corners?
Yes, I'm planning to use 17" wheels, those are around 26".

[Miatav8,MstrASE,A&P,F]

Nope, still can't find that build topic.
Is the actual build just on the computer at this point?

[tibimakai]

I didn't create a build thread yet.
My inspiration is the car in those pictures above.
I have most of the chassis build, except the rear.
Engine and trans is installed, tunnel is 80% done, purchased the Mazda NC rear subframe, Wilwood pedal/cylinders(just picked them up from Offerup= $100(!)).
I need the diff to figure out the height of the rear subframe, also the driveshaft would be useful to get the right pinion angle.

[KB58]

I'm curious how tall the car above is. Assuming the driver's head is below the top of the roll bar by a couple of inches, it's got to be at least 42" or more. I suspect the basis chassis was either on purpose or just ended up big, with the driver's head sunk way down, so adding small glass really helped the overall look. Something backing up that suspicion is the fairly small looking header, which provides a clue for the size of the engine compared to the rest of the car... , pretty sure it's not "Lotus" size. Whether that's good or bad is entirely subjective and depends upon its application.

[Miatav8,MstrASE,A&P,F]

Tibimaki,

I assume you'd want the irs lcaps the same height as the front for a level lca at ride height, then adjust the pinion and trans output angles as needed for equal, minimal angles on both ends. The driveshaft assembly can form a U or an S as long as the joint angles are equal. If the diff is higher than the output shaft, you can raise the output angle and lower the pinion angle. Use a cheap digital gauge to check the angles versus a weighted pendulum protractor. Changing the output angle may require a small angle change in the engine mount brkts depending on the design at either the chassis or the engine block side.
The best way to fit taller engines is to increase the length of all the tubes between the upper and lower horizontal chassis rails for the full length of the car to maintain symmetry to the design (some of the angles will change but you can figure that out by doing the 90 degree to the rails tubes first, then running the diagonals after to the new chassis nodes. It looks like that is what they did with the car in your pics. That is how I'd do it.

If you don't like the thin cowl/bonnet look and just want a scaled seven in the side view, some of the increase can come from a higher bonnet and cowl over the upper rails but the rear still needs the full length added to the verticals.

I suggest drilling the rivets to remove the rear wall so you can weld in a new upper rail around the back and sides (to adjust the angle), then extend the tubes. It won't be wasted. Use the firewall sheet as a pattern for the new one and to pick up the existing rivet holes, then recycle it into some other panel like a pedal box cover under the bonnet, radiator ducting, tunnel cover, "trunk" liner panel, small brackets, glove box liner, etc

[tibimakai]

Thanks for all the suggestions, but maybe I did not explain myself correctly.
I'm at a stage in building my frame's rear end, but I don't like the height of the rear end.
In the first picture, is the MX5 NC rear subframe, that I'm planning to incorporate.