1967 Chevy Camaro Project - Engine Clearance

Welcome to the second installment of our build series on the Project Unfair Camaro. The first article in Super Chevy last month focused on raising the floor, reducing weight, and lowering the center of gravity (COG). This month we will focus on moving weight to get a better weight balance. The typical iron small-block first-generation Camaro from the factory is about 56/44 percent front-to-rear. The total weight of a '67-69 Camaro is usually between 3,400-3,600 pounds depending on body style (coupe or convertible), engine type and options.

The biggest influence on front to rear weight balance is the engine/transmission combination, which makes up about 20 percent of the car's weight, all in front of the vehicle center point. The typical iron small-block and transmission package can easily weigh 800 pounds. We are using a lightweight all-aluminum LS engine and accessories. When you add up the weights of the original small-block fully dressed and the weight of the LS motor fully dressed, the LS engine is almost 150 pounds lighter. However, we are adding 75 pounds to our engine with a huge Kenne Bell supercharger so our net weight reduction is 75 pounds or so.

1967 Chevy Camaro Project Custom Firewall

Still, 75 pounds is a lot of weight and that weight is all at the front of the car. However, moving that reduced weight 8 inches towards the rear makes a big difference in weight bias. We would like a weight balance of 50/50 or even a tiny bit of bias towards the rear. The sidebar provides all the engineering math and formulas for how much weight we moved and how much the F-to-R weight bias changed. To summarize, we moved about 60 pounds from the front of the Camaro to the rear by moving the engine and transmission 8 inches from the stock location. We also moved another 40 pounds (with us in the car) from the front to the rear by moving the seats back 4 inches. Thus, we moved 100 pounds from the front to the rear. As you'll see in the sidebar, the effect on weight bias is significant.

Also in this article, we set the engine and transmission height based on the subframe being installed with no body bushings. We already lowered the body over the floor 1.5 inches. Installing the Art Morrison subframe with no subframe bushings will lower the front an additional inch, giving the car a total of 2.5-inch front body drop and 1.5-inch rear body drop. This will give us a nice minimal rake without compromising suspension geometry.

After a lot of careful measuring for both height and set-back, we settled on a position for the engine that would put the crank pulley behind the Tony Woodward rack-and-pinion of our Art Morrison subframe. This put the engine 8 inches back from the stock Chevrolet location. We also needed to move the engine down as far as possible for clearance of our Kenne Bell supercharger. The side benefit (which was also very important to us) was lowering the weight of the engine/transmission package. (Helping our COG was discussed in the first article.) We moved the engine down as far as possible making sure the subframe crossmember would still protect the oil pan and bellhousing.
After a lot of careful measuring for both height and set-back, we settled on a position fo
A lot of measuring was done to find the exact spot we wanted the engine. Our work would be so much easier to do without having the subframe installed. We built some temporary mounts that we welded to our body cart so we had a unobstructed access to the firewall. Moving the engine back 8 inches put the engine past the firewall, inside the car and under the cowl 5.5 inches. For reference, the entire engine is behind the centerline of the front wheels in this position.
A lot of measuring was done to find the exact spot we wanted the engine. Our work would be
In this picture, the giant Kenne Bell blower still needs to slide back slightly more than 1 inch to bolt in place, so we have to relieve the cowl. This position is going to put the unit right at the forward edge of the cowl filler between the windshield and hood. Our 2-inch cowl hood will just cover the back edge of the Kenne Bell.
In this picture, the giant Kenne Bell blower still needs to slide back slightly more than

We used a lot of poster board to make templates for the pieces we needed to make, and also for tracing and cutting. It is funny how often I find myself back in second grade with poster board! In this case, it is tricky to cut through two panels (roof and floor) the same shape, so after cutting the top of the cowl, we made a poster board template that matched the cowl floor shape and traced it for cutting.
We used a lot of poster board to make templates for the pieces we needed to make, and also
The rough cut already looks pretty cool. We could have just made a huge cut and been done, but we love little detail like this.
The rough cut already looks pretty cool. We could have just made a huge cut and been done,
To roll out a hump around the engine either takes some really great fabrication skills and equipment, or a jigsaw puzzle of many pieces welded up like Frankenstein. A trip to the local hardware store and $40 scored us a big piece of our firewall.
To roll out a hump around the engine either takes some really great fabrication skills and

Raising the subframe does create a couple issues, though, which need to be addressed. The first is the engine and blower are pushed 1 inch closer to the hood, and our engine package with the massive Kenne Bell 3.6-liter blower is pretty tall. Second, the transmission tunnel has to be raised to make room for the T56 transmission.

Moving the engine has some great benefits, and in our case was a necessity because of our tall engine package and compressed subframe to body relationship.

If this were a naturally aspirated LS engine with no blower on top, we could have moved the engine back a couple inches and tucked the engine transmission package under the hood easily, even if we compressed the subframe and body by using no bushings. For us, we wanted to move the engine a lot anyway for the weight balance effect. But we also have to say that cars can still handle wonderfully without changing the weight balance. We do not want anyone to feel they have to move the engine to get a great handling car. Remember, we are being Unfair!

The above paragraph is a disclaimer of sorts because the firewall and tunnel modifications are by far the biggest scratch fabrication projects we will do on Project Unfair Advantage. There are no reproduction replacement parts for what we are doing. So we simplified the process so someone else could do this possibly at home, or at least trim labor hours at your shop building your car. A $40 wheelbarrow from our local hardware store saved dozens of hours trying to form a recess for the engine which is moved 5.5 inches under the firewall. In our case, we have to also notch the upper firewall for blower clearance. Our supercharger now is going to be even with the edge of the cowl filler between the windshield and hood.

Follow along, and next month we will put our super-trick Art Morrison suspension in. I promise you have never seen anything like it.

Calculating The Effect Of Moving The Engine
Moving the engine back is an old trick for hot rodders. On our front engine/rear drive muscle cars, moving the engine back solves several problems (but creates new ones-see below).

On Project Unfair, we not only had to move the engine back, but down as well. The massive Kenne Bell supercharger sits high on top of the engine and we want to keep our hood to a 2-inch cowl. No 4- or 6-inch cowl hoods for us, thank you.

We are going to need to widen the wheelbarrow a bit to get the clearance we want, but we will still be way ahead of the game starting with something that is already shaped.
We are going to need to widen the wheelbarrow a bit to get the clearance we want, but we w
The wheelbarrow is made of 20-gauge sheetmetal, which is perfect for this kind of work and plenty strong, especially in compound shapes. We choose the deep rounded front of the wheelbarrow and cut the nose off to fit the bottom of the cowl. We needed additional width, so to widen it a bit we welded in a 5-inch filler strip on the flat section in the middle.
The wheelbarrow is made of 20-gauge sheetmetal, which is perfect for this kind of work and
Before we could even install the transmission for mock up, we needed to figure out how much we would need to raise the tunnel and where to cut it. We had the car and the transmission both level, and used a level to measure at the same distance and find the difference in height.
Before we could even install the transmission for mock up, we needed to figure out how muc

Using the centerline of the top bellhousing bolt in the car, it is 6.5 inches to the tunnel, and it is 5 inches to the transmission. Difference plus 1 inch for general clearance means we have to raise the tunnel 2.5 inches.
Using the centerline of the top bellhousing bolt in the car, it is 6.5 inches to the tunne
Plasma cutters are so cool! A cutoff wheel would work just fine also. Even though we are modifying the tunnel, we are still way ahead of the game using the stock floor.
Plasma cutters are so cool! A cutoff wheel would work just fine also. Even though we are m
Setting the driveline angle, our base angle is 2 degrees down. Two degrees is ideal, but anything zero to 4 degrees is acceptable. This should point the transmission at the rear pinion yoke. This will give us some wiggle room if we decide to move the combo one way or the other.
Setting the driveline angle, our base angle is 2 degrees down. Two degrees is ideal, but a

Before going into the calculation of what moving the engine 8 inches will do to the weight bias of Unfair, let's quickly recap where we are with the car's weight:

Stock: 1,900 front/1,500 rear/3,400 total
56/44 front-to-rear weight bias

With a weight loss of 75 pounds for the engine and 90 pounds for aluminum sheetmetal before we move any weight (assuming 80 percent of the weight savings comes off the front, and 20 percent from the back)

1,900-0.8*165 pounds front, 1,500-0.2*165 pounds rear
1,768 front/1,467 rear/3,235 total
Putting us now at 54.5/45.5

In order to drop the engine, we have to go back 8 inches before going down because we have to get the engine behind the Tony Woodward rack in order to lower it. Making these changes was a last resort solution: We didn't want to have to do this.

Hopefully the use of a hardware store wheelbarrow is a trick you can apply to your own projects should you decide to grab your torch and welder and make a similar fix.

The math shows a significant gain in the weight bias front to rear. The mass of the engine/transmission is now completely between the axle centerlines (a factory Camaro has the number one spark plug even with the front axle). Let's assume that the car started out as 54.5 percent of the weight on the front tires, the engine/clutch/tranny combination weighs 800 pounds, and that the car will weigh about 3,000 pounds empty and 3,200 pounds with driver. We are moving the engine 8 inches and our wheelbase is 108 inches.

The approximate effect per axle can be calculated using the following equation:

Wb = (Mm/WB)*(M/TW)
Wb = change in weight bias
Mm = movement of mass (the engine/transmission) in inches
WB = wheelbase
M = weight of mass
TW = total mass of car

Plugging in, we get Wb = (8/108)*(800/3000) = 0.0197, then multiplying by 100 to get percentage gives us 2 percent.

Since we are moving the engine back so much, we are compromising the foot well quite a bit. We plan to move the seat back 4 inches also, which will put the driver's back at the forward edge of the rear quarter window. Back a bit from stock, but not so far back it feels like a Funny Car either. We will build an interior toe board 4 inches closer to the driver so the pedals are not hanging in free air. We realized after tacking in the main hump (wheelbarrow) that we still need some extra room.
Since we are moving the engine back so much, we are compromising the foot well quite a bit
We looked over clearances on the engine side of the hump and decided we could do a relief that would give us a few extra inches of footwell width and still allow room for headers and clutch removal.
We looked over clearances on the engine side of the hump and decided we could do a relief
The 2.5-inch fill strips will be welded in, raising the tunnel for transmission clearance. The passenger side footwell has plenty of space, and that extra 4 inches may turn out to be a great place to stash some electronics. For strength, we are using all 16-gauge on the closeouts on either side of the hump to tie together the cowl, floor, rockers, and tulips on the side of the cowl.
The 2.5-inch fill strips will be welded in, raising the tunnel for transmission clearance.

A few custom pieces will make our closeout around the blower look very clean.
We used easy-to-work 20-gauge for these little parts.
This could all have been done with everyday cutting tools and bent on a vice, or even with your thumbs for rounding a part, but Michael Serafine likes playing with the slip roll every chance he gets.
This could all have been done with everyday cutting tools and bent on a vice, or even with

In plain English, moving the engine back 8 inches moves 2 percent of the weight from the front tires, and puts 2 percent more weight on the back tires, for a total swing of 4 percent.

Since we are probably around 54.5/45.5 already with the aluminum panels, the engine movement results in us being around 52.5/47.5 now.

We are also moving the driver and seats 4 inches backwards since the firewall moved. Let's figure 200 pounds for the driver and 50 pounds apiece for the seats. That gets us another half percent (1 percent overall), putting the car around 52/48, or around 1,682 front/1,553 rear.

We'll be moving more weight rearward in the coming months: battery, wiring, and electronics, along with additional front of car weight reduction to get to our goal of 50/50 weight distribution. We still need to move about 65 pounds from the front to the rear, or take another 130 pounds out of the front. The battery movement alone will get us a long way towards our goal.

We also moved the engine down 1.5 inches, lowering the COGH (center of gravity height) a like amount (the best approximation of a car's COGH is the camshaft height). Now we can use that awesome Auto Metal Direct 2-inch cowl aluminum hood!

All this movement from stock locations isn't free. We've compromised our A/C evaporator position, complicated the driver's ergonomics, pedals, steering wheel, and shifter), made the header fabrication more difficult, and we'll have to make custom motor and transmission mounts. We should be able to return to more standard parts and fabrication sequences now. - John Parsons

Once all the pieces are screwed in place, all the welding and grinding begins.
I just love the way the blower intake to cowl looks. It'll be even prettier when we finish it.
I just love the way the blower intake to cowl looks. It'll be even prettier when we finish
Once we trim the air cleaner adapter from the bottom of our Auto Metal Direct aluminum 2-inch cowl hood, the hood will barely clear our blower. We were sweating this one!
Once we trim the air cleaner adapter from the bottom of our Auto Metal Direct aluminum 2-i

The wiper motor is always an eye sore on a pretty firewall, often in the way of tall valve covers and just ugly. In our case we needed the space on the firewall where the original wiper motor resided for our blower intake clearance, so we decided to move the wiper motor.
The wiper motor is always an eye sore on a pretty firewall, often in the way of tall valve
We cut out the original wiper mounting plate and welded it into the tulip (outer cowl), which will be under the fender. We found a powerful OEM wiper motor that is very compact and made an adapter plate. We made some wiper linkage that turned out to be much quieter than the original stuff and now the wiper operates smooth as glass and whisper quiet. Most importantly, it is out of the way and out of sight.
We cut out the original wiper mounting plate and welded it into the tulip (outer cowl), wh
Necessity forced us into creating a cool product. Introducing our new hidden wiper motor relocation kit. The kit will include everything you need to move your wiper motor under your fender including the new motor, switch, linkage, and mounting plate. Target price for the complete kit is $400, and by the time you read this, will be available at the Prodigy Customs online store.
Necessity forced us into creating a cool product. Introducing our new hidden wiper motor r

We are pretty happy with the final results. The wheelbarrow idea worked fantastic. We could have spent 20 times the money and not ended up with anything better. Next month we will get the incredible Art Morrison Dual mode suspension installed and get Project Unfair on the ground. Stay tuned.
We are pretty happy with the final results. The wheelbarrow idea worked fantastic. We coul