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This will be my first complete frame up build and I am very excited to get started. I am 58, Have been a metal fabricator for most of my adult life,
A couple of years ago I put a 302 ford motor and trans in a 86 Mazda rx7 and it turned out great. It's a blast to drive. I had to do a lot of design and fabrication because I made my own motor and trans mounts, radiator mounts, etc.
I like the idea of making my own frame but I might want to change it up a bit.
I was thinking of something like a tramontana with tandem seating and a formula one look but I also want to make it easy to drive and maintain.
I plan on using parts I have on hand and so far I am thinking 350 chevy, t5 manual trans and a disc brake rear end from a 98 camaro. All of which I have here at my shop.
I plan to do a build thread once I get started to keep everyone posted of my progress.
See ya, Dave

When the second engine in my wife's '79 bit the dust she got another car. I extracted the dead wanker motor and dropped in a 302. She wanted the RX back then...

I named it "Tyrannosaurus RX" and drove it for another fifteen years. That's where the handle "TRX" came from.

The Chevy engine will work OK. The T5 is bulkier than it looks. A lot of builders use it - I used one - but I recommend building the center spine *after* building the rest of the chassis, so you can wrap it as tightly around the transmission as you can.

The clutch fork will suck up footwell room; some of the GM applications used a cable mounted down low, such as the Monza, but I no longer remember if any of the T5 housings matched up with the V8 bell pattern. Worst case, a Saginaw housing with a T5 adapter would work. If you go that route make SURE you get the throwout arm along with the housing, as a push-type arm won't work. A hydraulic throwout bearing would be a perfect solution if your budget will stretch that far.

The '98 rear end is very wide. You're going to have to juggle that, wheel offsets, and your chassis width to find something acceptable to you. If the rear turns out to be too wide, the posi and discs will swap to some G-body or S-10 housings depending on which axles have what splines, or you can swap the whole rear for something more appropriate if you have to.

I also have a 8.8 rear from a mustang which might be a better fit. It also has disc brakes

I measured the two diffs today and the 8.8 ford is about 5 inches narrower. Thats what I will use

I have been looking at the plans and I really hate to rock the boat but I have a "what if" question.
What if the top frame rails and the bottom frame rails were the same? I noticed on the plans that the bottom frame rails have a extra bend to make it narrower at the front and just wondered why??? I am assuming that it is to make the lower a arms longer than the top???
Also would it not be good to make the bottom frame rails from a 1 x 1-1/2" tube to make it stronger? Or use a 1 inch tube with a heavier wall?
I am going to be running a v8 engine, Probably a small block chevy with a t5 trans.
So many questions, so little time.
Thanks

That made me scratch my head when I first saw it, too.

The lower rails tuck in because the lower control arms are longer than the top ones, and angling the vertical tubes gave the proper locations for the upper and lower suspension pivots.

Some chassis keep the lower tubes out even with the top. In that case, you have to mount the lower control arm pivots on some additional structure, and make sure the lower arm doesn't contact the outer tube at full droop.

Generally, it's simpler just to tuck the lower rail in and fold the side metal under at the bottom.

I guess it's just human nature to try to change things up to what we think is better but in the long run it is usually better to go with what someone else has already worked out. That doesn't mean I will do that of course

Didn't the '98 Camaro come with the LS1?

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Ford 5.0 into an M3
mikaelvroom.com | @MikaelVroom

The real Lotus cars varied substantially over the years; the Series 1s probably varied as much during the run as when they moved to the 2, 3, and 4 series.

Ron Champion's design used a British-market RWD Ford Escort. I'm pretty sure a Cortina would work as a donor, but I haven't seen a Cortina in forty years.

The Gibbs design used a Sierra donor. That was the Merkur XR4Ti in the US market; it has been at least 20 years since I've seen one of those.

Without the specific donor parts you're forced to improvise from the very beginning. Even people who luck onto a donor or are willing to chase parts generally go off in their own direction. Nothing wrong with that.

I started with three 8-1/2x11 chassis drawings of a 7; I didn't see the Champion book until after I began building. It was very nice to have a reference design to work from, for tubing sizes and wall thicknesses and all the other details, but I had no intention of building a Champion car. I was building my own car.

Back in 2000 I was on the old locostna mailing list. There was a lot of butthurt between the guys building V6 and V8 cars and the "One True Way 4 cylinder" crowd. Nowadays nobody really cares; Kubota Diesel? Fine. Supercharged LS7? Fine. Lotus-style bicycle tires? Excellent. 14" wide steamroller tires? Awesome.

Change what you like; this isn't like a Caterham forum where people only use imported English air to inflate their tires.

I have always done my own thing. Some people have complained about me putting a 302 in a rx7, That is until they drive it

I have a question for someone who has built a locost with a v8. Will a 350 chevy fit in the frame or do I need to widen it?

There was plenty of room for a 302 Ford, so I doubt a 350 Chevy would provide any problems. I think there are some pictures of a 350 car here somewhere; the 4.3 V6 isn't that unusual, but the 350 hasn't been very common.

Here is a link to an awesome table that I've stashed away for years. one thing to know.. The / between engine displacement designations is meant to include all motors of that family, the numbers are the smallest and largest displacement of that family as well. so for the 262/400 chevy with short WP.. it includes basically every gen I/II small blocks.. 262 289 305 327 350 383 396 400 etc..

http://www.carnut.com/specs/engdim.html

As you can see, the ford is 115lbs lighter than the chevy, probably in part to the aluminum heads. it is however, 1.5" taller, but the widths are the same. Also to consider, the ford is a front distributor where as the chevy is a rear. when it comes to clearance issues, I would rather have the rear dizzy, and be able to run a small ready to run with an external coil.

You can use the t5 with either trans, and I would +1 the idea of the hydraulic internal TOB.. save a ton of room that way.

In the interest of weight, (which is what the locost is pretty much all about..) I would consider the ford 302. If I were to go chevy.. I would go turbo 4.3. You can make plenty of power and be just as reliable. After all, the 4.3 is just a 350 with two cylinders lopped off.

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Tucker

The rear distributor is what caused so many of the problems when people were stuffing SBCs into 280Zs. It limited how far back you could set the engine.

Also keep in mind that you've got to be able to access the distributor after the engine is in.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

I can totally relate to that..



I can definitely understand why the front dizzy is more appealing.. but when it comes to height, It adds a good chunk to an already sloping nose cone. When you add in the 2" of additional height of the ford motor, along with the front sump pan (easy enough to change I guess) and the front dizzy. things get tight in tight spaces. Either way it would be tight for sure, maybe its just personal preference.. The small dizzy in the picture doesn't extend past the rear of the crank case, and requires no more space than the standard height valve covers would rearwards.

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Tucker