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Kiwi 26/27 RPU build


New Member
Ok i showed a bit of my project in my intro but i figured here is probably a better place to show what i'm building. This will take a while for me to write as theres six months in this so far and a few photos which i think may be of interest.

As a bit of background, I have had a lot of SB chev powered stuff in the past and had a few left over bits and pieces from a previous T. I was going to build another SB chev T as i still had my Weiand 4 carb intake, linefire headers etc which all look cool on the right car. Then a friend who had a manifold i was after for years offered to trade it for my smallblock stuff, and the direction changed, and nothing less than a 454 was going to do.

Hows this for COOL!! Obviously this had had a bit of work, all i got was a bare manifold, but what a manifold!!

I already had a glass body, but managed to find a good steel RPU shell.


After a bit more saving found a good running 454 & TH400 and I built a custom frame from 50x75x4mm RHS. Heres the motor installed.


Mounts are made from 5mm plate, tube is bushed with nolathane leaf spring bushes, so engine is virtually solid mounted.
The chassis/frame is a bit different from most in that i am running parrallel leaf springs front and rear with the front springs and axle mounted above the chassis to get the car a low as possible. I used a model A front axle as they have very little drop and a leaf sprung 8" rear. The rear of the chassis was set to suit the std leaf spring width, and the front to suit the width of the cowl. The chassis is the lowest point of the car so the engine & tans is mounted quite high in the frame and also the exhaust so a bit of thought has gone into the design.

The trans crossmember has been shaped for exhaust clearance, a 10mm plate welding inside full width, and then boxed. Very strong but allows room for the exhaust.

What you cant see from the picture is the sries of plug welds through the top of the cossmember into the 10mm plate, but you can see what i mean about the trans sitting high on the chassis, the drivetrain does intrude into the car a lot.

There is also massive kickup at the rear to allow room for the rear leaf set up, 20" or so.

Fopr the exhaust i have made a set of linefire headers, i had a local bike exhaust roll up some cones 2" to 4", 24" long. Pipes from the head are 2' and the pipe back under the car is 3".


I have fitted stainless "bellows" which flex to allow the exhaust to be solid mounted and not have problems with it cracking etc over time.



This shows how i got the exhaust through under the trans. I cut a piece of 2" in half, added an extra 4" to it to make a big oval, which acts as a balance pipe, before going backout into two 3' pipes to the mufflers.

With the body back on you get an idea of how close everything is,


Front end is A as noted earlier, probably would have been easier to use a chev or dodge but i had the A and prefered to use what i had.


Temp mocked in place to see how things move

Man u really have a lot of innovative ideas goin on there. Keep posting pics of your progress.
I'll jump ahead a bit to what ive been working on lately, which is the front frame horn which will mount the leaf springs. Cut these from 5mm plate, then bent some 5 x 50 strap to match the contour, welded a section of 2" pipe to the end so there is a nice radius at the leading edge. Dont have any flash tools in the workshop, just time & enthusiasum, a grinder and a big hammer. It may have been made with basic tools but came up OK.




OK... I think I get it... those front spring shackles are just temporary, the new mount will be in the new horns.. Do they mount straight into it or are there some short shackles involved... I'm still getting my head wrapped around all these different approaches to suspensions! :eek:

BTW... Nice job!
Front spring eyes mount direct in the frame horns, the shackles will be just behind the radiator. Springs are 24" long rated at 600kg per inch, travel should be around 2-3", which should be plenty. I've jumped up & down on front of chassis (i'm 6'3" around 130 Kg, 280lb) and only moved it 1-2' which was the main reason for the temp mounts to see how much it would move. There has been a bit of calculated guess work with this because it is very different, its not a 1800 bucketT buildup.
Heres a bit more of what i've done this week

Prior to clamping & welding

Got them welded now, will spend the weekend grinding & dressing the outsides of them, then cut the old temp mounts off and trim the chassis to suit the new frame ends and tack them on for inspection prior to final welding. The plan is to weld them on to the frame rails, open up the small holes in the side and plug weld them onto the frame as well, make it real strong!




Its a bit of a process here where certifiers have to check the construction at stages to ensure you are able to get your rod on the road legally. No big deal, you can pretty much build what you want as long as its safe, as long as you play by the rules. There are a genuine 8 sec street cars down here that drive to the track to run 8's at 160+ totally legal.
Don't know if this is of interest but this is part of the info i submitted to get design approval prior to starting. Like i said earlier we can pretty much build what we like, but you need to have put a bit of thought into it. The committee that manage the system here is made up of rodders and enthusiasts, and know what works, but the underslung front axle did throw them a bit. They made a couple of recommendations, using the bell crank rather than direct cowl steer so as to reduce bump steer issues, and it was approved.
I figrued with a multicarbed 454 and 4:11 gears i might go througha bit of gas, and as i like to drive a lot a big tank was called for. I also figured a bit of weight over the rear end might also be useful. I found a tank from a light truck, its about 100-110 litres or 28 gallons or there abouts which should be plenty, i just needed to make it fit.

As i have plenty of 60x30x2mm RHS but no means of bending it i set to with a cut off wheel, made lots of closely spaced cuts (19 actually) and welded it all back together to get the shape of the tank cradle to match the tank.

Tank cradle all fabricated and welded in.


Tank sitting in place, tailpipes will be mounted underneath as shown.

A front shot to show the height, or rather how low it is. To give it perspective the front tires are 29" tall, and its about 40" to the top of the screen posts.

real cool build. Are you going to have enough clearance so you aren't dragging frame after its all together?
When finished i'm hoping on about 5-5 1/2" under the frame. The way its been built there is nothing hanging below it, but with a wheel base of 130" i guess there is potential for it to belly out, pushing it in & out of the workshop shows that, not a lot of clearance there. the new frame horns are about 1 1/2" lower than the temp mounts so will lift the car by the same amount which will help.

Very innovative, some interesting ideas, this is going to be interesting when you get it done. I have to say your welding is as good as I have seen. keep posting and good luck with your build.:cool:....Francis

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