LS1 Cobra

Hi All,

Just thought I'd share a couple of pics of my latest development. I was never very happy with the serpentine belt arrangement on the front of my motor. Since I'm not running AC or Power steering all I've got to drive is the water pump and alternator.

My first try at re arranging it was to make a new tensioner bracket and run a shorter belt:

I wasn't confident that the small contact area on the water pump pulley would drive the pump reliably. A re think was in order.

I figured what If I drove the water pump the other way and ran a more conventional belt arrangement. To do this I stripped the water pump and machined up a new impeller with the blades in reverse.



Here's the new impeller next to the original


and here's the impeller installed



I've machined the impeller to a tighter tollerance than the original and it runs a couple of extra blades. This should make up for any losses due to the shape of the housing.

he next job was to make a suitable serpentine pulley. I turned a big lump of billet aluminium into a big pile of swarf all over my lathe and this is what was left.


I've just got to finish off the tensioner bracket on the right side of the pump. This will also add a bit of additional support to the alternator mount when it's done.

I reckon this might be the worlds first reverse rotation LS1 water pump setup. What do you think?

Cheers

Michael

Durien

thats one sexy looking engine

gwj

Really decent looking work. Let us know how it works out! No one can say you folks "down under" haven't done some damn good work w/LS1's.

kickassT/A

iTrader: (3)

that is a slick setup. i might have to try something like that on my jeep. no ac or power steering on it either. thanks for the info

BTLFEDSS

iTrader: (12)

Very nice work A+
BTLFEDSS

WILWAXU

iTrader: (6)

Nice work!

Looks like it will be a fun car!

BadAndy

You should go ahead and copyright your reverse impeller. Nice setup!

WJ SOM SS

iTrader: (11)

VERY NICE! Competent Machinists with imagination are becoming few and far between....That's a first-class job, right down to the pics and explanation process.... WJ

Z-286speed

Got to love it, nice setup, and one hell of a clean motor.

J-Rod

Very nice, but you put the steering shaft on the wrong side.

Besides I thought the water flowed backwards down there anyway.


All kidding aside, that is top notch work!!!

LS1 Cobra

Thanks fellas.

I can't wait to fire it up now.

Cheers

Krazy98Z28

iTrader: (12)

is this a FFR kit???

LS1 Cobra

No, It's a Classic Revival kit. Probably closer to an Everet Morrison kit in the US but the chassis is more like an ERA.

Classic Revival

Cheers

Michael

Another_User

That is cool as heck. What does a machine to do that kind of work cost? I need one bad!

LS1 Cobra

It's a big old Cincinatti Toolmaster Turret Mill. It's probably 40 years old. I picked it up a few years back for about $1200 and then restored it over a couple of months. It needed a fair bit of work but it's a good machine now and I'd probably get about $4K if I sold it. There are smaller machines available for reasonable money.

I had a bench top machine before this that I bought new for about $2K. This Cincinatti machine is much bigger and stands about 7' tall which means you can do a lot more things on it. My friend always says you can do a small job on a big machine but you cant do a big job on a small one.

You can make all kinds of things with a mill.
here's the shaft on my throttle body getting the streamlining treatment:

I did the fuel rails on it and a ton of other stuff. It's well and truly paid for itself.

I've got a picture of the whole machine somewhere, I'll try to find it and post it.

Cheers

Michael

1ScrudeDude

******* outstanding.

'Nuff said.

eallanboggs

iTrader: (1)

Must be nice having a vertical mill in the garage. This looks like a full out race car. If so, why do you even need an alternator. You could run a trickle charger in the pits. You could even run an electric water pump and eliminate the serpentine belt altogether.

Another_User

What is the biggest job you could do on the benchtop machine? I want to do TB spacers, and maybe some bigger stuff. How do you control the machine to make something as complicated as that water pump impeller? I thought they ran more than that...that's a tempting new hobby...

Sorry to hijack your thread...it is just cool stuff.

LS1 Cobra

This is very much a street car. It'll be street registered and mainly street driven with ocasional trips to the circuit and down the strip. I wanted to build something I could drive to the circuit and race all day then drive home again.

I'll even be driving to work on nice summer days.

Cheers

Mike

LS1 Cobra

No trouble, I enjoy talking machining with people too.

Most turret mills have 3 axis of movement. Left-Right, Back-Forth and Up-Down. Some have the ability to tilt the head either left-right and sometimes forward and back too. When you hear about these 5 axis CNC machining centers that they use to CNC port cylinder heads all of these axis are controlled by the CPU.

Since my machine is all manual you have to think a bit harder about how you make each cut. I use the rotary table a lot to give me another axis to machine and to allow me to machine curves etc. I also use it to machine splines on a shaft or the blades on the impeller. Most of the challenge in any machining process is to work out how to hold the work piece and how to make each cut to to end up with the finished product you want.

I use a Lathe and a Mill to make parts and pieces. Some parts need machining steps on each machine. The impeller was machined on the lathe to get the round shape right. The blades were cut on the mill and then it when back in the lathe to be finished off.

With manual machines you can only really work one axis at a time which makes things harder. A CNC machine gives you the ability to control multiple axis at the same time. This means the same setup can be used for several machining steps where I have to move the work piece arround for each cut.

You can make a lot of stuff on a bench top Mill. I sold mine to a guy who wanted to machine out the combustion chambers on his own cylinder head castings for ****** flat head 4 Cylinder motors. You don't need a machine as big as this for most things. That said though ex industrial machines can often sell for less than the small workshop machines.

here's the Mill when I first got it home. That's me on the trailer next to it and I'm 6'1".


Here it is all restored.


Cheers

Mike