Racing Saloon

[KevJTD]

fascinating thread

[Marlow Sud]

Hi Guys,
Bit of research on adjustable blow-off valves.
This supercharged car has two. It was made here:

Here is the car. Originally 1500cc supercharged, it is now 2.7litre supercharged running on methanol and capable of 140mph.

Here are the adjustable blow-off valves set to 8psi. This is the intake manifold one.

This one is next to the supercharger outlet.

[Kegsti66]

What a great place Simon.

[Marlow Sud]

Hi Keith,
Its Brooklands Museum. I was over there this afternoon.
Lots of lovely cars and motorbikes and aircraft.

All the best,
Simon

[Marlow Sud]

Hi Guys,

My new supercharger pulley arrived today. Beautifully made. The new one is quite a bit smaller than the old one as you can see. Old belt and new belts fit the new pulley perfectly. Just got to get it on the supercharger. In the mean time, I took the supercharger front plate off and replaced the oil seal that the pulley passes through.

Brgds,
Simon

[Johnboy]

That's going to spin up nicely

[Marlow Sud]

Hi Johnboy,
Ran into a bit of a problem today. The original belt is 99 teeth and you can only get 98 and 92 teeth in the UK as far as I can see. I thought the 92 tooth belt would do the job but it is too tight.
I confirmed that 94 teeth is perfect and have ordered a 352L100 synchronous timing belt from a supplier in the US tonight. It should fit here:

Brgds
Simon

[Johnboy]

Never easy, is it chap hope it works out now

[Simonsud]

Can't you move the tensioner stud and use the 92

[Marlow Sud]

Hi Simon Sud
Good thought but If I remove the tensioner wheel, the 92 tooth belt won't stretch over the two pulleys.
Brgds
Simon

[KevJTD]

been looking at this book over the last few months advertised in the back of the auto italia magazine, never got around to ordering it until now.
arrived today, fantastic book for the money.
5 pages on the 131 abarth in both stradale and rally Gp4 spec, some great pics too to inspire you mate
plus of course the 037, integrale, stratos, strada etcetc.....

http://www.auto-italia.co.uk/special-issue.asp

[Marlow Sud]

Hi Kev,
Top tip thanks. I will order a copy.

Brgds
Simon

[Marlow Sud]

By George it fits!
The 94 tooth belt just went on:

And the dump valve fitment using the pop-off valve with the guts removed:

The engine runs well. Noticeably more supercharger noise. Just needs a dyno run now.

Brgds
Simon

[KevJTD]

can't wait to see, hear and maybe even have a ride in it Simon

[Johnboy]

Sweet .Happy days

[Marlow Sud]

Autoitalia, Brooklands - 29th April Kev?
Brgds
Simon

[KevJTD]

ooh, that sounds a tempter mate

[Kegsti66]

Looking good Simon. Glad to see it all went as planned.
Good luck with the testing.

[Marlow Sud]

I thought I should test the dump valve before taking the car on the rolling road.
The testing was all a bit crude but quite helpful. Selected a socket for the manifold end of the dump valve pipe. Clamped the pipe around the socket and drove a cut schrader valve into the square drive and sealed it.
Then I pumped up the pipe with a bicycle stirrup pump.

The dump valve with the green spring opens at 5psi, blue spring 15psi and yellow spring 13psi. Valve operation is very smooth.
I realise that the manifold pressure is going to depend on air flow rate through the valve because with the green spring in place you could momentarily get nearly 20 psi if you slammed the pump handle down.

The conclusion I have come to is that the blue and yellow springs are too much and the green spring may be too little so I cannot achieve the 12psi I want.
I am going to dig out some large copper washers so I can shim up the green spring in the valve to get more boost if I need it during the rolling road session.

Brgds,
Simon

[jobeed]

A bit off topic, but I amazed at some of the ingenuity and engineering I read about on this forum, many times I have thought CAF could have put a good team together on that scrap yard challenge program. Worth bearing in mind if it's still on the telly, and unlike me you would be willing to appear on TV! Always wanted to be on the great egg race with Heinz wolf when I was a kid though!

This fiat looks ace by the way Simon! It's going to be a stormer!

[KevJTD]

scrapheap challenge, there's an idea

[Marlow Sud]

Kev - Fabrication
Shrew - Wheels & Exhaust
Lauren - Electronics
Keith - Finish
Bryan - Pilote

Engine?
Design?
Gearbox?
Elf n safety?
Works damager?

[Kegsti66]

[KevJTD]

that sounds like a great team line up

[Marlow Sud]

Hi Guys,

I previously was getting 4-4.5psi boost.
With the new pulley I am getting 10.5psi and the car accelerates a lot quicker. I used my phone to video the boost gauge:

I changed the spring in the dump valve to see if I could get 0.8 bar and the 12.5psi I was after but it made no difference.
I am very happy with the increase and looking forward to seeing what the proper dyno figures are.
It should be 190bhp instead of the current 117bhp but it doesn't feel as quick as that. We will see.
Brgds
Simon

[Marlow Sud]

Hi Guys,
Changed the distributor this morning for a Bluetooth programmable one so the ignition can be retarded at high rpm and boost. This is the old one:

The drive gear was challenging to remove:

New HT leads and new plugs that are one step cooler due to the boost being increased.

The new HT lead from the coil to the distributor was not long enough so using the old one for now until I get a new replacement from Magnecor.

It started first turn but I didn't have time to play with the advance on my iPhone. An important step prior to the dyno session.
Brgds
Simon

[Kegsti66]

Looking good Simon.
I took these today for you, sorry they are a bit blurred.

[Crank]

Sharp enough to make me drool.

[Johnboy]

Very cool cars

[Marlow Sud]

Hi Keith,
Thanks very much. Lovely cars. Clear enough to see the carbs, exhaust manifold and the cam covers showing it is a 16v engine!
Lovely!
Brgds
Simon