My Alfa Romeo 33 rebuild - FIRST TIMER

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Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 19th, 2012, 10:55 pm

Well that was not how I planned to spend my Saturday evening off . Feet up and a good movie was planned!

Carb blockage not knowing where it was blocked. Turned out to be the right side carbs float needle valve.
After 2 hours or so checking and cleaning out all orifices several times finally got all 4 cylinders running smoothly again.


Now I've got a leaking driveshaft boot to fix. Clip on the boot was not tight enough and has now sprayed grease all over the inner wheel arch and gearbox!
Previously had zipties on them which worked fine but decided to get the garage to fit proper metal clips!! Just can't get the staff these days.
Back to the garage to get that filled with new grease and tightened up properly. Not a nice job!

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 21st, 2012, 10:24 pm

A Hueco german fuel pump will be installed in a day or 2. I've had too many issues with my better half trying to start the engine after it's been sitting for some time. I won't go into details.
When the carb bowls are almost empty the mechanical pump just does not fill them up enough with the starter motor for the non-mechanically minded driver to start it effectively.

This well built electric pump is suction type so will be mounted next to the engine.
130 litres/hour
2.2 psi head
2.9 psi suction.

model 133010.

Urbancamo
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Urbancamo » August 22nd, 2012, 6:54 am

I have that same fuel pump on my car. Been there now almost 1,5 years. These are quality products with reasonable price tag. And these really doesn't make a noise - only slight "clicking" which cannot be heard when engine is running.

I know one guy who has been this similar fuel pump in his car now over 10 years and 100 000 kms. Still works perfectly.
GC_25

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 22nd, 2012, 1:11 pm

Urbancamo wrote:I have that same fuel pump on my car. Been there now almost 1,5 years. These are quality products with reasonable price tag. And these really doesn't make a noise - only slight "clicking" which cannot be heard when engine is running.

I know one guy who has been this similar fuel pump in his car now over 10 years and 100 000 kms. Still works perfectly.
Great good to know thanks.

Just purchased this morning.
Will test it out tonight.

Now I won't need to manually fill up the carb bowls to get her started again. Just turn on the ignition and voila; fuel lines and bowls fuel of petrol.

Brit01
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Joined: June 28th, 2011, 4:54 pm
Location: Uruguay

Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 22nd, 2012, 4:44 pm

Urbancamo wrote:I have that same fuel pump on my car. Been there now almost 1,5 years. These are quality products with reasonable price tag. And these really doesn't make a noise - only slight "clicking" which cannot be heard when engine is running.

I know one guy who has been this similar fuel pump in his car now over 10 years and 100 000 kms. Still works perfectly.
What kind of filters can these pumps handle?
Can they be used with the large injection type filters as my mechanical pump didn't have enough power to suck or push through one of those.

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 23rd, 2012, 12:54 am

Brilliant!

Pump in a temporary set up to test and worked like magic!
It is self regulating, you saw in the filter it pumped loads of fuel when starting up (much more than the old one), then when the carbs were full it slowed down to almost nothing.

Happy! :)

Just need to wire it up safely and give it some test rides.

Then comes my MSD.


Also just remaining the doubt about the appropriate filters with this.

Urbancamo
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Urbancamo » August 23rd, 2012, 8:49 am

Currently I have high quality plastic filter element on my car. It's installed in the suction side, of course. You don't want any debris on to your pump.

It should run nicely with FI filter as these are just large filter element inside the metal casing. But this is something you have to test yourself. Problems you discovered with mechanical fuel pump and FI filter aren't surprise. These mechanical fuel pumps have usually pretty weak suction force and they are usually placed pretty low compared to tank level.
So these commonly use siphoning effect to draw fuel from tank.
GC_25

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 23rd, 2012, 11:48 am

It was a different car today to work.
Much better response, acceleration, idled cold much better. Should have made this change years ago.


I'm assuming now my old mechanical pump had a worn shaft on the pump and was exceedingly weak.

Have to re-balance my carbs as they have changed characteristic though.
Probably getting a more constant level in the bowls.

Yes I'll make sure I have some good filters installed thanks.

nabihelosta
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by nabihelosta » August 23rd, 2012, 6:03 pm

Great mods indeed Chris! I'm so happy for you. Will be on your tracks very soon, just as I finish working on my BMW, and summer season gets a little fresher here (it's been 36C for nearly 2 months!)

I do feel my car needs an electric fuel pump, although my mechanical one is new. But the car can't run on the recommended float level for Weber 40IDF on mechanical fuel pump.

The closed float height recommended is 10mm. When I calibrate it that way, the car feels much torquier, revs higher and pulls stronger, but after 1 minute or so on idle, the carbs start flooding (black smoke from exhaust). By experience, I set float level at 13mm, sacrifying power to gain cleaner combustion and fuel mileage (better idle too). My needle valves are brand new (done 5000kms), carbs rebuilt. The problem seems in the fuel pump. Those mechanical little things deliver poor flow, and pulses of high pressure, seemingly capable to push the needles open.

Another thing, when I'm driving on a long uphill stretch say on 4th gear, full throttle, engine just stop revving at 4500rpm. As if it has no fuel anymore. Then I take my foot off, then again fully on the pedal, and it revs another 500rpm beyond 4500. Poor fuel delivery. (OR BACK-PRESSURE???)

Good luck in your future mods bro! Keep us up-to-date.

Nabih
HORSEPOWERunlimited

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 23rd, 2012, 6:10 pm

Hi Nabih,

Thanks a lot. Yes 2 great mods in 1 day. MSD and the Hueco pump.

Your cars symptoms sound like the ones I had almost. Maybe I can go back down to smaller idle jets now also.
My new mechanical pump just pumped so poorly especially on start up.
You could see the pulses through the clear fuel filter. It was always more than half empty.
Now it's 95% full!

And I have an extra filter before the pump to avoid any bits of tank debris getting into the pump.

Wish I had done it years ago.

Well worth it. A great improvement.

Don't hesitate go and buy the facet silver top or Hueco (either suction or push). The Hueco is self-regulating and you can also swivel in the inlet/outlet tubes 220 degrees.

Regards

Chris

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » August 24th, 2012, 6:38 pm

I think my mixture is richer due to the new electric fuel pump. The plugs are pretty black!

I will try the 55 idles instead of the 60's again.

I had hesitation issues before. This could have been a result of the mechanical pump not delivering enough fuel under certain loads.

Brit01
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Joined: June 28th, 2011, 4:54 pm
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » September 6th, 2012, 6:39 pm

I have been trying these new filters (lovely sound!), but I'm getting detonation under hard throttle.
For the meantime I retarded the timing but a little too much as it's heating up quite fast while idling (only coolant).

Now you know I fitted MSD 6A, and 1 plug heat rating colder. I have 145 mains and 55 idles along with small .33 pump jets.
Are these new filters dragging in more air much faster causing a lean mixture on hard take off?
Engine bay is pretty cool as it's winter so not much heat build up.

I will try colder plugs first (edited)
then larger pump jets
If not resolved then original airbox back on.
Then MSD disconnected if I still get detonation.
Maybe larger main jets for the extra air intake?
Attachments
filter pair.jpg
filter pair.jpg (128.11 KiB) Viewed 5447 times

Brit01
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Joined: June 28th, 2011, 4:54 pm
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » September 8th, 2012, 7:35 pm

I gave a good suirt of wd40 and some oil around the shaft to drip down and some down the sides to reach the weights(hopefully).
Rotor springs feel ok.
Sucked on the vacuum while idling and it did move. Not much but some.

Plugs were a light brown. changed to 9 plugs.
also noted the colour change on the grounding nose but each one was at a different part of the nose! Not an accurate way of looking at whether it's retarded or advanced.
Advanced it to almost 8 degrees. tested it at full revs and it didn't exceed the 34 degrees- just spot on.

had a spin around and did't hear ant pinging.
idled cooler.

but it needs a good hard drive to test fully

Brit01
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Joined: June 28th, 2011, 4:54 pm
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » October 15th, 2012, 9:45 pm

Tested the timing on a 100km run, mostly motorway but with some inclines and lost of overtaking (and undertaking! Unfortunately very common here on the 2 lane motorways).

I think the advance is still kicking in too fast and causing detonation from 1800- 3500 rpm zone. Most evident in 4th and 5th gear.
I'm suspecting weak springs. Maybe one of them can be changed for a stronger one.

I want to have the distributor removed and tested on the bench this week or next.

Brit01
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Re: My Alfa Romeo 33 rebuild - FIRST TIMER

Post by Brit01 » October 17th, 2012, 5:32 pm

Been speaking with fellow Alfa owners with Bosch equipment and it was suggested that the vacuum advance (ported) can be too strong at times when opening the throttle under load causing detonation (if centrifugal springs appear ok).

I will disconnect it and give it a try to see if the knocking improves.

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