My Alfa Romeo 33 rebuild - FIRST TIMER

[Brit01]

Electronic Bosch ignition - stock. 8 degrees +- 1 degree is stock at 850 rpm.


Wide band works on occasion when under hard throttle. I have some small pinholes in my manifold welds where the primaries join the secondaries (planning to have it replaced soon). It's 24 years old!

I believe these pinholes are allowing small amount of oxygen in when cruising and affecting the readings so it is disconnected now until this is fixed and all sealed properly.

Chris

[WhizzMan]

How are you determining the engine is pinging? If you are going "by ear" inside the car while driving, you are only hearing the most severe pinging. That's not the proper way to set up ignition timing and it will not benefit the engine or the power output.

If you're serious about this, I'd advice you to build yourself a set of "det cans". They are made from the large "headphone style" ear protectors, 8mm tubing, a y-piece and a (copper) pipe crushed flat on one side (air tight, use solder if required to seal it). Bolt the crushed side on your engine somewhere, experiment for the best location, put the hose on the open end, run it inside the car. Put the other end of the hose on the y-piece and run two hoses from the y-piece into the ear protectors. It may appear to be a crude stethoscope, but the only way to really improve on this setup is to use a contact microphone and do it electronically amplified.

[Brit01]

If you're serious about this, I'd advice you to build yourself a set of "det cans". They are made from the large "headphone style" ear protectors, 8mm tubing, a y-piece and a (copper) pipe crushed flat on one side (air tight, use solder if required to seal it). Bolt the crushed side on your engine somewhere, experiment for the best location, put the hose on the open end, run it inside the car. Put the other end of the hose on the y-piece and run two hoses from the y-piece into the ear protectors. It may appear to be a crude stethoscope, but the only way to really improve on this setup is to use a contact microphone and do it electronically amplified.

Nice tip whizzman.
For sure if I did this then seriously my in-laws and family would lock me up.

I'm planning to retard it back 1 degree as it was before.
Also got some slightly hotter plugs NGK B6ES.

I'm in contact with NGK at the moment as the European site recommend '6' heat plug but the UK site recommend '7' for the same engines.

My 7 plugs have always been a bit oily/black even on a leanish mixture as we've discussed on this thread. Maybe due to the hundreds of short stop/start junctions here in Montevideo.

BUT when I bought the car it had Bosch supers 8 heat rating which is equivalent to a very hot '5' NGK plug!!
Surprised it didn't have holes in the pistons.

[Urbancamo]

If your engine and car are both pretty quiet, you can certainly hear the most severe detonation. It usually appears in middle rpm when load is high.
But if your engine detonates near max. rpm, you won't hear that without headphones. But these are things you don't want to worry with stock production cars.

My advice is to change smaller gear and give her some juice, and avoid full throttle accelerations on low rpms. This the point where engine is gonna detonate if its gonna detonate at all.
It aint diesel, it's an Italian Stallion!

If your NGK number 7 plug is too sooty, then number 6 isn't gonna cause any detonation. It's probably just fine for your engine.
I would quess your Alfa wouldn't detonate at all with European, high-quality 98 RON gasoline (which is usually 98.5 - 98.8 RON). There are pretty huge differences in fuels.
If I go our border neigbour to fill up, most stations have 92-octane fuel on both 92 and 95-pistols...and 98 isn't even available when you go to off the big cities.

What comes to mixed up heatranges, one of my former cars had similar situation. It was using NGK heatrange 6 in OE condition. One of the Bosch equivalents had some misinformation on various catalogues, and it was a match to a NGK's heatrange 4. Little too hot, eh...porcelain never got any color. Very "cooked" looking plugs when I found this thing.

[Brit01]

My advice is to change smaller gear and give her some juice, and avoid full throttle accelerations on low rpms. This the point where engine is gonna detonate if its gonna detonate at all.
It aint diesel, it's an Italian Stallion!

I like that advice for sure.
Yep it's an engine that likes revs (2nd and 3rd gears are my favourites) and tends to ping at WOT at lower revs in 4th and 5th if I get bad fuel on a hot day.

We have imported Brazilian petrol here into Uruguay (bad quality). You never know what you get. Sometimes it runs like a dream, other times horrible.

Just about to set the gaps on the '6' plugs to 0.6mm and hope to fit them this weekend and retard to ignition just a touch to avoid that pinging I felt the other day.

The old bosch (which I still have stored away) were brown on the outside!!!
Burnt to smitherines.

[Brit01]

Also it appears that my Alfa had the quintessential Alfa romeo low oil pressure at hot idle even with 20w/60 oil. 10-12 psi at 850 (if the gauge is showing a correct reading - both)

Soon as I hit the throttle and it's above 1100 rpm it shoots up quickly. I get 50 psi at 3000 rpm when hot, unless I'm going up a steep hill fast and falls a little (5psi maybe). wet sump - stock with no modifications.
Crank a little worn but still within specs.

Lovely boxer sound and gives me so much pleasure to drive.
Oil accumulator would be a nice gift from Santa but not in the books at the moment unfortunately.

[Guy Croft]

The hotter the oil the lower the pressure as the bleed-down rate at the bearings increases the thinner the oil.

What is your delivery/sump oil temperature hot Chris? If you don't have a gauge - get one!

G

[Brit01]

What is your delivery/sump oil temperature hot Chris? If you don't have a gauge - get one!

Funnily enough I was just thinking about that on the bus to work this morning and where to locate it.

Maybe on the free main oil channel plug on the block? (That would be the easy option)

I was reading about the fast break down of the polymers if the oil reaches 110 degrees or so.

Ideal it should be 75-80 degrees, shouldn't it?

[Guy Croft]

Maybe on the free main oil channel plug on the block? (That would be the easy option) YES

I was reading about the fast break down of the polymers if the oil reaches 110 degrees or so. NOT RELEVANT TO US

Ideal it should be 75-80 degrees, shouldn't it? NO 85 DEG

G

[Brit01]

Thanks for the corrections Guy.

I will try and find a sensor and gauge here next week.

Probably another classic OrlanRober gauge to match the oil pressure gauge theme.

But where to fit the gauge now - running out of space on my dash. I'll find a corner somewhere.

Also looking at the majority of the oil temp sensors they tend to have a long tip.

This will not fit into the main oil channel on the block unless an extension is used (this may not read accurately then as it will interfere with the blocks temperature also).

Maybe I can place the pressure warning sensor on the main oil channel on the block and the temperature sensor at the filter connection (where the oil pressure sensor is also connected).

Or another location could be a fitting on the oil sump drain plug.

[Brit01]

I think the best place would be the oil sump.
There are plug adaptors out there.

But I need to wait a few months before my next oil change. I've just done 500 kms on 100 USD worth of 20w/60 gold oil.

When the colder days arrive I will change to Castrol Edge 10w/60 and fit the sensor in the drain plug.

Have a great weekend.

I'm actually excited about changing my spark plugs to a hotter plug and retarding the timing before going for a test this weekend.
I need to get out more also!!! lol

[WhizzMan]

There are two causes of breakdown for the polymers. Mechanical (ground up in gear systems) and chemical (temperature, mostly). This leads to the obvious conclusion that chain driven cam shafts tend to wear oil faster than belt driven ones. Oil pumps that have a high rpm will also grind up oil faster than bigger ones that turn slower.

The use of headphones+microphone or det-cans is rather common amongst the professional tuners these days. The only alternative is to use a frequency spectrum analyzer (gadget or software) with the a microphone. Those tend to need extensive setup for each engine you bolt them onto, while your ear can be very simply tuned to that engine by tapping the side of the block with a spanner with the det-cans on. If you can hear detonation in the car without "equipment" you are seriously detonating and you should consider retarding ignition advance more than just the one degree. I personally would feel safer with at least two, possibly even three degrees. Most people tend to listen with det-cans and then retard one or two degrees, if they don't do a full torque analysis for ignition advance on that load/rpm cell.

Regarding the low oil pressure, I'd be checking the accuracy of your sensor. Alfa is notorious for putting on sensors that wear down and get inaccurate on the twin sparks and V6. I'm fairly certain they wouldn't suddenly choose a better supplier for those sensors for the boxer engines. You refurbished your pump and put new bearings in, so you should be alright.

[Brit01]

Just got back from the garage, put the hotter plugs in and retarded the ignition back to 8 degrees BTDC.

Without road testing it, the hotter plugs felt and sounded different. Nice clean water was coming out of the exhaust pipe. This seemed to have disappeared lately with the '7' heat plugs. A healthy boxer always dripped out clean water.

Blipping the throttle once warmed up made me feel good. Good response and crisp. Tweaked the idle mixture screws a little to borderline rich and it was idling nicely before I put it's cover back on to come back to look after my son.
Wife has a girls night out tonight so no chance of testing the alfita today.

Father/son night tonight.
He'll be 2 next month. Maybe some TopGear episodes with him tonight. He loves cars and is always saying 'brmmm brmmm'!


Thanks gentlemen.

Chris

[Brit01]

40 min road test today with the hotter plugs.
Good response, smooth and louder sounding rasp above 3000 rpm.
Engine temp really stable even with a hot day of 30 degrees. Fans didn't come on once.
I like them.

Still got a flat spot under hard acceleration.
I am having a spare 142 mains set increased to 145 to see if this helps at WOT.
Idles are already 55's (factory spec 52).

At WOT the mains are open right? So an increase in these could help smooth out the acceleration issue.

[WhizzMan]

At what RPM are you getting the flat spot? What AFR are you measuring there?

Mains are open at WOT, but don't fully get going until air velocity picks up. There are a lot of things depending on other things with carbs and just increasing your main jets won't guarantee to "fix a flat spot". It could very well be that the proper fix would be a different air corrector, or possibly something else altogether.