That's a lot of oil. I don't know what specs Alfa gives, but I'd think 750 miles/qt would be more like a reasonable minimum. My 74 GTV burned that much, even after a valve job. Original Borgo one-piece oil rings are not great, especially after a ton of miles.

You can get the pump number and tipo off the plate. 74 pump would be a T255/1. Not that it makes a ton of difference by now, especially if it's been gone through.

Andrew

 

Thanks for the feedback Andrew... I'll know better after this tank and see if things are consistent. I just started documenting my trip mileage and really monitoring the oil level by trip mileage and tank of gas. It doesn't seem to smoke too much from my view in the drivers seats. > I just don't have a reference for 'excessive'.

I'll start with a benchmark of 750/1qt and see where I compare. I'm assuming there's a three quart difference between the Min line and Max line on the dip stick. I'm not certain but it measured about that much from a 5qt Castrol bottle.

 

44 mpg !!! - maybe need to recalculate that... best I can get is 29mpg (US) and that's pretty much spot on setup on Dellortos, a well set up Spica would probably do better but not much,
An engine in good condition should easily be able to achieve a minimum of 3000 miles from high to low readings on the dipstick depending how you drive it, is the back end covered in oil spots and does it smoke after a long downhill - if the engine is 100,000 miles old it will be pretty worn unless its been worked on as you say?

 

Best I have gotten on a Spica car is high 20s, though I'm working on a Berlina now set very lean, gets mid 30s in cruising. Probably too lean for its own good.
Andrew

 

Andrew, I think you're situation is same as mine. I think I'm too lean. I know my blog leaves a lot "to be desired", but it has a lot of the missing details I won't post here. I'll just summarize by saying that I'm looking for the logical reasons why the all alloy inline 4 cylinder burns a lot of oil other than 100000 miles on the US Spica injector pump. Right now, I'm going to blame an old Spica pump based on Wes Ingram's manual and comments about the cylinder tolerances..

What engine issues would cause more oil to be burned? I drove 455 miles on 11.02 US gallons last tank. I lied... 41.288 mpg. I honestly think running her lean right now is good but I don't want to do it for long. The previous owner admits a long time between 'Italian Tune-Ups' and a lot of short, low RPM driving.

I'll probably have to fill up after my drive tomorrow. I'll post the results.

 

What is the actual mileage on the engine? - if its 100,000 its likely to be pretty worn and in need of a full rebuild, bores, sleeves, rings etc, check your milometer against a sat nav

 

If you think you're getting 44 mpg you need to find a new source for determining how many miles you've traveled because whatever you're using is WRONG.

 

Well, if your car is adding that much oil into the combustion process, I suppose you should expect at least a few extra MPG out of it for the money... ;-)

 

Just had a look at your blog - really nice. You're in Texas too ? Will you be at COTA for the Vintage Racing championships?
2016 Hagerty Show & Shine at Circuit of the Americas | SVRA on 5/6 Nov? I'm in the Dallas area, so while I'll be there, I won't be bringing my Spider.


On your oil-(burning?), have you borrowed a compression tester from PepBoys/ O'Reilly's et al and checked your rings and valve guides? I notice that you apparently didn't have Alfaman do rings when he worked on the engine.... Another silly question is, are you sure you have the right dipstick and aren't over filling?

Oh, and something is pretty definitely odd if you are really getting 44 mpg. I owned a 74 back when they were new and I never got out of the 20's......

 

i didn't expect to have to test the odometer but I've been wanting to test drive next to another vehicle and check speed as best I can. I guess I can test with GPS for distance as well. I'll look into that, but for now I'm just going to post all my numbers and we'll see. I'll be filling up this weekend... just not enough data on the oil. I honestly have no clue about the dipstick. I hope I'm not over filling. That 41.2mpg was the trip to Shiner. I didn't stop much and was over 80 most of the trip. I thought maybe running lean and highway miles might have been that high?

Lokki: I got that email from Hagerty too! I'm trying to make it. My girlfriend won't go, so I have to 'get approval'. I'll PM you if I can go. I'll definitely drive my 74Alfa! I got a drivers suite (imitation) and helmet in Italy when I went for the Mille Miglia. I'll wear them too. I can use Halloween and beer as my excuse for acting like a 10yr old. Is that becoming Alfisti?



I never claimed to be a car guy, so maybe I don't know how to get the correct mpg. Check my math...

12.2 US gallon tank is full in a US 74Alfa Spider 2000 Veloce

mileage from current fill-up - mileage from previous fill-up = miles

Assuming tank was full at last fill-up: 12.2 - current fill-up = fuel

miles divided by fuel = mpg (455/11.02=41.2)

 

I'm confused on your fuel calculations. Tank size is irrelevant.

Fill it up, note mileage, drive, fill up again, note mileage again.

Fuel consumed is whatever it took to fill it up the second time and mileage is the difference between two odometer readings.

so you drove 455 miles, and how much gas did it take to fill up car? Surely it was more that 1.18 Gallons (11.02 = 12.2-1.18).

Did you make the 455 on one tank of gas?

 

Both of your calculations are hurting my head but if you really went 455 miles on a tank, that's going to be around 40mpg or more. Even if it was totally full and you ran it completely dry that's still nearly 40. Count me in the highly skeptical category - I've never heard of a 2 liter Nord getting anything close to Prius mileage. Maybe it's the aerodynamic helmet?

 

OK... as I said, I'm just getting all the numbers written down on paper. For the MPG it turns out it was me that was way off, of course. As it turns out, I completely missed a fill up on 10/13. So ironically, if you split my 41.2 mpg into two tanks, it's exactly what we'd expect. Stupid mistake. I've been taking pictures of my gauges and the gas pump to document things when I fill up until I found a small enough pad and a real pencil to add to the Alfa glovebox!

The oil burnoff is a different question. I'll have pictures but need to fill up the sump and measure it to be sure. It's at the 'I' in MIN but above the Min. line. This is assumed about 2.25 quarts in ~200 miles. I'll post the specifics on oil shortly.

MPG:

9/28/16 - 180m / 10.019g = 17.965mpg
10/2/16 - 178m / 8.452g = 20.838mpg
10/13/16 (tank I missed) - 234m / 11.014g = 21.245mpg
10/22/16 - 221m / 11.04g = 20.018mpg
10/30/16 - 197m / 9.514g = 20.7mpg

Mileage is becoming very consistent.

Assuming it's 3 qt. of oil between the "MIN" line and the "MAX" line on the dipstick, I believe it's about 2 - 2.5 qt. burned in 197miles.

 

Properly tuned '74 with SPICA should get somewhere around 27 mpg. Soot on garage floor indicates you are running rich, not lean. SPICA tolerances are very tight so even a worn out pump is still only going to be a tiny amount of clearance plus fuel pressure is much higher than oil so SPICA is not source of oil consumption. For high mileage engine most likely cause would be valve guides and seals. Also you could have a clogged drain on oil/vapor separator causing oil to go through throttles. Look for oil in intake box.

 

So do you have any idea how many miles the engine has done? - as I said before 100,000 is a lot on a Nord and I would expect it to be pretty worn which would give you high oil consumption and rubbish mpg, at the very least do a compression test to give you an idea of the engine condition

 

Thanks kcabpilot, the previous owner suspected the oil vapor separator might be a concern as well. I don't know a whole lot about it but I've started my research. It seems an awfully easy part to replace if I can find one, but I read somewhere that just taking all the hoses off and soaking it overnight in carb cleaner then rinsing all the clogged stuff out would do the trick? Is it mechanical or have a filter?

When I go through Wes' SPICA maintenance routine, of course I'm running the car with the air box off. If I leave the bottom hose from the oil vapor separator level, oil drips out after a while. I also see constant vapor thin enough to almost call smoke. That hose is connected to the bottom of the air box.

I'll continue my research and plan on cleaning it out first and confirming all the hoses are connected properly.

 

Thanks BMX as well... yeah, I've been waiting for a week day I have off to take the car to my Alfa mechanic in this area and planned on doing a compression test; but I've taken on maintaining the fluids and Spica pump myself... so why not checking compression? I'll plan on a trip to Harbor Freight and doing that this weekend as well.

 

There are two small hoses on bottom of OVS, lower is drain that goes across to dip stick on driver's side and this is the one that often gets clogged because it most likely has never been replaced or even looked at in the past 42 years. The other small hose goes to the idle manifold so OVS will function when throttles are closed. Start by checking the drain, it's the most likely culprit

 

Unless I'm mistaken, the lower of the two small hoses goes to the idle manifold, not the dipstick. The upper of the two small hoses goes to the dipstick. It's easier to see on the two graphics below.

-Sandy

 

Thanks again kcabpilot! Very helpful. I'll go through it all and see how that affects things. I'll report back soon...

 

So I took kcabpilot's advice and checked to see that the oil vapor separator was connected properly and the hoses were clear. I found there was a slight blockage in the hose to the oil dip stick. I don't know if it was the pressurized cleaner stick nozzle poking down in the hose or the cleaner blowing in a few times that broke through but there was something and I could hear the pressurized fluid blowing into a pickle jar under the oil sump on the other end once I blew things out.

I started the engine and used a large screwdriver to shim the throttle cable at a good spot and set the RPM to 2000 once the engine was at 170F. Then I leaned the cutoff solenoid clockwise as much as I thought reasonable. It ended up at about 1/3 the way around the solenoid. I also finally noticed the little red paint dot on the top of the solenoid that likely set where the mixture should be anyway. I still don't see anything on the base of the logic section to match it to though.

I filled the oil up to the Max line again and find that the distance between the Min and Max line is really 2 qt.

So if my calculations are right, I burned 2 qt. in 197 miles. Will running rich account for that much oil? I do see indications the blockage between the OVS and the dipstick inlet caused things to back up into the airbox and throttle bodies... under the air dox and onto the side of the passenger wheel well and SPICA pump as well. I'm hoping that this will clear up a backfire issue I've had as well even though I seem to have power to the microswitch. I'm already very careful of lifting completely off the throttle.

I hope to put 25-50 city miles on her tomorrow to see how the fuel mixture changes pan out. More soon.

 

One quart per 100 miles? Mama Mia -sumthin's wrong.


Where in Texas are you? If you're anywhere near a good Alfa mechanic, I'd have your car professionally checked out... We have one here near Dallas but there's nobody home this week; he'll be at the Vintage Racing championship at COTA in Austin campaigning a couple cars and prepping some owner cars.


shadetreeenginetrics

 

I think your wasting your time until you get the engine checked out, its either leaking or burning oil, the fuel system will have little impact on that

 

What is the crankcase pressure like?
If you remove the oil cap with engine idling, can you lay a piece of thin paper over the filler hole without it being blown to hell?

 

So after driving for a few hundred miles and monitoring things...

I'm losing less oil after clearing out the hose from the oil vapor separator to the sump/dipstick. 1 qt / 137miles. Things are improving but still way too much oil I'm hearing.

I clearly see oil now backed up into the airbag and getting into the throttle bodies. Creating a mess under and around the OVS. That's where it's all going. It's running out the bottom of the airbox as well.

I bought a new Oil Vapor Separator from Centerline and will be swapping it out this weekend and will make sure the other hoses off the OVS are clear. Any other reason oil would back up into the airbox?

I also leaned up the fuel mixture before my last trip. I still have some soot coming out the tailpipe but increased the MPG to 22.

 

You need to do a compression test, no point messing about with anything else till you do that - what your seeing is crankcase pressure forcing oil through the breather, crankcase pressure is generally caused by worn rings/bores passing pressure into the crankcase, so save yourself a lot of time and oil and fuel and do a compression test, wet and dry

 

Or do quick simple test as BMX suggested earlier - with engine running remove oil filler cap and lay a sheet of paper over it. The paper should just flutter slightly, not getting blown up nor sucked in. It should do this even if you rev with the throttle.