My Alfa Romeo 33 rebuild - FIRST TIMER

[Brit01]

Reading through my manuals the clearance between the crank journals and rod end bearings should be 0.032 - 0.064mm.

I will measure the journals tomorrow and select the appropriate big end bearings, either standard or 0.010 inch oversize.

[Brit01]

Crank journals measure between 49.99mm and 50.03mm

Just measured the inside diameter of the old connecting rod half bearings also and the first reading was ~50.00mm.


The smallest oversize shell is 0.010 inch = 0.254mm!

The standard size shell should measure 50.024 - 50.048mm. (this needs double checking)

0.010 inch oversize would make this 49.77mm - 49.794mm Way too tight for 49.99-50.03mm crank journals.

[Brit01]

ok visual measurements of rod bearings.

old ones - 50mm across in rod end. (good for journals that measure about ~50mm -just very slightly under triple checking them).

new ones (Alfa) way too big! BUT same oversized as the old non-Alfa ones.
So standard is the way to go here.

[WhizzMan]

That vernier is not the tool to use for these kind of measurements.

[Guy Croft]

Don't take measurements inside the brg fitted in the rod, you won't learn anything useful. If you want to look at the clearance betw bearing (fitted) and crank use Plastigauge.

I rarely do that. Ordinarily you simply measure the crank journals (with a micrometer) and compare with brg mfr data on those sizes (and I have never seen a mistake in a bearing catalogue - Vandervell/Glyco etc). The journals will either be standard and good - or worn and in need of regrind - if that is permissible (which it is not in the case of the Fiat/Lancia 2 liter units because they are nitrided FWIW) or it will already be at an undersize and oversize bearings are needed.

You can get an idea of the rod big-end bore with a vernier calliper but finding true diameter is a bit tricky and a bore gauge is best. The rods will invariably be a bit oval after prolonged use and one needs to have an idea of how much out-of-round you can get away with before putting them back in.

G

[Brit01]

That vernier is not the tool to use for these kind of measurements.

Thanks. Yes I was discovering this while trying to find an accurate figure.
Other measuring tools here are very difficult to find, and if you're lucky will cost a small fortune.
Plastiguarde would be great but it is not imported to Uruguay (like most things - very high import duties deter many investors here). Just trying my best with limited resources like most people/mechanics here.
Envisage someone trying to buy these tools in Cuba or import them. Similar situation here unfortunately.

The journals will either be standard and good - or worn and in need of regrind - if that is permissible (which it is not in the case of the Fiat/Lancia 2 liter units because they are nitrided FWIW)

Alfa cranks are nitrided so no regrinds possible.

You can get an idea of the rod big-end bore with a vernier calliper but finding true diameter is a bit tricky and a bore gauge is best. The rods will invariably be a bit oval after prolonged use and one needs to have an idea of how much out-of-round you can get away with before putting them back in.

Yes I saw this as I took several measurements while turning the crank and using the vernier.
Overall the crank appears to be in good shape and within specs.

The standard shells will be the ones. The smallest oversize (0.010 inch = 0.254mm) will be too tight.
Measuring the crank journals several times in different places they ranged from ~49.96-~50.01mm (with the vernier).

Thanks very much Guy and Whizzman.


Specs of Alfa shells:

Part Number: 66625RA
Chemical Properties: Unleaded
Component Number: 66625RA For bearing clearance from: 0,02 mm
For housing diameter from: 53,7 mm
For shaft diamater from: 49,99 mm
Quantity Unit: Pair
Supplementary Article/Supplementary Info 2: Aluminium alloy on steel base
Thickness: 1,84 mm
To bearing clearance: 0,07 mm
To housing diameter: 53,71 mm
To shaft diameter: 50 mm
Width: 17,8 mm

[Brit01]

ok pistons in, rod ends on, torqued up, crank moves firmly but feels good. pump in.

Now just got to double check the angle of the pump shaft in relation to the distributor. Supposed to be at 22 degrees when crank is at TDC.

[Brit01]

all ok. I moved the pump shaft one tooth either way and the angle varies greatly.

The original position shown is spot on at TDC for the distributor to fire at cylinder One.

Just finished bolting on the left bank cylinder head. Just need to torque the bolts up in the correct sequence and in 3 stages.
That part is a little fiddly due to the limited space.

Photos will be uploaded later.

[WhizzMan]

There is plenty of space to do the head bolts? Are you using the correct sockets?

[Brit01]

Are you using the correct sockets?

Sorry what do you mean by this?

Standard hex 17mm socket with a small extension attached to the torque wrench.
In a specific diagonal sequence in 3 stages of torque.

All went ok - both heads on now, exhaust manifold attached. Few sore muscles today though. Lol

[TomLouwrier]

I guess you fitted the heads loosely, put the engine back in the car and then torqued the head bolts up?
That would be pretty fiddly yes.

Tom

[Brit01]

Heads were put on with the block in the car. Didn't have any other option.

But many boxer owners have done this and it is possible, but only with the 8v version.

Bit fiddly but possible with some patience.

[Brit01]

Guy,

I'm aware of the process I need to follow to initially break in the new cams and tappets but is there any type of driving style I need to follow after this to ensure quick and good seal of the new piston rings?

Update: just found your correct info at:

http://guy-croft.com/viewtopic.php?t=78

But my doubt about the oil still exists.

(I can only get hold of Castrol GTX 20w/50 here mineral) or Valvoline 20w/50 semi. I'd prefer mineral to break in - would the castrol 20W/50 be ok?

After break in I will be using Motul 15W/50 semi.

Use a mineral oil like Castrol GTX 10W/40 for break in. No-body overloads an engine during this critical phase, that's why you don't need a race grade oil with upper temp viscosity rating of 50 or higher. Use light load only and use the gears freely. These days I prefer to recommend about 300-500 miles during bedding in although blocks honed with FlexHone will actually bed in on a dyno within 1hr. In a car however, it's equally important to test out the 'whole installation' really so that is why I'd really take longer over it, and did a while back with a new V8 engine in my wife's Range Rover.

There are semi-synthetics which work fine during bedding in, but rather than list them all I'd go with the oil above or equivalent. If you try to bed-in an engine with synthetic oil it may never bed-in at all!

The only exceptions are engines with coated bores and rings eg: nicasil, which don't bed-in (by friction and mating wear of ring against bore) in the old fashioned sense.

Hope that helps,

GC

Thanks.

[Guy Croft]

I would ignore that advice you want to be progressive about bedding-in (break-in).

Try this - it's my regime if a dyno is not used, ignore the bits about the oil accumulator:

GUY CROFT RACING ENGINES

data issued May 11

GENERAL ENGINE START-UP INFO – READ ALL THE WAY THRU - BEFORE STARTING ENGINE!

1ST START-UP

1. Ensure sump plug is secure. Check all oil and water hose connections and oil filter for security. Fill cooling system with 50% genuine Fiat Paraflu mix.. Fill engine oil to level on dipstick. If engine is new use a non-synthetic 10W/40 oil for break-in eg Castrol GTX. Semi-synthetic is OK. It is recommended for initial start-up that the feed to the oil pressure accumulator (if fitted) be closed off via the manual valve as the solenoid valve will permit oil to be drawn off from the sump even with no current feed to it. This can lead to a low oil level in the sump. (The accumulator will not however discharge unless current is applied). The additional oil for the accumulator can be added later and the system connected up and wired up.
2. Competition cams should be liberally coated with a good brand of cam lube or smeared with molybdenum disulphide grease. Use engine oil to fill the camboxes, the oil filter, cooler, remote filter and as many of the oil lines as practicable..
3. Remove spark plugs. Disconnect the electric fuel pump and the ignition coil live feed. You must ensure the oil pump is wetted and primed by removing the oil filter housing - or - accessing the feed from the oil pump and squirting oil down the gallery to the pump. You must NOT hook up oil lines until oil backs up from this gallery or hose line from the pump when the engine is cranked or aux d/s spun.
4. Once you are sure the pump is primed and functioning correctly crank up main engine oil pressure with the plugs out and the throttle wide open. Do not crank the engine for more than 7-8 secs continuously and for more than 20sec altogether, the oil pressure should easily come up by this time. Do not start the unit until oil pressure registers on the oil pressure gauge. An excellent method of priming is to spin the aux driveshaft with a high-torque electric drill, although this does mean removing the cambelt.
5. Connect the fuel pump, allow the system to fill and check for fuel leaks.
6. Connect the ignition system and check that it generates sparks when the engine is cranked, by holding the main feed from the coil to the distributor 0.5cm from an earth point.
7. Fit the plugs. GC supplied NGK race plugs can be used for break-in.
8. Prime the carbs by several applications of full throttle to actuate the pump jets.
9. Start engine with minimum application of the throttle. If new cams have been fitted it is vital to keep the engine running at 2000 -2500 rpm for 10 minutes to allow cams to bed in. If engine will not run comfortably at this speed without overheating turn off and investigate the cause.
10. Adjust idle speed to 800 rpm and strobe/set ignition timing (usually 10 deg +/- 2 deg at 800 rpm is about right). Do this immediately and as quickly as possible.
11. You have just run the engine for the first time - so double check that everything from the silencer to the alternator belt is secure!

Note: If an accumulator is fitted, the sump needs to be overfilled depending on its capacity. The unit will automatically draw off this extra oil after the engine starts.


2nd START-UP

1. Check cooling system for leaks.
2. Check oil level and top-up if required.
3. Start engine, check oil pressure and run at 2000 rpm to allow cams to bed in if not already done., When the engine reaches 75 deg C, throttle back and adjust idle speed screw to give 800-850 rpm, then adjust idle mixture to give optimum running, balance carbs if used. Switch off.
4. Accumulator equipped models: connect live feed (it should ideally be wired so as to be activated by the ignition switch) and fill engine with additional oil. Restart engine and run at idle for 2-3 mins to allow unit to fill. The unit should register the same pressure as the engine oil pressure gauge at any given speed. The air precharge is far more compressible than oil, and it may well be full even though the gauge reading on the accumulator shows a relatively low pressure.
5. Run engine at range of speeds to max 3000 rpm to warm up and check cooling system integrity and temperature. The engine should respond normally when the throttle is blipped lightly. You can now drive the vehicle but for no more than 1/2hr and only at low load and speed, or leave it idling for 1/2hr, but do keep a careful watch on temperatures and make sure the cooling fan cuts in by 90 deg C max.
6. On models where the head gasket is required to be retightened it should now be retightened but you must first leave the engine to cool overnight. Get the torque setting direct from GC – settings depend on bolt and gasket type.


BREAK-IN PERIOD BY DRIVING IF ROLLING ROAD NOT USED

1. For the 1st hour do just local driving and do not exceed ½ throttle and 4500rpm. Use the gears very freely and at all costs avoid ‘high-gear – low engine speed’ as this will lead to heavy bearing load with low oil pump output. Stop frequently and check the underbonnet region for leaks and problems. Make sure oil pressure and engine temp is OK and stop immediately at any sign of overheating. Test the engine response on a quiet local circular route void of traffic lights and congestion and don’t venture too far, as the engine jetting may be wildly wrong. Do periodic spark plug checks; the plugs should be pale brown to grey around the outer body of the plug with insulator nose pale brown to yellow-white. If the mixture is too lean the engine will overheat and if the mixture is very over-rich, terminal piston ring and bearing damage may result. If the engine shows any sign of labouring switch off and recover the car by towing or trailer.
2. After the first hour of light running you can carry out a compression test. Typically the low compression engine (7.2/1) will give 180 psi or over and high compression units 210 or more. There should be no more than 5% variance between cylinders.
3. Continue the break-in phase and extend throttle to 3/4 and 5000rpm. Ideally the engine requires to be driven at a range of speeds within these limits for a further (say) 200 miles to fully bed in and prove-out the new installation*, but make sure that increased speed and load is accompanied by periodic plug checks to confirm mixture or damage may occur.
4. Do not attempt full-throttle runs until you have put the race oil in the engine.


For all GC engines race grade oil must be used, eg: Selenia Racing 10W60 or similar. GC strong recommendation is use oil with not less than 50 high temperature viscosity rating.

After any break-in period and major overhaul - change oil and filter. Remember that a remote filter set-up requires a filter with an anti-drainback valve.


The engine may need a confirmatory rolling road power run to check jetting.
On the rolling road, make sure your coolant and oil temps do not exceed:

Coolant: 75-80 deg C
Oil: 80-90 deg C

* just as important as bedding in the rings I can assure you. Most 'new' engines that fail do so due to second-rate installation eg: cooling system leaks - hoses & clips...

[Brit01]

Thanks very much Guy.

The only Castrol mineral oil available here is 20W/50.

I was thinking of using the Valvoline semi 20W/50 for the break in.
Is this on your list of 'ok' semi oils for break in?

Regards