Project car - 1989 75 3.0 V6 [Updated 12 November 2021]

Started by shiny_car, July 05, 2011, 09:38:53 PM

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Even though you've put things back together, I thought I'd mention that the inlet runners on my V6 were of very poor internal quality, having some pretty decent port misalignment (strangely, it was from excessive material in the runners). From memory, the bakalight spacers had good consistent finish  and alignment amongst the 6 of them and also with the head ports. So I match ported each runner with the bakalight spacers and generally smoothed (not to smooth) the runners and 'nipples' (couldn't think of any other description  :P) on the plenum chamber so they were pretty consistent 38mm.

The 'Butt Dyno' said better performance  8)

Sheldon McIntosh

You bought a Butt Dyno too?  They're worth every penny in my opinion.

My inlet runners were pretty good, maybe a PO had already looked at them?  Shame he didn't do the same for the extractors, they were appalling, I spent hours smoothing those welds out (and then rewelding the holes where I went too far...oops).


Quote from: Sheldon McIntosh on November 10, 2011, 06:35:56 PM
You bought a Butt Dyno too?  They're worth every penny in my opinion.

Yep, I bought it to set the tension on the adjustable power band that I put on my skate board yeearrs ago.
It doesn't work with my MR2 or Silvia, though. I emailed the manufacturer and they said that Japanese power is different to American and European power. Apparently there is a conversion kit, but I never bothered to look for it. I'll probably just permanently install it in my 75, it should triple the value of the car, so it'll be worth it............



Cheers for the suggestion Duk. Unfortunately I don't have ready-access to the facilities to do any grinding and porting (unless a Dremel counts!). So I'll keep it simple, and continue to chase reliability ahead of power output. But it makes good sense, especially with a boosted engine like you plan.

Quote from: alphie75 on November 06, 2011, 10:48:15 AM
shiny_car  I thought my car was costing me a lot  :obut you have take the cake ( good on you)mate  :)
my bumpers cost me about with paniting in 2pak 130 red $2500 Went finished . :'(

Thanks alphie. You'd expect a good quality paint job for the money you paid!

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey


Update for this month: main work has been related to the camshafts and changing the cambelt.

Distributor removed for cleaning, and R-side of engine block cleaned up:

Old cambelt removed, then cam pulleys, distributor/oil pump pulley, detensioner, and waterpump with thermostat group:

Cam pulley tools bought from TotallyAlfa. The tools are replicas of original factory versions, well made, and well worth the money for this job.

Unbolting the main retaining nut:

Extracting the pulley hub:

Water pump and thermostat assembly removed:

Front of engine cleaned:

3 pieces make up the thermostat group: thermostat in its housing + sensor housing + connector to waterpump. These were disassembled for cleaning; polishing (Dremel + wire brush attachments) cleaned the surfaces but the finish was not nice and even, so I decided to respray them.

3 senders/sensors: thermo time switch + coolant temp sensor (for Bosch ECU) + coolant temp sender (for dash gauge and warning light). These were removed and the brass fittings polished. The thermo time switch tested as faulty, so a picked up a secondhand replacement, courtesy of Monza Motors.

I noticed the bare metal centre of the old waterpump pulley was corroded, so I decided to respray the centre of the new waterpump for protection. Masked and lightly sanded in preparation. The old waterpump had perished seals.

The thermostat group was reassembled with new gaskets, smears of sealant, and new bolts. A small cut-out in the gasket for the air-bleed hole was in the wrong position, so a new cut-out was formed.

Detensioner was disassembled for a rebuild using a kit supplied with new seals and parts, from Alfissimo.

I used a vice (I will buy a proper hydraulic press at some stage!) to press out the metal piece holding the piston seal, which was replaced. Then pressed the piece back into the main housing.

A new bearing was fitted. First, the central piece holding the bearing was pressed out from the old bearing, then pressed into the new bearing.

Piston and spring refitted, with new gasket. New protective rubber bellows fitted over exposed shaft of piston.

Bearing refitted. Bracket bolted onto bearing holder. The bearing pivots according to the forces applied from the cambelt and piston.

Next, onto the camshafts. The camcovers were removed, and oil sludge cleaned out.

Camshaft caps removed. 4 secure each camshaft; their order labelled with a stamped number

Out of curiosity, I measured the valve tappet clearances between the original camshafts and tappets.

The original L-head valve tappet parts (cylinders 4-6), which looked in good condition. Regardless, all the tappets are being replaced with new ones, because new camshafts are being fitted. New camshafts and tappets means new shims are (nearly always) required to achieve the desired clearance. The exhaust valve tappets have adjustable rods instead of shims, so clearances are easy to set and adjust.

The old camshaft oil seals were removed and replaced with new.

New camshafts: these are slightly 'hotter' profiles for increased valve lift and duration, though still relatively 'mild' in the scheme of things. They are standard cams for the US-spec Alfa Romeo 164S (?equivalent of the Euro/Aus-spec 164Q); thus referred to as 'S-cams'...or scams   ;) because of their normally-high cost and marginal improvement in performance. I bought these cheaply from the UK, from an unfinished project, making them decent value. New intake and exhaust tappets to go along with the new camshafts. Plus Scorpion 'Cam & Lifter Installation Lubricant', which is meant to be a formula rich in ZDDP (zinc dialkyldithiophosphate).

The new camshafts and intake tappets were trial-fitted using the original shims. Then the clearances were measured and compared with factory-spec (aiming for 0.018" / 0.46mm). Only cylinder 4 shim remained suitable; the other five cylinders had gaps either too large or small. Measuring the thickness of the original shims determined the thickness of the new shims. Again, at Monza Motors, Hugh Harrison measured my shims and supplied new ones.

Shims, tappets, and camshaft fitted into L-head, and intake valve tappet clearances all rechecked to confirm the desired clearances were achieved.

Once confirmed, the L-head camshaft was again removed, and the new exhaust tappets fitted, and cam lubricant applied. Then refitted the camshaft for the final time, and the cam pulley.

Cam pulley and hub were cleaned and refitted with a new O-ring seal. Only after cleaning the hub did I find the timing notch I'd read about, which was disguised amongst grime and corrosion. There are also timing marks for the L-head on the #7 cap and camshaft.

Whilst working on the camshafts, I cleaned the cam covers, intake plenum, and partly-disassembled throttle body. These were painted with VHT Wrinkle Plus black spray paint. Once touch-dry, I oven-baked them for an hour at about 90 degrees celsius to help cure the paint and tighten the wrinkles.

That's it for now! December is busy, but I anticipate finishing off the camshaft in the R head, and finishing the cam covers/plenum by sanding back the raised fins and lettering, so I will show these details next month.

Thanks for looking.

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey

ARQ164 Shane

hi shiny ,
nice work with your cams ,you are a braver man than me .
I found this site you mite like all about 75 ,s
Please let me know wot you think.cheers
Hi Neighbour,
1973 L beetle "Tilly" sold
87 QV 75 ALFA 2.5lt sold
92 auto 164 3lt RIP
91 white 164 Q
89 164 Q part car


hey richard
very impressive, I admire your bravery to do the intake valves...............I paid a fortune to have mine done

will look forward to the finished project
GTV 2001 3 LITRE


Yes, as mentioned above, great work!  I also admire your efforts on replacing the intake shims & like Gergory paid someone to do mine too.  Did the timing belt tensioner bearing come off the holder ok in the vice?  Those bearings are a bit of fun to chase up these days too.  Totally admire your effort and attention to detail.   ;D
2007 159 SW 2.4 JTDM
1993 164 Super
1994 164 Super (Blue)
1992 164Q (Black)
1989 164 (White)
1988 75 3.0 V6
1983 Sud Ti


Thanks guys. I'm learning a lot about engines as I go along, which is rewarding. Doing the intake shims is no big deal, if you have the time, workshop manual, and tools; and the help of Hugh Harrison to measure 'old' and supply the 'new'.

@ stustustu123: the bearing-holder pressed out and in easily. I had a UK Alfista also ask about sourcing the bearing. I believe they are the same as the 164 versions (and presumably other Alfa tensioners). Alfissimo supplied mine.

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey


Hi shiny car,
How did you determine your ecu thermo sender was faulty? Did you stick it into a boiling pot and measure resistance?
I am trying to cure an erratic idle on my 75 3.0 potenziata , most noticeable when cold.....


Yes, though I'm actually not so sure now!

According to Greg Gordon's tuning article, Step 4, the TTS should measure around 0ohm when cold, and increase to over 100ohm when hot (the threshold is around 35 deg C).

I used my multimeter, and dunked it into hot water. However, my readings have been around 30ohm increasing to around 65ohm, for the original and the secondhand spare I picked up. What are the chances both are faulty and provide similar readings?

So the acid test will be trying it in the car, once my engine is back together. I'll first check that the cold starter injector squirts when the engine is cold, and check that it doesn't squirt when it's hot.

I also found some useful info in this thread from :
It also suggests that a digital multimeter like what I have may not be giving the appropriate readings. Dunno.

Erratic idle probably isn't related to the TTS. But there's other tips in that article that should help you.

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey

Anthony Miller

If the thermo sensor is faulty the ecu will run at full rich, making it an absolute bicth to start and when you do eventually get it going it will blow thick blueish white smoke and will not idle at all.

Richard, this thread of yours kicks arse, keep those updates coming, your pictures and lables rock and are a great help for any one with a 3.0l 75, cheers mate
Now-  '99 156 2.5l V6 (rosso)
         '88 75 3.0l V6 (grigio)
Then- '81 Giulietta 2.0l transplant (ol whitey)
         '82 Giulietta 2.0l transplant (ol brownie)
         '82 Giulietta 2.0l TS transplant (ol red)


Thanks Anthony. I'm glad some people are enjoying the progress.  :)

Update for work during December: unfortunately, busy month with Christmas and stuff, so I didn't have much opportunity to do much.

The detensioner has been refitted, and the cambelt is ready to be fitted (job for this month). Also refitted the thermostat group + waterpump, including new silicone pipes. Cam covers and plenum have been sanded back for the contrasting black-aluminium finish.

New O-rings for the oil-feed pipe and oil-return hole for the detensioner; these parts were from the rebuild kit. Then slid the detensioner back in position and completed the fitment with the reaction spring. There is meant to be an official Alfa tool to hold the spring-loaded bearing back, to aide fitment onto the engine block, and fitment of the cambelt; an Allen key does the job ok!

Coolant that flows from the waterpump through the cylinder heads returns to the thermostat group via short pipes. In the 3.0 (compared with the 2.5 V6), the right-side pipe steps up in diameter to join the thermostat group. So the R and L pipes are different; unsure of the merit behind this. As part of the pipe/hose upgrades throughout the engine bay, the original rubber pipes were replaced with nice silicone ones (from Greg Gordon,, US). He also includes some grease to help slide the tight hoses onto the inlets/outlets. New stainless hose clamps complete the fitment.

The water pump was bolted to the engine block using titanium bolts. New gasket was used, smeared with compatible silicone. Thermostat group bolted to the pump with a new gasket, and silicone pipes clamped to the engine coolant outlets.

Plenum and cam covers were masked around the edges to prevent accidental sanding. The raised ribs and alphanumerics were sanded back to raw aluminium, and are now ready for fitment.

From here-on in, it's pretty much reassembly of all the pieces I've removed along the way. Most parts will need cleaning/polishing along the way, and refurbing the wiring will be a big job...but fun!

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey


Cheers mate. Not bad for a novice, eh?  :D
Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey


It's been 2 months since an update. Reason being, I had no time to touch the car during January, so there was nothing to show! However, I managed a few days work in Feb and made some decent progress. The engine is starting to be pieced back together now!

New cambelt fitted. I used a screwdriver in cylinder #1 to confirm that TDC (top dead centre) was as-marked on the crank pulley. 41mm socket wrench required to turn the crank over. Lining everything up properly for correct timing was a little tricky, and 'walking' the belt over all the pulleys required a few goes. Detensioner locked into position once belt was fitted.

I fitted 6 new NGK BP6ES spark plugs. Interestingly, 4 existing plugs were the same model and looked in good condition, presumably changed fairly recently; but 2 were Golden Lodge 2HL, and possibly the original plugs! I was chuffed that I finally found a use for the spark plug socket piece in my wrench set; I'd never used it before because other plugs were smaller diameter. And I'd read about requiring a 'thin walled' socket that fits down the spark plug wells in the engine; this worked fine.

New gaskets were fitted, sandwiched between the camshaft covers and heads, including 6 round ones atop the spark plug wells. Then the covers were bolted in position using titanium M7x25 Allen head bolts. A modern-look oil filler cap replaces the original.

The cleaned distributor was refitted, with attention to timing position; there is the tiniest 'notch' on the distro indicating the position for the rotor at TDC; most people simply say aim it at cylinder #1 (which works). New rotor and new distro cap added.

Cambelt covers refitted. I managed to buy NOS (new old stock) replacements for the rightside cover (left of photo) and circular front pieces, but reusing the original leftside cover (still want to buy a NOS replacement when I find one).

And finally, my favourite new upgrade: a full set of Recaro sport seats. These were bought through Arese Spares (SYD), imported from the UK. Took 7 months to arrive, but worth it! The cloth inserts on the front seats are worn through, but I have always planned to do a full leather retrim, so this is no big deal. These seats are nice and firm and body-hugging, compared to the cushy, flat original seats.

See you next month!

Giulietta QV TCT . 1.75 TBi . Magnesio Grey - Black
GT . 3.2 V6 . Q2 . Kyalami Black - Red
75 . 3.0 V6 . Alfa Red - Grey