912 Targa : A slow restore / refresh

[Bruce M]

A nyloc might soften with heat?

I'd go with riv-nuts fitted to the cover or just long rivets to attach the hose fitting.

[Lightweight_911]

I'd re-route the pipe to a separate catch tank ...

[neilbardsley]

I'd re-route the pipe to a separate catch tank ...

The purpose of that pipe is to take moisture out of the oil filter canister?

[Lightweight_911]

No, it vents fumes/oil mist from the oil filler cannister back into the intake.

I would vent it to a separate catch tank (where it condenses & you can empty it periodically).

[neilbardsley]

No, it vents fumes/oil mist from the oil filler cannister back into the intake.

I would vent it to a separate catch tank (where it condenses & you can empty it periodically).

Apologies I meant to type 'filler'!

[neilbardsley]

I picked up the 912 today from Max. Mrs B had to drive the car home as I was the only one insured to drive the hire car. However, once we returned the hire car I took over and the 912 was running like a remember. Firstly I thought maybe it was changing from a modern car to an older car but then it started to back fire quite loudly while slowing. To be honest I wasn't enjoying driving it at all. Max suggested that one of the cylinders might be running a bit lean. He offer to sort it but we were already 100 miles away so I had a go myself. First I checked the timing and noticed that it wasn't quite as advanced I would of expect so I changed to about 32/34 at max advance. Suddenly the engine felt much better and more responsive but now was idling higher (about 1200/1300rpm) so turn each idle mixture screw in a little. The idle did move a little lower but I then decide to reduce the advance a little (since I understand the least amount of advance you can use is better). I settled on about 30/31 at max advantage. Now I heard the carbs/engine popping a little so I opened up each mixture screw a little (still leaner than where I started from). Now running much better, no backfiring and idling about 900rpm. However, not quite as quick as the more advanced setting but I happy in between for now. I suspect I still have a little more work to do.

[neilbardsley]

More miles and more smiles now that the 912 is back and running nicely.

It starts well and runs smoothly through the rpm. It idles quite low about 700rpm so low in fact that it's below when the generator starts working! I drove it back down to London early Monday morning (2nd time) and the temp gauge was bearly off the green of low! I did have a chat with Max about getting a Ali oil cooler, as they were about the same price, but he recommended going for the regular one as they could be fixed to the fan at the top of the cooler too. Good job because if the engine ran any cooler it might not be up to operating temp.

I fixed the remaining fixing for the cover for the soft top so we can now enjoy it without it flapping around.

I missed going to Hedingham on Sunday but a day with the family was more fun! I already drag them to enough events.

[Lightweight_911]

Great news Neil - glad you're finally getting to enjoy the car.

[210bhp]

Good news Neil.

You will probably find that adjusting the timing (slightly) is a regular thing as the engine does more miles and 'beds in'. Longish runs are best to really find out where the setting is the best. I adjusted mine before CLM and thought it was about right but after a good long hard run from Scotland to France found it needed a wee tweak after the engine operated at full temperature and swallowed the miles using the all the rev range. It doesn't hurt to adjust your engine till you find the sweetest spot. Great learning about how adjusting affects all the parameters too.

After your recent bad luck it's time you had some smiles and trouble free driving from your cars.

All the best

Regards
Mike

[neilbardsley]

Earlier in the thread I removed and refreshed the oil filler cannister because it had "mayo" in it. I got it cleaned and painted the outside. I left the inside as is thinking that there is oil present to prevent the rust. Unfortunately shortly after picking the car up I noticed that the "mayo" had come back. Possibly more than before. I guess this could be because while the car was being worked on there where lots of short runs? Now my plan is to take the cannister off again and seal on the inside with something like

http://www.ebay.co.uk/itm/FUEL-TANK-SEA ... 4897.l4275

I guess this is suitable?

[Mr Pharmacist]

yes that will do the job, but do you need to do it? The inside of the cannister will have a good coating of oil on it anyway so it wont rust so you dont need the POR kit really?

[jb]

My understanding is that the mayo comes from frequent short journeys where the oil does not get sufficiently hot to get rid of the contaminants.
The answer is to have frequent italian tune ups

[neilbardsley]

It has sudden occured to me that another reason for this problem is that I fited a new seal to the cap! Unfortunately the mayo get a little to thick for my liking. However, my trying to take the canister off was halted by the engine lid closing and refusing to open!

[neilbardsley]

I thought I would post this. Work and bits added to my 912 during the latest bit of work

• Install vehicle on inspection ramp, drain engine oil
• Work as required to remove engine and fit to mobile work stand
• Engine saturated with oil, degrease with soluble solvents
• Remove all tinware from engine, carry out second degrease of engine block and tinware
• Work as required to cut away rusted exhaust system, remove heat exchangers
• Remove carburettors and inlet manifolds, note incorrect / 356 inlet manifold to cylinder head base gaskets fouling fuel flow
• Remove worn clutch assembly, fit engine to rebuild stand
• Remove both cylinder heads, both combustion chambers heavily coated with soot/carbon deposits due to incorrect carburettor jetting / over fueling
• Solvent clean both cylinder heads, machine decoke valves and combustion chambers. Fit heads to test stand, carry out overnight wet leak down test / OK
• Machine decoke all piston crowns
• Remove two cylinders to gain access to full width crankcase thru-bolt, remove and replace oil seals. Re-fit, torque, re-fit cylinders
• Remove, clean and seal all leaking crankcase thru-bolts & pressure relief valve plugs
• Remove leaking oil pressure relief valve, thread seal and re-fit
• Remove leaking sump assembly, solvent clean and re-fit with new gaskets, HT sealants and stainless Nyloc hardware
• Remove blanking bung from oil can breather vent, fit correct diameter tube with new clips
• Remove leaking oil cooler, clean up all sealing surfaces and install new cooler
• Degrease and clean all cylinder head studs
• Remove and replace oil pressure switch
• Fit all new pushrod tubes and oil seals, install cooling baffles
• Re-fit cylinder heads, fit two new head breather grommets
• Seal up non-original holes in rocker face of head, replace two incorrect head bolt washers
• Blue Loctite head bolts and install with new oil seals and HT sealants
• Carry out weld repairs to both cracked exhaust box support brackets
• Supply and fit new special order exhaust box assembly and tailpipe kit
• Fit missing plastic shims to clutch release fork
• Fit complete new clutch, install with new stainless bolts and DIN spring washers
• Fit new clutch release bearing
• Clean and inspect all pushrods and rocker gear, replace two badly pitted inlet rocker arms.
• Re-fit rocker gear to heads, re-set valve clearances. Fit rocker boxes with replacement heavy duty gaskets and sealants
• Clean sealing surfaces of inlet manifolds, re-fit with correct type gaskets, fit carbs
• Re-fill engine with Valvoline VR1, remove and replace oil filter
• Breather pipe from RH head to oil filler can found to have gone hard with age, poor seal with head grommet insert. Remove and replace, fit with new clips
• Change perished fuel crossline between carbs, fit new clips
• Re-fit all ancillary parts and tinware – Tinware originally secured by mismatch of various screw types, refit with new stainless cheese head screws and washers
• Replace badly damaged side tinware piece
• Replace split breather tube in RHS head
• Remove fuel pump and fit custom machined blanking plate
• Bench test engine to check for additional leaks or problems
• Install motor back into vehicle and test drive – Carry out numerous test drives, amending carburettor jetting and making adjustments as necessary.
• Advise customer of poor and unresponsive R/H carburettor
• Supply new 40IDF carb, install correct jetting, modify linkage as required to fit. Install with new base gaskets.
• Test run vehicle, check/set timing as required, check distributor internal setting. Clamp not pinching tight, replace.
• Remove and replace faulty HT lead set & distributor cap / carbon contact split
• Note problem with second carburettor, incorrect chokes fitted. Remove and attempt to replace, carb found to be incorrect for the vehicle (44IDF)
• Supply replacement 40IDF, modify linkage as required, re-jet to match other carburettor
• Carry out road tests as numerous speeds / OK
• Investigate smoke in cabin from N/S heater outlet. Left side heat exchanger found to be internally saturated with oil. Cut open N/S heat exchanger, scrub clean with solvents and weld back up. Grind finish and paint. Road test / OK

Parts

OE tinware piece / re-enameled:
(x2) OE Sump gaskets:
Stainless Nyloc sump hardware kit:
Braided breather tube, heat shrink and clips:
Clutch plate:
Clutch disc:
Clutch release bearing:
(x2) Clutch shims:
Clutch fitting kit / Stainless:
Water soluble solvent degreaser:
Oil cooler:
(x2) Refinished & hardened rocker arms / inlet (Exchange)
OE Oil cooler seals and O'rings:
(x2) Cylinder head stud washers:
Cylinder head breather tube insert:
(x2) OE Breather grommets:
(x8) Pushrod tubes:
(x16) Pushrod tube seals:
(x8) Cylinder head O'rings:
M6 stud and stainless Nyloc fixings for cooler:
(x2) Anular washers for rocker stands @
(x2) Crankcase thru-bolt oil seals:
Oil filler can seal:
Fuel pump blanking plate / billet aluminium:
(x2) Heavy duty rocker gaskets:
(x2) Solex manifold base gaskets and ss hardware:
(x4) Weber IDF to inlet manifold base gaskets
OE Fan backing gasket:
(x4) Exhaust manifold gaskets:
Exhaust box:
Exhaust tailpipe kit:
(x1) Exhaust assembly paste:
(x8) Exhaust 12mmATF copper coated nuts:
(x1) OE Exhaust clamp large:
(x2) OE Exhaust clamps small:
(x4) Stainless heat exchanger clamps
Welding consumables / exhaust brackets:
(x2) Rubber bungs for heads / Wurth:
OE Knecht oil filter:
Valvoline VR1:
(x2) Wurth grey HT sealant:
Fuel for engine bench test:
BS fuel hose and stainless clips:
Loctite Blue, Wurth Pipe Seal, Wurth grey, stainless wave washers:
Workshop consumables – Lubricants, solvent cleaners, degrease bath, test fluid, grease etc..
(x2) OE fan belt:
Stainless cheese-head tinware screw kit:
(x2) Weber 40IDF carburettor
(x4) Weber base gaskets:
HT leads:
(x2) HT lead grommets:
Oil pressure switch:
Distributor cap:
Distributor clamp & bolt:

[neilbardsley]

Just got the car back from Max. I had been back to him because the car was back firing at speed when dropping below 3000rpm. He had previously played with the mix setting a little but the problem was still here. The history of the car was something like this

-> We found out that it had 44 webers on it with 170 (or 175) main jets. This was partly because the small choke size 28/30 that Max tried to put on the car wouldn't fit in the larger carbs
-> Max recommended going to 40 weber with 135 / 55 jets. This was never quite right on the car
-> Now we are at 160 mains with 32 choke. The initial impressions are that the car runs a lot better. More torque and smoother across the rev range.

In the back of my mind it seems like we are back to a similar setup to the start and I wonder if the 44 weber would of been ok. Who knows but a longer drive is needed.

I'm thinking about a drive on the 5 Apr to celebrate the 50th year of 912.