Derek's 308 engine rebuild

Look like a downdraft carb car by the engine cover.

 

Yes it was a QV downdraught, I think '86. But back to the engine...

After reading several discussions about stripping the engine, I was expecting the heads to be stuck on the studs and they were. As soon as the engine was out I removed all the head stud nuts and washers, and started spraying a bit of PB Blaster every day for a week and then took a 5 week vacation leaving them with pools of PB Blaster.

When I came back, I followed one suggestion and hung the whole transaxle from one head for a few days (just a few mm above several closed cell foam pads. Nada! Then, for a few days I left it in the hot July sun hoping that the heating and cooling would draw in the PB Blaster. Hung it from each head for a couple of days but still nothing. Perhaps all of these efforts were in fact slowly loosening the heads, but I don't know. The action that finally works probably only does so because of all the things that you did before that last action. But enough philosophising...

While it was hanging there I found a couple of places on the exhaust side where I could use a scissor jack and some pieces of plywood (to protect the aluminium) to put some pressure on the head. Then I used an old axe handle and a 2x2" piece of wood to lever against the opposite corners (the thickening curve of the axe handle helped a lot.) Suddenly, when I was almost ready to give up and make a lifting plate, DUNK! It came loose. I then did the same on the other head and it came off with just the one jack.

Once they were off it was clear that coolant gets past the top of the liners and through the head gasket to the studs. A couple of studs had a little aluminium oxide on them from where the coolant had acted as an electrolyte in the steel/aluminium galvanic cell, and that was what was holding the head. When I rebuild it I will use Yamabond or similar on the liners to keep coolant out of the head gasket and put a copper anti-seize on the studs.

In the pictures you can see where I put the jacks and where I levered with the axe handle. Also shots showing the rust up the sides of the liner and in the threads of the one stud.

Later this week I'll get to splitting the engine from the gearbox and more disassembly.
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Great job!
How are the heads and valves?

 

Don't do that. Copper anti-seize and aluminium make things much worse, because of their electrical potential in the electromotive series.
Use some ceramic anti-seize.

Best Regards
Martin

 

Thanks Martin! Will do.

Harry the heads are fine but the valve guides are rubbish-- too soft. I was also surprised that the valve stems (both inlet an exhaust) had about 0.04mm of wear (taper.) I am probably getting a few hundred 21-4N valves made in China. Having trouble findings supplier that will do low volumes with stellite seats and tips. This may be overkill and tufftriding or similar will suffice with the bucket tappets?

Ill get the guides lined instead of pressing them out and risking wear on the head (and needing oversize guides. I need to find an engine shop that has an 8mm liner kit (or buy a set for $400.) If anyone has a set they can sell, rent, or loan, let me know.

 

So, once the heads were off they came apart easily with no surprises.

I don't have a valve spring compressor so used a big C clamp and a spark plug socket onto the valve spring retainer (do it with the head upside down and once you feel the collets/keepers let go, screw it in a mm or two more and then give the clamp a tap and the collets fall out. I numbered everything based on the strange Ferrari cylinder numbering (1 is rear bank right, 4 rear bank left, 5 front left and 8 front right.)

For the drop gears, flywheel etc. I followed Birdman's clutch replacement instructions and just remember that with the early cars (like mine) you have to take off the second snap ring to get the bellhousing off. This was an engineering flaw (or a way to discourage independent clutch jobs.) I will bore out the hole in my bellhousing to match the later versions (silly things like that annoy me!)

I didn't want to wait for the proper tools so used a grinder and a file to put 4 teeth onto my new 36mm socket (for the big nut on the front of the crank.) It worked so well that the nut looked fine after a rat-a-tat-tat with my rather lame electric impact wrench. Everything came off as expected except for the cam drive housing which was loose but would not come off with a wiggle and a pull. I spent hours reading online and studying diagrams to see what was catching but decided it was probably the gears being stuck into the inside bearings so started tapping and levering until it slowly came off.

Feeling all smug about the results of my home-made large ring nut tool, I was a bit less fastidious with the small tool and the nuts were butchered-- but they came off.

Separating the transmission took hours as I finally got all the nuts off (the ones near the diff are hard to reach), but it was still stubbornly stuck together. Lots more online reading and it turns out there are two nuts at the back near the rear main bearing cap which are hard to see (but easy to remove as they are inside the oil.) I'll go out and take a photo.

The one inner cam drive bearing came out by tapping with a short bolt through the hole behind the bearing. The other wouldn't budge so I found a carriage bolt that just fit into the bearing (after some filing), put the bolt head behind the inside lip of the bearing, wedged a wad of paper into the hole to keep the bolt eccentric and its head behind the inner race, a washer and nut to lock it all together (it should press on the outer race to avoid rotation), then my multipurpose 36mm socket and a washer and nut to pull the whole lot out. It worked like a charm and I used it on the pilot bearing (much faster than the wet paper or grease method.)

If you have any questions or need more photos to explain, just let me know.
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I read a few discussions about whether or not to remove the liners (sleeves) and decided I would rather see what's in there than do all this work only to have a water jacket leak and have to rebuild the engine again. I'm glad I did remove them because it is clear that they were leaking coolant into the head gasket and causing the corrosion up the stud tubes. If you are pushed for time and are sure there was no coolant leak, you could probably just put some high temp sealant into the hollow segments at each end and an o-ring or sealant around each stud (and some ceramic anti-seize on the studs as suggested by Martin.)

They came out easily (thanks for the tool Chris R.) and were all a bit corroded around the tops where they sat in the block. The head sealing (horizontal) parts were all good, just some gasket to remove. I used a combination of wire brush on a drill to loosen the rust, some mild rust dissolver with a quick brush every hour or so (it took 2-3 hours each) and then a blade to scrape off what looks like some sort of shellac.

So it looks like they did use something to coat the liners but it clearly didn't work for all of the almost 30 years that this car was driving. I'm guessing that the movement caused by the different coefficients of expansion cracked it over time. As I said, I'm glad I pulled the liners.
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One thing I should mention to anyone taking on this job is that you do have to be careful what you use to clean the various parts of the engine. A lot of cleaners are strong alkalies or acids and will eat into aluminium (quickly) or steel (slowly.) Acids can cause hydrogen embrittlement so I was careful to use a gentle cleaner recommended by the machine shop that is machining a pilot bearing hole into the back of my 348 crank. I'll do a low and slow bake of my liners for a few hours this evening just for good measure-- maybe throw in some ribs while I'm at it

 

I also finished my torque plate this week. I read in another thread that someone measured the liner bore deformation with a torque plate and it was a couple of thou which makes sense, so I decided to bore and hone the liners in the block with the new o-rings, old head gaskets and a torque plate. Granted the engine probably flexes again when hot but I'd rather have correct clearances when assembled and add some unknown distortion when hot, than start with a distortion and then add another.

My machine shop wanted $300 to machine the 85mm holes for the cylinders so I took my $40 25mm 6061-T6 offcut to HydroTech and they charged $75 to water jet cut the holes (plus I can make 4 liner pulling tools with the 4 nice slugs I drilled the stud and location holes myself and will use it to press in the liners while the sealant at the top cures (or doesn't.) I can't decide whether to use Yamabond/Hondabond/Loctite 5109 which cure or something like hylomar that doesn't cure. Anyone have any suggestions?
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I just got a sample of the air injector plugs I'm having made to replace the blocked off injectors that were in my head. The long extension reaches the port so can be ground off flush with the port wall (smoother flow and no whistling.) I'm going to have them anodised (silver or red.) Let me know if you want some.

It reminded me to mention that a couple of my air injectors were corroded enough to not want to slide out. I had to file their sides with a small file (turning the injector to reach all sides.) once the corrosion was off they unscrewed all the way and slid out no problem.
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I'm trying to find some decent outer cam drive bearings. These are the ones that often fail and I think it's because many are using standard clearance (not the high clearance C4) and/or lower spec grease (the original HT51 which is Chevron RPM SRI2 grease, seems to be unavailable.) They later switched to the bigger 44mm OD SKF 630647 so perhaps the solution is to machine the casting for the bigger bearings or find a later casting?

The usual F-part suppliers I've asked don't know what grease is used except Superformance who told me it was HT22 which lasts one third of the time of HT51 or the Timken Mobil Polyrex grease in the ASTM D 3336 high temp test.

The C3 and C4 clearance tolerance has a big overlap (C3 is 11-26μm and C4 is 18-33μm) so many of the C3 bearings will probably have sufficient clearance but more worrying is that the standard clearance is up to 18μm so many C3 bearings will be within the standard clearance range and may be too tight. I'm guessing the clearance is to allow for the misalignment of the inner and outer housings and the expansion of the drive-shaft when hot.

Does anyone know what grease is in the "new" SKF bearings supplied by Ferrari? I email SKF to ask about some C4HT51 bearings but heard nothing back. Maybe it will help if call Gothenburg and speak Swedish. I'll try to source some Timken C3 bearings with viton seals and see how they compare in radial and axial play with the SKF C4.

 

Regarding the cam drive bearings, we recently had a similar discussion:

http://www.ferrarichat.com/forum/308-328-sponsored-yellow-compass-group/534241-cam-drive-bearings.html

Best Regards
Martin

 

Thanks Martin, I see someone else is having trouble finding the right bearings. It would be nice to know what specs Maranello, Ricambi, Rutlands are selling. I'm sure any non-counterfeit off the shelf 62032-RSH/C4 would work fine for a few years but I'd rather find the best solution, even if it takes a bit of research. I'd actually prefer a Timken bearing but haven't found a C4.

 

Detailed and informative posts. Thank you

 

Derek - I too searched high and low for the outer cam drive SKF bearings for my Lancia Thema 8.32,until I realized these cars don't use the same bearings...

But - I did come across these : S6203ZZC4 Stainless Steel Ball Bearing 17x40x12

And the grease used : Klübertemp HCB 83-402 - Lubricants - Klüber Lubrication

I know nothing about VXB - never heard of them - but it's an option anyway if ZZ can be used. I suppose the metal shield could be changed to plastic.

 

Just a thought. Since the bearing is not compromised by dirt on its inner side and there's the shaft seal anyway, why not remove one of both seal disks, replacing the grease with a suitable HT-grease and filling half of that remaining small room between bearing and shaft seal with it. Or using a 1RS-bearing (only one seal disk) if it's available in C4.

Or, like Arvid told, using ZZ-versions. Those steel covering (not seal) disks can be removed and reinstalled. If it works on the Lancia 3.2 I cannot see any reason why it shouldn't work on the Ferrari engine.

Best Regards
Martin

 

Martin, These thoughts did occur to me-- puncture the rubber part of the inner seal, warm up the bearing and suck out the grease with a syringe and replace it and seal the hole-- or use a bearing with one side sealed and ensure oil can get in. Both ideas seem a little extreme, even for me If I don't find the right bearings I'll just buy them from Maranello Classic Parts and hope they have done their homework.

 

There is nothing exotic or glamorous about Ferrari dirt. It's as much fun to remove as any other dirt (although I do have a sentimental soft spot for Old English Car oily dirt.)

The sleeves (liners) and the seats they sit in (in the block) needed quite a bit of scraping with a blunt blade to get all the hardened yellow sealer out. I want clean surfaces before I do the liner protrusion measurement (supposed to be 0.03-.07mm.) I didn't use anything abrasive on the seating surfaces as I'd like to reuse the liners if they are ok.

One interesting thing that the rust stripper did is highlight some spots in the one liner where the surface was clearly a different metal composition/structure. I can't feel a difference but the stripper clearly preferentially etched a couple of spots. My guess is that those areas had a bit of corrosion during the 16 years of sitting and will be gone with the 10 thou re-bore.
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Great thread Derek, keep the info and pictures coming.

 

I took one look at the weather forecast this morning and decided I had to get the cleaning done before it's too late. Up here we have to shut off the outside water taps and put antifreeze in the lines or they crack during the deep cold.

This afternoon I put together my $62 ebay soda blaster, loaded it up, found a mask and went to work. My small compressor could only manage a minute at a time but in between I went at the remaining bits of gaskets on the block and heads with gasket remover spray and a hard plastic scraper. I was impressed with the soda blasting finish-- it cleaned off the baked on crud, the carbon build-up in the combustion chambers, and seemed to close the pores of the aluminium a bit, leaving a nice, dull shine. That's me with the steamed up glasses (from the mask which made it hard to see.) There was a lot of wind so I threw caution to it and ditched the mask for most of the work. I definitely had a craving for pickled onions afterwards.

I wanted to take some "after" photos but it was a rush to pressure wash everything afterwards before it got dark and while trying to not burn dinner.
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Awesome thread. What measuring devices do you have? And what experience with engines do you have?

This past winter I took my old Harley apart down to removing the heads and cylinders. But at that point I had no equipment for making the correct precise measurements required, nor did I possess the skill nor equipment to go further. I took the heads and cylinders to an expert.

The end result was excellent. My expert (working at the dealership when I bought the motorcycle in 1989) refreshed the valves, bored out the cylinders and provided me with the pistons and rings. I did the re-assembly. Riding it now with a big smile on my face .

I ask because I am trying to gauge taking on a somewhat similar project with my 308.

 

Good job getting the liner seats clean. I really had a hard time with mine. I have the same soda blaster but did not think to use it on the seats. Smacks forehead with palm of hand.

 

Derek, it is rare for someone to just leap into the scene with such technical knowledge and can-do enthusiasm.

Thank you for sharing your adventure. We will enjoy following your progress.

 

Kevin, I did some rallying in Zambia in my early twenties so spent a lot of time fixing things on the car (and a relatively short time breaking them.) I then started restoring Triumphs and MGs as a student in Florida and spent almost two years travelling around the US in my '69 GT6 (120k kms and 44 states!) Since then I have slowly been migrating up the food chain to a '61 Jag, '70 Porsche, and now the 308.

For measuring, I had bought a few cheap Chinese micrometers for about $20ea before I found a great deal on a set of 5 Starrett micrometers. Honestly, I could not measure any difference between them but I'm not sure how long the cheaper ones stay accurate (they do come with a reference/calibration rod which helps.) I also have a set of telescopic T bore guages but would suggest a proper bore gauge as there are good ones for around $100. Your machine shop will have good measuring equipment if you just do the proper preparation (cleaning, assembly etc.)

One thing I will do is torque up the heads, main caps (with new bearings), and rods (with new bearings), and measure the inside of all the journals before we grind the crank. Plastigauge is a good check for after grinding/polishing but you can't put any steel back and I dislike modifying the caps to take up extra clearance. I have a really nice machinist who is calm and careful, not stressed and has his machines in his garage.

I ordered some Loctite NS5109 from Amazon for the sealing. My local Loctite distributor said it was not available in Canada so would take 2 weeks. Amazon was much faster and the same price.
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I still miss my GT6MkIII
I could change a fan belt on the side of the road and be back driving in under 5 minutes... and sit comfortably on the front wheel while doing it!
What a contrast to working on the GT4!