Engine Rebuild Suggestions & Tips Needed

I've had opportunities to drive quite a few 365 GTB/4s, including couple of them right before & after comprehensive engine overhauls/rebuilds, one had about about 68K mi. (+/-110K km), one with unknown miles above 100K (160K+ km) prior to these services and while each ran seemingly well, in both cases, the difference in performance was clearly noticeable.
OTOH, both were also treated to full brake/suspension/steering/clutch/transaxle/etc rebuilds at the same time...

 

This is also what I would investigate first. As long as you've got an issue here, you should definitively fix it prior to look anywhere else. Once the pump is sorted out, check that coolant is not leaking any-more. As mentioned by @Al Campbell a severe coolant leak in the cylinder dome would be a far more serious issue. I have experienced first hand what Al is talking about, here is what cylinder 9 looked like in my car:

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If the next oil analysis are acceptable and the coolant stays in the system I would refrain from taking the engine out. If you cannot sort out the coolant leak maybe that a complete overhaul is the way to go.

I must confess I am chasing additional HPs on my 400i. Not sure however that it makes sense as I've spent more in new engine parts than the actual purchase cost of my car. At the end of the day it will still be significantly less powerful than my brother's 365. (My brakes are better, my gearbox is faster my suspension is stiffer, my TRX are less scary, and my stereo sounds much better, but he has carbs and high compression pistons... ).

If you want more power, just invest in another car than a 400i.

 

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I’m going on memory here. I believe depending on which hose you are replacing there are different sizes. I bought from this company.

https://www.aircraftspruce.com/?gclid=EAIaIQobChMI0Nms_uTj7QIVxyCtBh0sRAfOEAAYASAAEgJTB_D_BwE

The ducts I used were the same size as used in some airplanes. One of the sizes was only available in a reddish color. Not an exact match color wise but at least it was the correct size. One of the ducts I replaced was really just a coil spring, most if the material was gone. Made the ventilation in the car noticeably better.

 

Has the cooling system been pressure tested? I would start with this and see where the coolant leak is.

The copper is most likely from the big end bearings at the far ends of the crank.
I know your engine has less km on it than mine but coolant in the oil will increase bearing wear.
This is what the end conrod bearings look like in my 68,xxx mile engine and it didn't have any coolant leaks.
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Remember there are 18l of oil in this engine, so it may take quite a few oil change until all the debris are taken out of the block.

You should really perform a coolant leak test. The bad news is that this test does not reflect the condition of the engine when hot (for instance, the cracks I posted earlier do not let coolant flow when the head is cold). However if the cold leak test is correct there is little risk the engine is about to fail on you. At least there is not enough coolant flowing so as to significantly damage the piston and liners.

If the cold leak test is bad, you should take the engine out. If the test does not exhibit an obvious leak, If I were in your shoes, I would run the car and monitor oil and coolant for a few more miles (>1000miles). If your mechanic is still concerned by the oil analysis after this additional "probation" period, then take the engine out.

Out of curiosity what type of oil are you using? Any recent change?

 

Yep, still using Castrol 20/50; you’re not wrong.

 

My brother got his parts from Ferrari.That's the best you can find. Priced accordingly though... Genuine Ferrari sodium exhaust valves are approx >200€ compared to £50 for Superformance stainless valves.

I've not tested US based suppliers, but these would be the ones I would consider first if I were based in the U.S. On a European perspective I buy new off the shelves products from Superformance, hard to find items from Eurospares. Superformance quality and order management is top notch. Eurospares quality is sometimes lower but they have multiple suppliers and can provide various alternatives for the same product. Eurospares do also have used parts obviously. You have to drop them an email, as the online catalogue does not fully reflect what they have access to.

For hoses, CohPro (Cohline products).

Whenever I have to hunt for custom made parts, I try as much as possible to let my machinist & mechanic choose their preferred suppliers, as I'd rather let them endorse the product and assume whatever adjustment has to be performed in order to match my specific engine.

Based on my own experience, I would advise you to discuss this with your mechanic and select suppliers he is comfortable with, as the price of the parts is only going to be a third of the rebuild cost.

 

Good day Daren,

I would not put sodium valves back in. In fact I will be replacing the sodium valves in my car (along with a few other items) as a preemptive measure. Stainless Steel valves are not overly costly these days and technically you would only need to replace the exhaust valves, as these were the ones that were sodium filled. Although my car's engine only has 15000 kms (9000 miles), the engine has been unused for many years and so there is a bit of concern with sodium valve embrittlement over time and especially from non use. Although pulling the engine, rebuilding the heads, etc is a bunch of work I feel this is much better and potentially a lot less costly than having a valve failure while driving. I say this, as I had a valve failure on my old 308 Gt4 and the aftermath was nasty ... basically the entire bank was knackered including damage to the heads and sleeves. I keep one of the pistons as a reminder (see pic) and use it as a paper weight. This piston was one of the lucky ones, as the rest were in pieces.

Cheers,

Sam


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That's a kinda cool memento Sam. Though I'm sure you could've done without the blowup and rebuild etc!

I was discussing valve replacement on 400 engines with my parts supplier a few weeks back, and he couldn't recall ever seeing 400 engines having had sodium valve failure. Not that it doesn't happen mind you. Maybe it's because there's less 400s out there, and perhaps percentage wise they do have a similar rate of failure. His assumption was along the lines that our engines don't rev as high as 308s, so they don't work as hard, and put as much stress on the valves. Is it just from embrittlement that they fail or are there other stress/heat factors involved? I'd love to hear thoughts on it from those of you who have more V12 experience than me!

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These are definitively sodium valves. See the impact highlighted on the first photo. These bits are what's left of my 12th cylinder. I still have the broken valve in my glovebox...

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My Brother Raphael's 365 had stainless bent valves, cost him 12.000€ to fix. I had Sodium broken valves, it did cost me quite a bit more and the car has been stuck for 7 years... Needless to say all the remaining old sodium valves had to go! I was quite surprised to see that the remaining valves & guides had very little play and were still within spec. Morale of the story, even if they do seem acceptable, better to change them.

I've decided to go stainless in order to save 3000€ on the restoration. Some on the Forum are advising to use new sodium valves, which is a better solution for cooling. That's a valid point given the design of this head. Apart from the lower cost, I am playing with the camshaft timing, so If things go wrong I'd rather have bent valve instead of broken valves.

 

Despite my engine failure, my bearings were not as bad as yours at 98.500km. I had been using Igol 10w60, Baldwin filters and driving the car a lot.

It's difficult to make definitive assertions, but I guess good filters and frequent use, is the most sensible way to prevent dry start. One may consider the slightly thinner cold viscosity may have reduced the starvation delay (or is it the pure Ester oil?). This being said I would not recommend 10w60 as my piston rings were worn-out (hot viscosity was probably too high).

So based on my pistons __w60 is too thick, and judging by your bearings, 20w__ may cause dry starts. Ferrari 10w50 guideline may be the way to go after-all!

 

Thanks for sharing those pics. That totally sucks for you, but it's a good advertisement for changing the sodium valves. My engine has timing case, sump and cams removed. I was debating to do a leak down check to determine if I'd remove the heads and check the bores, rings etc but seeing those pics is good motivation to do it all while I'm this far into it.

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Will let you know soon if the rebuild was worth the effort...

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It was not so long ago that my Father's one had to be scrapped. Was really heartbreaking. I decided this one had to be saved, regardless of the market value.

 

Will take a picture of the broken valve: the walls are extremely thin (~1mm). This leaves room for more Sodium and better cooling, but this makes them more fragile.

I doubt however that this was due to a valve failure, as my Brother's 365 had "Z bent" valves. So my guess is that we both experienced a timing problem, which ended up less costly for him due to the stainless valves. My valve springs were still within spec, and valve clearance had been updated 10.000km before the failure. All I can think about, is that maybe the stretch of the chain can cause timing problems and valve failures on high mileage engines.

Lessons learned:

1) Change the valve regardless of how good or back they look. (buy stainless if you want to keep cost down, but new sodium valves are probably the way to go).

2) I know we checked valve clearance regularly on my car, but we did not check the timing marks on the sprockets. Will do now!

 

Good day Tim,

It was indeed a bad day when valve let go... which was the second time for this car. I say this, as the car experienced its first valve failure shortly after the first owner took delivery (I was the 2nd owner). Apparently at the time (1976/1977) valve infant mortality did happen. Ferrari stepped up and sent a complete replacement engine including carbs, etc from the Factory to the Dealer to install into the car. When I bought the car it came with the original, but damaged engine, etc which corroborates the events told to me.

As for valve failures with the 365/400 series... Since these cars were made when the Internet did not exist as it does today, wide spread information of these type of issues was limited. Consequently, it would be tough to find or know of any trends representative of these issues. Anecdotally, there has been several reports of engine rebuilders experiencing valve head fractures during rebuilds on similar Ferrari models. Were these reports accurate, hearsay, etc is simply unknown. Also, I have noticed that a number of the documented valve failures seemed to have occurred after a head rebuild that reused the original valves. Speculation is that there may have been valve seat modifications, etc which could affect the temperature gradient across the valve head surface and thus stimulating a fracture. This makes sense to me, as my 308GT4 did have its heads rebuilt a few months prior (seats were simply reground and valves reused) and the failure occurred when the outside temp dropped dramatically and so the engine was very, very cold (-10C). At the time I did not give it much thought and simply focused on repairing the damage.

Given the above I would rather not roll the dice and so I decided to replace the valves, etc so I do not have to worry about it.

Cheers,

Sam

 

At 98,500km your engine has about 10,000 less miles on it than mine.

I have used Shell Helix HX7-K 15W 50 for the last 6 years I have run it, but my car has had about a dozen previous owners and who knows what they used.
I made sure my my car was warmed up properly but other than that I have always driven it hard.
The rings still look like new but I will replace them as the bores look glazed so it will get a light hone.

Cheers,
Al

 

The damaged bearing in a prior picture was due to a connecting rod issue. It was not normal wear.

Sodium valves are stupid in the modern era for these engines. Modern metalurgy makes it totally unnessary. Besides very high quality solid valves from the best American companies are available at a fraction of the cost. Same with pistons. Modern American made pistons are vastly superior than the old Borgos at a fraction of the price. Many years ago I could bore all 12 sleeves, buy 12 American custom made pistons, and the very best rings known to man for all 12 for the price of one Borgo sleeve, one Borgo piston and 3 rings. The price difference is now wider and the OE parts are of poorer quality now than then.

The very first Ferrari I ever worked on was a 250 Lusso with a broken valve over 40 years ago. I am still fixing Ferrari engines with exactly the same problem. For the life of me I don't know how many times we need to learn the same lesson. A very well known author of Ferrari books wrote me a couple of years ago telling me he had finally become a believer when his BB512 broke a valve. He asked if he should change the valves in his 308. I told him they were the same part number and what did he think?

 

It does look like a conrod issue but everything measures up fine.
The bearing shell has worn with even thickness across it's surface area indicating the copper layer on the bearing may not be at a uniform height.
I should know for sure though when the new bearing shells arrive & they are checked with plastigauge.

Cheers,
Al

 

Plastigauge? False sense of security. I will not nor ever have allowed it in the shop. Its made for those that do not know how to use real meausering devices. Sorry if it sounds harsh but its garbage.

Its a rod problem.

The OE rod bearings in use at the time were one of the best engine bearings ever used in an automobile. I find it amusing that anyone would even suggest it as a cause. We still miss their availability.

In my own 328 engine project since we couldn't get them we ground it to a different size and used bearings from Honda Racing.

Don't know what you guys think but I don't just sit here and guess this stuff. How many engines have you rebuilt and how many were Ferrari?