308gt4 engine noise

I recently purchased a ‘75 GT4 in Nov’2020, delivered Feb, 2021 sight unseen, from Vancouver Island to New Jersey. Buying sight unseen is something I never do, but due to COVID restrictions at the borders, etc, my hands were tied. I was able to do some research on this car, and found the restoration was documented on FChat in 2012 here. https://www.ferrarichat.com/forum/threads/gt4-colour-opinions.187076/
Since the car only traveled 4000 miles, i decided to go for it. The car looked really nice in the photos but was missing a few things which I have since located. So, when I received the car I noticed a noise coming from 1st bank, added some MM oil just for the hell of it but nothing changed. It certainly sounded like it was coming from the valve train so I pulled the cover and checked the clearances, all were in tolerance. I certainly wasn’t going to chance driving the car with an undiagnosed sound, so out came the motor. Took off the rear valve cover and I swear, a waterfall of at least 2 quarts of oil fell out. Ok, something was blocking the oil drain back holes. Took the head off and found the head gasket was reversed, sealing off the oil holes! Unbelievable! Went a bit further, took the pistons out this weekend and found the wrist pin bushing worn, either were not checked and reused or, and I doubt, worn from lack of lubrication. See here.
Crank looks great. Main bearings look new, rod bearings need changing. Liners are slightly worn on the rear bank but haven’t dial bore gauged it yet. I might just go up a size on the pistons.
Anyone have experience with Wossner pistons?
I’ll send the rods out to be reconditioned, and have the block honed. Clutch looks new. It’s a bummer this happened. Overall the car was put together pretty well, but a stupid mistake like reversing the head gasket could have had catastrophic results. I’m still happy I have the car and can’t wait to put the motor back together and in the car. I’ll post the progress as I go. Pete.

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Wow... I've seen a lot... Never that though..

If you don't need to go up in size on the Pistons, we've got a set of std JE 10:1 on the shelf. Recent build needed custom and JE goofed and made a stock set. 10wks later we got the ones we needed. Kept the stock set on hand in case somebody needs a set. Lead times on engine internals is crazy right now. Gudgeon pin is 0.748" though.

Engine looks clean... That's a plus.

 

That's for sure. But I'm confused how the reversed head gasket caused damage. Oil supply holes weren't blocked, just the return. For sure coolant passages weren't right. But did that lead to damage?

 

Pete- thanks for sharing and posting the pictures, bummer regarding initial expectations, but sounds like it’ll be great when you’re done.

Just to clarify, it looks like the first picture posted is of the right (rear) bank with the head gasket correctly installed, and the second pic appears to be with the head gasket reversed… Is this correct? v/r Paul

 

The dowel pins supply the oil, they act as a needle valve of sorts. The gasket would have to be rotated 180*, flipping it won't work as the dowel pins holes are not in all 4 corners.

Very surprised the oil/water didn't mix and make milkshakes. But the oil return blocked would lead to severely reduced oil flow, that'll wipe bearings and wrist pins real quick. Must've been puking oil out the breather, surprised it didn't push out seals on the cams. Couldn't run very long with blocked return.

 

I think its a testament how robust these 3L motors are. My guess is at least 3 quarts would fill the valve cover with oil, another 1 1/2-2 quarts in the system, filter galley's, etc, so that leaves how much in the sump? Take a spirited drive on some tight twisty's and you can have oil starvation. This motor had 4000 miles put on with the head gasket this way but the previous owner was 90 when I purchased the car so I'm guessing they were easy miles. I'm certainly glad of my decision to rip the motor down.
The photos of the gaskets were how it was found and how it should be, same bank.

 

Smg2, you are correct, head gasket was rotated and flipped to fit. The motor did not leak at all from the head or the cam seals. The motor was very clean an dry, and no oil coming out of the breather. Main bearings are in great shape too.
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Sorry if I'm being slow. What's the mechanism for this? All nine quarts won't fit in the cam cover. Why would there be reduced flow?

 

I’m not sure myself if flow would be reduced, I still had good oil pressure and coolant temps. My thoughts are once the valve cover was filled with oil, it just went it’s normal way. Does anyone have a drawing of the oil passageway?

 

Since the return was blocked wouldn't it lead to low dipstick readings and subsequently overfilling?

 

Oil at pressure is fed to both the mains and the cam journals. From there it gravity feeds back to the sump. The cylinder heads have no other return path then those 2 drain back holes. If they are blocked, the head will fill until pressure builds and pops a seal. Flow to the heads is not huge, those dowel pins control the rate. Would take some time to fill up. It would eventually happen though. 4k miles should have been suffecient though, I'd be looking at oil passage flow in the heads as well.

The galled gudgeon pin is proof that oil starvation was occurring. It really would have gotten worse with time. I'd check the cam journals for scoring.

Yrs ago we got an engine in that a previous shop had the cylinder heads glass beaded to clean up... Yeah bad idea... Passages gummed up with fine glass abrasion material. That was not fun fixing.

 

Here's the 328 oil diagram in color, should be similar to the GT4.

https://www.***********.com/attachments/328-1988-us-481-87_nopw-54-lubrication-system-rotated-jpg.34136/

the **** is f....life

GT4 B/W:

https://static-data2.manualslib.com//pdf2/46/4526/452565-ferrari/images/308_gt4_workshop_manual_44_bg.jpg

 

Wouldn't you get some flow back through the dowels when the car was off?

 

Not really no, they are pressure feed ports to the cam journal, very tight tolerance. Really wouldn't want flow to revert thru those as it would mean a "dry" start on the cam journals after every shutdown.

 

Camshaft journals are pretty good with a couple of journals with some slight scoring.
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Right, and under normal circumstances you wouldn't have any back pressure, but with the heads full wouldn't you have sufficient push back to drain some of the oil out of the heads?

4k miles and 8 years is a long time. Don't know about the maintenance after the rebuild, but it's strange no one noticed the missing quarts.

 

The oil looks pretty clean.

 

It is indeed strange, at a certain point the oil is going to get sucked into the breather port. Then it'll be burning it.

Doh... There is a return path to the sump for the 1-4 Bank.. port between cams feeds to the mid plate (later qv it's the exhaust cam end plate). It's a path, not ideal and will still leave the head filled with oil.

If it was the 5-8 Bank... It would have built up till it pushed out the breather hose.

 

Oil is clean because is has about 50 miles on it, the car had a service in 2017, belts, water pump, carbs rebuilt, etc. just under 400 miles on that service. Everything will get checked, and I’ll post my findings here.

 

I'm not saying that wrist pin isn't knackered, I'm just asking how the head gasket could have caused it. I think the two aren't related.

 

Here's my take based on rebuilding more of these engines then I recall.
The wrist pin is "splash" oiled. The engine block sits atop the gearbox. Now what's interesting here is the oil return layout. Bank 5-8 feeds right into the sump, Bank 1-4 drops onto a partial shelf before falling the rest of the way into the sump. That means that oil return from bank 1-4 will be closest to the crankshaft and windage tray. There's also the the oil return via the mid plate that feeds at the back of the crankshaft.

Blocking the return to the oil sump on 1-4 would stop the majority of oil "splash" that occurs before returning to the sump.

And there's the issue of reduced capacity since the head is filling up vs returning.

 

Oil starvation was most likely to happen on the first oil change after the rebuild, as subsequent oil changes compensated for the quantity in the head.

Was the first rebuild elective?

 

Update.
Block, heads, and reconditioned rods are back from the machine shop. Block was bored and honed for 82mm pistons, head with new guides, stainless valves (still had the sodium filled ones) and valve springs. Rods reconditioned. Installed the crank last week and the the pistons and heads yesterday.
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Nice looking mechanicals!