Cams deeply worn, advice needed for new ones

[bussone]

Bad news, about 2.5 liters of oil appears to be lost rapidly and the consequence seems to be bitter. My 4 month old OEM cams had significantly worn in just 10 days, requiring now a replacement. Aside from the fact the engine is now on the bench and a detailed invesigation is still being carried out to see where and how that much of oil is gone, I still keep my hope that the damage is limited only to the cams and I tend to see this as an opportunity to have better performing cams for good. Below are the options I could think of. Any recommendation, experience, comparison is appreciated. Please also consider that I aim for a 300-350hp in the long term and I don't want to lose that much low-end performance.

Options 1&2. C&B road max or race min cams
http://www.cb-cams.com/catalogo_auto...sel_id_marca=7

Option 3. Catcams Part Nr. 1900426 (The ones Jim Nielsen uses)http://www.catcams.co.uk/acatalog/La..._2.0L_16v.html

Option 4. OEM Cams

Option 5......

[Steve Webb]

Options 1&2. C&B road max or race min cams
http://www.cb-cams.com/catalogo_auto...sel_id_marca=7

Option 3. Catcams Part Nr. 1900426 (The ones Jim Nielsen uses)http://www.catcams.co.uk/acatalog/La..._2.0L_16v.html

Option 4. OEM Cams

Option 5......

Option 5. Swap a standard inlet cam over to the exhaust and fit the Fiat Tipo 2.0L 16v (3 Door) inlet cam.

But first job is obviously find out where all that oil went to. Did you run the engine with a low oil level or did you keep topping it up?

Was this a new built engine or did you just replace the cams?

[jimnielsen]

where did the metal from the cam lobes go! ??

[AlfaJack]

Hopefully to a magnetic sump plug or the filter. It is something I worried about when mine started munching through the exhaust lobes. Just had to trust it would be OK...it has been so far.

[Brul(tm)]

I had one of the OEM cams with worn lobes, replaced at aprox 180.000km.
The engine seized due to belt failure a couple of years ago, didn't find anything abnormale at 292.xxx km.

If the cam is worn in a very short period of time, it might give a different result on the engine wear.

[bussone]

I also got some more bad news today completing the whole picture. Piston rings and liners are also gone causing piston skirts to wear out. It seems that the oil passed through the combustion chamber through the worn rings and burned oil with fuel. As the oil level got lesser and lesser, rings are completely gone with friction, the piston skirts began to rub the liners, more oil is lost and this worsened the killer loop process including the cam wear. On the positive side crankshaft bearings are still sound as there was 2+ liters of oil left in the sump. Inyersiting thing is that I got no abnormal EGT (shouldn't I?) to wake me up in this process. Anyway now I also need new pistons apart from cams. I think I will go for forged Wossner's rather than OEM ones, but keep the conrods.

[Steve Webb]

Ouch, not a good outcome of ripping the engine apart. At least you know the problem now and can get things upgraded.

[bussone]

You're right Steve. The expense is expanding to spacecraft development budget levels, and I'm so annoyed about this situation. I begin to think that if I will be spending bucks I'd be better building a strong engine now rather than getting more performance. If I buy forged pistons and performance cams, the original conrods I will be leaving there will eventually give way due to 16 years of fatigue cycles and I will again need to buy everything if I will be this lucky that time.

My engineering rationality and safety side is (needs to be) dominant now rather than my Mediterranean enthusiasm. So I think I should (again) buy OEM spec cams about half the price of the performance cams and throw in forged pistons and conrods, forget about the engine problems for good and enjoy the car at 250 hp for a while.

[the wombat]

I think there is a strong rationale for that approach.

The previous owner of my Q4 did the same. He has built a very strong engine 9think he was aiming for 300hp approx). It has forged pistons and all the good bottom end, but original cams, not chippped etc.

We reckoned (untested) on it producing about 215hp. Thats plenty quick for our roads and my driving. I have no desire for more hp at the minute, and the car drives very nicely

[bussone]

Some updates.

I have ordered forged Wossner pistons and PEC rods (on the way)
I had to resort to OEM spec Pitattore cams as the budget blew up. (these are also on the way)
Cometic MSL head gasket is received.
Oil pump seems to be sound, replacement is not needed.

Do any of you guys know how to increase the engine oil pressure?. Removal of balance shafts does a bit of increase in this regard I guess. I read that Lancia guys grind the inner face of the bottom plate of the oil pump near the sprocket to increase pressure, but I have no clue whether this is a reliable or noteworthy solution.

[Steve Webb]

Sounds like the rebuild plan is going well. I'm not sure I'd mess about with increasing the oil pressure, I'd just try to get hold of a new oil pump to make sure it was working as well as it could be, and you were getting the correct pressure.

[colibry]

by grinding the inner section in oil pump you should get aprox 0.5 bar increes in oil pressure.

[Steve Webb]

So assuming that the engine is in good condition, you are using good quality oil and the oil pump is fine, what would be the advantage of running a higher oil pressure?

[bussone]

I always suspect that low oil pressure in the Lampredi engine tends to speed up the cam wear rate with respect to other similar DOHC engines. That is the reason I thought higher oil pressures might prevent this wearing process. But I may be totally wrong, mine is just a qualitative approach.

[Steve Webb]

I've not heard of the Lampredi engine having excessive cam wear due to low standard engine oil pressure before. The only problem I've come across has been down to very high cornering g forces causing the oil to move away from the pickup.

Making sure you have good overall pressure is a sensible thing for sure, but I personally wouldn't go out of my way to raise the standard oil pressure.

[jimnielsen]

Its not 'normal' to have excessive cam wear with this engine - its abnormal - some other forces must be at play to have caused this other than the 'normal operating conditions'. My my oil pressure logging of the engine I can tell you that the oil pump produces very high pressure when the oil is cold - sufficient when it is hot - and little when it is very hot at idle. I have seen pressures at about 1.1 bar with the oil at 145 degrees C at 900 RPM. This is quite common to see in a track prepared car.. jim