HI everyone, this is my first post so please excuse me if I am in a learning phase till I get natural here.
I have an issue/many engine issues with my 81 Lancia zagato.
Purchaed a nicely maintained Zagato which performed OK till I noticed a little wisp of smoke coming out of the cyl #4 by the timing belt. I took it to the Local Fiat/Lancia/Ferrari expert to have them inspect the leak and replace the timing belt.
They did not see much of a problem and replaced the timing belt.
After I got it back, the smoke got worse, and I noticed a bit of a grinding sound coming around the #4 piston/timing belt area.
Took it back to have them take another look at it. After re-inspection
they had thought the engine needed a head re-surface, valve job, refresh of the upper half of the engine. Compression test was 145 in all cylinders, a bit low but livable.
They took off the head, found that something small & metalic had got into the #1 compression chamber and hit the head/ piston top a bit. In addition, the Exhaust valve was a little bent. So they remanufactured the whole head to clean it up. Smoothed out the piston top too.
Then they looked at the cylinder bores....
A big gouge/groove in the cyl wall on #4 toward the timing belt and leak.
So, they hoisted the engine and dropped the pan.
What did they find....
-Pistons with missing ring sections as if they rings where installed broken
-Gouge in #4 cylinder wall due to wristpin with no retaining clips as the wristpin had machined a grouve/gouge into the wall.
-Crank throw bearings wearing out with some small scarring
-Crank throw surfaces not evenly worn, more tapered on one side than the other
-they have not yet looked at the mains
Path forward: they want to replace the engine with a known... good used shortblock that they will strip and check.
My thought is:
use the same block
-85 to 86 mm pistons/rings/pins/clips if the cylinder wall gouge can be removed through boring and honing.
-New stock crank - no regrinds according to Guy's posts - correct?
-Do a good prep on the block, rods, etc to insure trueness.
-Replace rod bolts/nuts.
-Lighten Flywheel.
-Ballance.
-New clutch since the engine is off of the transmission
Questions:
-Where can I get the right piston/wristpin/ ring setup? CP Pistons?
-TS Rings where noted in the forum, so I'd have to get custom as well?
-Would I need a special head gasket if I go to 86mm bore? If so, where to get?
-Unless Guy has some better way, I'd like to maintain near stock compression deck height etc.
-How can I get the correct specs to order?
Note: this engine is just for med hot street use 6500 -7000RPM max - not sustained high RPM driving.
It is origional Bosch FI so I understand that I have to stay fairly stock on most everything related to the fuel transference/timing etc.
I know my story is a bit rambling but what are your thoughts on my path forward?
Paul v
Portland, Oregon USofA
76 Lancia Scorpion - awaiting fix
81 Lancia Zagato - awaiting fix
81 Chev Scottsdale 20 4wd - still running
Gouge in 2L 81 Lancia Zagato cylinder wall -a shortstory
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pv269
- Posts: 14
- Joined: December 29th, 2006, 12:07 am
- Location: Portland, Oregon, USA
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Guy Croft
- Site Admin
- Posts: 5039
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hi Paul
85 to 86 mm pistons/rings/pins/clips if the cylinder wall gouge can be removed through boring and honing.
That gouge might machine out by reboring, I certainly wouldn¢ž¢t junk a block over that unless it¢ž¢s broken through, it can be sleeved with a good quality close-grained SG iron sleeve. Don¢ž¢t go oversize more than you need to rebore and hone to clean.
New stock crank - no regrinds according to Guy's posts - correct?
Yes, or good used it the journals and thrust faces are OK; I would be suspicious of the old journal condition without a most thorough inspection, then polish, deplug GC style, mod oilways.
Do a good prep on the block, rods, etc to insure trueness.
Block, yes, replace coolant core plugs and reface for true, full degrease and detergent wash. The honing finish is critical and depends on ring choice. Don't on any account remove the aux d/a bearings.
My advice don't reuse the old rods. The one from the damaged cyl could well be overstrained. Go to race rods, I have no confidence in the OE rods any more, I no prep or longer work with them or even advise on them, they¢ž¢re just too old.
Lighten Flywheel.
Yes and regrind friction face and do 20 thou" step machine op for clutch too.
Balance.
Yes, crank fw combo with new OE 12mm fw bolts.
New clutch since the engine is off of the transmission.
OK
Where can I get the right piston/wristpin/ ring setup? CP Pistons?
Well FWIW I¢ž¢m an agent for them and they work direct from my CAD dwgs, which no-one else provides to them as it ahppens, everyone just copies which I ahve learned is a useless way to do it. Because I do that so the pistons are accurate and can be sized to TS or CP rings, I can get them shipped direct. CP only sell to shops but I reckon they are the best around today. I have no time for any other piston manufacturer, sorry. I would be the first to say even on my own website that if say you want forged pistons agents and ‹Å“suppliers¢ž¢ will form a long queue to supply, you get what you pay for. Mostly anyhow. Sometimes less. You'll forgive me for saying but certainly since I introduced the name here in the UK every 'man and his dog' is chasing CP now.
TS Rings where noted in the forum, so I'd have to get custom as well?
The rings must be sourced before rebore op, CP themselves only supply race rings at 84.5 or 85mm bore.
Would I need a special head gasket if I go to 86mm bore? If so, where to get?
Don¢ž¢t even try, those 86mm gaskets no longer exist, only Abarth ever had them.
Unless Guy has some better way, I'd like to maintain near stock compression deck height etc. How can I get the correct specs to order? If you are flying solo I cannot help, for myself I design every piston set individually where I can get setup data from the client - at no cost over list. I need certain info from you to proceed, price is per list on GC V/W less some for direct stateside shipping.
It is original Bosch FI so I understand that I have to stay fairly stock on most everything related to the fuel transference/timing etc.
That¢ž¢s mainly true, certainly forget cam swap, although the head can be gas-flowed and the fuel pressure raised 3-5psi using a an adjustable regulator, yields about 130-135 bhp if properly done. That said, it would need a race exhaust layout to get there, as for an old OE stock header and muffler setup, no idea.
GC
85 to 86 mm pistons/rings/pins/clips if the cylinder wall gouge can be removed through boring and honing.
That gouge might machine out by reboring, I certainly wouldn¢ž¢t junk a block over that unless it¢ž¢s broken through, it can be sleeved with a good quality close-grained SG iron sleeve. Don¢ž¢t go oversize more than you need to rebore and hone to clean.
New stock crank - no regrinds according to Guy's posts - correct?
Yes, or good used it the journals and thrust faces are OK; I would be suspicious of the old journal condition without a most thorough inspection, then polish, deplug GC style, mod oilways.
Do a good prep on the block, rods, etc to insure trueness.
Block, yes, replace coolant core plugs and reface for true, full degrease and detergent wash. The honing finish is critical and depends on ring choice. Don't on any account remove the aux d/a bearings.
My advice don't reuse the old rods. The one from the damaged cyl could well be overstrained. Go to race rods, I have no confidence in the OE rods any more, I no prep or longer work with them or even advise on them, they¢ž¢re just too old.
Lighten Flywheel.
Yes and regrind friction face and do 20 thou" step machine op for clutch too.
Balance.
Yes, crank fw combo with new OE 12mm fw bolts.
New clutch since the engine is off of the transmission.
OK
Where can I get the right piston/wristpin/ ring setup? CP Pistons?
Well FWIW I¢ž¢m an agent for them and they work direct from my CAD dwgs, which no-one else provides to them as it ahppens, everyone just copies which I ahve learned is a useless way to do it. Because I do that so the pistons are accurate and can be sized to TS or CP rings, I can get them shipped direct. CP only sell to shops but I reckon they are the best around today. I have no time for any other piston manufacturer, sorry. I would be the first to say even on my own website that if say you want forged pistons agents and ‹Å“suppliers¢ž¢ will form a long queue to supply, you get what you pay for. Mostly anyhow. Sometimes less. You'll forgive me for saying but certainly since I introduced the name here in the UK every 'man and his dog' is chasing CP now.
TS Rings where noted in the forum, so I'd have to get custom as well?
The rings must be sourced before rebore op, CP themselves only supply race rings at 84.5 or 85mm bore.
Would I need a special head gasket if I go to 86mm bore? If so, where to get?
Don¢ž¢t even try, those 86mm gaskets no longer exist, only Abarth ever had them.
Unless Guy has some better way, I'd like to maintain near stock compression deck height etc. How can I get the correct specs to order? If you are flying solo I cannot help, for myself I design every piston set individually where I can get setup data from the client - at no cost over list. I need certain info from you to proceed, price is per list on GC V/W less some for direct stateside shipping.
It is original Bosch FI so I understand that I have to stay fairly stock on most everything related to the fuel transference/timing etc.
That¢ž¢s mainly true, certainly forget cam swap, although the head can be gas-flowed and the fuel pressure raised 3-5psi using a an adjustable regulator, yields about 130-135 bhp if properly done. That said, it would need a race exhaust layout to get there, as for an old OE stock header and muffler setup, no idea.
GC
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