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How Can You Tell If An Engine Was Ruined By Running It Too Rich?

2K views 14 replies 9 participants last post by  Spider73 
#1 ·
My question is how do you tell if an engine has been ruined by running it rich without tearing the engine apart?

- Drew
 
#2 ·
Too much fuel down the bores could cause wear there, low compression to be low, check that. Worn oil rings you can't really check for other than monitoring oil use.
Too much fuel in the oil could cause loss-of-lubrication damage all over. Without tearing it down completely, I'd check the oil pressure and look at the cam lobes and tappets, which is easy. Change the oil and filter if you think it's diluted. How long might this have been going on? If not for a real long time I wouldn't worry to much after an oil change, and it runs decently.

Andrew
 
#3 ·
Too much fuel down the bores could cause wear there, low compression to be low, check that. Worn oil rings you can't really check for other than monitoring oil use.
Too much fuel in the oil could cause loss-of-lubrication damage all over. Without tearing it down completely, I'd check the oil pressure and look at the cam lobes and tappets, which is easy. Change the oil and filter if you think it's diluted. How long might this have been going on? If not for a real long time I wouldn't worry to much after an oil change, and it runs decently.

Andrew
Thanks Andrew -

My compression numbers are 200 across the board.
Too much fuel down the bores could cause wear there, low compression to be low, check that. Worn oil rings you can't really check for other than monitoring oil use.
Too much fuel in the oil could cause loss-of-lubrication damage all over. Without tearing it down completely, I'd check the oil pressure and look at the cam lobes and tappets, which is easy. Change the oil and filter if you think it's diluted. How long might this have been going on? If not for a real long time I wouldn't worry to much after an oil change, and it runs decently.

Andrew
Thanks Andrew. The engine has been running rich since my former mechanic installed the pump that Wes rebuilt. My former mechanic said that he couldn't get the engine to run unless he set it rich. He claimed that the pump was bad. Sent the pump back to Wes twice and it came back with a note that said it bench tested good. It also idles at between 1500 and 2500. Although this has been going on for several years, I've only driven it about 250 miles. It's not fun to drive.

I have a new mechanic and my compression numbers at 200 for each cylinder. He wants me to flat bed the car to him so I don't ruin the engine. Unfortunately the bad weather is setting in and I only have summer tires so getting this car running right will have to wait until spring. At least I won't be stressing out over an engine replacement.

- Drew
 
#4 ·
So it's just running on the rich side but you're not getting gas leaking into the oil through the pump? If your oil pressure is good and your oil level is not going up (which happens when the plungers pass fuel into the oil), I wouldn't worry too much. What is your oil pressure? What weight oil? Does it burn oil?

The pump comes from Wes, but you still have to do a full setup on the car once installed, actuator, rods, bellcrank, mixture. Was that all done? Good actuator? Maybe it just needs good setup. You are where?

Andrew
 
#6 ·
Thanks. Oil pressure is at 57 lbs and is not going up or down under throttle. I'm using Mobil 1 15w 50 and I'm not seeing soot on the end of the tail pipe. I'm hoping that it just needs a setup done properly. I know that Wes has explicit instructions to setup pumps that he has rebuilt. I doubt that his instructions were followed when it was reinstated. I'm in Connecticut, about 65 miles from Norfolk.

- Drew
 
#7 ·
What makes you think it is running rich? The fast idle (very fast idle!) might be just that an idle issue. Guess we have to wait 'till spring to hear the findings of your new guy.
 
#8 ·
Unless the engine is running so rich it's significantly down on power all the raw fuel is being burned. Otherwise, the only effect you may find from excessive fuelling is carbon fouled plugs after a while. Before emission controls all engines ran rich compared to modern engines which had to be redesigned to protect them against high combustion temperatures from mixtures on the lean side. Lean mixtures can destroy engines quite quickly but not rich mixtures. The only damage running rich mixtures will normally cause is to your budget.

If you've no soot on the exhaust pipe tips your engine cannot be running that rich. If you drive a modern engine hard you get sooty exhaust tips because at full throttle even emission controlled engines have to run rich to prevent damage from leaning out, not to mention full power is only developed while the engine is running just slightly rich of stochiometric.
 
#13 ·
Hey Drew,
I have a 78 Spider, and a few years ago I had Wes rebuild my SPICA. Having lived in CT, I know the frustration of not having a knowledgable mechanic. Heck, I now live in San Diego and still can't find one. They are a rare breed, which leaves us to becoming our own crack mechanics. Thank goodness for this BB.
Just wondering what you have done to find the cause of the fast idle. After Wes rebuilt my SPICA and T/A, the T/A died after 3 years. This caused the engine to idle at 2500 RPM. Sounds like what you are experiencing. I sent mine back to Wes and he replaced it free of charge. (Thanks Wes) Do you know how to check the T/A? There are many posts on this BB explaining how, and also in the manual that came from Wes with your rebuilt SPICA. Have you checked the Idle Adjust Screw? Just place your thumb over it while the engine is idling, the engine should "CHOKE" out. If it doesn't, there is an O-Ring behind it that might be worn and needs to be replaced. An easy fix. But I agree with what others have been saying, the SPICA needs to be set up properly. You really can do this yourself. I didn't think I could, but as Wes explained, there's no greater satisfaction when you do it yourself and get it right. It will make for a good Winter project.....There are some things that I'll point out to make your life a little easier....
1. In order to get the pump belt on and off properly, the timing pointer for the crankshaft needs to come off. This needs to be reset correctly. The engine will not run properly if this is off even a little. You will have to find TDC, install the belt on the crankshaft, and align and tighten the pointer before installing the belt on the SPICA.
2. While you're in there, upgrade to an electronic ignition. It makes all the difference.
3. Your oil pressure should move. Check with an external meter (you can probably get a loaner from AutoZone). You might have a bad sender, gauge, or ground.
4. You will need a RPM counter in order to adjust the fuel mixture.
5. Follow Wes's instruction completely.
6. Check your linkage ends. The plastic ends wear and crack over the years. If one has a hairline crack you will never get the settings right. (Don't ask me how I know)
7. I made a gasket for where the T/A enters the SPICA. Its a metal on metal and oils seeps out. Make it before adjusting the T/A as the gasket will change the setting.

Hope this helps......
 
#14 ·
My question is how do you tell if an engine has been ruined by running it rich without tearing the engine apart?

- Drew
Get an oil analysis. The amount of fuel, wear metals and contaminants will tell you if there is any damage. I use Blackstone Labs in Ft Wayne, Indiana. The raw data will be compared to other Alfa and similar engines and you will get a personal analysis of the results.
 
#15 ·
Hi Sorry I haven't responded in several days. I had a deadline to get some photos finished up. Thank you all for your suggestions, questions, and comments. I'll try to respond.

I'm basing my overly rich running concerns on 2 things. The plugs:

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#1 Plug

and my former mechanic's comments that the rebuilt pump is defective and he could only get the engine to run at all by adjusting the mixture to be extremely rich. I don't believe that the pump is defective. Because of the rich running condition and the high idle i don't drive the car much. I've heard from several sources that driving a car that is running rich could ruin the engine.

The engine is a what I called a "mystery motor" in a previous post. The P.O. told me that the guy she bought this spider from put several thousand dollars into the engine to make it competitive against Porsches in it's class. Unfortunately there is no documentation to let me know what he did to the engine. I did find out though the help of the good folks on this board that the pistons are most likely Borgo 10.4:1. Compression numbers of 200# per cylinder and what looks like 7222 engraved on the tops of the pistons support this. The cams on the other hand appear to be stock cams. Wes based his rebuild on these cams. Could have been swapped out by the P.O. before I picked up the car from her. My former mechanic told me that both cams have been advanced. I don't know anything about the valves or any other head work that might have been done to this engine. I vaguely remember that either IAP or CA offered an upgrade package that included theses pistons but don't have a clue as to what else might have been included or required.

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The summer tires, Yokohama Sdrives, issue is that the manufacturer states that they should not be run if the temperature is below 40 F and should not be run in snowy or icy conditions. My new mechanic is located in the northwest corner of Connecticut, better known as the icebox of the state and have already had their first snow. He is well known in the Alfa world but likes to keep a low profile. I will have the car flat bedded up to him but will hopefully have to drive the car home when it is fixed. With so many unknowns about this engine, I don't want to complicate things further by trying to tune the Spica system myself.

The oil pressure is at 57 when warming up and then will drop down to about 30 at idle when it reaches a temperature of 178F. I feel fairly confident that both the oil pressure and temp gauges are working properly. Additional comments, suggestions, and questions are always welcome. They will help me get me through to spring when hopefully I will get this car running right. This board is truly a great resource to the Alfa world.

Thanks again,

- Drew
 
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