looks rich, shows lean

Anyone have any experience with an engine that shows like it is rich but burns lean? By this I mean tell tale signs, no heat on spark plugs, raw fuel shooting out of pipes, low egts, but the engine also beats out (widens) the top rod bearing. Could being too rich cause this, or is leaning it out going to make it worse? Do I have an atomization problem?

 

Is this a blower motor?

At what approximate RPM's does it shoot out alky?
Is it all cylinders that blow raw alky? I had a single plug wire get cut once and it would shoot alky.

How does it perform on the track?

 

umm, could you have to slow or fast of timing and be smashing them like that? I dont know so Im asking that.

 

Yes this is a blown application. It shoots alky out of the pipes at stage, feels like its raining. Stage EGT's are in the 3-400 range with the down track egts around 6-800 (depending on the run, all 8 stay pretty tight). The oil has been coming out diluted, and I was thinking that maybe the lack of lubrication from the diluted oil was causing issues, but everyone that I have talked to seems to think that because the top rod bearing is beat out, that it is detonating somewhere, some how. Most (if not all) of the bearings were blackened also (some worse then others).

 

Bearings

2 things squeze bearings 1st way to much timing next to much fuel per turn this will usually bend a rod. Did this motor when you tried to fire it tend to kick back?

 

bearing

Mike he didn't say a blackened bearing he said a beat bearing.

 

Chevy style wedge head, psi d 60lbs boost. timing was set at 25* for all of the runs except the last one, bumped it up to 30*. There was only one run where oil pressure fell off a bit on the big end (down to 65 from 120ish) and that was about 3 runs ago. Changed oil after the run and pressure came back up. Engine has only been over 8400 once (last pass) as it was too rich before to get there before. No kick back while starting. I spoke to the person who previously owned this engine and they ran it with less compression (9:1 as opposed to 10.3:1) and a larger bore. He never had any bearing issues at all which makes me think that it is because of the over rich condition. I will say that the previous owner ran 36* of timing had slightly more nozzle area then I currently do. I will post up some pictures when I get a chance.

 

I mentioned both.

 

I would say the bearings are blackened from the oil being so diluted. I find it hard to believe you have 60lbs of boost with all that fuel.
As far as everything else is concerned, you need to give more info on the motor.
1. Clutch car or auto?
2. How much nozzle area?
3. Info on the fuel system. What pump size? Do you run a pump loop? Fuel pressure at 8000 RPM?

 

clutch car have been leaving between 4500 and 5000 RPM. Total nozzle area is .0528 square in. Waterman fuel pump with the .850 gears. Boost is a realitive figure and were not running as much fuel through the hat as others. No pump loop, 100 psi @ 8,000.

 

Wow, that's a lot of nozzle area.
1. Nozzle area is too big. You need to squeeze down the ports to raise your fuel pressure. If you haven't had your system flowed, get it done.
2. Fuel pressure is too low. It should be at least 150 psi to atomize and burn correctly. Too much fuel, not enough fuel pressure will give you the results you have now. What's happening is the fuel isn't atomizing and is forming droplets. Droplets don't burn. That's the shower you get at stage.
3. What is your port check set at?
4. Pump is too big. You need to run a pump loop.
5. Stage EGT's are fine. Down track EGT's should be upwards of 1100 degrees at the end of the track. Again, this tells me too much fuel.
6. We run a BBC with a Big Chief head at 36 degrees of timing. Anything under 32 and it's a fat lazy pig.
7. You should be leaving at 6000 to 6500 rpm.

 

I have been low 5.80's at 231 with the current combo. The last run I bumped the timing up to 30* from 25. no other changes, a sliver of aluminum plugged no. 5 dribbler causing that cylinder to go to 1050* on the EGT and burned the piston up. Upon pulling number 5 piston out it was discovered that the bearings were beat out of it and blackened. After checking them all, they were all sqiushed and or blackened (not off of them were blackened).

 

Is this a doorslammer or dragster?

 

it is a dragster

 

Thanks for the reply. I haven't pulled the crank yet to check the mains. I have been busy here with work. I would think that if there was too much fuel in the cylinder and it was hyrolocking that I would see it in pinched rings, not in the bearings. I know where I would like to go with the tuneup, that's not really the question. I feel the same as you Mike, and think that there is something fishy going on with the bearings and I would like to figure out what is going on before proceeding. Again, the guy who ran the engine before did not have any bearing issues, with a similar pump and a similar nozzle area. Running the same MSD 44 amp mag, recently checked. The only thing different from when he had it is the compression is higher and the bore is smaller. I do have to ask, what makes a bearing black? High load? Here is a picture of #8 rod bearings. These were the worst of the bunch. By looking at the damage it looks like it has been like that for some time, not just the last two or three runs. The other thing that I wanted to mention is that the engine is so rich that it wouldn't really RPM it would just 'labor' along at the same RPM, shift it and the RPM would pretty well stay the same the whole way down the track. When I put the 30* of timing in it on the last run, is when the RPMS came actually came up to 8400 before being shifted. Would running too much fuel with that much boost at that low of an RPM be detrimental to the bearings?

http://i290.photobucket.com/albums/ll253/rb0804/dragster/DSCN3258.jpg

 

IMO You have an oiling issue