Engine woes-just had to walk away

[madkaw]

I actually did swap carbs. I thought I found something when my #4 cylinder issue followed to the #2 after swapping the front two. Then after trying to verify with some more runs #2 looked great. That's what is making this so frustrating. When I think I have found something I can't seem to verify it. I am not totally counting out carbs and I need to get with Todd.

I don't like what I am seeing inside the head chambers in 3&4 though.

[madkaw]

Well after walking away for a while I am back with sockets in hand. The engine is coming apart. The head is off to check HG and internals. I'd say I have a definite oil issue with combustion. Not sure if it's guides or seals but certain cylinders have that oil sheen to them. #4 is pretty bad with the top of the piston covered in a nice black oily paint. # 2 cylinder intake valve is grungy ( baked on oil?) on the back side of the valve. Head is going to the machinist

[madkaw]

The head is in the machinist hands now. He agreed that he didn't like what he saw at initial look. Valves coming out as we speak to check guides and seats. Kind of anxious for the diagnosis.

[grannyknot]

Steve, I hope he finds something conclusive for you, or atleast it all sparks up nicely when you get it back together.

Nothing worse then multiple gremlins.

[madkaw]

Talked to Kevin Cantrell at Schnedier cams and he said he would inspect my cam at no charge to check for any issues caused by my rockers.

He said the rockers come from a MSA supplier when you order his cam kits- and they are no longer Nissans. He did say if a regrind was necessary he would do that at cost- whatever that entails. Hell- I might just go bigger anyway!!

No updates from the machinists.

[madkaw]

Well the motor is completely broke down with no drama. Everything inside looked like normal wear with nothing jumping out at me. The rear main seal that has given me fits did look troubling. With the block in front of me the seal didn't look parallel to the block. It was installed at the slightest of angle. After removing the seal I noticed a mark on the bearing where the seal rode. It looked as if I put the seal on dry and the seal left a burn mark on the bearing. So I guess I did something wrong. Atleast this time I can see what I'm doing when I install the seal.

The plan is to plastigage the bearing to check for oil clearance and paint the block a color other then black. Clean pistons and inspect them. Then reassemble.

[siteunseen]

Well the motor is completely broke down with no drama.

You'll be "walking away" now for sure.

[Zed Head]

Doesn't the rear main seal ride on the end of the crankshaft itself? Not a bearing? Just wondering. That's why they make those Speedi-sleeves for the end of the crankshaft. Unless you mean that it was pressed in until it touched the bearing. (Aside - Monroe puts the seal on the crankshaft before installing the shaft.)

Might help the process to list all of the problems you were hoping to find causes for. The oil leak, high oil pressure, oily cylinders, etc. And, for your own future pondering, take a good look at the rear main seal area just to see how it's wide open to the crankcase. No oil pressure on the seal. And did you check all of the bearing orientations and locations before removing to make sure that there were no blockages? Don't forget to check the crankshaft passages themselves for blockage.

Just living vicariously...

[madkaw]

Bad terninology Zed. You are right, the seal rides on the crank. It's finished surface makes me call it a bearing for some reason.

Zed, I was reminded of your posts regarding the seal and what was behind it and I see your point. I wanted to tie my pressure issue and leak together, but they do seem seperate issues.

I did look at all bearings as i pulled the engine apart and so far everything as far as oil passages line up perfectly. Oil passages look clear and I have blown pressurized air through them. Still have some cleaning to do, but nothing jumps out at me yet. Need to check crank passages as you have said.

Also going to disect the oil pump. Plastigage the bearings...

...and I am always open to advice and suggestions.

[madkaw]

Some pics of what I have been seeing. The cam looked good but it is still at Schneiders for evaluation. You can see the build up on the back of my valves. looks more like 100k mile engine then a 10k engine. Lots of soot everywhere. The engine builder questioned my PCV system right away.

Looks like I will be replacing valves and guides minimum.

I still have no cause for high oil pressure, but I haven't plastigauged bearings or examined oil pump. Right now I am cleaning all the soot off the pistons tops and examining things there.

[240260280z]

Re: deposits on valves....Were you loosing oil?

Did the valve seals have enough clearance from the valve spring retainer when the spring was at maximum compression?

[madkaw]

They weren't stock seals, but seals that were recommended for a higher lift cam.

Not enough to tell if i was.