My Motor Ate Something?

[josh]

I just took my motor apart to take a peek over the winter. 2017cc with 44IDF's, that I built last year, 3500 miles this summer. Found a couple little problems.

1:#3 intake valve mushroomed the top of the stem(SS with hardenend steel tips) and the single heavy duty springs sit crooked when lined up on the bench. running stock rockers,w125 cam solid shafts and swivel feet
2:#3 cylinder swollowed something mashed up the bottom part of the piston top and the inside of the head too. might of been a little chunk of the cheap sheet metal air cleaner base, that poped the spot weld.
3: The combustion chambers had some pretty good carbon deposits in the heads, I don't know if the rings seated properly cylinders look pretty glazed and were oily when I took it apart. I was new to carb jetting and was running a little lean for a bit.

Questions; what causes a mashed valve tip & tweaked springs? I think I had the geometry set up right.
Would you run the dinged up piston and fly cut the heads?-only 8.2:1 compression and it looks like 50 thou would take it out
And could I get away with re honing the barrels throwing the total seals back in,mabey with some of that quick seat stuff from total seal?  

thanks for any input
 

[Hansk]

OK I'm not with the dvkk, hope they don't mind.
What was the condition of the valve seating surface and the seat?
My guess is what ever did the damage in #3 also held the valve open
or bent it creating excess clearance damaging the stem.
Carbon deposits , ...sounds like a rich condition . What jets ya running?
BTW , what was your deck hight set at ?

[vdubn4x4chik]

are their little bits of metal (aluminum) in the head? Almost little balls? Or is there a 'chunk' you can find? If possible take some pics cause it sound like detonation.  :unsure:  

[josh]

The valve seat condition was fine- no damage but something I noticed was that the seat grinds weren't that consistant. Empi 044's that I bought complete, gave a quick port match, cleaned up the castings and blended the seats. but If you took a staight edge across the top of all the valves, the intakes sat a 1/16\" or more lower.  Would that screw up the geometry? I tried to get an average but the adjusters were screwed in quite a bit more on the intakes, I was wondering after reading an article if mabey the oiling pasage was blocked off, by having it adjusted out to much and starved the swivel foot of oil.

As for the piston I had conformation (from an old timer engine builder) that it was s a chunk of something swollowed not detonation. I don't think you can buy a single 90.5 so anyone with a decent spare out there I would gladly take one off your hands. Oh ya the carbon is too thick to be just a rich condition it was definately burning a little oil. Even though the air jets are too small 175's. I think the other's I ended up with are 57.5 idles and 170 mains on 39mm vents.

[josh]

sorry I forgot the valve stem wasn't bent but the teeth were the retainer seats on the valve in question was pretty fuct too. ( I might be kinda guilty of floating the valves a little too often.... oops) I don't have a digital cam so can't post pics but the marks are pretty distinct- little triangle dents like a corner of something, gradually pounding smaller, grinding up. If it was detonation wouln't there be some damage in the other cylinders?              thanks again

[Hansk]

Check out Jim martins \"primered chop \"  build up in the members section. I think he had issues with oil and total seals also . It's a huge thread but I'm sure it's in there somewhere.  
I don't think there is any oiling at the top of the stock rocker for your adjuster unless your talking about ratio rockers with adjusters at the push rod. At any rate , that did not cause the damage .  Valve float could have though . Dual springs?  You may want to consider lash caps also .


Sounds like your heads could use one new valve and a nice 3 or more angle valve job or even a custom radiused seat cut and a back cut on the valves .  And then trim them all to the same height .  Oh, and new springs ?

[Cameron]

I'll add my two cents worth of advice also.

I've run pistons that have had minor dings in the top with no problems. Use a feeler guage to check the ring grooves for distortion. If you have a tight ring, get a new piston. As for machining the piston, you will have to do all four, to keep the weights, and deck height the same.  A few dollars more, and you could probably buy a new set of balanced pistons and cylinders.

What is causing your motor to burn oil? Is it rings not seating? Or grooves in the cylinder wall, from debris bouncing around in the combustion chamber?

Valve float? W125 requires dual springs. Valve float will cause valve stems, retainers and keepers to distort, and eventually lead to a catastrophic failure of your motor!
No lash caps? Stainless steel valves usually require lash caps. You never said what kind of swivel adjusters you were using. Courier or Porsche style? Courier style have smaller contact surface, and usually need a lash cap.

[josh]

I took a look at Jim's chop build, talk about a sick car! dont even want to guess how much $$$$$$$$$$$$ he has into that thing. the tops of my pistons look just like that one of his in the picture, really black on top but nothing around the edge. The cylinder wall isn't damaged, just really shiny. The adjusters are from scat, with a pretty decent contact area. What will cause rings not to seat? I was reading something in the callook fourum that said a lot of people have that problem with 90.5's- didn't say why? anyone know why one size would differ from the next?  

[jim martin]

Questions; what causes a mashed valve tip & tweaked springs? I think I had the geometry set up right.
Would you run the dinged up piston and fly cut the heads?-only 8.2:1 compression and it looks like 50 thou would take it out
And could I get away with re honing the barrels throwing the total seals back in,mabey with some of that quick seat stuff from total seal?   

thanks for any input

-i think you've gotten some great advise from people here already!!
the only thing i would also do is  remove your oil sump plate and take a look for contamination . as well as , toss the total seal rings and run stock cima or see what airspeed has in stock for replacment rings.
aircooled .net will sell single pistons,but measure your weight first so you can get one matching

[josh]

thanks jim, what kind of contamination am I looking for in the sump? I've got it tapped for full flow and running a HP1 filter. What's the deal the with total seals, yours didn't seat either? I was told by quite a few people that they work well, less blow by etc.  

[jim martin]

thanks jim, what kind of contamination am I looking for in the sump? I've got it tapped for full flow and running a HP1 filter. What's the deal the with total seals, yours didn't seat either? I was told by quite a few people that they work well, less blow by etc.

first i would like to say good for you doing your own engine work !!!!!!!!you just want to make sure the is no heavy metal bits or grey sludge down there.those are obvious sighns of wear.by a berg cow magnet and strap it to your inlet oil pipe.[maybe get airspeed to bring some in !!]remember a filter can not catch everthing .if oil can pass through it so can other things.
as far as total seal rings go .3 strikes your out.i'm not a fan of the product , many have had great luck and i'm not one of them . i think there is many better products out there .but remember there is a time and place for all products . total seals on street engines may not be one of them.but thats a whole new topic.
good luck on your top end rebuild.