CD11 Need advice

[Stickler]

So ,today i opened up the power head,as soon as i split the case i noticed water droplets and milky residue, i removed the crankshaft and pistons and this is what i found the pistons are scored,the lower crank journal is blue from getting too hot,and the cylinders have light scoring.
Im not to sure what to do now, dont really want to put any more money into parts, pistons, crankshaft alone is likely to be 100$.So i wonder if i just clean really well and reassemble and see how she goes, and if i do that will it be ok, or do i just have a time bomb waiting to go off.It had great compression,only reason i took apart was because im compelled to take things apart and put back together,now i wish i hadnt seen this, but glad i did, im restoring this motor and this is bothering me, was this all caused by an overheat? can the crank be reused, its not scored,just discolored,put it on v blocks and dial indicator shows its straight and true, big question is, do i need a new power head, had i not torn it apart i would have assumed it was good to go,any advice appreciated
Stickler

 

[Stickler]

Re: CD11 Need advice

the yellow in the score marks is paint pen to make it more visible.

 

[Rick.]

Re: CD11 Need advice

Stickler. I don't know enough to give advice on this but I'm hoping you get good news. Rick.

 

[HighTrim]

Re: CD11 Need advice

Looks like the previous owner "knew a guy" that said with today modern oils he could run it on 50:1

Too bad people listen to these "guys they know"

That motor needs a 16:1 mix. That crank journal looks like it has been heated pretty good. The scoring is hard to judge by pics as they are always emphasized more in online pictures. Can you catch your nail in the score marks? You may be able to polish the journals, hone the cylinders, and re ring. At least your bores are true.

I have a spare CD powerhead. Let me open it up and check out the crank in it.

 

[Stickler]

Re: CD11 Need advice

Wish i had a spare, when i looked at the rings they looked unscathed and none were siezed, i was thinking of reusing them if the end gap is in spec, and yes you can catch your nail on the score marks on the piston and a liitle bit in the cylinder, i appreciate all your help with this, Im a liitle frustrated at this point, unfortunately i think i need new pistons, its so sketchy buying used pistons from someone who likely hasnt checked or measured them.

 

[nwcove]

Re: CD11 Need advice

dont want to sound negative, but i wouldnt put money into that powerhead. cheaper to find a replacement. jmo

 

[Stickler]

Re: CD11 Need advice

Unless I can find one on eBay , or some other site, it could be a long wait until I find one, they don't pop up in my neck of the woods that often, I'm hoping I have other options here.

 

[HighTrim]

Re: CD11 Need advice

I just spent the last hour pulling apart a stuck powerhead for ya. I was hopeful, but it was stuck due to a broken rod. 1 of the crank journals was good, the other had water damage and was rusted. The bores were pretty rusted as well. May be 1 good piston, we will see when I get them out.

I have another CD powerhead around here somewhere as well. I just have to find it.

 

[Stickler]

Re: CD11 Need advice

i really appreciate you going out of your way to help me, im pretty sure the pistons are toast, do you think the crank could be reused, or is that one journal going to be to weak, as for the scoring in the cylinders, im hoping a light honing will clean most of that up.

 

[nwcove]

Re: CD11 Need advice

i may also have a good piston ( cd 13) if you are interested, crank may also be good, but the bottom cyl had water in it and is well pitted so the block is toast.

 

[Stickler]

Re: CD11 Need advice

I appreciate you guys breaking into your parts motors to help me out when im in a bind,any good reusable parts would be appreciated,send me a PM in regards to any good parts,youd be really helping me out. Thanks

STICKLER.

 

[nwcove]

Re: CD11 Need advice

will wait for hightrim to post back, if he has a good powerhead, thats the way to go. im not even %100 sure that a piston from a cd 13 will work in a cd 11.

 

[HighTrim]

Re: CD11 Need advice

The bad news is this powerhead is junk. It is so rusted I dont think much of it is salvagable.

The good news is my fish now have a new home to live in.

Sorry tried to help. I still have another power head to check for ya. Keep your fingers crossed.

 

[Stickler]

Re: CD11 Need advice

Fingers crossed, even if i can get 2 good pistons, i think that would be better than nothing,nwcove has generously offered one good piston from a cd13, part numbers same as cd11, im going to hone the cylinders on monday to see how they clean up, most of the scoring should be removed, if there is even a little scoring still left, would it be adviseable to at least try to salvage my powerhead, or does my heated lower con rod journal make it a right off, ill clean it up and see how she looks and ill post more pics, thanks again you two for helping me with this and going the extra mile to help me salvage this restoration project,keep me posted . Thanks.

Stickler

 

[Stickler]

Re: CD11 Need advice

Hey guys, so today i got some time to work on my power head situation, i had two hones,a three stone spring load which i used first, it shows more imperfections in cylinder wall than ball type, and it deglazed nice and evenly, i hit each cylinder for about 20 seconds lubricated with atf at about 500 rpm or so.
The next thing i did was use a 2 inch ball hone to smooth out any rough edges around ports,and to give a nice final cross hatch, i lubed cylinders with 10 weight oil as per instructions with hone, and then hit each cylinder at about 600 rpm slowly moving in and out and got a nice cross hatch, all the scoring is gone, it wasnt as bad as i thaught,and all that remains is a couple brown spots where the score marks had been, but there smooth, cant catch a nail on it.
So there is still hope, im pretty confident that with some good used pistons and new rings, shell be good to go, was wondering if anyone has a spec sheet for a cd11, including ring end gap, piston to cylinder wall clearance and such, i have manual for cd13, but am unsure if specs are the same, attached are some pictures of my progress so far.

 

[Stickler]

Re: CD11 Need advice

the last photo is a before honing pic

 

[nwcove]

Re: CD11 Need advice

when i get home tomorrow evening, i will pull the powerhead apart and post some pics of the piston(s). im confident the top one is worth using, and with any luck the bottom may be ok .

 

[Stickler]

Re: CD11 Need advice

That sounds great, tomorrow im going to clean up some of the other power head parts, carbon build up and such, try to get everything as clean as possible, im pretty happy with how the cylinders cleaned up, its hard to see the cross hatch in my pics.
Thanks again, Stickler.

 

[HighTrim]

Re: CD11 Need advice

The ring end gap should be between .005 and .015. The total clearance between piston and cylinder should be .0013 to .0025. Your piston diameter is 1.938"

 

[Stickler]

Re: CD11 Need advice

Thanks, i wanted to make sure the specs i had were correct,and they all match, i have a pdf manual for a cd13, actually it covers several models up to the mid sixties,not the greatest but still has good info.