Author Topic: 420/350 teardown and check out  (Read 6913 times)

nuke em

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« on: June 13, 2006, 10:22:43 PM »
Ok, finally decided to dive in to it tonight. We noticed a patch of blow-by burned into the cylinder wall (in one of the pictures)when I was changing the inner O-ring coolant seal, back at Killpecker. The seal allowed combustion pressure to get into the coolant system forcing the coolant out. That all started happening around the 25 hours of engine time. Jetting is right and compression is still the same as when I broke it in. It still ran like a raped ape, it was just pushing my coolant out.

   After I pulled the head and cleaned the carbon off the piston dome, I noticed some pitting in the clear ceramic coating. There was some short light scratches here and there in the walls, but none very long or very deep. Maybe the ceramic coating missing matter is causing the scratches? I decided to take a flat feeler guage and gently check the piston to wall clearance after noticing what seems to be alot of piston movement. I could just get the .024 strip in along the top edge. Oh, that has to be bad, it was bored .0055 thousandths over.

  I pulled the jug to get some good pictures. I also noticed the piston could be twisted some(that was the wrist pin bearings), cheap fix. The piston doesn't have any sharp edges(thats good) and only has a few light scratches. The jug defiantly has some shiney wear areas mainly around the exhaust port. The black on the piston is whats left of the moly dry film coating.

   I just finished beer #7 so I better quit while I am ahead. I will get the bore guage out tomorrow for exact measurements.

Anyone want to venture a guess?

ludedude

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« Reply #1 on: June 14, 2006, 06:27:10 AM »
Hey Gary,

I played with your pictures a bit...he one that was namws MVC_020F.jpg   The thumbnail was screwed up, but the fullsize was fine. You, or someone else had already uploaded a picture with that filename...so it took that old thumbnail....glitch in the system  :roll:  Try and rename your files before uploading to something other than your camera's default file system...or if it happens again...you only have to edit that one picture....just rename that file on your PC...proceed to upload as normal (browse, select new photo), but then move down, find the photo you need to chanhe and click upload new version.....it will overwrite the screwed up one ;)

nuke em

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« Reply #2 on: June 14, 2006, 06:58:35 AM »
Thanks LD. I'll just rename them on my PC before uploading, normally do anyway.

PilotHawK

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« Reply #3 on: June 14, 2006, 02:55:19 PM »
Port timing mismatch is probably what the blowby is all about. I tore into a pilot motor a few months ago and saw some of the same stuff. I asked around on McDizzy's board and the conclusion was that the motor spent a lot of its time "off the pipe" In other words the aftermarket pipe that was on the motor wasn't meant to be used/run like the motor was run (mostly in the low rpm range) I'm not sure what pipe you are running or even what your port timing looks like, but unless you see a lot of burning down into the transfers I wouldn't worry too much with it. Or you could try a different pipe that works with the port timing a little better.

On another note the wear you are seeing seems excessive. You might want to talk to Bill Moeller at boretech http://www.bore-tech.com and see if he can process your cylinder for you to cut down on the rate of wear. The more you hot these things the harder it is on parts so you will have to inspect and replace parts more often that you would on a stock machine anyway.

nuke em

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« Reply #4 on: June 14, 2006, 06:12:02 PM »
Thanks PilotHawk, I was thinking along those lines(boretech). I am pretty much out of bores on this sleeve(probably too many already). Hoser had said while out in the dunes that plating the cylinder usually lasts 4-5 pistons. I have zero experience with that stuff so I need to start doing some research. The pipe is of unknown origin and make. I don't want to change too much, this combo seems to run good.

Is boretech the best one? I know of a few other companies around but I am looking for info on who is the best. Prices? Is that the one Big Tom used?

I did notice the long brown streaks in wierd places in there too. I love this port work, makes incredible power from a 350. Ask the sled powered guys! LOL :wink:

FL670R

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« Reply #5 on: June 15, 2006, 12:35:09 AM »
Yea its not bad - BUT...

It didn't make it to Saint Anthony's...

Kinda like a young buck good at the beginning but so far no stamina...

LOL........

My moto will always be - "There is no replacement for displacement..."

See ya at the mountain top - maybe  

 :lol:  :lol:  :lol:  :lol:  :shock:

nuke em

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« Reply #6 on: June 15, 2006, 07:32:05 AM »
I hear ya Dennis, nice poke in the eye. I'll have the gremlins worked out soon enough. It will be ready for St As by the fall haul! Still looking to unload your 24"paddles?????  Beed looking at the Skat trak rippers or extremes and maybe the paddles with the kevlar reinforcement layers. Any suggestions?

Skeeter should be shipping out the EFI sled engine when he gets back from vacation. I may have it ready for that trip too.

See ya at the top... , hell, I'll be waiting for ya! LOL :twisted:

Gary

ludedude

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« Reply #7 on: June 15, 2006, 09:32:27 AM »
I shipped out the starter...so Skeeter should have that when he arrives home ;)

nuke em

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« Reply #8 on: June 15, 2006, 11:16:49 AM »
Thanks LD, Hear that Dennis? Electric start! HEHEHE

Hey Lude, got any tips or advice on engine mounting? build a cradle? I would really like to use my factory mount incase I need to drop a 350 back in someday.

I probably will start a new thread when I am ready to go with it.

FL670R

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« Reply #9 on: June 15, 2006, 11:34:36 AM »
Yea Yea Yea

Quit your clucking...

I happen to have a brand new electric start kit for the 670 sitting right here beside me on the workbench.

Only problem is the previous owner mounted the engine at such an angle (to clear the stock FL400 Tranny) that I have no room to mount the starter under the  exhaust.

Maybe I'll do the Moskito mod and put it on the intake side of the motor.
I really don't mind not having electric start thou.

After I add a simple sled primer I'm sure it will start with one or two pulls.

EFI motors almost always start by the 2nd or 3rd pull so just think of the weight savings You'd have by not having the electric start  :shock:

BTW - I love the 24" paddles (Not for sale) - They have great traction and make the buggy pull like a mother when going vertical....

Hoser should have some video of him following me and you'll see me bring the front tires in the air when I pin the throttle
Only problem was its hard to steer when your font tires are not on the ground...  LOL

ludedude

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« Reply #10 on: June 16, 2006, 09:03:37 AM »
Quote from: "Nuke Em"
Thanks LD, Hear that Dennis? Electric start! HEHEHE

Hey Lude, got any tips or advice on engine mounting? build a cradle? I would really like to use my factory mount incase I need to drop a 350 back in someday.

I probably will start a new thread when I am ready to go with it.


Yup, I'd go and build a cradle. The 600 has a four bolt pattern in the bottom of the engine that you can use in addition to the the mounts on the front and back that the sled uses. I'm using the bottom four and one front and one rear mount (cross corner). My cradle uses the stock front mounts and makes use of the OEM tranny to engine mount plates. It's still in FUGLY form until I can throw some testing at it...then I'll redo/neaten it up and maybe have it cast in aluminum. The great thing with the EFI is the ability to tip the engine...allowing you to point the exhaust more downward and the air intake upward to clear the tranny.

nuke em

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« Reply #11 on: June 16, 2006, 10:00:07 AM »
Nice LD, and fugly fits my machines anyway. I call it "All go, No show". Any pictures of the just the cradle? I already had the EFI engine tilt thing in mind too.

Dennis, what paddles were you using? Kevlar reinforced? I am deciding which model to buy and whether to add the Kevlar paddles. They will be 24" too.

ludedude

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« Reply #12 on: June 17, 2006, 08:05:41 AM »
Quote from: "Nuke Em"
Nice LD, and fugly fits my machines anyway. I call it "All go, No show". Any pictures of the just the cradle? I already had the EFI engine tilt thing in mind too.


Other than what I have in here http://p-o-ps.com/pops/album_cat.php?cat_id=3 nope, sorry :( It's not here either to take more of :cry:  :cry:

nuke em

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« Reply #13 on: June 18, 2006, 06:08:01 PM »
I am still deciding on what to do next. I am leaning towards getting a new sleeve, but want to do more research on all the different cylinder coatings. I am just not sold on them yet, but it may be quite a bit cheaper than having a new sleeve installed. Any inputs ARE appreciated too.

More bad news, I took the normal 350(Ol Dependable) out Saturday for some Walden dunes play action. By the end of the day, it was feeling just a little heavy or slugish. I attributed it to the heat of the day and jetting getting richer, 8500ft. Wrong. I came up out of a steep climb about 2 miles from camp and heard a pop then grinding sounds.  I looked behind me, a nice trail of tranny oil full of sparklies. S.O.B., *^%#$@>*%$#!!!!!!!!!!!!!!!! Took one look, cracked both sides of the case. I have regularly beat this poor thing(like a red-headed step child) for better than 10 years with a fair amont of jumping too, before I knew it was bad for 350 trannies. I do however change my tranny fluid yearly with Mobile 1 and add extra to keep everything well covered. I just did my Spring change shortly before the big western ride(mabye 6 hours of riding there) and it just had the normal small amont of light shimmer in the draining. I have not touched it yet but will do some CSI with lots of pics later. Fed has my spare tranny in his 350, for now. I guess I can drop my 350 engine into the 420's frame, just to keep riding, being that it may be a while before the 420 gets finished. Fed and I now have a tranny each to rebuild. Maybe we can do a very detailed/pictures "how to"(or how not to) LOL, for the board members?

Remind me not to go to Vegas, my luck is sucking ass lately. LOL

Here some measurements I just took on the 420 jus and pistons. I am not sure what the areas I measured are supposed to be called so I named them as I went. Front to back(F/B) is intake to exhaust, and left to right(L/R) is transfer to transfer.

Cylinder is 88.55 top and 88.56 bottom. Bottom of the cylinder sleeve is 1.90MM on one side and 1.43mm on the other. (Not bored straight, slightly) If I am reading the piston to cylinder clearance right(and I am), I have better than 20 thousandths slop. The piston was an 88.5MM before. Really weird, never had a piston shrink. It was bored .0055 over piston size on the original rebuild.

In Millimeters
PISTON      F/B       L/R
top---------87.95---88.02
middle-----88.15---88.25
bottom-----88.30---N/A


Changes in thousandths of an inch
                                              F/B                      L/R
Line above rings(top edge)------ 0 ------------------0
Top of compression area--------- 0 ------------------0
Middle of compression area------ +.5----------------0
bottom of compression area----- +1----------------- +.75
just above exhaust ports--------- + 3 ----------------+ 1.5
top of exhaust bridge------------- + 8 ----------------+ 1.5
middle of exhaust bridge--------- + 6 ----------------+ 1.5
just below bridge------------------ + 4 ----------------+ 1.5
Just below transfers--------------- + 2-----------------+1.5
bottom of sleeve------------------- + 2-----------------N/A

Do you think not having a balanced piston skirt could cause this? One side of the skirt has a port opening and not on the other.

Moskito

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« Reply #14 on: June 19, 2006, 07:48:44 AM »
Quote from: "Nuke Em"
I am still deciding on what to do next. I am leaning towards getting a new sleeve, but want to do more research on all the different cylinder coatings. I am just not sold on them yet, but it may be quite a bit cheaper than having a new sleeve installed. Any inputs ARE appreciated too.

If you're on your last bore, you need to go ahead and just get a new sleeve.  To my (limited) knowledge in this area, nobody does a coating that builds surface.  I'm not sure that there are very many processes for a standard iron liner bore.

Bore-tech's Carbide Bore process is more of a bore "upgrade".  It impregnates a ceramic material into the surface of the sleeve. - in essence, making the bore harder.

When Bill (bore-tech) was first getting the process dialed in, a processed jug had a brownish look with a texture of 2000 grit sand paper and you saw no cross hatching.  At that time, he was putting too much carbide stuff into the jug and there was an occasional problem with flaking.

Now, it doesn't look much different than a regular bore, except it has a very slight brown tint to it.  Cross hatching is present too.

It's great for wear resistance and as long as you don't have damage to the bore during a seizure (like a ring getting caught and gouging the surface) you can wipe the aluminum off the cylinder with muratic acid, stick in a new piston and go again.

There may be a chrome type coating that they do to iron liners, now that I think about it - don't know if it's a build up or if it's an impregnation type of process.

I wonder if you could take a stock jug, push the liner out, build up and basically form an aluminum liner (lots of welding - lots of heat - not good) and then process the aluminum liner with Nika-Sil? (nickasil?)  Seems like this is the setup used on most performance engines now. - may not work on an air cooled engine?  Dunno...

If I were you, I'd have Bill resleeve the jug you have and carbide it.
Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'