350X Valve Carnage

[manbearpig]

Went racing with CALVMX last weekend and after the first moto, dad pulled into the pits with a loud metal-on-metal 'ticking' coming from the head of his 350X

HairyJR was there with his XR500/350X and was gracious enough to lend it to dad to run the 2nd moto and gain his points.

Just got the motor pulled apart this morning and heres what i found:

http://i1115.photobucket.com/albums/k557/proct103/5BCF6409-E68D-482B-BF4D-818447383D3C_zps0ebvmbcd.jpg (http://s1115.photobucket.com/user/proct103/media/5BCF6409-E68D-482B-BF4D-818447383D3C_zps0ebvmbcd.jpg.html)

http://i1115.photobucket.com/albums/k557/proct103/9E110DA7-09A2-491B-9DDC-43662AA97DFB_zpsfw58bqhb.jpg (http://s1115.photobucket.com/user/proct103/media/9E110DA7-09A2-491B-9DDC-43662AA97DFB_zpsfw58bqhb.jpg.html)

http://i1115.photobucket.com/albums/k557/proct103/125D6B2E-8910-4D2D-8333-1BBD8549B69B_zpsqcc4d0lb.jpg (http://s1115.photobucket.com/user/proct103/media/125D6B2E-8910-4D2D-8333-1BBD8549B69B_zpsqcc4d0lb.jpg.html)

http://i1115.photobucket.com/albums/k557/proct103/024A5BBB-AC10-4C4B-9F12-5A1CB0B9D5A8_zpsqfpghg6k.jpg (http://s1115.photobucket.com/user/proct103/media/024A5BBB-AC10-4C4B-9F12-5A1CB0B9D5A8_zpsqfpghg6k.jpg.html)

http://i1115.photobucket.com/albums/k557/proct103/39890A5C-DC86-4266-8A56-C514677A8402_zpsjsslagtk.jpg (http://s1115.photobucket.com/user/proct103/media/39890A5C-DC86-4266-8A56-C514677A8402_zpsjsslagtk.jpg.html)



Top of the valve broke off at the keepers, valve dropped down and piston punched it

Bike still ran.
DUH... its a HONDA:D

[jb2wheels]

Amazing!

Is that a Honda valve?

[El Camexican]

It's just a little bent;) Looks like you got lucky, could have been a lot worse.

[atc007]

Hmmm, They usually do that with the left ex valve.. I never saw one drop the intake. Nice clean engine :)

[6speedthumper]

Ouch!! So... What's the game plan? Big bore? Wink, wink ;) lol

[manbearpig]

from what i can tell, its an OEM honda valve.

Plan of action is already under way. New OEM guides + seals, OEM valve, OEM keepers, and a top end gasket kit have already been purchased. Taking the head to Keith Lynas (Owner of OSSA and Weixeldorfer's mechanic while riding for Nicholson/Holiday Honda) for a valve job. should be back together by next weekend

[350for350]

Even though it doesn't look like a lot of damage, it might not hurt to pull the piston and inspect it closely. There could be a crack on it somewhere. It's probably not real likely, but it's still a possibility.

[HairyJR]

Glad we where able to trouble shoot your Dad's engine noise before other major damage may have occurred from the dropped intake valve keepers. I think the valve finally dropped down and hit the piston when we listening after checking valve lash clearance the first time.

If I can help give me a call.....have to ask does Dad now want big bore and head mod?

"HJ" :beer

[shortline10]

I pulled a 400ex motor apart yesterday with the same issue , left side intake valve snapped at the keepers .
I would replace the valve guide and would be surprised if its not damaged .

[atc007]

It's funny. Out of all of these I saw come through here. 250X,300EX were the only ones that ever had broken/visibly damaged guides. I think this 350X head may be in good hands ,,lmao :) I would at least Wiseco it while in there if the rules permit?? But that's just me :)

[BOB MARLIN]

What would cause the keepers to fall out ?

[shortline10]

Its not that the keepers fall out , the valve snaps off were its machined down to hold the keepers , just a weak spot .



What would cause the keepers to fall out ?

[HairyJR]

Sorry my mistake in saying keepers fill out, should have read all posts and viewed pics.....:wondering wrote my post from memory at what it looked like at the races during our limited inspection. MJB is it big bore time? .....bb......bb.....

[manbearpig]

Sorry my mistake in saying keepers fill out, should have read all posts and viewed pics.....:wondering wrote my post from memory at what it looked like at the races during our limited inspection. MBP is it big bore time? .....bb......bb.....


We researched some parts to do the conversion and already have a couple useable heads, but ultimately the 350X is just getting its head redone and being put back together. We have 2 XR500 trikes with mildly modified motors (cams, porting) and building the 350X to be just as powerful isnt on the agenda. For pops its not about how much power the motor can make, its about how much power can he hold onto for 5 laps without falling off. Thats one of the reasons he races the 350X instead of the Nicholson 500. Lots of torque, but not so much that it wants to rip your arms out of the sockets. He (and I) loved the overall power your 420X has and there was some serious conversation about who and how to do the conversion, but getting the stock head redone and back in our hands next week would ensure the 350 can be ready for the next race.

[manbearpig]

Its not that the keepers fall out , the valve snaps off were its machined down to hold the keepers , just a weak spot .

yuup. what really concerned me though.. i didnt find the broken off piece of the valve. found a small sliver of metal that might indicate that the valve didnt break, but slipped past the keepers when the groove they sit in was damaged. ill know more this week.

[atc007]

Most of them I see were ran with far too much clearance. Obviously not your case here :) But could have been in a previous life?

[manbearpig]

The man himself...
http://i1115.photobucket.com/albums/k557/proct103/05EDE1DE-0E75-4ECA-9C0E-F032EED6D223_zpsbvouqald.jpg (http://s1115.photobucket.com/user/proct103/media/05EDE1DE-0E75-4ECA-9C0E-F032EED6D223_zpsbvouqald.jpg.html)

Parts list keeps growing. while in there, might as well do everything...

[manbearpig]

Little Update..

Parts list is as follows:
4 new OEM valves
4 new OEM valve guides
4 new OEM guide seals
8 new OEM keepers
4 new OEM tappets
Athena gasket kit
new ROCKY STD bore piston & rings (cylinder bored to fit)
Cam is at DCR (Dan Crower Racing) for hard welding and regrind

Doing things the RIGHT WAY costs $$$.

[ironchop]

must be something about those valves.

I had the exact same thing happen to my XR250.....however, inside my head and cylinder was beat all to hell by the time I got stopped and the piston had a hole in the top where it punched the valve right thru the piston

[Dirtcrasher]

You don't want a Wiseco 10.25:1 piston??

The cam that compliments that piston gives you allot of mid-range power.....

[6speedthumper]

You don't want a Wiseco 10.25:1 piston??

The cam that compliments that piston gives you allot of mid-range power.....


What he said^^^

[manbearpig]

We have a mildly built 350X motor already. That motor will probably be transplanted into dad's 350X for this next race as partzilla has the exhaust valves on back order until next week. The motor that dropped the valve is being rebuilt as close to stock as we can get it. its not about how much power the motor can make, its about how much power my 58 year old father can hang onto for 5 laps on a motocross track.

There are only a few guys out there that can actually ride a stock 250R or 350X motor to its full potential. Until you can do that, there is absolutely no point in modifying a motor to pull harder or rev higher.

[Poco Loco]

So thats what happend. Sounds like you have a good handle on it. I believe I have a complete head in my vault somewhere thats ready but your well on your way with repairs. Did you find the keepers? Did they make their way down the cam galley and into the lower case?

[manbearpig]

Thats right.. you wouldnt have needed the stock 350 head after your 500 head swap. should have put 2 + 2 together sooner. But yes, we're in pretty deep. the keepers were held in place by the mushroomed tappet. they came out with the spring/retainer assembly after removing the rocker cover.

[Ol Deuce]

Any luck on Raced Parts.....? LoL How's the project going?????



yuup. what really concerned me though.. i didnt find the broken off piece of the valve. found a small sliver of metal that might indicate that the valve didnt break, but slipped past the keepers when the groove they sit in was damaged. ill know more this week.

[Dirtcrasher]

What he said^^^


DCR? Never heard of them. Just webcamshafts, megacycle cams and white bros that one of those 1st to venders supply....

[manbearpig]

Keepers, intake valves, and valve guide seals are here. still waiting on exhaust valves, valve guides, tappets, and gasket kit. Then machine work.

Daniel Crower is the son of Bruce Crower. www.crower.com/crower-history/

Dan now runs DCR. www.danielcrowerracing.com/p-4650-about-dcr.html

the cam is going in for a hard weld and regrind. they dont produce 350X cams, but Daniel has experience with 350X motors (from back in the day), and can redo any stock cam into any level of performance you need. I will be sending him a couple 200X cams with different motor setups to grind cams for

[manbearpig]

first $150 in parts has arrived

http://i1115.photobucket.com/albums/k557/proct103/1ECDFE22-D043-4863-B22F-AB13F33659FA_zpstmfqfr6p.jpg (http://s1115.photobucket.com/user/proct103/media/1ECDFE22-D043-4863-B22F-AB13F33659FA_zpstmfqfr6p.jpg.html)

[Poco Loco]

I have an account at Motoworld. If your buying more parts I can save you $$. 25% off all oem parts

[manbearpig]

Probably would have been smart. all parts are ordered, just waiting on arrival