Author Topic: head gasket failure  (Read 3767 times)

O-J

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head gasket failure
« on: January 07, 2006, 06:54:00 AM »
Hi guys I'm new here but have been snooping around since a friend and i bought 2 89 pilots a few months ago. i like what i see.. thanks! great info.
     Any way to the problem. my pilot blew a head gasket not long after getting it. it may have happened due to detonation- i guess race gas is important for this machine.
     I have it torn apart  and am wondering what to do now. It's an LRD modified top bored to 500 and ported...in a stock head. I called LRD but they haven't touched pilot stuff for over 10 years and didn't know what to tell me but said cool heads might have something.any one know them? Can i use a stock gasket? A 500 gasket maybe? should i replace the piston now? or just rings? hone the cylinder bore tec? and on down the line.......I'm pretty sure this is just the start.

     Just looking for a little guidance from the gurus. I defiantly want to dial this thing in right and have a long road ahead. but running would nice!! luckily its winter and the snowmobile is keeping me busy so I'm not as anxious to be driving the pilot and i have time to do it right.

Thanks,
Oregon-Jake
PS...  i have some pictures i could post if it would help.

ludedude

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head gasket failure
« Reply #1 on: January 07, 2006, 11:45:53 AM »
Welcome, and congrats....on the pilot...not the engine trouble  :P

You've got a rare bird there, there's not very many 400 jugs bored to 500 engines around.

Dennis had one...just sold it I think....did you buy from him? And someone else just got one not too long ago....Odypilots?

I have two 500 engines, but they have the bottom ends modified for CR500 top ends....so I dunno much about the LRD setup, sorry.

I've heard of cool heads, I don't have contact info for them right off....someone here should..PolitHawk?? (link king LOL)

Personally, first I would decide whether you want to be running race fuel or not. I got both mine set for pump fuel, I didn't want to have to screw with race fuel every time I wanted to ride.

Then decide on whether to keep that 500 setup or not. I would get ahold of someone else who has one and talk to them about their experiences with them, and find out where you can get the parts you need for it...guess head gasket is the only issue?....what do they use for pistons...CR500? It's easy to swap back to a OEM 400 cylinder....so that's always an option.

I'm not trying to steer you away from the LRD 500 setup. But for me, I'd want more info on them before I decide to stay with that setup.

I'm selling my runinning CR500 engine, the spare CR500 engine that's in pieces and a spare 400 engine in pieces (almost all there) LOL there's some more options for ya  :P

PilotHawK

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head gasket failure
« Reply #2 on: January 07, 2006, 12:22:51 PM »
Pictures are always good. the more the better. The amount of work you put into the cylinder and head all depends on how much damage has been done. I'll hold off on recommendations until I see a few.

O-J

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pictures
« Reply #3 on: January 07, 2006, 03:41:16 PM »
OK here we go some pictures-I have a bunch more of it completely out and cleaned up a bit but I misplaced them or there still in the camera.
   This should get things going...let me know if you specifically would like to see something and ill get it up.

Thanks for the quick response

O-J

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more pictures
« Reply #4 on: January 07, 2006, 07:47:53 PM »
found my other pics.....and there is morewhere that came from if needed :lol:

PilotHawK

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head gasket failure
« Reply #5 on: January 07, 2006, 08:30:39 PM »
Do you have any of the ports? Maybe a few pics from the outside of the jug looking in through the exhaust and intake ports. The head gasket "looks" to me like it is an aftermarket gasket from cometic possibly. What are the markings on top of the piston if there are any? Go ahead and post all of the pictures you have. I don't think that is a 500 cc jug. On the pics you have posted so far I'm pretty sure that factory casting marks are there on the inside of the ports, and the port matching is poor (A sign of a factory jug) If you bought that pilot as a ported machine....well I don't think there has been much port work done to it, and what is there is nothing more than could be done with a dremel. It may have had a prted jug on it at one time, but I suspect that LRD scratched their name on the head because the reworked it. Pictures of the top of the jug AFTER the gasket material has been removed would be a good thing to see. At a minimum you are probably looking at a new head. I would also replace all the studs in the jug based on the amount of corrosion I see. Depending on the wear on the cylinder you may be able to get away with nothing more than a hone and a new piston and rings.

PilotHawK

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head gasket failure
« Reply #6 on: January 07, 2006, 08:45:39 PM »
Looks like that jug has a spacer on the bottom of it. The red arrow is pointing to the joint between the space and the jug.

O-J

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exhaust and intake
« Reply #7 on: January 08, 2006, 11:46:23 AM »
it defiantly has a spacer on the bottom.i was under the impression it was a stock head bored to a 500 sleeve but don't really know for sure what was done. here are a few more pics.

thanks again..im off to the mountains and a foot of fresh snow!! woo hoo :D

PilotHawK

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head gasket failure
« Reply #8 on: January 08, 2006, 12:18:21 PM »
Can you measure the bore and give us a general idea on what it measures. 80-82mm would be a "stock" bore. 89mm is the 500 piston.

O-J

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measure
« Reply #9 on: January 09, 2006, 04:06:01 AM »
looks like its 89.509 on my crappy Gage as far as my eye can tell. seems to be about a 500 and .6 mm...is it workable?

ludedude

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head gasket failure
« Reply #10 on: January 09, 2006, 06:48:58 AM »
Not sure on OEM, but Wiseco Pistons for the 500 go up to 91mm ;)....errr...looking at Service Honda..OEM goes to .5 over only??

So in Wiseco you have 90, 90.5,  and 91mm left to go through if you need to bore out what you have.

O-J

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what now?
« Reply #11 on: January 10, 2006, 02:17:22 AM »
I checked out cometic website for a gasket. they have a fl 400 listed in their catalog.  would i have to modify that or do they do custom gaskets?
  Pilothawk said i would need a new head why?
  It looks like the numbers on the piston are 181a9 at the top then it looks like 0.50mm over 554p2 over TD with an arrow under that. on the bottom there is 554 and then the weisco w. there is a bit of pitting on the top of the piston and noticeable scraping at the 4 corners. would it be best to replace the piston or would just rings be fine.
  How does one hone a cylinder or tell if it needs to go to the next size piston?
   Pilothawk also said the porting looks bad would now be a good time to send it  somewhere to do it right?
  What would need to be done to have this thing run on premium pump gas or even know for sure it needs race gas?
  My pictures of the top of the cylinder cleaned up didn't turn out that great so ill get more and post them soon.
  Oh and where should i get new studs from?
Sorry so long thanks for all the help,
Jake

ludedude

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head gasket failure
« Reply #12 on: January 10, 2006, 07:32:26 AM »
I don't know if there's enough of the metal ring on the Cometic head gasket to turn the hole to the 90mm diameter you'll need. I'll look and see if I have one at home and measure it. If not...I'm not sure what was used.

I would think the head could be cleaned up and rechambered to allow running  on pump fuel. The compression will determine if you need to run race fuel, what is it over 185psi and you're into race fuel to prevent detonation? Rechambering the head could lower the compression to the ~165psi "safe range"

If you want it ported, yes now's the time to do it as it;s apart :)

New studs you can get from www.servicehonda.com or Hillside Honda oryour local dealer for that matter.

If you're going to get the cylinder ported, I'd have them hone/bore as needed to match a new piston and rings.

My $0.02 ;)

O-J

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thanks
« Reply #13 on: January 10, 2006, 02:38:59 PM »
thanks for the help

any sugestions on who to send it to or should i find someone local?

ludedude

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head gasket failure
« Reply #14 on: January 10, 2006, 06:52:58 PM »
If you can find a local guy who you know, know's what he's doing, go that route. If not, ATV Racing.....I'd suggest MacDizzy, but he was way too busy last time I checked with him (months wait!)...I dunno who else to suggest right off.