G'Day Hoser....Baz has a BIG problemo!
After finishing the last races at Northam 21-6-08 Sat,I went to my mates place for the reg Beer/Barbie stayover,before heading back to Perth Sun morn. Pilot went fine at the races,no probs until I did my Helmet cam vid run test Sun morn at his property and ironically I vid my Babie's Poofkaboom!!!
I had recently for these races gone back to the OEM cyl base gasket and had Pro- made up a 1.5mm 4th Oversize head gasket. This resulted in a 190PSI comp,on 98 oct,40:1 Amsoil. Too high I know,but seemed OK testing and did'nt show high water temps. On the way back to my mate's house,after the run ,bout 1/2 to 3/4 throttle running it just died. Did a comp test-only 30psi.
Plug and exhaust all show signs of lean out.
Have just done leak down test,before Engine removal and have found long crack across LHS crank case between starter motor (( Internal Combustion Engine ? )) and bearing housing boss.
I have a bad feeling that the 190 PSI was part of the recipe for this disaster.
Any clues? Which do you think came first,crack then leanout? or leanout then crack?
Carb has fuel in it. I also remember having to reinstall the cyl stud at that location due to being loose and came out when I did the base/head gaskets.

Big ouch!

I have never seen a Pilot case crack like that maybe once the Engine is apart you can tell what happen.

Hoser it is night time here now,and I'm on the grappa n Coke. (Again!):shock:
Been thinkin' about the install (Rewinding my memorybanks)and I think the inlet 6 bolt Cyl Carb inlet housing boss thingy, must have beeen touching the Starter motor (( Internal Combustion Engine ? )) when I tightened up the cyl base nuts,and subsequently levered against it to crack the case? If you look at the direction of the crack,it is heading towards the center inlet bolt.I did check this when I first got it from Eddy and there was daylight between them.Not much,but enough to seperate them.You can see where the starter motor (( Internal Combustion Engine ? )) has been ground for the clearance. For some reason I think THIS time the clearance has cleared OFF! I'm still trying to work out why. Tomorrow morn I will do a DIRTY feeler gauge check. ....Bit late tho!

That could have contributed to the crack for sure let us know what you find, you might as well start pulling the Engine :-(

Pulling the Engine tomorrow will be less painful than the hair I have pulling out tonight!

Well ive just pulled the Engine,and I think I know what has happened!....Note I say I think!
The Bondo fillers that were used to mate on the FL400 Crank Case transfer-transition to the CR500 Cylinder under the inlet section,came loose and were mashed by the Crank Weights against the Crank case. The corresponding crank weight had some "Finger Feel" Nicks. I washed out the crank case with 2 stroke-3 times and it does'nt seem that bad. But the cylinder has obvious leanout damage.The rest of the Bondo must have exited via the exhaust.
I checked the crank,big end bearings and they seem tight and free.
Do you think I can have the " crack"Tig'd up? Without dissmantling the Case?

More CSI Pics.

Sorry to see your misfortune Baz but I feel confident that it can hold up after a weld job. I had a chunk knocked out of the case directly below the crank lobes in my first 350 back about 1995. I had it welded up and it is still running great to this date, grant it, its not under a built 500cc topend.

I never seen the JB fill work before. That might be something the welder can fill and then blend to match what you want/need.

You may get away with a hone and new piston, no boring, but you need to get that mic'd to be sure. She would have lost compression very quickly(maybe next race) if you didn't find it now anyway. Do you do compression checks after a weekend on racing and a leak down occasionally? Its kind of a pain in the arse but will let you know whats going on internally and you may catch the scuffing before major damage. I read somewhere that a lot of racers swap rings after every weekend of racing and some even more often. What shape is the piston/rings in? Dome OK?

Good luck, get her fixed and back the track!
Gary

PS Fix those damn copper gasket tabs hang into the transfers, it will help the flow! LOL

I don't see the missing epoxy in the pics.

You need to trim the gaskets to fit.

Your cylinder match the cases better than this ATVR CR500 ? wile you have the cases split for welding you should match them. http://pilotodyssey.com/PO/viewtopic.php?t=3948

Some of these 500 convertions seem like a right strap up and putting all that weld and heat in to the cases is bound to cause problems, get a sledge Engine in it, loads more power less trouble and less cost.

I would seperate the case before welding. Weld the crack, machine/lap it flat again and reassemble. Welding is going to cause a lot of heat in one area and possibly lead to a case to warp/crack in another area that you may or may not see with it all bolted together. You may also burn the gaskets between the case halves.

is this a crack were i put the white arrows? also i would use a dye to check for other cracks.

http://en.wikipedia.org/wiki/Dye_penetrant_inspection

Not to mention you will never get all the oil out of the weld affected zone and it will just pull into the weld and the carbon will make the weld worthless.

Not much to report yet,cept that crack was NOT due to the epoxy resin jamming the lobes and case.
Ol' Dean was good enough to take the LHS case off while I was there, and the crack went right thru and was worse on the inside. Def, a stress or fatigue crack! I also suspected this and changed my mind before showing it to him,due to there being NO hole or dent punched thru the case,like I am used to seeing.
This lil' motor (( Internal Combustion Engine ? )) has done a lot of work when you think about it. Neil had it made for stadium racing,using 110 race fuel ,72HP for how long not sure,then the subsequent owners that followed.Case was designed for 37hp? I have been using for racing,jumping etc, so suppose something had to give....eventually.....WHY ME! If you look at the strengthening webs and bosses around the case,it's really NO Fort Knox.
He said that he would give it a go,the welding,but said that due to the porousity and contimination that it was "Suck it n see"
Also not sure if the cyl can be reused,last 4th over bore. Dean said that if the cyl bore was no good that it would be better,stronger to try an get another OEM cyl. Reason being that the cyl are keyed in with the Alu casting for better amalgamation,than resleeve.
If worse comes to worst,does anyone have or know of a LHS FL400 crank case and CR500 cyl and head(not on last bore)
Will try and get some pics tomorrow,when I go for update.
I really,REALLY miss my Pilot ........Like one of my brats being in Hospital......Sad is'nt it?

Hello
To get the oil out of the case half.
I put them in oven at 350 Deg F for a few hours
I have done this many times on old harley davidson case sides that where broke in half.
make shure you bevel all cracks and drill a hole thru at the end of each crack . Pre heat before tig welding at aprox 300 to 400 Deg. F

Speed Chaser

Thanks Speed,will pass that on to Dean.

Ended up making my own Crank Case and Cyl Base gaskets... .5mm thick as OEM> Will also end up making a LOT more in the future.Can't believe how easy they are to make, and at about $1.50 each, compared to OEM avg Aus $25ea+shipping+time+agro=!@#$ Used my hole punch kit that I bought in an All up Garage Sale
Found a Company that had a good fella to sell me a couple of small Gasket sheets,250deg C oil.fuel rated etc.
I bought 4 small 14'' x 10" sheets for $10 all up! No waiting...Back to work!

When I was a kid we use to make our gaskets for our lawn mower engines (used on home made dune buggys) out of paper bags, they worked good and never leaked

I see the tell tale white silicone type gasket sealer all over the old gasket in the pics, I have seen this on many ATVR engines, their is no reason for using it, the gasket should take care of any surface imperfections mold to them and seal them.

Yes, that brings back memories.
When I was 17 ,I made an oil pump pickup gasket (on a Sunday) for a V8 Windsor ,from a Corn Flakes packet It work well....But I won't crow about it.

Corn Flakes / Crow haha good!


Update this thread please!

Slacker...

SLACKER! ME?
Not much really Hoosier,been told to work on my drivin' style!


Nah,it all went well.My Ol' mechanic Dean did a great job on the welding and fix.
Unfortunately,he died a few months later.Since then,and a few more races,swapped over to the Drak
and the LT has been givin' the red headed stepchild treatment,and under covers now.
Here's a couple of pics of Dean using a pre-heated solid rod-same size as crank inner bearing race- to heat up and expand for crank mounting.

Hey Baz! Did you get this put back together?? Do you remember what your water temps usually ran when you were running the Engine hard on your 500? Thanks mate

G'Day Stixy,temps from 5 years ago? I don't even remember what I had for tea last night mate?
Nah from memory they were always hot,it came with the std Pilot radiator,I should have upgraded it to the double pass types.
I think it used to be around 90C-200F,way too hot.

The double pass rads I'm now running are awesome.Have one on the FL800 now,and another on the AC550 Pilot.
They both run at around 63C-145F at full race conditions.130HP-800 and 85-90HP AC550?
Running these sled mowtors cooler rather than hotter produces more power,both stated by articles on the net,plus what I've been told by Ian Williams Tuning http://www.ianwilliamstuning.com.au/home/
He told me he's seen an article where Rotax shows via graphs the power output relative to coolant temps.
Most power was just after the thermostats open(47-50C) around 55C,anything over that shows actual drops of power for every 1C over optimal 55C.
The AC550Pilot was running the std rad at 93C,put in a double pass and it dropped to 63C.
The hot climate I race in,I need all the scary cool I can get!

mowtors? Didnt realize they had hicks and skillbillies down under you find that terminology in one of your automotive hack and wack rags haha

I might need some Frankenstein cool if I keep running in 95F weather, whew!!

Looks like some good reading in the tech section at Ian Williams. Ill have to carve out some time to take a gander or two.

Do you have any pics of your rad set up, I checked online and found a few double pass rads but not sure what size or brand?? I was running about 200F then I moved my clip from the middle position to the 4th position to lean out some, then my temps went to 220, I guess I was making more power and building more heat.

Thanks again buddy!