Posted 27 May 2012 - 04:40 PM
Here's what I found.
Cam tower loose.
Cam chain so kinked up that it wouldn't even fall down in the chain hole.
OEM tensioner flattened like a pancake
The bearing collar on the crank had eroded something fierce. It almost looked like it was a bad casting beneath where the bearing rollers ran. There must have been .030-.050" of slop in the bearing.
The boot where the white chain guide rests in the case had the upper portion of the tab broken off. The oil pump pick up hold down had one of the fingers cracking off of it too.
But I think the root of the problem was the silicone that had plugged up the oil pick up screen.
The spark plug tube had come loose for whatever reason. The dealer that had their hands on it last tried to silicone the tube back into the head. A big flat piece of the silicone had come loose and worked its way down to the bottom end and plugged the pick up. Now, what further plugged the pick up is a guess because of the SAND, metal shavings and other random shit, its impossible to tell what caused which problem.
But, What I did find was a Hot Rods 3mm stroker crank, the rod was still good. The bore was edgy to say the least. The piston was worked over by the metal in the oil. Which was sad in and of its self because it was a JE with probably only a couple hours (Id say less than 20).
So we needed a cylinder and a piston, a main bearing kit for the crank (they come with a new collar) gaskets, chain, MCCT, new hold for the pick up, Oil pump etc..
Owner decided to go with the 100mm big bore to go along with his 3mm stroker which takes the engine out to 511cc. The compression worked out to 12.67:1. I ported the head to flow a bit more for all the Cubes...
Holy crap that thing is fast! It doesn't sign off the way I thought it might either. It just kept pulling and pulling. I had to shut it down since I was in the neighborhood, but the throttle response was instant and the front wheel just claws at the sky with ease.
It kicks easy, fires the first kick too.
Pretty proud of this one.
Posted 27 May 2012 - 08:59 PM
I took him an oil filter and my stock engine covers (they might work with a little mod'ing) And he rode it down the street to warm it up. He got into third and was flying and he thought that it was topped out but when he turned it WOT it roared and the front wheel took off for the sky. I couldn't believe how fast he was going IN THIRD GEAR!!
Hard to believe it is the same bike. It sounds so much different. AND lets not forget it is running the stock pipe. Dave should have his new MRD exhaust ready for it soon.
We are probably going to Lake Elsinore MX tomorrow and I will ride it then. He kept bugging me to ride it yesterday but we had to leave early to go to family functions.
He is fricken stoked! He could see that very first time he met you that you are a top notch ace and he never had any worries. Never questioned anything. He knew all along that engine was in the best hands possible.
I really need to thank you too, you got my riding partner back out there with me. Thanks man!
Posted 28 May 2012 - 05:48 AM
How long is the motor expected to last with this setup or power
Posted 28 May 2012 - 12:44 PM
Posted 28 May 2012 - 02:18 PM
Posted 28 May 2012 - 03:31 PM
Posted 28 May 2012 - 04:10 PM
How long is the motor expected to last with this setup or power
For a vet, probably 150 hours.
If you've got the 100mm bore already, you need the stroker crank. Porting the head doesn't add displacement. It does allow it to breath and help the head handle the extra displacement.
The porting is why it doesn't run out of breath in the upper RPM ranges. You could do the crank without the porting for trail riding and be super happy I think.
Posted 28 May 2012 - 06:20 PM
At first I installed just the stroker crank and a 13.5:1 piston and this put me at 14.2:1 compression and 470cc. I then added the hot cam and shortly after (10 hrs) I blew a head gasket. At this point I had just over 50 hours on that rebuild. Anyhow whenever I went to replace my gasket I just got greedy and ordered a 99mm piston and sent my jug out to millenium to be overbored/plated. I also opted for the 12.5:1 piston because this ends up at a tolerable 13.1:1 with the stroker. 14.2:1 was just... too much. Pain in the rear to start and too much money spent on $8 gallon gas.
I now have 25 hours on my stroked/bored rebuild and am extremely happy. After getting jetting dialed in I have no issues and it runs like a CHAMP!! power is head and shoulders above stock. I crushed my stock header and slip on this weekend in the same wreck.. so now I'm shopping for an exhaust system for this bike.. and I dont wanna hijack this thread but any suggestions? thanks. Also, i need the option of a spark arrestor/quiet insert for tech @ enduros. And I also plan on having Ron do work some magic on my head @ next valve job (probably this winter). Sorry for the novel, thanks!
Posted 28 May 2012 - 07:48 PM
Posted 30 May 2012 - 07:36 AM
On a side note... what have you guys been calling these beasts? I find myself still calling mine a 450 because when I say 510 nobody knows what on earth I'm talking about!
I love when people ask "is that a 450?"
"Well, it USED to be....."
Edited by pur3evil, 30 May 2012 - 07:37 AM.
Posted 30 May 2012 - 08:16 AM
Posted 30 May 2012 - 08:20 AM
Posted 30 May 2012 - 08:44 AM
Also, thanks for the reply, I'll give MRD a shot!
Posted 30 May 2012 - 08:51 AM
Posted 30 May 2012 - 02:21 PM
I fitted the guide and there's enough of it left to hold the guide in place. From what you described I found exactly the same thing.
I also found a big flat super thin piece of black silicone in the oil pump pick up. Somebody at one time tried to glue the spark plug tube back into the head using black silicone. Its not tough enough for that...I cleaned it all up and put the tube back using Permatex HighTack. I got it spotless first with Acetone and skuffed the tube a little bit. Its perfect now. But a sheet of that black silicone worked its way down to the pick up and blocked the oil pump from pulling all it could.
I think that was the root of the main problem which was the main bearings being totally used up.
As far as the porting goes...I opened the bowls, broadened the cross section, sharpened the divider, cut out a couple random bumps and blended the seats. I didnt go nuts.