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RingKingPin

Barnums Cam Specs

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Hi Guys,

I am drawing a blank and Rob is out of town for a couple days. I was getting ready to do the valves on my 650r with a barnums cam and I can't remember the settings. I first thought that it was 5 in 6 out but then started second guessing myself with 4 in 5 out. Is there anyone out there who can PLEASE help me??

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Hey Jeff,

Thanks for the link. However, that "don't help." I know how to do the valves, just having a major brain fart and can't recall if my Barnum cam needs 4 and 5 or 6 and 7. At first I thought it was 6 and 7 but now am almost positive it is 4 and 5. Rrrrr I guess I might have to wait for Mr. Barnum to get back. :)

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I just went through hell with my bike... and not "apparently" doing the valves correctly according to Rob. I had a 'mild grind' cam from him.... and he didn't tell me I had to releif the piston for valve clearance. Well... my valves hit the piston and bent... lost compression in about 10miles... and within 80miles I was stranded in Mexico, having to be towed back that 80 miles in dirt/sand/rocks/tree roots...etc. Not a pretty site.

My next move will be a stock cam.

Less hassle... and still enough power.

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That had to be one of the all-time bummer deals.......being towed 80 miles out...DANG!! Doesn't usually happen on a Honda. ......I do remember my friend's Hussaburg just giving up electrically on some really nice single track. Certainly put a damper on that day.

Just curious........anyone else here on TT that has done a "mild" cam install like this needing piston/valve relief??

How many different ways are there to "correctly" adjust the valves with a "mild" cam?? :D

Seems as if there was a need to clearance the stock piston(??) to the "new" valve lift the seller of the cam most certainly would have (OR should have) informed!!?? :):D

Hang in there and future happy 'XPLRN' with your stock cammed bike! :D

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I installed a HotCams stage 1 cam in my xr650r which is mild compared to some cams (I had no clearance issues), but I still double checked my VOTDC (Valve Opening at Top Dead Center) which is the distance the valves are off their seats at TDC during overlap to get a better idea of how this cam differed from the stock cam. I also used a degree wheel to find true TDC and did not depend on the flywheel timing marks. You just can't take anything for granted when installing any kind of a performance cam into an engine unless you're willing to take a risk. One of my neighbors installed a new cam in his buggy engine and he bent a bunch of his valves because he didn't check things out carefully enough and or didn't take into account thermal expansion. No matter which aftermarket cam you buy, its critical to make sure the numbers work out with enough margin. If the numbers are close enough, then its important to use plastic to check the actual clearances.

I'm not an engine builder, but I've seen enough people put together engines only to find their engine suffering from inadequate VPC (Valve to Piston Clearance), which means the engine must be disassembled so the pistons can be fly cut for additional relief. I've also seen people & even mechanics learn their lesson the hard way after the engine fires for the first time only to go up in smoke with bent valves, broken pistons, etc, all because they assumed they had sufficient VPC as opposed to actually checking it. It happens more often than you might think, especially in performance applications, so don't take anything for granted when installing a new cam or changing the timing.

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You just can't take anything for granted when installing any kind of a performance cam into an engine unless you're willing to take a risk. ~snip~ If the numbers are close enough, then its important to use plastic to check the actual clearances... ~snip~ so don't take anything for granted when installing a new cam or changing the timing.

I guess there's three of the most important comments... First, don't ever take anything for granted. HOWEVER... I am much further from an 'engine builder' than you (telling from your lingo) and I wasn't informed to any such thing. I wish I was or had been! Now my mechanic... he said he would have checked if I told him the cam was needing it, but I had mentioned to Barnums that I didn't want to have to do anything special. Hence the reason I didn't do a "hot" cam... and hence the reason the mechanic was 'trusting' of Barnums. Otherwise I would have bought stock!!!!

Lesson learned that's for sure. 100% by me... my mechanic is now checking the clearance with 'plastic'... and getting it back to me this week. I'm not about to again... go by a stock cam and be out the 'mild' cam I bought from Barnums. That'd be a waist. I sure wish Barnums would have taken it back for refund... so I could just go about my business and be back to 100% stock. Oh well... Many lessons learned on this one. Too bad it cost me a pretty penny to learn!

But again, thanks for the advice... AND comments... Knowledge is key!!

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The usual method is to put a thin layer of modeling clay on the piston dome and then assemble the top end. You slowly crank it through(minus spark plug so its easy) and then pull the top end off. You very, very carefully cut the clay and remove it from the piston and see if there are any spots thinner than they should be. I had to do this with my Mustang since I have big valve heads and an equally big cam.

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Do you have the same cam as I do? The mid cam? I checked my valves after he put my bike together and they were at stock settings. Dose you setting have to be different because you have a stock piston?

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That had to be one of the all-time bummer deals.......being towed 80 miles out...DANG!! Doesn't usually happen on a Honda. ......I do remember my friend's Hussaburg just giving up electrically on some really nice single track. Certainly put a damper on that day.

You think that 80 miles was a "bummer"....?!?!?! :cry:

Try 140 miles this last weekend!!! :cry:

My bike finally died... almost at the exact same spot as it did the time I responded to this thread. 80 or so miles into the 250 mile ride... *BANG* Good thing I had CycoActive TOWDOWNS!!! (tie-downs that also act as a tow strap!). 70 miles of the tow was in the rough stuff... sand, rocks, hills, mud, ... you name it. The other 70 miles was on the highway, and in the dark! Talk about a bummer....

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Thats a good question BWB. I think I went with his "mild" cam as well--you can ask him, I'm sure he'll remember. Does the 680 keep 10:1 compression? I have the stock bore but an 11:1 piston.

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Barnum, told me he learned one thing though all this. He will not sell a cam without the piston to go with it.

Noone gives installation instrutions with a cam, it is to much of a liability.

Barnum has my bike right now. If the cam is put in right there should be no more problems with it compared to a stock cam.

AirTime, you sure have more patient then I! I would be hunting down that mechnic and gutting him like a fish. No talking, Just bam! 300 pound bike on top of him.

Mechanics just don't seem to be Professional anymore.....just get it close and out the door and cash the check. No calipers, plasic guage, torque wrench, micrometers. Nothing it's all by "feel". That "feels" close enough. I don't want close enough, I what perfection! Well I better shut up before I say anymore.......... :cry:

680cc 11:1 Piston Kit $180

102 Sleeve $80

Corrillo Rod Kit $160

Install Rod kit $160

102mm head gasket $15

Install Big Bore Sleeve and bore 102.4mm $160

cam Chain $68

Heavy Duty Valve Spring kit $160

3 Angle Valve Job & Shorten Guides & Cut for Larger Valves $165

Four Stainless Steel Valves $128

Gaskets and all New seals $100

Barnums Mid Cam $160

For the Labor you would have to call Rob Barnum because that is a veriable that changes from bike to bike.

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Hmmm...

That's not too bad on parts. I know labor needs to be added in there.... but wow... for the horses gained, not bad at all.

And ya, the mechanic who worked on my bike is a friend of many of my friends... as well, he's well known. And honestly... I've over it. It's not really patience anymore, it's more like count to 10... and just breathe. Otherwise the closest handgun would have been picked up a long time ago. (And I'd shot that steed that broke on me for the second time!! Not the mechanic or myself... just the bike! LOL!).

Thanks for the pricing, and I hope all goes well for ya.

I continue to run into people who know people... in Baja, you'd think it's a big place. But not when you ride an XR.... I mean come on, it's only a bike! However... everyone knows everyone, and it actually is kind of interesting how many people I know or who knows of who. I'm sure I have some enemies somewhere, but if I do... they're hiding. EVERYONE I meet is just awesome. My point to this?? Well, a guy just camped with us at Glamis this past Halloween that is the mechanic for BajaBound... And Tim who owns BajaBound knows me and Rob and many others. So to have his mechanic in our camp... just crazy. We laughed at many common relations, and stories of how small this world really is. So It's imperative that your bike come out well! :cry::cry: I'm sure it will.

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