Cracked Camshaft bearing cap???

[gregvhen]

You're kidding....right?

What he said!!!!!!!!!!!!!

100% SERIOUS the exhaust cap on the the right side is in two peices, just both bolted down. Ive run prolly 200 miles like that so far.  Also, its not Aluminum, its magnessium[/size]. Some people say theyve had them welded before when i asked a while back, but the welding teacher at my school said it couldnt be. so i dont know who to beleive, cause the teacher at my school is as close to a welding god as Ill ever know.

[BaltimoreGS]

You're kidding....right?

What he said!!!!!!!!!!!!!

100% SERIOUS the exhaust cap on the the right side is in two peices, just both bolted down. Ive run prolly 200 miles like that so far.  Also, its not Aluminum, its magnessium[/size]. Some people say theyve had them welded before when i asked a while back, but the welding teacher at my school said it couldnt be. so i dont know who to beleive, cause the teacher at my school is as close to a welding god as Ill ever know.

I'm hoping your teacher doesn't condone using JB Weld to repair bearing caps!!  At the very least you are looking at a destroyed engine if that lets loose.  Now imagine it letting loose while you are doing 60 mph on a busy highway!  Spend a few bucks and make it right with a used head before you hurt yourself or others.  My 2 cents...

-Jessie

[gregvhen]

700 bucks may be a few to you, or even 125 (the best price i could find used) may be a few bucks,  but thats alot for me. and i trust that it will hold. in order for something bad to happen the camshaft would have to be putting enough pressure on the cap to break it in a new spot and have the detached peice break off.  then that peice could fall into the crankcase and lock something up, and the chain could come off the cam and fall into the case and lock up the engine.  yea, this would be bad to lock up at 80mph, but im trusting that it wont.  at least until i find a cheap enough head.  You got one you wanna sell me fo 50 bucks?

[sledge]

Your teacher, like most teachers is 100% correct  

The cap is not made from magnesium, its made from an alloy formed mainly from aluminium magnesium and zinc. Pure magnesium lacks mechanical strength and would be totaly unsuitable for the application. Yes it can be welded by several methods however owing to high thermal conductivity heat distortion is a big problem when welding magnesium alloys. Given the fact it the cap is a high precision component with very little mass it will probably come out the other side looking like a banana and be so far out of tolerance its doubtful it would even go back into place let alone maintain the required clearances between the cam and the cap itself.

[BaltimoreGS]

700 bucks may be a few to you, or even 125 (the best price i could find used) may be a few bucks,  but thats alot for me. and i trust that it will hold. in order for something bad to happen the camshaft would have to be putting enough pressure on the cap to break it in a new spot and have the detached peice break off.  then that peice could fall into the crankcase and lock something up, and the chain could come off the cam and fall into the case and lock up the engine.  yea, this would be bad to lock up at 80mph, but im trusting that it wont.  at least until i find a cheap enough head.  You got one you wanna sell me fo 50 bucks?

Only you can decide what your life is worth.  Mine is worth enough not to risk things riding a bike with a known serious mechanical defect.  You put time, effort and $$$ into making the frame and all look nice, why not put as much time, effort and $$$ into making it mechanically sound?  I don't have any spare heads at the moment but if the OP doesn't take lilwoody's generous offer you should speak to him   

-Jessie

[lilwoody]

700 bucks may be a few to you, or even 125 (the best price i could find used) may be a few bucks,  but thats alot for me. and i trust that it will hold. in order for something bad to happen the camshaft would have to be putting enough pressure on the cap to break it in a new spot and have the detached peice break off.  then that peice could fall into the crankcase and lock something up, and the chain could come off the cam and fall into the case and lock up the engine.  yea, this would be bad to lock up at 80mph, but im trusting that it wont.  at least until i find a cheap enough head.  You got one you wanna sell me fo 50 bucks?

You do realize you are playing Russian roulette with a automatic pistol right? It's not a matter of if this "fix" will fail but when. It sounds like you are a young man just starting life, don't squander your well being because you can. I know I offered the disassembled head I have to the other fella first but if he doesn't take or will forgo to you I'll give it to you for the shipping cost to try to keep you from killing yourself and/or possibly others. I'll dig through the garage tomorrow to see if I can get all the parts together.

[Gisser]

If money is that big of an issue the cap can be welded for now.  Take off the head and leave the cap bolted in place with the camshaft through the bores.  The dowels will be a big help keeping the cap centered while the weld cools and give the best chance to minimize the tendency to spread.

With respect to the OP, it's also not obvious to me that the crack is the result of a bad casting     Many years ago I learned to be very cautious after trying to loosen a stubborn cam cap bolt by tapping on a short wrench with a hammer and ended up with a crack just like the one in the picture     I was so    I couldn't bear to internalize the blame     I had it welded for $15 and it held up until I sold the bike--at a steep discount      Well, the  is a stretch; let the buyer beware      I have since learned that there is a higher level of morality    

[Missile]

Alright I'm in the Air National Guard & a friend in another unit is certified on a vacuum welding chamber so I removed the cap & had him weld it, both sides, then had machine shop clean up the bearing surface. Just got it back together & everything seems fine. Thinking I may still sell the bike though, we'll see. For the guys asking about pics, there was a link in the opening thread that provided pictures. And yes it was totally cracked, when I removed the bolts it came off in two pieces.
I guess I was lucky to have access to a $180k  piece of welding equipment & someone willing to help me out.

[gregvhen]

700 bucks may be a few to you, or even 125 (the best price i could find used) may be a few bucks,  but thats alot for me. and i trust that it will hold. in order for something bad to happen the camshaft would have to be putting enough pressure on the cap to break it in a new spot and have the detached peice break off.  then that peice could fall into the crankcase and lock something up, and the chain could come off the cam and fall into the case and lock up the engine.  yea, this would be bad to lock up at 80mph, but im trusting that it wont.  at least until i find a cheap enough head.  You got one you wanna sell me fo 50 bucks?

You do realize you are playing Russian roulette with a automatic pistol right? It's not a matter of if this "fix" will fail but when. It sounds like you are a young man just starting life, don't squander your well being because you can. I know I offered the disassembled head I have to the other fella first but if he doesn't take or will forgo to you I'll give it to you for the shipping cost to try to keep you from killing yourself and/or possibly others. I'll dig through the garage tomorrow to see if I can get all the parts together.

If the OP doesnt want that head anymore, and you still wanna ship that to me, at my expense of course 20 bucks for shipping or whatever it is i can afford, i couldnt thank you enough, PM me if he doesnt want it

[lilwoody]

Good news, I've dug out the head. Bad news, the thieves at STRIETS MOTORSPORTS in Gainesville, who farked me on the warranty omitted one cam bearing cap and one bucket shim. They also didn't put the timing chain in the box of parts (doesn't matter for you) and didn't label where the cam bearing caps go. The cams also have some surface rust (3 years in a garage in S. FL will do that. So I guess you have 2 choices. Put this head together with your parts and these parts. Or use these bearing caps to replace your broken bearing cap. I'm not sure what the tolerances are for them but I'd imagine it is similar to mains (maybe around .004". If you mike it out well one of these 3 might be good. I'd think the Budda fella on here could give you much more insight than I can. Either way you'll be much better off than riding with a JB Welded bearing cap. Let me know how you want to go.

[Paulcet]

Good news, I've dug out the head. Bad news, the thieves at STRIETS MOTORSPORTS in Gainesville, who farked me on the warranty omitted one cam bearing cap

It's screwed without that one bearing cap.  They probably broke it!

[gregvhen]

Good news, I've dug out the head. Bad news, the thieves at STRIETS MOTORSPORTS in Gainesville, who farked me on the warranty omitted one cam bearing cap and one bucket shim. They also didn't put the timing chain in the box of parts (doesn't matter for you) and didn't label where the cam bearing caps go. The cams also have some surface rust (3 years in a garage in S. FL will do that. So I guess you have 2 choices. Put this head together with your parts and these parts. Or use these bearing caps to replace your broken bearing cap. I'm not sure what the tolerances are for them but I'd imagine it is similar to mains (maybe around .004". If you mike it out well one of these 3 might be good. I'd think the Budda fella on here could give you much more insight than I can. Either way you'll be much better off than riding with a JB Welded bearing cap. Let me know how you want to go.

yea, i was thinking that the caps off another head cant be that far off that they wouldnt work.  i mean i know it has to be pretty precise, but i wouldnt think itd be off by anymore than .0005 or so of an inch.  so you could send me 3 caps then and ill pay shippin? ill PM you my address and stuff and just reply and let me know who to paypal and how much, thanks again for doing this

[utgunslinger13]

I would think that a slightly off cap is better than a JB welded cap?

[burnymcstalls]

i've talked with some friends about fixing a sheared bolt for extraction out of a head before I outsourced the labor. Apparently JBweld has a retarded high tensile strength. The website has hundreds of claims about how crazy people have used it for all kinds of uses, including fixing a cracked head in a dragster. I would imagine when done properly, you could possibly put enough of the stuff in the cap, then sand off the excess, making sure to keep it out of the portion that rides against the cam. http://jbweld.net/products/uses.php

Properties (psi)
Tensile Strength:    3960
Adhesion:    1800
Flex Strength:    7320
Tensile Lap Shear:    1040
Shrinkage:    0.0%
Resistant to:    500° F

Mechanics -- you can use J-B WELD with confidence. It is designed for safe, reliable, permanent repairs in engine compartments and heated environments up to 500° F. It's strong as steel and impervious to water, gasoline, chemicals, and acids. Working with J-B WELD is quick, easy, and convenient -- and saves you time, work, and money!

Not recommended for use on manifolds, exhaust systems, and other engine components which normally operate at temperatures above 500° F.

[sledge]

, but i wouldnt think itd be off by anymore than .0005 or so of an inch. 

Thats half of 1 thousandth of 1 inch???......I admire your optimism 

[gregvhen]

, but i wouldnt think itd be off by anymore than .0005 or so of an inch. 

Thats half of 1 thousandth of 1 inch???......I admire your optimism 

yea i know, im sure theyve gotta be within the range apart. i couldnt imagine it being any more offset than that.  they are all the same engine and computers/machines wouldnt make too much bigger of a differance between heads.

[lilwoody]

I measured the 3 caps that I have. I put them on a level and measured with a dial caliper and they all measured exactly the same. So if they are off it's by less than .001. The cam journals measure the same too, at least not noticeable on a caliper that measures to .001. After checking this it appears that this just might be horse pucky from Suzuki about the bearing caps, we'll see how well they work on Gregvhens bike. Nice scam to get you to buy a complete head for hundreds of dollars because you broke a 10 dollar part that is overly fragile to start with. Sort of like the little stupid window on the front master cylinder that deteriorates in a couple of years. A dollar part and they want you to replace the 175 dollar master cylinder.

[sledge]

A vernier measurement of a cap wont tell you a thing. What matters is the diameter of the complete journal, thats your cap when fixed on Gregs head. The two halves need to be the exact same dameter otherwise the journal will not be circular. It could result in the cam being to tight, to loose, misaligned or lead to low oil pressure and oil starvation on the bearing surface.......Then you have to hope the fixing bolt holes in the heads and the caps are in the same place relative to the centerline of the journal otherwise the cap will be offset and affect the clearance even more.

Its not a scam by Suzuki, to manufacture these parts with 100% interchangability would dramaticaly increase costs. Its far easier and cheaper for them to manufacture each head this way.

[the mole]

I totally agree with sledge.
You might possibly get very lucky and find that another cap would be close enough to work, but no way would I assume it would without very careful measuring of the bore when the cap is installed on the head.

[lilwoody]

Some how one of the three went MIA over the weekend. I have no idea where it is  so I sent the 2 i had. They are in route on me, let us know how they work. It can't be any worse than the one you have.