Cub problems!

[RNBRAD]

I pulled off the v-force 2's to find out why it was not running well and this is what I found. I found a crack at the base of the left boyesen ports (looking from rear) near the base on both cylinders. They are identical on both sides. Hopefully you can tell by the pics. This motor has less than 10 hrs on it and this shouldn't be happening.

 

 

 

 

This was my initial problem. That piece broke off the cage and was holding a cuple of the valves open.

 

[yamaha04]

did you mean a crack by the boost ports if so i think i can see a line on both jugs where they have cracked. thats shitty do you think it will hurn anything? what if you take that port right out and open it all up?

[RNBRAD]

did you mean a crack by the boost ports if so i think i can see a line on both jugs where they have cracked. thats shitty do you think it will hurn anything? what if you take that port right out and open it all up?

 

Yea it's the boyesen boost ports. You can see the line, it's small in the pics and really need to click on image to see them. Opening it up would not be a good thing.

[FireHead]

Is the crank on the floor of the intake port? I am having a hard time seeing it on my Blackberry. I would maybe shoot Calvin at CP an email and if he has heard of any issues like that. If I had designed the cylinders, I would be pissed if there were manufacturing defects like that floating around. :ermm:

[RNBRAD]

Is the crank on the floor of the intake port? I am having a hard time seeing it on my Blackberry. I would maybe shoot Calvin at CP an email and if he has heard of any issues like that. If I had designed the cylinders, I would be pissed if there were manufacturing defects like that floating around. :ermm:

 

It's not quite at the bottom but close. The crack is no thicker than a hair and it's perfectly straight. I emailed Calvin and sent him these pics.

[FireHead]

It's not quite at the bottom but close. The crack is no thicker than a hair and it's perfectly straight. I emailed Calvin and sent him these pics.

Now that I am home and can look at the pictures on something larger than my Blackberry, it appears the crack may have been caused by a variance in the aluminum or residual stress left in the part during casting after the core had degraded. Either way, I don't think that repairing the cylinders by welding or cast welding is a reasonable option. You may be able to use a structural adhesive to repair them, but since the cylinder have been fired, there is a good chance that ally has absorbed enough of it's surrounds to make an adhesive solution hit or miss. If Calvin has a good enough relationship with his casting vendor I am sure they can work something out. If not, and I were Calvin, that cylinder block would be going up my casting vendor's ass.

 

On a side note, find a decent casting house in North America is pretty rough. I am not sure that I can even think of one worth talking about. The Union Foundary in Bellingham, WA is the best I have used in North America thus far, but their capabilities are a bit limited and they usually have a very high work load making ski boat propellers. Edelbrock has a great, recently expanded, casting facility, but I would be willing to bet that they make alot of internal scrap that they don't tell anyone about. Besides that, Edelbrock doesn't really do work for anyone outside of Edelbrock. Japan has several great cating houses, but they are long lead time, expensive places. Germany has a few good places as well, but they can be tough to deal with sometimes. As I get further away from my old job, I should be able to start sharing more about some of the inside racing industry stuff.

 

Good luck getting this sorted out. If I can be of any help, give a shout.

[wesw]

ouch brad!!!

 

ive heard of the intake bridge being cracked directly from cp. havent seenyours problem yet. hmm hope he will warrenty it, and jeff can get you a new one going.

 

was there bits of alum on top of your pistons and domes, figured some small debris might have gotten loose???

[RNBRAD]

Thanks for the input Firehead!!

 

 

 

ouch brad!!!

 

ive heard of the intake bridge being cracked directly from cp. havent seenyours problem yet. hmm hope he will warrenty it, and jeff can get you a new one going.

 

was there bits of alum on top of your pistons and domes, figured some small debris might have gotten loose???

 

No Wes, the crack is just that, no pieces loose or anything. You have to look at the pictures close or a person may think the actual bottom of the boyesen port looks like a crack but it's a shadow. The actual crack is about 1cm up from the base. I don't think this will have any effect on performance as the rings never go that low. Glad I pulled the reeds though. One was shot.

[wesw]

so you getting vf3 from moto or they wont warrenty them now??

 

ill call you later this morning got to tear up the hiways.

[bigboybanshee]

Oh man, that's not good!!! The more I see threads like this it makes me wonder if I should have stuck with my stock cylinders...nikasil peeling, deck heights wrong, cracks in intake ports, and the list gets longer. I hope everything works out for you, I'll be very interested to hear Calvin's response. He's always seemed like a reasonable person to deal with.

[FireHead]

I don't think this will have any effect on performance as the rings never go that low. Glad I pulled the reeds though. One was shot.

I would be very careful if you are having any thought of continuing to run that cylinder block. Aluminum that has a fissure (sp?) in it tends to not stay in the same condition very long if it keeps going through heating and cooling cycles. :thumbsup:

[Alex!]

I am having a hard time seeing it on my Blackberry.

 

 

Hard core! Got to love it!