LU cracks

[Burke Kilgour]

I'm sure you guys have seen cracks in this location before, what do you guys do to fix it up? Just weld it? anything more/extra?
It looks like the Bobs plate caused this. Both sides, front side of the exhaust slot approx 1", back side of the exhaust slot approx 1/2".

[jimmyj]

Get rid of the Bobs try a Allison plate

[props4u2]

Jumping waves with the rear over hang will break anti-vent fins, as Jimmy7 stated, get an Allison fin.


Lee

[Burke Kilgour]

Will do.
I'm probably going to remove the Bob's plate and run it like it is, and keep an eye on it till I weld it up.
Anybody have an Allison plate kicking around?

[T-REX]

Dump tha Bobs plate, first!!....Weld it and ride...

Mine haz cracked ther more than once...I use a plate on my lil bote to make it launch good, so the more that plate works, the more pressure it put's on that part (the weakest) ov the geercase...I had sum flat bar welded inside, then juss drilled holes instead ov the slots...never broke agin...

Seems like after they crack, they juss keep crack'in after juss welding them, unless U add sum support...

Corse, U may not have dat problem wit a 330 HP mota...It'z probablly juss kuz my ole 500hp chizler haz so much torque:eek: ;) :D

[vector mike]

Get rid of the Bobs try a Allison plate

Bob's had their head up their arse when they designed that plate. Having the rear stick out past the original cav plate is just ridiculous. Nothing like putting extra stress on the cav plate and you unluckily happened to see the consequences first hand. Get an Allison plate like mentioned or better off yet, do what I did and find someone with one already and make your own and save $100.

[hsbob]

you need to stop drill the cracks. at the point of each end drill about a 3/16 hole more or less. this will usually stop the crack from growing. im a firm believer in fin but there a limit on how big they should and need to be.

[Burke Kilgour]

I actually didn't want to put one on. I asked on here and that was the plate of choice at the time and came highly recommended.
I think I have the drawing for the allison plate here somewhere too.........
Thanks, I'll be reinforcing it with some plate behind it. I don't think I'll put any holes in it at all.

[speedinmyblood]

those fins are not flat across you have to put washers between the plate and the fins on the back holes or it will crack the fins bolt them up tight in the front washers in the back

[hsbob]

dont waste your time until you stopdrill those cracks.

[Burke Kilgour]

I have all the washers and rubber mounts installed.
I'll probably just fill the entire vent grooves with weld too, all of them.