building cag motors

TheClaw70 · #1 (**permalink**) 24-11-2009, 11:14 PM

Why the flippertygibbert is it that everytime i build a cag motor (almost) on the third or fourth time i put the head bolts in does one of the little fuggers strip out on me? I know you have to tighten them, but i seem to always get caught out on the third or fourth re-assemble.

I imagine i'm just being a little too forceful on the bolts, but bugger me, i had a good one going

does this happen often? If so, why is cag alum so friggen soft....Blimey guvner

Glen · #2 (**permalink**) 24-11-2009, 11:40 PM

haha its complete sh1t metal isnt it. im hoping one day ill see the remenants of a recycled coke can in there lmao. if it happened to me again i was going to see about milling some flats where the bolts holes come out underneath in the flywheel/clutch area and use nuts on the other side or you can always drill it out for the next size up. theres tons of meat there for it

if yah dont hurry up and get one done im gunna take that cag title at wcr next year

mwahah mines looking awesome now, goes alright too. its so nice to ride it and not have my knackers irreversibly pulverised within 2 minutes :P

oh yeah did you want me to post that tyre lever back to you? got my own set now

TyD · #3 (**permalink**) 24-11-2009, 11:49 PM

yep, its crap metal! thats why i use to use this signature..

I have stripped a few bolts in my time, mostly the mounts under the motor..

thing I have learned was to do the bolts up with my fingers first so i know it will go in the thread properly..

or send your parts up here and I will build you a rinky dinky fast motor

TheClaw70 · #4 (**permalink**) 25-11-2009, 12:00 AM

Yes, folks, i'm a shirty as folk over this. i'd just slipped a spanking new set of seals, some new bearings, a new crank, piston, rings and such in when this happened. It gets my goolies, i tell you. I'd spent a good half hour dremelling out the cases and it would have flown. I dunno, maybe i might put a helicoil in later but i know i wont be running a cag this weekend...grrrr..

TyD · #5 (**permalink**) 25-11-2009, 12:15 AM

that sucks dude.. what about the old motor that was in the l7??

should chuck some BZM bearings in your next motor

ringo · #6 (**permalink**) 25-11-2009, 02:45 AM

1 word helicoil
(recoil) kit

SpyGuy · #7 (**permalink**) 25-11-2009, 06:38 AM

Helicoil it, or tap it for a slightly larger bolt.

TheClaw70 · #8 (**permalink**) 25-11-2009, 07:44 AM

Helicoil, eh?...hmmm...might investigate that today...thanks..

morty · #9 (**permalink**) 25-11-2009, 09:59 AM

yeah, a helicoil will do the trick nicely.....
All headkits for cags usually require different size head bolts... When putting your cases together, and you use allen key bolts to bolt your cases together, the head bolts on the crank side need to be exactly the right length, otherwise if they're too long they will bottom out a little on the allen key bolts and just burr the thread a little and this is enough to wear your thread in the cases when undoing them over and over! If they're too short, it won't have enough thread! just use a few washers to get the disired length....
You have a lot more room on the flywheel side... Is enough room that side to just use a nut to tighten it up... try using the nuts from a 14mm del rep carb.. the one that tightens it up on the manifold!!
morty

wbr · #10 (**permalink**) 25-11-2009, 10:20 PM

know exactly how you feel chris, mate im sure morty will agree, out of say every ten cags you build. at least 1 will do this!! lol helicoil is the best option or at least till i used studs like polini engines. this makes it a bit harder to work on. but once there in the cases thats it!! but one tip allways run a thread tool thru all your threads before you do a build, for example we have built engines for customers and the amount of dry lock tight and silicone that comes out of the threads is enough to rebuild it twice with some to spare!! this silcone or lock tight that sits in there eventualy wrecks the threads. one tip tho if you decide to go the heli coil path, make sure that ur cases have enough material to warrant useing them as i have done a few that have bearly had enough to use one on.

cheers and good luck be sure to let us know how it go's

building cag motors

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