Topic: 18 hp intek AVS parts?

[ctown75]

Sorry- I'm an extreme NOOB to the world of mower racing.  Been playing with mud trucks for years but some buddys and I started leisurely racing in our back yards.  So I have an 18 hp intek motor.  Where can I get aftermarket parts for this motor?  Is there an advantage to having AVS when modifying?  I'm looking to start with piston, rod, maybe crank, cam, valvetrain, flywheel.  No major mods just bolt in stuff to start. Anything I need to know please fire away, I am all about learning in this point.  Thanks in advance,

Scott

[sparks]

scott there a lot of parts you can get for that motor. cams rods pistons flywhells. read some of the post in  eng bild post on here. all the help you could ask for spark 58

[jerb]

one of the biggest problems with the avs, is once you start modifying them for more rpm, the stock balancing system will self destruct, i believe arc is working on a fix for this, or you could have the crank balanced to do away with the avs, older 31'' synchro balance parts can be used with this engine, but not a bolt in deal!

[ctown75]

Cool thanks guys.  Well I guess my next step is finding out more about what to do with this avs.  Sounds like some machine work is involved with using synchro balanced parts, and without many donor parts that may be a little over my head at first.  Is it really as simple as balancing the crank, and then you can scrap the avs?  I really don't know what all it entails.  I haven't tore this motor apart yet so I will have to take your word for it.  That's not a terrible process in terms of detail or cost either, at least with car motors.

[jerb]

i believe the crank journals are bigger on an avs, have heard of making bushings that either press in the block or steel sleaves that press on the synchro balance cranks, and just use the arc brass weights for the snychro crank and presto, no more avs, there is probably more to it than that, i have never done it, maybe some other guys will chime in on what is involved!!

[nic_hayes]

I had one I built a few years ago for another mower and just had don balance the crank, $100 done deal.

[The Tank]

I started to build one of these AVS engines but I was told the timing gear on the crank was the weak point.

[Hitch]

They are,the ones off the flatheads is a little thicker but still a weak point.I'm working on a billett one now.Should be out soon got so much going on now but it's coming.

[ctown75]

So if I am reading correctly there is no real way to correct the weak timing gear at this point?  How weak is weak?  What should I avoid to not test this weak point?  What exactly is this AVS system?

[The Tank]

AVS=anti vibration system. The motor will not run long at high RPMs with the AVS balancer still in place and no there is no remedy to the weak timing gear as of now. Some still run the AVS engines but change the timing gear every few races from what Ive picked up on.

[jerb]

So if I am reading correctly there is no real way to correct the weak timing gear at this point?  How weak is weak?  What should I avoid to not test this weak point?  What exactly is this AVS system?

your valve springs is what put the biggest load on the cam, so i would definately just run single springs, if your still running a stock cam, keep on using the stock springs and you shouldn,t have a problem, but be sure to get good retainers for the springs, i assume the intek's use the same keeper as the standard 31's, which are junk!

[ctown75]

So this AVS is basically a harmonic balancer?  And if I want to run aftermarket cam and higher RPMs with the stock timing gear, am I asking for trouble?  Would it be realistic to have a hardened timing gear machined at local machine shop?  A friends dad runs one just up the road.

[The Tank]

Yes somewhat similiar to a harmonic balancer. You could try a hardened gear but don't know how it would work. If you do I'm sure lots of people would like to know

[Old Goat]

I assume that this intek is a single cylinder? The avs motor and the regular I/C motors do not have harmonic balancers. They have a heavy weight that bounces back and forth, exactly opposite from the piston. When the piston is going one way, the syncro weight is going the opposite way. Basically, the difference between an avs motor and a regular motor is how the weight is attached to the crank, what holds the weight in place and the rod/piston combination.

[ctown75]

Yep this is a 31 cu in single.  so balance the crank and scrap the AVS?  easy enough.  Should I check out this don guy, or can my local shop do something like this?  thanks in advance