What the best most reliable way to gain engine cc's? i know it have the big bore and stroker kit available, but which is more reliable for street use and will not kill engine life?

2 mil overbore is the most reliable way to gain cc's for a street engine.

3 mil bore will take a chance on killing head gaskets

Any stroke will cut longevity on rod bearings.

If you WANT to stroke a street engine, a 4 mil stroke IS decently reliable, a 5 mil stroke is not recommended.

Daily rider: 2 mil bore.

Weekend warrior: 2 mil bore/ 4 mil stroke

Drag/ lsr bike: 2 mil bore /5 mil stroke

how good/bad will the 1451 and 1570. engine kit from muzzys work for street riding?

1570 is 3 mil bore and 5 mil stroke. This is the engine i ran last year. For a streetbike... Dont.

The 1451 is also a 3 mil bore. As i stated before, the 3 mil bore is prone to head gasket failures. You're reducing the amount of meat between the cylinders greatly. There isn't much room there in the first place. Mine lived an entire season through the abuse of nitrous, and so far has lived most of the year in a streetbike in florida..

So, a 3 mil will live.. I would not suggest it, but it will live under the right conditions.

Thanks for the advice. So what are the right conditions? And what engine kit or setup would u suggest if you don't mind sharing that? I was told that the 1451 would give me the best of both worlds for street and strip. But I see now it don't.

Right conditions would be very little riding, you can't let it get too hot.. No nitrous or power adders and changing the head gasket every so often.

Best street/strip engine would be a 4 mil stroke and 2 mil bore. I would call someone like Adam's performance or Carpenter Racing as far as the engine build. Problem is, they're usually pretty slow to build (busy).

i read a lot of good things about carpenter race engines also....who is better carpenter or Competition CNC

As far as headwork, I've become a fan of Competition CNC. Carpenter used to be the 'big name' but later, stories of inflated dyno numbers (a "happy" in house dyno) came up. People were running good, and getting good HP readings but not what carpenter advertised or claimed. Plus, i've called and talked to Bob Carpenter himself.. It just didn't seem like he was too interested in hearing about my motor to suggest a head.. He just said to send it in and he'd port it. I haven't actually spoken with Jim (competition CNC) over the phone, but i have PM'd him quite a few times on psychobike and he's very helpful. Took the time to explain certain things that I asked, so on and so forth.

My best advice, would be to call both of them. The good thing about Carpenter is he'll build the entire engine.. Jim will just do the headwork. Ask questions, be thorough.

I wouldn't, however.. Go with an Adams head on a bigger motor. My hand ported head (i.e. dremel tool) made more power on my old 1570 then a Adams head.. lol