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Who makes a solid, reliable BIG BORE kit??

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Thumper Racing? Athena? Wiseco? Yoshi? Who's got the best? Will be pro installed. Thanks,

—DiZzY

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If you go yosh you end up with some propriatory parts that can only be purchased from them. Which means the price is a little higher to start with and their commitment to the drz is going away fast.

Millinium Technologies does a majority of the boring/plating for the big bores here, whether you go to directly to them or not. Many places like Lukes racing and LRD use them for their replating.

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I was very happy with my transaction at Lukes racing. They got it out real fast and they were great to deal with. Good price too.

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stock E compression is 12.2:1 so yes you can run pump gas with 12:1 just make it premium 🙂

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Thanks, I know that a lot of guys are fitting up the 436 kit, is there something scary about the 470 kit that I should know about? 🙂

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The 470 kit involves resleeving, I think that it's also NOT a bolt on. I may be wrong, but I think at the very least you're adding stroke which means a longer crank, and spacers...ect ect. You'll have to check with 10guy, burned, noble, bronco or one of those guys for more info. The 436 kit is a straight up bolt on, quick and easy power.

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The 470 uses a rather large piston, 97mm?, and stock stroke doesn't it? If so there is no way there can be enough cylinder skirt left to be reliable. I believe it also uses an iron liner which can have problems of it's own.

The 436, which is actually 434 (94mm), is as large as you can go without using a sleeve and the aluminum sleeves are currently being bored out to either 94.5mm or 95mm yielding either a 439 or 450.

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Oh and the biggest advantage to using a 94.5 or 95mm piston kit is that you can get it with a 13.5:1 compression ratio 🙂

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Oh so the 470 doesn't use a longer stroke? I almost thought it would have to. But I'm not motor expert as you probably have figuired out 🙂

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Not as far as I know it doesn't. I may be wrong though. Like I said it makes the cylinder skirt dangerously thin.

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Oh and the biggest advantage to using a 94.5 or 95mm piston kit is that you can get it with a 13.5:1 compression ratio 🙂

Does this work okay using pump premium gas?

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Does this work okay using pump premium gas?

NO, Race gas only with that high of a compression. 100 octane or higher I think 🙂

Some people use that octane booster but I heard that it's snake oil.

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Oh so the 470 doesn't use a longer stroke? I almost thought it would have to. But I'm not motor expert as you probably have figuired out 🙂

The only people I know using a 97mm piston on a stock stroke is thumper racing (see their web site). They bore the cylinder precariously thin, and then install a steel or aluminum sleeve (your choice) Obviously you then would have to plate the aluminum sleeve if you went that route. I talked to the owner ... He acted like he would rather sell the steel sleeve, as he was voicing issues with the aluminum sleeve moving after install and therefore needing to be welded in. Ironicly enough ... You also acheive 470cc displacement by using a 94mm piston on a 67.6mm stroke (5mm extra from stock) ... So it can get confusing.

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Ironicly enough ... You also acheive 470cc displacement by using a 94mm piston on a 67.6mm stroke (5mm extra from stock) ... So it can get confusing.

AHA! That makes more sense to me, I can't see boring the cyclinder enough to get that HUGE piston in there. Adding stroke makes more sense to me. Not that I'll ever do it, I think I'll be happy with my 436cc kit (434 or whatever the hell it is) 🙂

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