to big bore or not to big bore

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rebeltaz83

Well-Known Member
Joined
May 8, 2013
Messages
783
Reaction score
237
Location
Landrum, SC
Recently acquired an 96 with almost 50,000 on the clock. Doesn't run, used a carb body for my 97. Was looking in to pcw 1570 big bore kit. Still in planning stages. Anybody done this? Anything I should look for or do while it's apart? Also looking into higher revving cam shafts. Longer duration lower lift. I got all the time I need as I have my 97 to ride. But that engine will go into my 97 when it's done. And I'll convert the 96 to stock. Possibly for the wife, since it's purple.
 
Lots of power potential though I would suggest a chain drive if you go that big. I do have a couple of longrod chaindrive engines up there getting freshened up that will be available at a cheaper cost then new if you're interested. Still not a super cheap way to go but it will be a lot of fun.

The shaft drives are still a lot of fun and less maintenance though you give up 20% of the power potential. The 1570 has thinner walls but again gets you the most output. One of the 1500 chaindrive's i've got was in one of the fastest vmax's ever to hit the track with it running 8.30's @ 160 mph! I've got the flatsldies available and even a fuel injection kit (though the injection is not street friendly since it is not the self learning kit and needs constant tune adjustments).
 
I forgot to mention. If you want to get the most dependable as you can while getting the most power available the 1428cc is a very good option (i've got one of those too). Leaves a little more wall thickness to better heat distribution.

The tour master 1500 he offers is a good option for the shaft drive setup (got one of those around here as well lol). Give up a little power for less effort to maintain.

If you're donor engine has spun a bearing you will not want to reuse the block/crank. For sure you want to do the larger cams. Consider the larger valves (I am pretty sure the 1500 longrod has the larger valves in it already and of course the big cams). The largest of the cams requires the shim under bucket conversion.
 
Buy a nice used Gen 2......190 HP, modern suspension, and awesome brakes. It will be the same amount of money and be extremely dependable. You might even find one with an extended warranty still in effect.....Not that you'll need it.
 
IMHO a Vmax and Gen2 are not synonymous . Last May I rode a Gen 2 for sale here at Coyote Motorsports
that was nicely upgraded, exhaust, 210 and tuning mods. The bike felt like a big strong quick bull, (still a five speed though). Last July I rode a Gen 1 with an "early" 1500 from pcw, stage 7 with a kerker and shaft drive. The gen 1 with that motor was SICK!!! I mean a fun bike with a unmatched sound and look never to be reproduced , rough crude and I loved it. I would or will build a gen 1 before Id get a 2. Just my 2 centavos.
 
I plan on a gen 2 down the road. But I figured I have a spare gen 1 sitting, and currently a ridable one might as well have some fun. It's a project bike. Why have two identical horses in the stall?
 
The Gen 2 does everything well and tons of power. It still doesn't have the character of the gen 1 though. Plus it's larger and bulkier feeling. The main thing for me is the "cammed" sound of the gen 1. Hard to beat.
 
IMHO a Vmax and Gen2 are not synonymous . Last May I rode a Gen 2 for sale here at Coyote Motorsports
that was nicely upgraded, exhaust, 210 and tuning mods. The bike felt like a big strong quick bull, (still a five speed though). Last July I rode a Gen 1 with an "early" 1500 from pcw, stage 7 with a kerker and shaft drive. The gen 1 with that motor was SICK!!! I mean a fun bike with a unmatched sound and look never to be reproduced , rough crude and I loved it. I would or will build a gen 1 before Id get a 2. Just my 2 centavos.

Lots of us feel the same way. I only rode a Gen 2 once, and it was impressive. I like my Gen 1 though, and maybe we're just used to each other and the way she handles. It sits low and close to the ground with the 17" wheels. If I haven't been on her awhile she will still scare the hell out of me.
 
IMHO a Vmax and Gen2 are not synonymous . Last May I rode a Gen 2 for sale here at Coyote Motorsports
that was nicely upgraded, exhaust, 210 and tuning mods. The bike felt like a big strong quick bull, (still a five speed though). Last July I rode a Gen 1 with an "early" 1500 from pcw, stage 7 with a kerker and shaft drive. The gen 1 with that motor was SICK!!! I mean a fun bike with a unmatched sound and look never to be reproduced , rough crude and I loved it. I would or will build a gen 1 before Id get a 2. Just my 2 centavos.

No doubt that a built Gen 1 is a BAD ASS bike, just plain nasty with LOTS of character.

But the Gen 2 does everything better and is more dependable to boot.... and it can be quite bad ass itself with a 4-2-1 pipe.
 
I think the gen 2 has the efi going for it. We can upgrade brakes, shocks, tires, wheels on the gen 1, but we don't have the efi. I'd prolly never get a gen 2 if we could do an efi setup on the gen 1. How is the 1570 big bore kit for rideability on the street? I want something fun, but also streetable. I don't mind doing a little tire roast at a stop light, but not at every stop light lol. Anybody ever deck the block? Or shave the heads? Does it mess with the alignment of the intake and carbs? Like on a v8.
 
I think the gen 2 has the efi going for it. We can upgrade brakes, shocks, tires, wheels on the gen 1, but we don't have the efi. I'd prolly never get a gen 2 if we could do an efi setup on the gen 1. How is the 1570 big bore kit for rideability on the street? I want something fun, but also streetable. I don't mind doing a little tire roast at a stop light, but not at every stop light lol. Anybody ever deck the block? Or shave the heads? Does it mess with the alignment of the intake and carbs? Like on a v8.

From my understanding, there is plenty of deck to shave. Milling heads and thinner gaskets has been done by plenty of people. Some misalignment will happen, but the pipes will bend into place. Intakes not so much an issue. Multi- port EFI, would be very cool to have. But I spent so much time messing with carbs, I like them. Our carbs are very street capable. A vmax'd 1300 is a good compromise.
 
A vmax'd 1300 is a good compromise.

+1
Well pleased with mine - the motor is capable of dishing out far more performance than the idiot riding it can take advantage of.

Two other points if going down this route:
1) It ain't cheap - however much you think it will cost the final bill will be a lot more (I know this to be true!)
2) If you get more performance from the motor you should also budget to improve the brakes and suspension. Another GDP output of a small country required to pay for it.

My advice would be to start at #2 - suspension and braking improvement mean you can ride quicker with the power you currently have. When funds allow then go for the motor tweaks,
 
My advice would be to start at #2 - suspension and braking improvement mean you can ride quicker with the power you currently have. When funds allow then go for the motor tweaks,

+1. I upgraded the brakes to 6 pot calipers and rotors, and upgraded the suspension front and rear, and stiffened the bike before I EVER upgraded the exhaust, and put in the jet kit.

If you GO faster......you need to STOP quicker.
 

Latest posts

Back
Top