Is big bore really worth the cost??

aqua

aqua

the taco
Location
Jefferson City, MO
I am about to send a cylinder (61x) off for some work and was contemplating on whether or not I should just go ahead and have big bore sleeves put in. Is there really that much of a difference in power between say an 82mm bore and an 84mm bore. Max bore on a standard sleeve is about 84 and max on a big bore is about 86-86.5 so that is only about 2mm maybe 2.5mm. Is it worth paying $800 more? What kind of power difference are we talking here? :dunno:
 
DBLOCK

DBLOCK

Location
Camano Island
Where are you sending cylinders off to for an $800 big bore conversion?

Check with NW Sleeve, or LA Sleeve...

I went with NW Sleeve, they installed already ported sleeves & matched up the cylinder casting for me. I think it was $200 per sleeve.
 
N

njfl

X-H2
aqua said:
I am about to send a cylinder (61x) off for some work and was contemplating on whether or not I should just go ahead and have big bore sleeves put in. Is there really that much of a difference in power between say an 82mm bore and an 84mm bore. Max bore on a standard sleeve is about 84 and max on a big bore is about 86-86.5 so that is only about 2mm maybe 2.5mm. Is it worth paying $800 more? What kind of power difference are we talking here? :dunno:
Click to expand...

Is it worth it? It depends on a lot of things, but if you are willing to take your 61X to the max bore (and not have any overbores, then I would say that it is not worth it). All you would gain is a few cc's and you likely will not notice that gain.

I would consider a stroker crank with your current sleeves (I'm assuming tey still have good metal left). The cost of a 4mm stroker crank would be about the same as the total for sleeves, big pistons, and porting (matching/cleanup) and you would have a brand new crank to boot. Plus, for a given displacement (whether attained by boring or by stroking), the stroking gives more torque (bottom end).
 
DBLOCK

DBLOCK

Location
Camano Island
My total cost for conversion has been $1400.

That includes new Wiseco pistons, the big bore cylinder, a new crank, all the machine work, and other parts I've had to buy to make this work (how I want).

I started with a pile of parts, so my build may be more expensive than yours...

It hasn't been a cheap ordeal, but will be totally worth it in my opinion.

I stayed away from the stroker crank conversion because I like occasional high speed WOT runs and don't want my piston speeds to get that high.

Here's the sleeve I used (http://www.nwsleeve.com/water.html):
95 - 98 701CC SUPERJET 84 - 86.5MM BIG BORE FULLY PERFORMANCE PRE-PORTED; Part No. 1588BB $119.00
 
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RiverRat

RiverRat

.......
Location
Louisville, Ky
I don't think it is worth it. A standard stroke ported lamey will eat a big bore 61x and you don't run the rish of a cylinders cracking, at which point you have to reweld it or start over again. A standard 61x cylinder is limited by its design where the lamey is an immediate improvement right out of the box. More bang for your buck and a wiser investment IMO.
 
waterfreak

waterfreak

I had a vision!
Site Supporter
Vendor Account
Location
s florida
RiverRat said:
I don't think it is worth it. A standard stroke ported lamey will eat a big bore 61x and you don't run the rish of a cylinders cracking, at which point you have to reweld it or start over again. A standard 61x cylinder is limited by its design where the lamey is an immediate improvement right out of the box. More bang for your buck and a wiser investment IMO.
Click to expand...

I love my standard stroke Lamey:woot: Just start saving about $1900 for it!:frown:
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Yes, The big bore is a great start for 61x cylinders. A big bore done right will have better bottom end than a Lamey on pump gas and will cost less than half the price if you building for freestyle riding with a budget. You can build a complete new dual 46mm carb system for the price difference of the non-PV Lamey top end. Now if your looking to kick serious a-s-s without limits the PV-Lamey cylinder can't be beat! Lameys I build will and do win Championships.
 
D

duckman1

X
RiverRat said:
They won't but the cylinder itself is still prone to cracking while the lamey is not. I should have phrased it differently.
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I still don't have ya, how would this cause cylinders to crack? Why would a ported lamey be anymore reliable than a resleeved bigbore?

Then my final question, a ported lamey will eat a bigbore 61x? Guess if someone didn't set the big bore up correctly, but that would be the only way. If one of the guys from lameys shop does the porting, as in the past, you may end up with a pile of do-do, I've seen it. There are alot of guys out their who can port just as well, for alot less money.
 
RiverRat

RiverRat

.......
Location
Louisville, Ky
duckman1 said:
I still don't have ya, how would this cause cylinders to crack? Why would a ported lamey be anymore reliable than a resleeved bigbore?

Then my final question, a ported lamey will eat a bigbore 61x? Guess if someone didn't set the big bore up correctly, but that would be the only way. If one of the guys from lameys shop does the porting, as in the past, you may end up with a pile of do-do, I've seen it. There are alot of guys out their who can port just as well, for alot less money.
Click to expand...

Lameys are a thick casting and do, from my experience, perform better than big bore motors. OEM cylinder can and do crack under exterem conditions which is why I would rather invest in a platform that eliminates those types of failures. I also think that the lamey has more potential than a BB. It is more $$ up front but I would personally rather put $$ toward a lamey cylinder. Both run well......all depends on your budget.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Advents for pump gas and saltwater mainly riding, for the 'I want the most I can get'... MSD-TL always! MSD-TL's for all freshwater flatwater set-ups, even on pump gas, they make the power and acceleration!
 
1550

1550

Location
I
have nobody ever made deck plate for those 61x stock cylinders for bigbore? Like they do Honda Vtec engines? To strength top of the cylinder?
 
Idok

Idok

F1pro
Location
Nations oldest muthaF+++kin city
this weekend at the secret spot we had a nice motor comparison going on....myself, slutty and ski daddy all traded out ski's to compare:

my 720mm complete 61x LPW freeride motor with single 48..

skidaddy's TLR 790 with dueling 44's and incessant tuning...

slutty's LPW 785 BB (???) with dueling 44's and lightened fly...



were both of these ski's more powerful than mine? yes....do I have HP envy? NO.

i honestly couldnt feel a major differnce in carburation....but I could feel the slight differnece in displacement..



If I'd never had a ported cyl or a bigger carb..I'd say go that route first...

if I was used to a ported cyl and big carbs and wanted more power then a BB might just do the trick..



awhile back I rode a Ed Brazina BB with 48 full specs and TL (belonged to kahn funk of funk motorsports)...by far the most rippin' boat I have ever been on...the power was like a lightswitch and hit H.A.R.D...I went to do a topturn on a small wave and the boat literally whipped right out from under my feet and i fell straight down...lol





the moral of the story is a freestyle/freeride ported cyl, properly propped :biggthumpup: with a good ignition can be enough motor for a LONG time...
 
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Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
how can you feel a difference in carberation vs. displacement??

Nice Set of tuned 44's on a ported 81mm motor that is dialed vs. a set of full spec 46's on a 86.5mm ported motor that is not dialed in, or a single carb setup with same size motor???
 
Matt_E

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
yeah Scott.....what's this difference in carburetion vs displacment? :dunno: :fingersx: :biggthumpup:
 
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