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Premium Member
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Discussion Starter · #1 ·
I was wondering is the 3 extra inches worth the 500.00 ? Or are you better off using that money for somthing else?
 

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killer sperm
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I asked myself the same question & decided I'd get more bang for the buck with headwork.
 

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Premium Member
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Discussion Starter · #3 ·
Milehog said:
I asked myself the same question & decided I'd get more bang for the buck with headwork.
But say your going to get headwork regardless, is it worth it then?
 

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Premium Member
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290 Posts
My answer is yes and no. No, you won't get much if you pay $500 for three inches. But, if you are going from an 88 to a 95 the difference in going to a 98 is almost nill. Then, a few extra bucks are well worth it.


Stan
 

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2005 Road King Classic
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Is a Harley worth the extra $$$ over a Victory? It's purely a hypothetical question that only you can answer after you research it and determine what is right for you.
 

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Revperf
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281 Posts
mori55 said:
But say your going to get headwork regardless, is it worth it then?
Hey Mori,

Just thought I would throw my two cents in. There is nothing wrong with a great set of finely prepared OEM cylinders. The advantages that the 98" kit have are pretty vast though. I'll run a few down a few for ya.

1. Larger bore size physically unshrouds the valve curtain area and allows the head (OEM or ported) to work better. Improves low lift/low velocity flow=improved torque.

2. Sheds heat 5 times more efficiently than a standard cast iron sleeved cylinder. (Independant study at Northwestern University) Physics 101 - All aluminum pot cools down way quicker than a cast iron pot. These things are cooled with air and oil.

3. Nickel-Silicon-Carbide has 10 times the wear resistance of conventional cast iron liners. It would cost you more than the difference to tear yours down for a hone and oversize.

4. Lower ring drag coefficient by nature of the plating in the bore.

5. Proprietary, aerospace grade, high silicon content casting.

6. Warranteed for LIFE against warpage or plating defects.


Thanks for the time!

BN
 

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Average Dude
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6,263 Posts
And in order to get similar numbers out of a 95" that you can get from a MILD 98", you have to spend alot of money on head work. And the hot 95 may not be as reliable as the mild 98".
So, for the extra $500.00, I think it is well worth it.

JMHO

YB
 

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0043--Licensed to Doof!
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4,369 Posts
Hey Mori, you rode along side of me and watched me dissappear, right? I just got my dyno done yesterday. The HP is down a little, we're discussing changing the carb, but I posted 99 lb/ft of torque. And there is still more in there! Steve is working with me to find the last bits of power and tq. Here's another thing to consider. He talked with the tech yesterday while my bike was on the dyno. Gave him some tips. He called me today, on his dime to ask how things ended up and if I'm happy with the numbers I got. 50 minutes later, we hung up. You gonna get that kind of support from another company? Hell, thats worth the 500 clams right there!!

Oh yea, if you thought it was fast the other week, you shoud see her now!!!! And... theres more to come!!

And one last thing. Sure, the extra three inches never hurt anyone, but seriously folks..... physics tell us that a square motor makes power and TORQUE! The 98" is a 4X4. The 95" is undersized bore so you will never get the same numbers using part for part. (ie: same cams, exhaust etc. etc. in a 98" will beat a 95")
 

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Banned
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21,644 Posts
So what are you looking at for costs? I got stock motor and will go gear cams and ?" in the next week, hopefully. Are you still doing heads with 98" I got a helicoil in one of my heads, so I am a little reluctant to do head work. In case I need to buy new one someday. Then again if I got the heads off....
 

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0043--Licensed to Doof!
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My bill was just under $1500.00. I did NOT do cams, I already had S&S 510g's in there. I did: 98" bbls/pistons, Cometic gaskets, Comp Cams lifters, headwork. I had to have a couple of cooling fins straightened out (poor packing on my part) and a spark plug thread repaired. I did the new tulip nitrate valves too.
 

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Premium Member
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Discussion Starter · #12 ·
revperf said:
Hey Mori,

Just thought I would throw my two cents in. There is nothing wrong with a great set of finely prepared OEM cylinders. The advantages that the 98" kit have are pretty vast though. I'll run a few down a few for ya.

1. Larger bore size physically unshrouds the valve curtain area and allows the head (OEM or ported) to work better. Improves low lift/low velocity flow=improved torque.

2. Sheds heat 5 times more efficiently than a standard cast iron sleeved cylinder. (Independant study at Northwestern University) Physics 101 - All aluminum pot cools down way quicker than a cast iron pot. These things are cooled with air and oil.

3. Nickel-Silicon-Carbide has 10 times the wear resistance of conventional cast iron liners. It would cost you more than the difference to tear yours down for a hone and oversize.

4. Lower ring drag coefficient by nature of the plating in the bore.

5. Proprietary, aerospace grade, high silicon content casting.

6. Warranteed for LIFE against warpage or plating defects.


Thanks for the time!

BN
See this why i asked the question theses are the things you find out if you ask.
Geezer, i just had to ask , tomorow i'm going to order the kit from Steve. In my book customer service is worth alot also.
Guy's thanks for your answers it helped me make up my mind.
 

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IronButt
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6,364 Posts
WOW

Ok there are few other things the tq curve on the 98 is broader and starts lower, TQ is what is hurtling these over weight monster down the road , sooner you can get into the curve you are moving faster. And sure what man would't want three extra inches??? :banmep: Sorry could not stop myself.
 

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Doing time, behind bars!
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1,480 Posts
Don't let facts ruin a good story...........

Geezer-Glide said:
And one last thing. Sure, the extra three inches never hurt anyone, but seriously folks..... physics tell us that a square motor makes power and TORQUE! The 98" is a 4X4. The 95" is undersized bore so you will never get the same numbers using part for part. (ie: same cams, exhaust etc. etc. in a 98" will beat a 95")
No offense intended, I certainly agree with your statements, but the figures are inaccurate as shown by this copy & paste from Rev Perf website
Bolt-on big bore kit, 98 ci 3-15/16 bore Revolution cylinders 10.5:1 forged pistons, pins, clips, rings head and base gaskets
 

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0043--Licensed to Doof!
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The_Snowman said:
No offense intended, I certainly agree with your statements, but the figures are inaccurate as shown by this copy & paste from Rev Perf website
Bolt-on big bore kit, 98 ci 3-15/16 bore Revolution cylinders 10.5:1 forged pistons, pins, clips, rings head and base gaskets
No offense taken. Thanks for the update, I was wrong, thought they were 4". My bad!! #[email protected]
 

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Recon
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839 Posts
mori55 said:
I was wondering is the 3 extra inches worth the 500.00 ? Or are you better off using that money for somthing else?
Yes...in a word. Had them on my 03 and hope soon to have for my 06 SG.
 

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~~Finder Of Paths ~~
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203 Posts
[B said:
Bolt-on big bore kit, 98 ci 3-15/16 bore Revolution cylinders 10.5:1 forged pistons, pins, clips, rings head and base gaskets [/B]
ok can someone point me where to find more info about what bore would make what c.i. with a stock 4" stroke? looking at revolution perf. web sight they show piston kits up to 4.25" can a factory cylinder be bored to that size? what is the limit for a factory cylinder? someone know the formula I need to figure c.i. from bore and stroke.. I should probably be able to figure it out but to many years since high school.
 

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~~Finder Of Paths ~~
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203 Posts
ok wait, never mind maybe went and did a little looking for formulas online. Looks like 4.25" bore gives ya 113 cu.i. so for that you have to bore the cases correct? so whats the biggest you can go without boring cases? 98?
 

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IronButt
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6,364 Posts
95 inch is the SAFE limit for a stock hd cylinder. 3 15/16 gives you a 98, bump that to 4.125 ( 4 1/8) you get a 107 go to 4.250 (4 1/4) and you get a 114 that is all on a stock crank stroke of 4 inch. Now go back to the 4.125 add a 4 3/8 (se 103 crank) you get 117, add the 4.25 and you get a 124.


Borex Borex.7854x stroke x 2 ( for a v-twin) that will get you displacment
 
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