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Discussion Starter #1
Im looking at some of these big bore kits from dennis kirk. I have arlen ness big sucker, slip ons and PCV on my 11 dyna. Any pos/neg feedback on the S&S 106 piston/jug kit? Im also looking for some good cams. Im 90% highway riding, no passangers I dont think Ive ever hit the rev limit but I do like to crank it wide open once in awhile, so maybe something starting power at mid rpm and up? I already have enough passing power, but its really never enough, u know what i mean? Budget wise im looking for around 1500 bucks on the motor, plus maybe auto-tune modules for the PCV. Im also not sure whether to buy the cams first or the big bore kit. Im trying to space things out a little rather than buying all at once. also I wonder if S&S gives the torque specs for installation.
 

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Are you saying you want add either the 106 kit or cams now, and do the other later ? If that is what you are asking, I would do cams first or all at the same time. Stock cams in a 106, I think would not work very good. JMO
 

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Discussion Starter #3 (Edited)
either cams now then 106 or buy all the stuff seperately to be a little easier on my wallet, then install everything when I have all the components. This is my daily driver so Im not looking for anything too radical in a cam. Im also not looking for any headwork anytime soon.

edit: 10:1 compression is a bit high, I wonder how well that would do in south texas weather. also would I be looking at compression release?
 

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I have this same kit in my 02 dyna, it's a really good kit, comes with everything needed to install it yourself. I ran it for 500 miles on stock cams( just to break it in). After I installed it I joined this forum and learned about all the other options (like boring out to 98", or 107" for you). If I had to do it over again I would have bored my cyclinders. Also, the S&S kit comes with .043 head gasket, I switched it for a .030 from cometic. Check out my earlier post "97 build" I have a link there to pictures of the build in case you would like to see it installed.
 

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You would definitly need compression releases or run easy start cams like I did. Before I installed the cams it was really, really hard on my starter, now it's no problem at all.
 

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Based on my recent experience with the S&S 106 kit....STAY AWAY from it!I removed my heads on my recent build to mill the heads for more compression and the cylinders were both scored where the skirts ride.Not just streaks,but smeared and the cross hatch in those areas were wiped out.

In my case,going with CP 3.938 in. pistons and using the S&S cylinders.I like the S&S cylinder because they are designed to use a 3.938 piston for replacement.However the pistons that are supplied with the kit are junk.I'm pretty sure they are Wiseco pistons.
 

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put in you budget ...a dyno tune
 

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When I pulled mine apart after 500 miles it looked perfect, I also run amsoil and changed the oil at install and at 50 miles, and then at 500 when I did the cams and heads. I also followed the break in instructions for the first 500 miles. Now I ride it like I stole it from an a**hole :)
 

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Discussion Starter #10
any recommendation on pistons, and shops in the corpus christi area? how are easystart cams different from other cams? I need to find a good bike shop, but im not willing to trust my baby to just anyone. :( I really dont want to trailor the bike anywhere so it'd have to be somewhere in the corpus christi area
 

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My 2 cents...I am with the guys that say bore your own cylinders and used cast 3.875 flat top cast pistons. This will give you a solid, proven reliable 103". The good things about going to a 103 are: You get almost the same power as a 106", but you get it cheaper and you have the option to later hone your cylinder and run an over sized piston...once you get some miles on the bike (sort of looking out for the future). The "same power" quote comes from S&S themselves...and when you think about it...we are talking 3 cubic inches.... If you have the same compression ratio...the difference will be 2 hp maybe. The only real reason to get the 106....is bragging rights. "O...you have the new 2012 103? Well I have a 106!" Don't let your ego get the best of your wallet. Especially when you can build a 103" to be faster when you saved the money on the kit.

If you want EZ starts...I'm not going to try to sell you on them cause S&S ain't given me a kick-back...but I'm about to buy some for myself so that might point to where I stand. The cam is held slightly open when pressure is building by a moving lobe on the closed side of the cam. When you engine starts the lobe moves out of the way and your engine runs normally. Some people are worried the design could break and cause issues, but I have heard of ZERO instances of this happening.
 

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When I pulled mine apart after 500 miles it looked perfect, I also run amsoil and changed the oil at install and at 50 miles, and then at 500 when I did the cams and heads. I also followed the break in instructions for the first 500 miles. Now I ride it like I stole it from an a**hole :)
Your signature says 97 in.

So which is it,106 or 97?

Big difference between the two.
 

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Discussion Starter #13
ok, what about piston brands? Ive got choice between wiseco and kb from dennis kirk. Any other recommendations? wiseco 3.875 9.1 and 10.5:1 forged and kb 9.5-10.5:1

I wonder what the performance diff is between 9.5 and 10.5:1 is? I might not have trouble if the compression's only bumped up by that much, but higher compression will have more bang?
 

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Your signature says 97 in.

So which is it,106 or 97?

Big difference between the two.
Well...you are correct that he has a 97 when putting those cylinders on an 02 softail. Big difference though? The difference is .375 on the crank.

He started with an 88 that had a stock bore x stroke of 3.75 x 4.00. When harley went to the 96, they only changed the stroke to 4.375 and left bore at 3.75. So if I want to make an 88 a 96, I add 4.375 cranks. Also, a 95 and a 103 have the same bores of 3.875. There are other differences in the engine (IE cam plate, oil pump, oil passages, etc.), but that doesn't pertain to displacement.

So with that said, the cylinders he is running for a 97 would be the same cylinders in a 106. The pistons skirts might be different lengths to avoid contacting the crank on down stroke. Someone with the 97 kit can vouch for the quality of the components as they are pretty damn close if not exactly the same. Of course, anyone that strokes is going to get a bit more power....
 

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I have heard that KB pistons will not hold up good....My buddy builds top fuel drag bikes and says that CP pistons are closer to specs than any other piston made. I used a set of SE 103's in my build. The CP pistons are high..about 300.00 a set..I picked my pistons for 100.00 new...Someone decided not to use them...
 

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Well...you are correct that he has a 97 when putting those cylinders on an 02 softail. Big difference though? The difference is .375 on the crank.
Apples and Oranges.
Grab a 97 in. piston and a 106 in. piston in each hand.

Big difference.

To the original poster.
If you are set on more than 103 go with CP or Axtell.
 

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If you are running anything 10:5:1 and lower, I would suggest the Harley Davidson cast flat top pistons. They are cheap, solid, and reliable. I would start looking at those forged pistons if you are going to run over 10.5, NOS, or a turbo kit. If you are going that high, then sure...wiseco, or the others. Wiseco has the time in the business to know what they are doing. Whatever you do/get...be sure to break them in properly. That's my brand suggestion, others I am sure to follow. Harley also makes a slightly domed cast piston if that is how you want to bump up compression, but not as far as 10.5:1. I am on crappy internet here...so I can't look up the whole SE book and get the exact specs.

Another option would be to get the flat tops...and have the heads cced and milled. That will cost less that $100 and can get you to the exact compression ratio you want. You could also have them ported while they are away....saving the money on the cylinders/pistons by going with the HD flat tops and the machined cyliders would make this more possible, but again...that is if it is in budget.

Note, increasing your bore has already increased your compression. It would be a good idea to cc the heads and see where you are at before throwing in random domed piston kits and the likes. You might already be over 9.5:1 if you bore to 103. Its hard to tell without doing the math. There's a good bit to think about when you are increasing compression. Don't think it through enough and you could find yourself in a rough spot. Just a warning, not a deterrence to building your bike.

I still say HD flat tops, cam (S&S, andrews, HD), find your compression ratio, and refuel it right.

Steel

Edit: Then there you go. The pistons are different in length so one doesn't meet the crank. Must say I don't have a bunch of S&S piston kits laying around to look at so I haven't had the opportunity to compare the pistons. This goes the same for 95s and 103s though, for the same reason. Still should hold valid the comment about the quality of the parts...unless S&S jacked up their larger stroke pistons and they are eating cylinders. So what if dyna put 4.375 cranks in his 02? He would probably just have to swap to the other piston because of the skirt. Then he would have the 106 kit. Or no?
 

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Discussion Starter #18
k, flat tops sound good. I'll check prices on the SE stuff. what about a cam for midrange power on a 103?
 

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Apples and Oranges.
Grab a 97 in. piston and a 106 in. piston in each hand.

Big difference.

To the original poster.
If you are set on more than 103 go with CP or Axtell.
if you call axtell they just use a je piston so just call je
 
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