Hi everyone and thanks in advance for any help.

Ok so here's what's going on. I have a 99 dyna and I purchased a S&S 100ci performance pack with big bore, cams the whole kit. I realized after I started my teardown that I need to have my crank redone or buy a new one. I asked a few different companies about the cost of my options and one company gave me a answer that I was under the impression I couldn't do. This company said that since I was already doing the crank I could put in a stroker crank 4.375" in there and up my CI even more. I was under the impression that with the kit I have already purchased I was unable to use a stroker crank. Do any of you know if this is a true option or if the company is not exactly correct? The pistons with the kit are a 8.75 dome and a 4" bore. Also this company said I could put the stroker crank in without any case modifications. I'm just not wanting to get that and them be wrong and I would have to redo everything over again and be out the cost of that crank. The cost of the stroker isn't any more than the cost of a new crank and if my calculations are correct it would put me at 110 ci and well bigger is better if it would work.

Thanks again.

 

[QUOTE=Viper0463;18843879]Hi everyone and thanks in advance for any help.

Ok so here's what's going on. I have a 99 dyna and I purchased a S&S 100ci performance pack with big bore, cams the whole kit. I realized after I started my teardown that I need to have my crank redone or buy a new one. I asked a few different companies about the cost of my options and one company gave me a answer that I was under the impression I couldn't do. This company said that since I was already doing the crank I could put in a stroker crank 4.375" in there and up my CI even more. I was under the impression that with the kit I have already purchased I was unable to use a stroker crank. Do any of you know if this is a true option or if the company is not exactly correct? The pistons with the kit are a 8.75 dome and a 4" bore. Also this company said I could put the stroker crank in without any case modifications. I'm just not wanting to get that and them be wrong and I would have to redo everything over again and be out the cost of that crank. The cost of the stroker isn't any more than the cost of a new crank and if my calculations are correct it would put me at 110 ci and well bigger is better if it would work.

Thanks again.[

then your getting into a whole new ball of wax. I can't remeber the max allowable stroke without machining but still then your talking about port or new cnc heads, ensuring your piston to valve clearance is safe and machining etc. Also something overlooked alot are the clearances between the oil squirters underneath the Pistons. I have also been looking into that same kit but the thing that worries me is how thin the liners are in the cylinders. If they are just basically punched out from 88" or are they reinforced liners like fuel motos severe duty heads (which I highly recommend). Also with stroker setups I always coat the skirts of the pistons due to the higher speeds and more loading and unloading the skirts will endure

 

[QUOTE=Viper0463;18843879]Hi everyone and thanks in advance for any help.

Ok so here's what's going on. I have a 99 dyna and I purchased a S&S 100ci performance pack with big bore, cams the whole kit. I realized after I started my teardown that I need to have my crank redone or buy a new one. I asked a few different companies about the cost of my options and one company gave me a answer that I was under the impression I couldn't do. This company said that since I was already doing the crank I could put in a stroker crank 4.375" in there and up my CI even more. I was under the impression that with the kit I have already purchased I was unable to use a stroker crank. Do any of you know if this is a true option or if the company is not exactly correct? The pistons with the kit are a 8.75 dome and a 4" bore. Also this company said I could put the stroker crank in without any case modifications. I'm just not wanting to get that and them be wrong and I would have to redo everything over again and be out the cost of that crank. The cost of the stroker isn't any more than the cost of a new crank and if my calculations are correct it would put me at 110 ci and well bigger is better if it would work.

Thanks again.[

then your getting into a whole new ball of wax. I can't remeber the max allowable stroke without machining but still then your talking about port or new cnc heads, ensuring your piston to valve clearance is safe and machining etc. Also something overlooked alot are the clearances between the oil squirters underneath the Pistons. I have also been looking into that same kit but the thing that worries me is how thin the liners are in the cylinders. If they are just basically punched out from 88" or are they reinforced liners like fuel motos severe duty heads (which I highly recommend). Also with stroker setups I always coat the skirts of the pistons due to the higher speeds and more loading and unloading the skirts will endure

 

The pistons in your kit will not work if you increase your stroke, the deck height of these new pistons for the 4" stroke crank will be too tall to use with any crank with a greater stroke than 4". Although you now have the added cost of a crank repair (or replace), the upside in your situation is that this is a perfect time to increase your cubes by installing a stroker. You need to split your crankcase to do the necessary bottom end work in either scenario, this too is the perfect time to bore your crankcase so it can accommodate larger bore jugs (either now or in the future). Sorry to say it's extra $, but I doubt you will be able to get away without this cost now that you have crank issues to deal with as well. Do lots of research and come up with the best combination of components for your style of riding.
Good luck

 

The OP has two options:

1. Replace the 4" crank with a built for purpose trued, balanced and welded crank to use with the S&S 100" kit.
2. Replace the 4" crank with 4.375" crank that has been trued, balance and welded and replace the pistons in the 100" kit with pistons designed to run on the stroked crank. S&S might even swap pistons out given the choice of returning the kit or swapping out pistons.

The 8.75" domed piston would be a concern. The OP must do the math based on cam selection and final borexstroke configuration to make sure compression is manageable.

 

I don't think anyone makes a 4" piston for the 4.375" stroke. 3.938" is the largest I've heard of. More than that and you're going with a case bore to fit the larger pistons. That's why the S&S 100" kit is so popular. You get 100CI without case boring.

Now the question is, do they have an equivalent 4" bore kit for the 4.375" stroke cranks? I don't think so, last I checked.

 

S&s has pistons for that set up, the ones in the 07 and later kit are designed for the 4.375 stroke. Should be easy enough.
m

 

Pretty sure axtell does as well.

 

if thinking of going with a 4.375 crank,your piston/cyl kit wont work (well,cylinders will but not the pistons) if doing so id go 107 & bore your 88" cylinders.you can also bore your cases & go with CVO 110 cylinders bored to 113" (a better way to go than the paper thin "drop in" 110 kits avaliable

 

the 110 drop in kits are a 4" bore as well as CVO 110 pistons (the CVO parts require case boring)