The Zippers 128 kit is a complete engine kit with performance heads, cylinders, pistons, cam etc, all matched. When I did my 128, I kept my thundermax, exhaust, S&S oil pump and cam plate, and changed everything else.

I my opinion, if you want to do the 128 big bore, I would skip the 468 cam install. You would be paying for labor twice to take out the cam chest, pushrods etc and need new mapping as well.

i found Zippers tech support to be very friendly and helpful. You could contact them and see what they would recommend.

 

Yes, you may be right. You know how it is though.. I'm itching to get something done now. Maybe better to get the exhaust and breather and tuner and leave the cam for the 128" kit. Certainly save a bit of cash. If the 468 kit has to be stripped out and replaced for the 128", camming it now as a stop-gap doesn't make sense, I agree. But I would like to buy and fit now a breather and exhaust system that will also serve for the 128" kit. I've messaged Sawicki to ask them if their M8 mid-length system will cover me for the big bore but haven't heard back from them as yet.

Fuelmoto say the Riot pipe will work for both the 117 and up to and beyond 128. I like the Riot but I also like the latest Sawickis for the up-swept look and the ground clearance. But I thought the headers at 1,7/8 to 2" seemed a bit on the narrow side for the 128". Maybe I'm wrong. I'm sure Blockhead tested a mid-length Sawicki very successfully on one of their big bore bikes but I can't find the video.

 

Check this out

 

I would suggest doing the cam now and see if you really want a 128". These M8 respond so well to cam/pipe/tune upgrades it might be enough for you. I just put in a CR480MT, FM Riot, FM cast intake manifold and 5.5 injectors. Powervision from Fuel Moto tuned it. I'm thrilled with the performance. The thing is a monster in the mid range, which is where the bulk of riding is done.

While a 128" is going to deliver more power everywhere, it could come with some PMS as well. Heat, vibration etc often go along with larger CI builds. Just something to think about.

Zach

 

How much power are you trying to make? My buddy has a 2017 cvo ultra that he just had done. He bought it with 9,000 miles on it and the 114 was smoking on decel. Rust in the cylinders, probably bad storage. So our builder bored it to 117, put a rocket 474 cam, a Cobra 2 into 1 exhaust, An S&S 55mm intake on it, With stock heads it's making 132HP. and !42TQ. When he gets on it hard even 2 up it will smoke the tire.

 

Both good points. I've not got any specific target in mind for power figures. Just trying to get best bang for my buck. I am more interested in big toque than top-end bhp.
Even when tuning my Ducati, which essentially now has the spec of a 1098 race bike, I focused on the mid-range because it's a bike that would be ridden on the road, not the track, and the mid-range is where you spend most of your when road riding.
I remember a friend boasting how his S1000RR had 200 bhp whereas my Ducati "only" made 180. But I pointed out his 200 bhp came in at 14,000 rpm with the throttle against the stop. Where he was actually riding most of the time he would have had substantially less power and torque available under his right hand than I did. Which is why he couldn't overhaul me out of the bends and resorted to head-down straight-lining to overtake. Personally, I never ride any bike like that. It's response and instant punch I'm after, not what it can do when maxed out.

Obviously a Harley is a very different beast to a screaming metric sports bike but the principle is the same. When I look at the dyno charts for tuned bikes, whether it's Harleys or anything else, I tend to look at the shape and timing of the curves more than the headline figures. What I definitely want to avoid is torque dips and flat spots because these will be more noticeable on a big slow revving engine. That's why I'm inclined towards the Redshift 468 cam with the stock engine as it's been profiled specifically to work with the stock heads.

I'm maybe getting carried away because much of the kit I buy will have to be imported direct from the US, so the temptation is when paying all that shipping and import duty to just throw the Kitchen sink at it in one go.

Maybe I should just go for the cam, pipe and breather at this stage (sorry to use that word). If so I need to settle in my mind what other cam chest, transmission and primary side upgrades I need to make as well. If any.
I'll send an email to Red Shift and Fuel Moto and see what they say. But if I do decide to go further at a later date, while I accept that I'd have to change the cam it would be annoying if I had to ditch the pipe and breather as well as that's money down the drain.

 

I think you will be really impressed with just a cam, pipe, breather upgrade. On my recent upgrade I do feel like the clutch is slipping. I ordered a Trask Power Plate that should be here any day. That should be all that is needed. I have not seen or felt a need for the Trask trans breather on my bike. I think it's a great option for those bikes that need the additional venting.

Zach

 

I think you're right. Rob from Fuelmoto got back to me today. Great info. As I tend to shift quite often around 4000 - 4500 rpm rather than habitually below 3500, he recommended the Woods 22XD rather than the XE. Only thing he added to my list was tappet cuffs and a compensator ramp. I've queried and await his response on throttle body and manifold size. I want to get rid of the stock plastic items and I don't mind spending on a larger manifold and body to accommodate future upgrades if it isn't detrimental to performance with the stock 117 top-end I'll be running in the meantime. And I've asked whether I need 5.5 injectors. Otherwise he gave me the big thumbs-up to my choices and said crack on - and no necessity for the crankcase breather or any further cam chest upgrades. His input has thinned out a lot of dead wood in my thinking which is just what I was after. And saved me diving into unnecessary expense. Fuelmoto gets my business for their customer service.

I'm getting a Thundermax auto tuner. It's expensive but it will future-proof me against further upgrades as custom mapping for Harleys isn't that easy to come by in the UK and Fuelmoto can support me with down-loadable software and get me going safely with a solid base map.
I will keep a weather eye on the clutch performance but that will be easy to remedy if it becomes necessary.
Looks like a plan is coming together. Bring it on.

 

One comment about the tappet cuffs. The stock plastic ones aren't known to break. What is known to break is the bolt holding the tappet cuffs when removing it. If that bolt breaks you are going to have a really bad day. That's the only reason I haven't installed the S&S cuffs. Not willing to chance it for something that isn't known to fail. My Harley dealer has had several break when I asked them about it. JMO

 

So I guess I will add my two cents to this conversation. First, before you decide on a cam, watch the video link below. I think you might get some additional information that will help you make a better decision. The cam testing is toward the end of the video. There's good info on doing a cam change in the first part.


Now, just to be clear, I own a 22 FXLRS with the 117" motor, but I have not even had a chance to ride it yet. That doesn't mean that I haven't looked at what I might want to do to enhance the performance of this bike.
First, my cam choice is the CR483. Two reasons. 1, it did really well in the video above. 2, I already have one which I loaned to FM for their 114" cam testing last year.
This may be a better choice for you also. It is available from FM.
You have said that you want to use the Thundermax tuner. I'm sure they are ok, but they use outdated Alph N technology. As far as I know you will lose the anti-knock function by going to this tuner. It is also much more expensive than the TTS or Powervision. If you are using Fuelmoto you will be able to get good support for the Powervision through them.
You are talking about going with the S&S lifter cuffs. The automotive industry has been using the plastic cuffs for years without a problem. I have actually seen at least one article that said unless you were using a really high lift cam, the aluminum cuffs weren't as good.
As for going to a 128" motor, how much power do you want. I know you ride sport bikes, so you might want more than I do. The stock 117" motor is 10.2:1 compression. Just changing to a .030 head gasket will change this to 10.49:1, or the same as the 114". If you CC the heads to 86 cc's you will get an additional .2 bump to 10.7:1. This should enhance the performance of the stock engine. I would say torque to the north of 140 ft/lbs. is achievable with hp in the 125 area with much $$$ saved. Larger injectors is probably advisable, but a larger throttle body is not necessary, although the aluminum manifold would be a good addition.
Two other things I highly recommend.
The Rekluse Torq-Drive clutch. It has four additional plates that give you much more hold without the higher spring pressures. You can get quite a bit stronger than stock with much lower spring pressure which results in a light clutch pull, much like your sport bikes.
Then an aftermarket compensator ramp. This is available to you locally through TTS in England.
There, you have my two cents. Good luck with your upgrade.