My question is,.
What is required to turn a 80ci into a 88ci?
Is it just pistons and jugs or do you have to go to a different connecting rod?
I know I need to change the cam and all them goodies but I am curious if I can do a swap with the pistons and jugs.

"94 FLSTC" 45k on the clock

 

If you are referring to the newer 88ci Harley Twin Cam cylinders, you would need to change the motorcycle. They don't fit the EVO bottom end. The Harley 88 is a completely different motor. Harley did make a 85ci kit for the EVO but discontinued it. They did not make a 88ci kit for the EVO motors.


Now there are after market 88ci and larger kits that will change the displacement of an EVO 80 displacement depending on how much you want to spend. Those usually require machine work to the cases.

Now there are kits that raise the displacement of the EVO to 85ci that are just a "Bolt On" kit and require no machine work. They usually run around $1000. And that is just for the parts, not including labor.


Does that answer your question?

 

Yes it did thank you.
Yea I knew I couldn't do the TC88.
Last summer I went with a 103 kit for my 96ci and very surprised with the ease of the whole process considering I have never done one.
So it got me thinking of doing one for my wifes Heritage evo engine and I had no ideal if they had a conversion kit. She will just have to settle for ev27 cam, which to be honest will probably be enough of a difference to put a smile on her face
Once again thanks for the reply, without alot of you guys us novice wanna be mechanics would be lost.

 

J&P has the kit here.

 

S & S makes a stroker kit to make it 89 CID. Bolts in, no machine work necessary.


http://www.sscycle.com/product/Evolu...it-p23325.html

 

This is a made to order kit. You will need to "Call for Pricing". And it does require spliting the case to change the flywheel assembly. Simple machine work is required for crankcase clearance operation and normal piston fitting. From the pictures, it replaces heads too. It is not just replace cylinders and pistons.

 

The Evo as a stock engine was not easily changed in size, in the same way as the later TCs are. They were made in far smaller numbers, with production increasing from around 50k bikes a year in the early 90s to around 350k bikes a few years ago. Changing capacity of the Evos became more popular during their later production and it seems Harley recognised this as a marketting tool when designing the Twincam. That is why it is easy to increase TC size, but they also have a lot more metal in vital places that makes them easy to enlarge even further than factory sizes.

The 85" Evo conversion is little more than going to the largest oversize bore, but a few more ci can be squeezed out of them by maching the crankcase mouths and using aftermarket cylinders. The 89" stroker kit was also popular for a while and I have a JIMS kit in mine. Using maximum cylinder size and a stroker crank it used to be possible to get up to 107" from an Evo, but to get a reliable motor that was only practical by using a lot of aftermarket parts, almost a new engine!

These days there are several brands of Evo engines from 96" up to 155" and beyond! Not for the feint hearted......

 

I was surprised as well that you can't just punch out an Evo like you can a Twinkie. For me the answer is pretty simple. Dump four grand on a 107 inch motor. Bolt it in, upgrade your clutch and put on a bigger carb. Done.

http://www.ebay.com/itm/HARLEY-ENGIN...sories&vxp=mtr


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I've thought about the Axtell 85" kit, but can't seem to decide either... Looks like a project for next year.

 

Yea, I'm on the fence also but I really need to go inside it anyway and change the base gasket(leaking) and I'm going to a ev27 cam. I'm that deep into it, I might as well do the kit but I just wonder how much of a gain I will see or feel going with a 85" conversion kit?