Yes, it's in the Wiseco catalogue ... and, yes, I have access to a big lathe.

I know the principles but not the specifics to fit to an H-D Evo, e.g. how thick/OD these are. ANd it would be good to read of others experiences.

There does not seem to be much meat next to rear cylinder tappet block ont he right hand side.

 

Luke, it ain't going to work! Original Evo cases are not man enough to take boring out in the same way that twincam ones will, there just ain't enough meat around the bores! That is why firms like S&S and Sputhe (plus many more) made such rich pickings making aftermarket cases for Evos, with much thicker castings. The routine way of making an Evo (or shovel) bigger is by stroking it. Been there and done it - that's why I now have an S&S 107" engine.

You're coming at this about 25 years after all the options had been tried, tested and many of them had failed. If you want to enlarge a stock engine then stroke it. If you want to enlarge the bore then use aftermarket crank cases, or change the entire engine. Simples!

 

I can believe that, I have a set of cases in front of me and have measured them up. This is why I am questioning it.

However, Wiseco specifically and only states, "Must use aftermarket engine case on models 1990-1995" for this kit. I wondered if the liners were just very thin. They don't, for example, offer overbore sizes for it.

It could just be the maximum overbore of the 3 3/5" kit (0.115) using the same liners ... perhaps using Sportster pistons and gaskets? I cannot find anywhere they publish the thickness of the sleeve.

I must say, I picked up a minor errors or two in the Wiseco catalogue, e.g. over dome volumes/compression ... is this one or are they right?

I'll try calling them again if no one has any hands on experience.

The catalogue is here if you don't believe me, http://www.wiseco.com/Catalogs/VTwin/EvoBigTwin.pdf

I see piston kits coming up on Ebay very cheap. The only thing anywhere near it in price - if you can bore your own - are Taiwan Ted's 88" kits.

 

It's not a case of the liners being thin, but the crankcases around the cylinders! The Wiseco 85" kit simply uses the max over-size pistons. Bear in mind that an 80" Evo is actually around 82"/83", a .040" oversize rebore gives the extra couple of cubes.

I had my 1990 stock engine rebuilt with a stroker kit to 89", with the aid of Sportster pistons, to give increased CR. However that was done by a top tuner using many years of experience and mixing his own cocktail of proven parts. No way would he bore out stock cases!

 

@ Luke as my post prove is that a Evo motor is a WYSIWYG situation. There no gain in performance in changing the jugs as there nothing that will fit. Basically an 80" will just stay 80". Unless you do an overbore but it more of a waste of money for just a small change in cu inches. As what I was told from everyone on the forum,its better to use the money for a good head job and exhaust.

If you really want more cubic inches its just better to buy a new engine as mention earlier on this thread. Be prepared to shell the money though,those bigger 3rd party Evo engines come with a higher price tag.

(BTW To everyone else this is the reason I ask hypothetical questions cause I do learn something and remember the answer. It does prove more useful than you may think,especially in my research.)

 

Axtell make a "Prostreet" 97ci cylinder kit for Evolution Big Twins and say you can use OEM cases (after '96 at least).

They use replacement cast iron cylinders and they claim 115hp and 120ft ft/lb

OK, I accept an argument in favour of cast iron and perhaps it has thinner sleeves and therefore less machining to cases.

But if you can poke a 97" into the cases, why can't you poke a 93" into them?

Looking for any other sleeves that might fit, I noticed out there in the real world the industry is off to reinforced ceramic sleeves, ceramic coated bores and silicon carbide impregnation. Didn't Porsche use the stuff sprayed directly onto the Al casings?

 

Luke, why do you keep mentioning liners and sleeves? In the case of Harleys and the aftermarket they come integral with the cylinder, nor separately.

 

Primarily because it's a good bit cheaper than buying a set of cylinders. The piston kit is $244.

The topic started with "budget" and, in my case, it's a shame not to use the original castings as they are decked to the right height too.

The get it made in China and just throwaway the originals attitude is terrible.

Wiseco sell them. They must have been designed to work. Someone must have used them. I'll try and speak to them today.

The nearest deal I can find is an 88 ci kit for $550 and it's Wiseco pistons in complete Taiwanese cylinders, machined in the US (V-Twin manufacturing).

 

Here's what I got so far ... Wiseco didn't know nuttin'. But they were kind enough to tell me the sleeves are made by Advanced Sleeve in Ohio (the matching gaskets are Cometic).

True enough, they list the sleeves as fitting, and the OD as 3.950".

The catalogue states, 'Evo Big Twin for 3.625" and 3.740" '84 to '99 (Extensive machining required)'. Price $95.

Now, that's a little smaller than the Axtell and others which, from memory, require the case bored to 4.010" and leave, what, a 210 thou/5mm thick sleeve? That's about the same as stock, isn't it?

 

I measured up the cases and at the thinnest point (rear cylinder by the tappet block) it looks like you would have about 4mm or .150" left after boring.

I'd be more concerned about coming close to the bolt holes in the cylinders but the makers are confident about them.