Anyone ever put Twin Cam rocker boxes on an Evo?

[BigAssSack]

I have an brand new set of Twin Cam rocker boxes complete with the rockers and support plates and everything, and the boxes on my bike now are just nasty. This seems like a feasible project, i think.

I have an 84 Evo that I'm slowly rebuilding, the heads that I'm putting on it are breather heads, but I plan on plugging the breather passages and just running the crankcase breather, so that shouldn't be an issue. I now that Twin Cams and Evos both use the same rockers and shafts, and by just lining the boxes up against each other, the 4 bolt holes that would support the rocker arm support plate on the Twin Cam line up perfectly with the bolt holes on the lower Evo rocker box, so the support plate should line right upend bolt through the box to the head. I think the biggest challenge will just be finding which holes I don't need and plugin them, and finding which ones I do need and drilling them.

Any thoughts?

[BadMonkeyMW]

First off, why?

Secondly, I would look very closely at the clearance you have in your frame, especially where it goes over the rear cylinder. If you're running a stock, or stock type, frame there is no way in hell that TC rocker box will fit in there. They are a good bit taller than an Evo rocker box.

[BigAssSack]

I mainly want to do it to try something different, but also because I need new boxes and I don't want to spend a bunch of money on a new set, especially since I have a new set of TC boxes handy.

Also, in my experience, Evo boxes have a tendency to warp and leak, and I'm not a fan of the extra gasket and center section, I like how the TC design did away with that, one less joint to worry about leaking, and less chance for warpage and such.

But I pretty much just want to challenge myself and make something work that probably shouldn't, lol!

[bobscogin]

Keep us posted if you pursue this. I'm interested.

Bob

[BigAssSack]

I'm definitly gonna move forward with it, just curious if anyone had seen it done successfully before. I have the lowers for both sets of boxes here, but I have my cylinder heads all blasted and cleaned and taped up so I can hopefully powder coat them tomorrow, makes it kind of hard to compare and contrast. I'll see if I can find a spare head in the meantime to have something to fit everything on, and I'll startgettingsome pictures together.

[BadMonkeyMW]

Good luck, man. Nothing wrong with taking on a challenge for yourself. Post pics of your progress.

[BigAssSack]

Well, my powder coating gun took a shit on me this morning, I had half of the first head covered in powder. Fuck technology. Anyways, I brought everything back home and did a little testing, and I'm pretty pleased with what I found. I think I'm going to start a "Build Thread" just for fitting the TC boxes to the Evo. I'll post pics over there. There are definitely going to be a few small challenges, but this seems like it will be relatively straight forward.

[RODMAN58]

Not tried TC but................

Sporty rocker boxes work just fine.
Rod

[bobscogin]

Sporty rocker boxes work just fine.
Rod

Sportster? He must have a Big Twin since it's an '84, so a change to XL wouldn't get him where he wants to go.

Bob

[bobscogin]

First off, why?

Why ask why on a forum that's dedicated to modifying motorcycles?

Bob

[BigAssSack]

Why ask why on a forum that's dedicated to modifying motorcycles?

Bob

Also, on a totally related side note, I found that TC boxes are in fact significantly short than Evo boxes:



Now, there are no gaskets, and the evo box is missing the center, but I'd say that assembled and torqued, the Evo setup it at least 1/8" taller, if not more.

[BadMonkeyMW]

Why ask why on a forum that's dedicated to modifying motorcycles?

Bob

Just because you can, doesn't always mean you should. But hey, go nuts! It's not my time being spent.

[Brendden]

Jsut because you can, means you should. People would only be able to tell by the cam cover that it's not a TC

[BigAssSack]

Well, that and the oil pump anyways.

I don't know, I just like to jump into shit I've never seen done before and make it work, I think it'll be kinda cool. The whole bike is really going to be unique in and of itself. It's an '84 FXST, and I've swapped front ends from an '02 Fat Boy and mounted an entire fairing from a '13 FLHX on it, radio and all, as well as mounted hard bags from an '11 Ultra and a solo seat from a '12 FLHP. I have a ton of wiring and some engine work to finish up, but it's certainly going to be one of a kind. I'm going for the Street Glide look, but I wanted it built off an Evo with a 4 speed kicker.

I know it's not really "cool" as far as most of the scene sees it, but it's what I want to make and what I want to ride, it's original, it's comfortable, it has a little storage space, and I can crank my tunes and rock out a little, so fuck it, lol!

[bigxrdoug]

Sorry twink boxes won't work on an evo,we have a big dog at work that runs twin cam tp eng boxes on an s+s mtr and all the chrome had flaked of so the owner got new evo ones and then thats when we found it wouldn't work so old boxes are off being rechromed.