Anyone ever bored factory cases to accept the Axtell 3.812" cylinders? Did it hold up?

 

Depends on the year cases , they get real thin in a few areas gutting that big , base surfaces will leak . Earlier cases till after 78 or later are fatigued at the age they are now if they don't crack which most did I saw the left bearing boss will loosen up in the casting on you , that's what got my 72 OEM's finally . later had more meat and better castings so your odds are better but that still a lot to take out .

Take a base gasket and cut it to size and take a hard look at what comes off and remember you have cut the side wall too for the cyl. spigot to clear . Been a while since I saw one of those running .

 

I have to assume by wanting to put the Axtels in your cases, you are wanting to hop up the motor. If you are going to go through and spend all of that money, spend a little more for some cases that will handle the power, and internal pressures a performance motor will dish out. By the way, what motor are you going to modify? Pan, Shov or Evo?

 

we`ve bored many shovels & evo`s for 3.812 cylinders,just about all years.bored properly,you wont have a problem

 

Thanks for the feedback, guys. Much appreciated. My Evo has already been bored for 3.625 cylinders, on my Bridgeport without the benefit of a case holding fixture. Won't do that again. They came out perfect, but if I valued the setup time at $10 an hour, I could have paid Kirby to do it 10 times over...
I've been running them that way for almost 3 years, with 10.2-1 compression pistons, actual ratio is probably higher due to carbon buildup by now. It dynoed at 107/112 a couple of weeks ago, after getting a long-time carb issue fixed that had been keeping the engine running rich regardless of jet changes, combined with jetting instructions from one of the S&S tech guys who told me I needed to stay withing the range of the factory supplied jets that came with the kit. NOT!
My '76 Shovel is what I've been considering the 3.812 cylinders for. A friend has a slightly used S&S 4.75 flywheel assembly available, and the combination would yield around 108 ci. It sounds like fun.
I'm not going to mess with the Pan, other than a little massaging to maximize the performance of the near-stock configuration.

 

Kirby, whatcha think of joey's 6.21@256?

 

You three guys have, in the short time I've been on this forum, struck me as among the most knowledgeable here. Any of you care to make an educated guess as to what my Evo should be capable of doing in the quarter mile, assuming an experienced rider, and getting the tire to lock up while keeping the front end controllably down? Empty weight is close to 700 lbs.
HP/Tq is 107@5500 (tapers slowly to the rev limiter @6300)/112@4450, stock gearing, (3.17-1 IIRC) a 150/80/16 Avon Venom tire, good clutch.
I found an E.T. calculator online for cars, that uses Crank HP and total weight to calculate E.T. I added 15% to the rear wheel HP, and my weight plus gas and fluids, and it came up with 11.99 ET. Seems to me it should do a little better than that, but I don't have any track time with a bike.
What do you think?

 

I'll leave that one to Alcherry he has grade on me for track machines and I'll bow to the smarter heads there . I'm about daily riders , reliability , and the occasional real healthy street machine for the average guy without a boat load of money .

Losing a front wheel on a drag bike and walking away , well limped anyway cured my urge in a very short career a long time ago I don't even watch them anymore .

 

Ouch! How the heck did that happen?

 

Ether the axle broke or the front bearing exploded we never figure it out there wasn't a whole left of the bike after doing enders like she did . I had an guardian angle that day , far as memory lets me what happened was the wheel just exploded and the legs made contact flipping the bike *** over . I went from face down head first to on my back feet first , the bike flew over me it bounced one way me the other and did the hockey puc slide for a bit while it flew apart with each hit . Best I can tell if was just fast and hurt , I do remember chin on the chest looking between my feet sliding had no helmet scratches at all .

That probably has saved life numerous times since , I got training and all types not just the average stuff like how come off one at speed , riding through an obstacle or over things that would put a bike down like dogs and car mufflers laying in the road ect . and care of my machines and riding habits got WAY better once I got back on one .