big bore cylinders

[vern]

Hope everyone had a great holiday season and that you all have a happy healthy and prosperous new year.
My build is coming along very well and here is a pic, but I need some info on big bore cylinders, do they all have a wider bolt pattern on the cyl. to case flg. and are the head bolts the same pattern or spacing meaning that the stock heads get machined for the larger fire ring?

[attachment removed after 60 days by system]

[shovelbill]

up to 3 13/16" is the "same"........4" and up is different.....the head will need to be machined larger to fit the bore of your choice.....up to 3 13/16".......hope this helps

[vern]

Thanks Bill. So the Delkron big bore cases I have must use the wider flange spacing at the case but I can use the stock heads with a bit of machining. If I go to buy a set of cylinders that are 3 5/8 will they fit?

[turboprop]

If you are buying Delkron cases, you can purchase them already bored for the 3 5/8" cylinders. The cases for the 3 5/8" cylinders will have the standard oem harley bolt pattern.

[vern]

A friend of mine  already has the Delkron cases and stock cylinders will not work, so before I buy a set of cylinders on ebay for him what should I know?

[Hillside Motorcycle]

Unless they are a set of raised deck cases, for a larger-than-3 13/16" bore cylinder, they will work, as long as they are for Shovel application.
Scott

[prodrag1320]

sounds to me like their EVO cases,thats why the stock cylinders wont line up.

[HotRodShovel]

3 5/8 shovelhead cylinders will fit the stock shovelhead case bolt patterns. The stock heads will have to be machined to accept the bigger jugs as will the case spigot holes. I have never done a larger bore so my experience stops at 3 5/8".  I'm talking stock cases and heads here. Others can fill you in on aftermarket heads etc...

I have pretty much worked out all the bugs on my 96" conversion. The last step ..pipes...Kirby, Prodrag1320 did my machine work. If you are looking for a top notch job there are a couple of highly competent guys here, you know who they are, but I can vouch for Kirby.....

Good luck...

[shovelbill]

Thanks Bill. So the Delkron big bore cases I have must use the wider flange spacing at the case but I can use the stock heads with a bit of machining. If I go to buy a set of cylinders that are 3 5/8 will they fit?

if stock shovel cylinder bolt pattern won't match the studs in the case.......and the bore is for 3 5/8" cylinders then it's probably an evo case as Kirby said.......

i'm not familiar with Delkron's "options", but if it's a case breather setup with the correct bore for your wishes, you can weld up the stud holes and drill/tap for shovel cylinder bolt pattern........i believe ONE stud is the same. if you can do the work yourself...or have it done "cost effectively" it's a good option........but Ultima BB (3 5/8") shovel cases are like $700 to your door.....and they're made in USA also.

the 4" stuff has an offset pinion as well......1/4" i believe, my memory's junk  ..................113" shovel?

i just saw the picture in the first post, don't know why it didn't show up before.......are those the cases you're asking about? what size motor is that?

[turboprop]

All of the shovel and evo cases from Delkron have the hole for case breathing.

[easyricer]

Bill, the motor in the first post is a Twinkie in a Shovel rubber glide frame. That's what we've been discussing in another thread.
EASY

[shovelbill]

thanks easy......i'll go find that other thread.

[vern]

Thanks for all of your imput, as it turns out the cases are Evo and the spigot bore is 3 15/16 by far the worst deal I have ever gotten on Ebay! Live and learn. The pic was of my Twincam into my 82 FLT but that would be a different thread. Any one got any big bore Evo cylinders?

[turboprop]

I have a brand new set of Axtell 3 5/8" ductile iron cylinders, with flat top pistons, rings, gaskets, etc. Send me a pm if you are interested.

[mrshovelhead]

If you want to be a big boy..The price for the Delkron 3.5/8 and the 3.13/16 is the same price about $1,000...the only problem is Axtell 3.13/16 jugs and pistons are about low price of $1,600..and that is as large as you can go on a shovel..but instant power...If I am wrong someone please let me know

[turboprop]

mrshovelhead - Welcome to the forum. $1,600 is about right for a set of ductile cylinders and pistons from Axtell. -Ed