Hey guys. I'm wondering what the differences are between the stock 96 and the stock 103. I have an opportunity to pick up some 103 cylinders and pistons and am wondering if I can just bolt them in and go. Can I use the same pushrods and cams? Is there a difference in the heads of these two engines? I have a PCIII so remapping should be easy. Thanks ahead of time for responses!

Shrink

 

96" 3.750" bore 103" 3.875" bore , same stroke. Factory 103"s have automatic compression releases so there are acr holes in the factory 103" heads but everything else is the same, cams are the same.

 

I would put some Cometic .030" head gaskets in to raise the compression a tad more. This will help you with cam performance later on....oh heck, just throw some in while your'e at it.

 

have the cylinders torque plated & checked.personally,ide get a set of pistons (or at least new rings with the used pistons) & have your cylinders bored.

 

It sounds like the 96 heads may make for some difficult starting if I put in the larger cylinders? Can this be mediated with a different battery, like the lithium Shoria? How hard is it to add compression releases to my heads?

I'm trying to keep my cost low and still get some good bang for my buck. I was thinking of Andrews TW48 cams, the big bore kit, and a .030 gasket. If I went with this setup, could I keep the stock push rods? Would the thinner gasket make much difference with regards to performance and starting?

The last harley I had was about 10 years ago. I went with a similar setup... 88 to 95 with a thinner gasket and SE203 cams, with an HSR42 carb. Loved that low end, and it ran flawlessly, all for around $500. I'm trying to something similar this time around.

 

I know you are trying to save money but if you are going through the effort of swapping cylinders I would just skip buying the 103s and just take yours in and have them bored to a 107", with new pistons and rings. While your there, have your heads drilled for manual compression releases. If you go this route I would pick out some other cams than the 48s because now you have compression and cu ins to run some stronger cams that will pay off in higher hp/tq. Plenty to chose from, Andrews 57s or 54s, Wood 555, etc.

Probably could do this for about $1000 doing the install yourself. Hate to suggest something that goes above your target but Kirby has already recommended taking the 103s in to a shop to get checked out with a minimum of new rings so....just think you might want to get the best bang for you buck.

Let us know what you decide, always interested in how things go on a build.

 

If money is tight, just put a set of cams and be done with it.

 

That $1000 107 upgrade is the best value you will find. not trying to spend your cash but you definitely will not be disappointed. Probably the best upgrade out there.................you can wrench, can't you......