My 1990Glide currently has the original standard crankcases, but is fitted with JIMS 89 cubic inch stroker kit. It also has a Crane cam, high comp KB pistons, etc. and is really very nice!

But this website has got me itching for a bit more! There are big bore kits which seem to be restricted to 1995 or later standard engines and I know the conventional wisdom is to buy after market cases to go bigger, but what experience do HD Forums experts have?

Is it feasible to rebore these older cases and fit bigger cylinders? Or does the engine become an instantgrenade? The cost of a pair of cylinders and pistons, plus a bit of machining, is very tempting!

What experience is there out there?

 

I can't remember the company, but there are cylinders that you can go to 97 inches but you do have to bor the cases.G&W Cycle in NC did my machine work on my Evo and he has done several big inch motors like this. Tried to talk me into it but I just didn't have the funds at the time. Wish I had done it anyway.

 

I'm curious, have you done any head work ? What carb do you have ? Have you put it on a dyno ? Wood Performance has a great page with different Evo engine configurations and real dyno numbers and sheets posted. They might helpful making a decision.

http://www.woodcarbs.com/dynoruns.htm

 

Hi jb,

Thanks for the tip. You are quite right about 97 inch barrels, so far I have found JIMS and Axtell do kits for stroked Evos, which give a juicy 106 cu in. That is more than I reckoned on getting! NRHS is an Axtell dealer and does not recommend using their this kit with pre-1995 engines, but JIMS specify their kit as being OK. I'll carry on looking.

Hi rizzo,

Thanks for your help, I'll go and take a look atWoods' website.

The man who built my motor was an English drag racer who has retired since, which is unfortunate, otherwise I would just phone him for advice. Yes the heads are gas-flowed, but no I haven't had it dyno-ed. It originally had an Edelbrock carb, which a local Harley mechanic demonstrated was not man enough, so I fitted a Holley twin-choke. I have recently had another mechanic demonstrate that one is way too much, so it will shortly get a Mikuni HSR42 (just received it!).

 

Message deleted!

 

Pre '95 cases have a tendency to crack when they are bored out for the 3 5/8" cylinders. That being said you might want to look into a ste of after-market cases.

 

John,

I had heard they can give problems, but those stories can become magnified over time and in the retelling. I was hoping someone who has actually bored out an early Evo might call by and tell it how it actually is!

The 106 inch kits I have looked at are actually 3 13/16" (3.812") which is larger than I expected when I started this enquiry.

 

Harley replaced a lot of cases in those days with thiers or any brand you wanted,aluminium quality control wasnt to good.Head-barrel studs pulled out of the cases,boring out the cases and high compression pistons caused cases to crack,but you could get the phone number for customer service,give em your vin and find out if yours were replaced.If so your good.

 

I have an 86 case at 96 inches by S&S - I ride the hell out of her and have no issues yet - but I only have 5K on the top end - don't know how much is on the bottom........Case has been bored - maybe I got lucky.

 

i just replaced the cases in a 1993 that had already been replaced by HD, kept pulling the samd stud, really shitty alunimum, if your going to go with a big motor, but a whole motor, that waht if or when it blows, you have a back up motor, that what i had to do with my '93 flhs ultima motors have been very good, and i've used many sets of their cases and have had no problems