I gotta ask this question. I'm not really up on the differnce between acheiving this piston compression compared to the simple stock build compression acheived, I'm just your average ride as much as possible guy. Been riding for 30 years and built many old brit motors upto new as well as my old 76 iron head motor back to new specs ( simple oversize pistons and new valve train ). So enough about past experience, I'm planning on giving my 89 FLHTP what ever is needed to make the motor to a fresher condition so when I get on it for a long haul I know I did my best. In my local area I know of one supposely competent machist but I also hear of a few that are suppose to do very good work, because I really don't understand the upping the compression factor I also don't understand the purpose of sending cylinders and heads out of town to get work done. Here in Ontario postal fees are outragous which also comes into play as to whether I get work done here or send it to someone that is more of a performance shop. So what are the pros and cons? Is the outcome going to be that noticeable for an average rider?

 

The biggest thing is getting someone who has the torque plates and knows how to use them. The design of the EVO prevents the average automotive machine shop from correctly boring and then honing the barrels. Then, some guys are just more meticulous than others and the longevity shows this. I've sold my boring bar, hone and valve and seat machines as they took up too much space for a s little as I was using them. (I'm no longer racing or building motors.) Most anyone can bore a cylinder, but few can bore, hone and fit everything well. I've got a shop locally that does better work than I was capable of so he is where I have things done. You just need to find a good guy local to you.

 

Winter is a good time to get engine work done, when tuning shops and dealers would like work to keep them busy during the low riding months. Also some of them will charge lower hourly rates, even offer special tuning package deals.

There are also a few specialist tuning shops here on HDF worth considering. It may seem odd to post stuff to them, but you can get far more for your bucks from them than many places. They can give you serious improvements in performance, even on an Evo.

 

Be careful when you design a better motor! With high compression comes an engine thats picky on it`s fuel just for starters. If you work the heads a lil to help them breath & focus on the right combination of carb, cam & exhaust, you will have a powerful good running engine!

 

the higher the compression the more power. thats what the cars had in the old days, high compression, but then the gas was a lot higher octane and contained lead. friend of mine had his top end done and went with 10/1 compression and it pings in the summer. it not really worth the problems upping the compression. id think a good 9 to 1 would be enough and you could buy gas any where with out worrying about detonation.

 

I'm kind of in a pickle here, recession has basicly depleted excess funds cutting the ability to make big money choices. This is how it is basicly the only problem I can see with the bike is a leaking base gasket, with compression even at 140# and aftr adding new HD lifters , easy install pushrods and a HQ cam last year I was quite happy with performance, after all I'm just an average hiway rider not looking for hi performance. This week I'm going to invest in a heater for the garage and pull the motor and do an inspection of cylinders and heads , for the heads could I not just check for play in the guides and any bent valves and perhaps I'm hoping the motor needs only minor work reringing the pistons or at very least if cylinders check out ok deglazing? I already have a James motor kit. And while top end is off check crank for runout and any obvious signs of wear?

 

Compression at 140 isn't bad. I assume you checked it cold and not having been run for at least a day or so? How many miles or Km does it have?

You're in Canada and I don't know how you're fixed for auto machine shops or how they charge but if you were here, I'd say just pull the top end, scuff hone the cylinders if there's no deep grooves, have an automotive machine shop do a basic valve job, install the new valve seals that you already have, new rings and you'd be good to go for another 50 -60,000 miles. That will take care of your base gasket leak, get the compression back up around 150 after the new rings seat and valves will be good to go. You'd be back to great specs for about another 75.00 if you go that route

 

These were kinda the same thoughts I also had, just to make sure I'm going to do another compression test cold with throttle wide open before taking top end off. Not sure on how many k's on the motor as I have no history , thats what you get for buying off a no nothing car salesman. I somehow expect top end isn't stock though.

 

you can leave the engine in frame & pull it down. it's tight but it does come apart without removal. I would lap the valves & re ring it but I dont think your into alot of worn out parts yet! Good fuel delivery, A lil' more aggressive cam & some modest exhaust work will help it breath which will give you a lil' more grunt out of the basement!!!

 

Thanks Wayne, in the old days thats all we would do is lap in the valves and re-ring , its just that past couple years from starting to work on bikes again that I've heard of needing to use torque plates for measuring the cylinders. I did put a HQ cam in the bike last summer and noticed a very satisfying differnce.
Hows the weather out that way anyway?