New cases preparation

[mikie]

I've decided to go with the new cases, as my original ones are covered with bubbles. In fact, it seems to be spreading to the transmission cover as well, so they're looking for authorization to do that too. This will happen in February. My question: While the engine's apart, as Al previously stated, this'd be the time to consider some modifications. I don't want to spend a lot of money on this, as if I wanted a rocket ship I would've kept my 929 or bought something other than the LeMans. However, I would like to have opinions on "sensible" mods that would be noticeable and fit a modest budget. Also, what would engine mods do to the warranty?

[al_roethlisberger]

1) Engine modifications of any significance(any we'd discuss in regard to the engine being apart) will void the warrantee on your engine technically. Depending on the dealer, they may choose to overlook the modifications and just not mention them to MGNA if anything were to happen, but technically...... technically ........

 

My warrantee is up in May, so that's only 4 months after my case replacement, so personally I'm not too worried about it.

 

2) Recommendations? Well the easiest engine modifications would be drop in pistons like Mike Rich's or FBF's(~$300), and a cam(~$350). I would recommend the the Megacycle 620x9 cam as that requires no head/valve modification. If you do anything else like new connecting rods or a wilder cam, you're looking at valve work and engine rebalancing. I think these two would give you the most bang for your buck, where other mods will start to offer diminishing returns.

 

Good luck. I've got some minor blemishes on my transmission as well, but it is where the headers run close. Now that I have the headers Jet-Hot coated, the temperatures should be much less, and hopefully the paint won't deteriorate further. We'll see

 

al

[Guest friz]

hey al, who is doing your cases??? i live in no ca . my dad has a 2002 lemans i have a scura both are bubbling thx friz

[al_roethlisberger]

My dealer... Moto Italiano in San Mateo, CA is supposed to have me on the schedule for February.

 

They are supposedly bringing their old tech "Sean" up from SoCal for the work, and he's supposed to be some whiz, and is well recommended. I have not had a confirmation on dates or anything though yet

 

al

[mikie]

My usual disclaimer: I'm not very mechanically oriented.

Now if I go with the FBF pistons, what kind of compression can I expect, and will this exacerbate the pinging that occasionally occurs under full throttle?

And if I put in a cam as well, what will the effect be? Would it provide more power on top but rougher performance down low?

[Guest russ]

The first (and maybe only) mod I would make is a balance job of the reciprocating mass and a lightening of the flywheel. You could bump the compression and change the cam but the bike is not designed to run like a track bike, so IMHO limited results will be achieved. I think the Lemans is best as a Sport Tourer,too heavy to compete and the extra power would likely be top end oriented which would be limited in the realworld, but what do I know.....

 

BTW, Jaap what is this ????????????

[al_roethlisberger]

Oh geez, well if you put it that way, that's a simple answer... it depends, and it depends

 

 

...sorry couldn't resist.

 

 

Well, truthfully, and unfortunately... it does "depend", and it "depends" on a lot of things such as:

 

1) How susceptable your bike was to detonation before(because the combustion chambers can vary a bit)

 

2) What cam you choose, as they all have different sweet-spots depending on grind/specs

 

3) Tuning, other aftermarket mods, etc.....

 

 

But, as far as dropping in the FBF pistons, here is what I know simply based upon some conversations with others and Mike Rich.

 

- Although advertised at 11:1 compression, it's unlikely you'll really have anything close to that. MG rates the bikes currently at around 9:1 I believe, and that's optimistic given MG's wildly variable combustion chamber manufacturing tolerances. Mike Rich considers 10.5:1 about the max one would really want to run on the street, and considers 10:1 more reasonable. He guesses that the FBF pistons are really closer to 10 or 10.25:1 in practice?? I have no objective data on that though, and it would vary a bit by bike. But a slightly lower CR than 11:1 is a good thing if so

 

- ....because, it'll probably be more real-world rideable, and less likely to detonate. In fact, I haven't heard of anyone who's used the FBF kit having any detonation problems. So that's also a good thing Although I've only heard from people so far during the cooler part of the year, I assume many of them have had the pistons since the Summer, so However, you do increase the chance of detonation by increasing the CR, so it may be something you'll have to deal with. You can ameliorate it to some degree by increasing octane(using premium gas), stepping down to a cooler plug, running a bit more rich, etc...

 

If you're bike is pinging now under full throttle, yes... in general.... dropping in the FBF or similar higher CR pistons could and probably will make detonation more likely. BUT, as mentioned above, if your bike is pinging now, it may just be an issue of tuning the bike appropriately to quench the problem, and you may be able to run the higher CR pistons just fine. It's really going to depend on the bike and how many "hot spots" your combustion chamber has.... only a head guy like Mike can really tell and clean it up if so, if possible.

 

After I got the PCIII tuned correctly, my valves set right, I haven't had hardly any pinging even under hard acceleration.... and I always run premium gas

 

- In regard to the cam... now this really DOES "depend".... the 620x9 is still a mild cam, but should boost the low and midrange, where we all generally really ride in teh real-world. I don't know if it does much for the high end. Perhaps someone with this cam can chime-in.

 

 

Well, hope that helps a bit. Most of my info is anecdotally gleaned from other's experiences here..... but maybe some others with experience first-hand can add their perspective.

 

al

[gthyni]

The first (and maybe only) mod I would make is a balance job of the reciprocating mass and a lightening of the flywheel.  You could bump the compression and change the cam but the bike is not designed to run like a track bike, so IMHO limited results will be achieved.  I think the Lemans is best as a Sport Tourer,too heavy to compete and the extra power would likely be top end oriented which would be limited in the realworld, but what do I know.....

The voice of reason

how boring

 

Balancing/blueprinting with new pistons is a very good idea,

and you can always use a little extra power.

My opinion is that more power than we have at low/mid ranges

is not useful. I want it to move when I snap to throttle open

not just on the race track. Power is always usable and for sport riding

you want more peak power.

 

About pinging,

yes with higher compression it would likely ping more easily,

in Sweden we have 98 octane of good quality which is good

enough for most application. If you can't get hi-grade petrol

you perhaps need to lower the ignition to avoid pinging.

[Admin Jaap]

BTW, Jaap what is this ????????????

Check out this thread

[al_roethlisberger]

BTW, just got a call from Moto Italiano, and my work has been "pushed out" until later in Feb sometime it seems <_>

 

Apparently MGNA is doling out the parts as they get them.

 

 

Oh, and apparently what with this recall, and trans and con-rod recall as well, Moto Italiano said they are looking at about 30 bikes that have to have their engines pulled this Winter/Spring Sheesh... that's a lot of work.

 

al