Ducati Monster Forum

Looking to swap out the pistons on my 2003 monster 1000s, what does everyone think of the FBF drop in high compression kit? pros/cons ?

Mike

I've used 1 set of drop-in 94mm hi-comp pistons and had no issues.

I haven't yet fired up the 98mm hi-comp motor but I expect no issues w/them.

Other members have had equal success w/them, I'm just the first to chime in...




(I've also used 4 sets of their 88mm hi-comp pistons in 750's w/o issue.)

+1 on the 750 hi-comps  :) all pro, no con.

well, because of the E10 pump gas, the consensus was to stick to 11:1 pistons, otherwise I'd have gone 12:1

*sigh* oh, the memories...

Just some things to consider

Your bike will run hotter. If you live in a hot area you may need additional cooling capacity
Your bike will require more octane

And you're likely to need stronger pants, as you just might bust a seam after the first twist of the wrist. 

Mine did not come with a 6 pack of burgers, yours did?

Nope. Prunes.

Is this the same tech that led you to believe there was almost no difference in power output between a 750 and an S2R1000?

does your tech live in a cave with a bunch of old mopar parts?

the displacement argument is kind of silly these days

my 2.3l volvo put out 240hp whereas the current model xterra with a 4.0L v6 only puts out 260 hp.

engine design is far more important than mere displacement.  a well designed high-comp 900ss engine with stock compression will smoke a 944 with regular compression.

Really?


Really?

Sure did.  Read right through everyone blowing holes in your argument that there wasn't a significant difference between either the 750, 900 or DS1000.

Anyhow, this is off topic.  Back to the thread at hand...

Did I merge threads?  [evil] [laugh]

 [laugh]

Go for it. If you wanted you could go a big bore kit if you have the $$.

An option is DP cams. The stock cams are mild.
Increasing compression via managing head and base gasket thickness is worth investigating. Its worth checking with your tech if increasing compression through this option is possible.

Depends how much you got to spend. But me, I'd like to up the comp cheaply if possible with the stock pistons and use the money saved towards bigger cams.

All true, however when someone goes the big bore route, usually they will also put in high-comp pistons. After all, since the pistons have to be changed anyway, it makes more sense to get some high-comp ones.

There really is only so much you can do with the original 900 engine though.  Ask Chris at CA. 

+1. You just got to tune your ignition timing and run higher octane.

The DS motor's considerable untapped potential is promising. I 'spose it's the better stock ports and bigger valves. The extra capacity doesn't hurt either. I would like to know if someone has exploited the existence of the head gasket to up the compression a little, maybe get it a bit closer to 11:1. Like putting Yoshi head gaskets in your Gixxer.

What are the DP cams for the DS costing now?

While the small valve area, compromised inlet ports and mile long inlet manifolds on the carbed 900 hurt top end power, the long inlet manifolds give the carbed 900 a certain character in how it makes power. They are a little grunter.

Wait a second. Doesn't the stock DS1000 have a compression ratio of 10:1, so going up to 11:1 high compression pistons isn't going to change much.

Yeah, 10.7 or 10.5 or whatever it really is when measured (anyone measured it?) Bumping it up a bit with thinner gaskets and getting DP cams and some porting would be good. You know, pulling the heads and doing the work there.

The old motor, well thats a different story. Mine has hi comp pistons, porting, dialed cams, FCRs, a nice valve job and only has made 82hp/65 ft/lbs on the later gen dynojet dyno on it's best day. :P.

Yeah, but would you really go that far and NOT invest in hi-comp pistons?!?

I'm just skeptical of FBF's claim of a 7hp increase with the drop-in high compression pistons.  You would have to do more for a 7 hp increase.

If the stock 2003 DS100 has 85 hp and a compression ration of 10:1 (according to Ducati's specs) then increasing the compression ratio to 11:1 using the FBF drop in pistons would result in a 2% increase in hp up to 87 hp.

Here is a handy compression ratio HP change calculation tool. http://www.bgsoflex.com/crchange.html (http://www.bgsoflex.com/crchange.html)

I would big bore, hi comp as well, but if the kids teeth needed work, or one needs a graduation dress, college fees, etc...

Depends if there was a deal going.