Re: Fiero/FieroF2/FieroFx

How do you get the engine-head to match the size of the new bore?

With regard to this suggestion, see my below query whch remains un-answered.

Or do I have to buy a RTR 180 bore and further re-bore it to take the Pulsar 220 piston?

Any leads here.

I'm currently looking at a TVS Fiero Classic and a Fiero F2 (Remotely as I'm sitting in Amsterdam) which my friend back in Goa going to check them out. I am thinking of going the 200/205 cc way if I pick up the bike. Is it possible for someone to pen down a detailed step by step instruction for the same with photos that I can show a mechanic? I know most of the information is there in this thread (I have read the entire thread and also used the search function) but it is in various posts but the posters assume you already know something about this mod which I unfortunately do not know.

Re: Fiero/FieroF2/FieroFx

1.Basically, combustion chamber area of the engine-head is increased to match the new,increased bore size.It's done in lathes.

2. Fiero bore can be bored to increase the size to install the 65.5mm ,or 67mm piston of the zma,or p220 respectively.It will need a new matching piston liner to be installed as well. TVS themselves have done the same,as can be seen with rtr180 and now rtr200.X21 concept is supposed to be 212cc as well.

3. All the above modifications ,though not the proverbial "rocket science",they none the less will need us to have some detailed knowledge as to what's being done etc and obviously a knowledgeable mechanic is needed too.A mechwho is willing to work on the engine,carb etc to set it up properly.If not,i would suggest that you leave the bike stock and enjoy the stock fiero performance,preferably after a stock re-build.

Re: Fiero/FieroF2/FieroFx

From what I have seen in heads, this combustion chamber is a concave cavity with a diameter matching the original bore. Now with the increased bore, the diameter of the cavity on the head needs to be increased accordingly. This part I understand. But when you start machining out that section is there a calculation to determine how much you machine or is it that you just try to make is more or less visually concave similar to the original.

OK. So where can I get a p220 piston liner. Is it available as a part with Bajaj dealers?

Obviously that goes without saying. I'm not going to leave it to a roadside mechanic to do it. The reason I am asking is because even if it's done by a professional, I'd still need to check that he's doing it right. Unless of course if he has done such mods successfully in the past which most probably is not the case with mechanics in Goa.

If I'm going to keep the bike stock, it will probably not need a rebuilt at as as some members have mentioned that the bike ran 75K kms without a rebuild. The bikes I'm looking at have done 70K & 14K kms only.
In any case for me to satisfy my needs of a stock bike, I already have a stock KTM Duke 390 to ride. The max I may do with it is get a Code6 Re-map.

Re: Fiero/FieroF2/FieroFx

Stock fiero head doesn't have enough room for us to machine it in such a way that 9.5 compression ratio is maintained after the increase in bore.The stock combustion chamber is narrow,with closely spaced valves.So there isn't much room to machine out a concave to reduce compression.Mr Venugopal had done just that by lifting up the combustion chamber in order to install 29mm valve in his 195cc re-build which clocked 143 genuine kmph on the v-box.So all these things can be done,provided the one doing it has some idea as to what's being done.Mr Venugopal is a engineer by profession and has done lot of things on a fiero engine platform.But most of the lathes won't be able to do the same,because of lack of know-how.
Basically,you can't increase the combustion chamber area much,without lifting the entire combustion chamber up.So with the increase in bore,there will be a huge increase in compression too.
Liners/sleeves aren't available at any showrooms.You would be able to get them at lathes.The thing to be kept in mind here is that the reliability and performance of the modification will depend on the quality of the liner.So preferably get branded liners from usha etc.The other way is to get a used p220 bore,or a zma bore,then remove the liner from the bore and installing it on the fiero bore.This will any day be better performing and more reliable than a unknown liner installed at lathes.Provided, ofcourse that the entire lathe work is done properly.
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The entire work till now,starting from the 195cc set-up,to the current 180 set-up,everything was done by a mech who is pretty much just that,a road-side mech,with a garage which resembles one of your goan beach side shacks.So i am not hung up on 'professional' looking mechs/garages which newbies keep bandying up here on xbhp so often.The thing which matters is knowledgeable mechs and lathes which won't take us for a ride.

You can always wait for the RTR200 bore kit to come and then install the same.With this you will have a reliable factory bore-kit.I will be installing the 4 valve head of the RTR 160/180 which will be coming soon.If you can wait and do the same,then you need not even bother about combustion chamber sizes etc when you get the modification done.Difference in compression will still be there,but it won't be as much as the limited machining increase of stock fiero head will be.

Re: Fiero/FieroF2/FieroFx

Basically what I meant was not to reduce the compression ratio to the original value. I just wanted the head modification to be done properly to work reliably and properly. Anyway by your explanation, the compression ratio goes up which means more power. But increased compression ratio leads to problems like knocking with low quality fuel. Now with this mod is the increased compression ratio a big problem or is it manageable for daily use?

There are a couple of lathes in Goa which do reboring. Mostly Bullets and RD's/RX's. I guess they should be competent enough to do the job. Other option is to send the stock head, block etc to Bangalore and get the job done. Any suggestions?

By professional, I did not mean a branded shop with a reception and all mechanics in clean boiler suits, loads of computerised equipment etc. And by roadside mechanic I meant they type who will put 2 cans of 2T oil into a 4 stroke bike because 2T+2T=4T. And you said it right "knowledgeable" mechanic is the right word.

That should be ideal. Only question is how much is it likely to cost?

Re: Fiero/FieroF2/FieroFx

P3t3r I am no master like gixxer but I have gone through the phase of reworking on stock fiero head to match 180 bore and I was advised strongly against it by the same mech who gixxer is mentioning here. The compression will be too high and it's not reliable. Buy the bike and wait for sometime running stock to get rtr200 bore and head or the 4 valve heads of 160/180 which are supposed to come out sometime soon. I have seen and driven the 195cc set up of gixxer with zma piston and reworked stock fiero head and it isn't as reliable as it can be with rtr complete set up.

Re: Fiero/FieroF2/FieroFx

When i was running the 195cc set-up,it was with the stock fiero head,but with the combustion chamber diameter, as you put it, increased and area around the valve seat's machined out.But that's about it.So the compression,which i didn't measure as the guage was broken at ZEN TVS,the compression was so high that ,if there was even slightest of excess throttle than what's needed given,then the carb would be blown clean off the intake manifold with such a loud explosion that it would scare the others at the signal lights! I mean,if the air-filter box wasn't behind it and holding onto the carb,then the carb would have been ejected like a tin dabba kept on the diwali atom bomb!! The kick starter was very hard and she would kick you right back on the shins to express her displeasure,if you tried to kick-start her and ride her when she wasn't properly warmed up.But yeah,high compression also meant she had lots of power.The current 180 set-up feels anemic in comparison!Though mind you, bike's not exactly on stock set-up either,as she's running on RTR160 head with a 180cc config,so compression is higher than a stock rtr180.
The other thing about the 195cc setup was that the head was heavily ported,which also increased compression.The carburation was done properly,that is we had jetted it properly,so there was no knocking,or detonation of any sorts and she was a thirsty beast on higher revs.So,yeah higher compression set-up is actually lot of fun and when jetted properly,it can be ridden on normal fuel without any issues what so ever!
The only thing i hadn't done yet on that higher compression set-up, was that the silencer baffle was removed and made free-flowing,but the bend-pipe was still stock 18mm one.So along with the TCI ignition running on a advance map all the time,these both led to the carb getting blown off.Even in the current 180 set-up the carb was getting blown off,but once i got the bend-pipe modification done,which is now a 32mm inner dia bend-pipe,the carb blow out hasn't happened.
So if properly done,then high compression set-up is really fun and the engine revs like crazy.The other good thing is that the fiero engine is a over-engineered engine,so it's bottom end can take all the abuse that we can throw at it.High compression? no prob! higher cc? no prob!That's why this engine is respected so much by racing folks and mechs in general have lot of respect for this engine. I ran her for 13k kms on the high compression over-bored setup and when we took the bore-kit out,the bore and piston are still as good as new! So the work done by the lathe was good and fueling was good too.The piston kit is of usha brand and liner is probably from a zma.So it was still good and good enough for another 60k kms at least,as the mech observed.The reason i changed over to the 180 set-up was because of my own doubts as to what kind of liner was used,but it did turn out to be a good one when we took it out.
So definitely such modifications are nothing in comparison to what this engine can take. You certainly can get away with a lot provided the setup is decent enough.
They certainly can.I would suggest that you get it done where it will be assembled,so that in case something crops up,you can then take it to the lathe which worked on it and get it sorted.This is not a big deal for a lathe which knows what it's doing.
Hahhha yeah.As i'm sure you know this as well,most of the trained mechs in ASS ,are just that,arses!The mech i mentioned about was trained at hosur TVS on the fiero platform itself and then he had started his own garage.But importantly,he is knowledgeable in the sense that he finds ways to get things working properly and has a sound technical mind.Which is what is mostly needed when doing such engine modification works.

Coming to the cost factor,the boring out and sleeving had cost me 2k back then,which also included the usha piston kit.The stock fiero cam is a top-end biased cam,so provided the bike has a original cam,whichs isn't worn out yet,then stock fiero head will be screamer config itself. You can port it and make it even better,though most lathes say that the stock fiero and rtr head's ports are good enough and don't need porting.The lathes here know a thing or two,because they cater largely to the illegal night time drag race folks and these lathes do know how to setup properly such a modified bike,because of the same drag experiences.

Regarding the cost of a new RTR 180 bore kit,it costs 2.3k and a good used RTR180 head with all the parts in it,should be within 3k.So when the 4valve RTR's come out,then within a year the 4 valve heads will be available in the lathes as well.A brand new head assembly in showrooms will cost 7k i think.

Re: Fiero/FieroF2/FieroFx

So basically the RTR200 bore & head will work out to over 10K which I don't intend spending on a bike that costs 10-15K. Which leaves with with only the re-boring option.

Also does anyone know if the FXR150 engine is the same unit as the Fiero but putting out more horses?

Re: Fiero/FieroF2/FieroFx

This very bike's head was installed on a fiero by Mr Venugopal i think.

Re: Fiero/FieroF2/FieroFx

Another engine which appears to be from the same family is the GN 250.

Re: Fiero/FieroF2/FieroFx

The FXR150 specs are simply amazing!Mr venugopal and Mr Srinivas had somehow gotten this bike's head imported and installed it on their fiero,so that definitely means it's the same engine platform of the suzuki.

Re: Fiero/FieroF2/FieroFx

I remember seeing the FXR in Argentina somewhere in 1997 or so and the first thing that came to my mind was "Fiero". When will they launch this model in India.

Re: Fiero/FieroF2/FieroFx

After fiero ,this should have been the upgrade model,sadly the jv went splits and it needed tvs a fair number of years to bring the short stroke,big bore RTR.The timid GS150R which is also based on the same fiero platform,should have gotten the FXR150 upgrade,or as a sporty alternative.When gixxer was being rumored, i had hoped it would be the FXR150 .Even now they can convert the gs150 platform into the fxr and it'd definitely be a box office hit.

Re: Fiero/FieroF2/FieroFx

But sadly this is India and every manufacturer likes to give us crap while they give the rest of the world the good stuff. Even Pakistan gets better offerings from the 4 Jap manufacturers.

Re: Fiero/FieroF2/FieroFx

At least TVS is doing something about taking this engine platform ahead.RTR200 may not have the same mouth watering specs as the suzy fxr,but having recently test ridden one,TVS certainly has created a screamer.Though bias is now set for the midrange in the rtr200,it's just a matter of tuning the head and TVS can certainly make a top-end biased screamer like the fxr.Maybe the x21 concept will do that.Suzuki with the exception of the gixxer ,has majorly let us down till now.