Some hardware modifications to Sport Corsa 1100i

I am updating this page so that the new stuff is always added on the top of the page and thus the older stuff will be pushed towards the bottom of the page

This page is all about hoping to make this kind of bike to go a little faster. Older and more electrical stuff related to My16M ECU can be found here.

That small but important print :

These are experiments of a non-professional DIY mechanic, therefore, if you choose to follow these "teachings",
 you do it completely on your own risk !

July 2005, up and running again
The fuel injection map seems to be now quite well sorted and the new chain & tightener after the "forced" engine rebuild make the engine mechanically quieter than before. I manage to visit the Nordic Guzzi Meeting in Denmark without any problems just a couple of days after the rebuild.

At Kemora Raceway, for the first time in my life, I managed to lean my knee down when taking some of the track's fast turns. Here is my left knee pad that I am so very proud of. A short video taken by Mika at Kemora. Kemora track has new surface with very good friction.

June 2005, assembling the engine
Had to make a few new tools to properly assemble the engine. Here is the cheap but practical  DIY tool to tighten the crank main bolt. A holder to prevent the camshaft rotating when tightening the cam bolt need also to be prepared.

Learning by experience I decided to secure the oil filter in place with medium strong Loctite and a hose clamp. Where applicable, all bolts in the engine where also glued to be sure that nothing falls off in the future :)

I used this opportunity to add a mechanical oil pressure meter to the cockpit. The pressure sensors are prone to fail in Guzzis every now and then so the oil pressure meter provides some added safety in this sense. I manufactured a simple bronze adapter to provide an outlet for the capillary tube going to the meter and to house the original pressure sensor switch.

When I was inside the engine, the following new components where used :
- connection rod big end shells
- front and rear crank bearings (just to be sure)
- clutch friction plates (Surflex items to replace the original riveted ones)
- front end chain and tightener (newer type curved blade for quieter running)
- all gaskets

May 2005, bike runs great until ...
The bike runs well. In order to ease up cold starting I added a relay to automatically cut off lambda probe heating during starting. It proved that a cold lambda probe draws a significant amount of current for a few seconds if the bike has been left out below + 10 C temperatures over the night. The simple relay makes the life of the battery a little bit easier.

First track session took place at Virtasalmi Motopark Raceway. The second one was then at Botniaring, Jurva. During this session then the unexpected happened : At full speed the oil pressure warning light came up ! What the hell ...

After getting the bike back home in a van with Ari's kind help, further inspections revealed the the oil filter had came loose inside the pan. The oil pump was pumping oil from the pan back to the pan without properly pressurized circulation via the vital engine components.

Ok,so it is time to drop the engine. Luckily, this proved to be very simple and fast procedure in a spine-framed Sport because the gearbox can be left in place. The connecting rod big end shells did not look too good after operating in oil starved conditions in a race track :) The softer bearing material had practically melted and sticked to the the crank itself. However, the nitrated Guzzi crank is a real heavy duty item and polishing the crank bearing surfaces in a machine shop revealed perfect connecting rod, front and rear main bearing surfaces. No harm was done to any other engine components either. The pistons, camshaft, lifters heads etc. did not  have any signs of damage.

To throughoutly clean the block, I used my garage dishwasher. It is so nice to handle clean engine components.

2005, time to start driving & tuning
The bike is now on the road with everything more or less ready. The long waited Tech Edge lambda system finally arrived and instead of a pre-production version I actually got a production version 2CO :) See latest pics below, click to enlarge :

bike ready side view new cockpit display inside
bike behind

Both the Optimiser display and the Tech Edge wideband-lambda display accomodate a single box, which became electronically quite crowded inside. The K&N pods with those red PreChargers sit quite nicely in place and the rear seat cowl gives the bike a little more Italian look.

According to my subjective seat-of-the-pants feelings, the performance of the bike is clearly more aggressive than prior to the hardware modifications. I still need to do some fine tuning of the fuel injection. I am running with the latest firmware from Cliff, which among other things facilitates multi-targeting for lambda values. In other words different parts of the map can be provided with different lambda target values. Some more road & track testing and then I suppose it is time to go for a dyno ride ...

March 2005, engine running
A small video. Best enjoyed turning the volume knob to the max :) The engine seems to be mechanically very quiet and wonderfully eager to rev. The sound is now different. This must be because of the slightly increased compression ratio.

2005, cosmetic stuff
The engine is now mechanically ready. Just some final attention to the throttle bodies and sync and I am ready to fire her up.

Still waiting for my new lambda system from Tech Edge : 0 258 007 057 LSU sensor + 2C0 unit + LD02 display.

I also ordered K&N pods in order to get rid of the rather ugly airbox and give the bike a little cleaner (and meaner) look. The pods are RU-1780 equipped with red RU-0510PR "PreChargers". A fuel pressure meter added to the cockpit

Here is some new paint job in the back of the bike, click to enlarge :
small flag

2005, heads attached & rockers resurfaced
Final measurements on the squish band height. Without tightening the head bolts to the final torque I got an average value of 1.10 mm using new gaskets. The modelling clay method did not permit measurements with higher accuracy than that :) However,  that is close enough because I was aiming to 1.00 mm final height. A finished head ready to be bolted down to the engine.

Before assembling the valve gear I decided to resurface the valve rockers that showed some "pitting" on those contact surfaces hitting the ends of the valve stems. This is the setup I used to ensure that the gliding surface of a rocker will remain accurately lined up with the axis of the rocker. Those surfaces are by the way amazingly soft material. There seems not to be any hardening at all. Here is a resurfaced example.

Then with the heads torqued down I adjusted the valve clearances to the spec values (0.15 mm exhaust, 0.10 inlet) with adding 0.05 mm extra safety to take care of the possible compression of the new gaskets.

Hi-tech Iridium spark plugs from Denso give final finishing touch for these traditional, almost agricultural like engine components.

Feb 2005, head porting done
I decided that I try to make this job myself  in order to learn something new about this subject. I hope that it does not mean learning from my own mistakes this time ...

The tool I have used is a Dremel equipped with a Proxxon Flexishaft. The figure shows the different grinding bits that I had available and the fact that the Proxxon Flexishaft head is much smaller and handier than the Dremel equivalent.

Here is a comparison figure showing the inlet port before and after my porting exercises. An the same for the exhaust port. The before and after figures are not identical in scale and als do not show correctly the surface finish inside the channels. In reality, the channel surfaces are now pretty smooth even if in the figs the light scattering and shadows created by the flash give an impression of rather non-homogenous surface quality. I did not remove too much material. The intention was merely to smooth down the channels to ease the flow. Here is a figure taken from the combustion chamber side.

In the inlet channels the most significant change was that now the valve seats sit smoothly in the channel without any step between the seats and the channel walls. Another issue was accomodating the inlet ducts smoothly and symmetrically into the heads. Originally, there was a significant difference between the L.H. and R.H. heads in this respect. I am quite confident that now the heads have flow characteristics much more closer to each other than before.

In the exhaust channels I smoothed down the step between the head and the Termignoni exhaust adapter even if not removing it completely. I also mildly shaped the end of those massive valve guides. It seems that both in the exhaust and inlet channels the least aerodynamic parts are those protruding valve guides.  However, in order to not jeopardize the long term durability, I decided not to shorten the guides.

According to Mike Rich, the new inlet and exhaust valves alone should provide some flow increase. Hopefully, together with the ported heads the net change will be even more positive.

Feb 2005, new pistons finally in place
Here is another figure showing the new piston stuff. Note the dark low friction coating in the piston skirt. The piston rings are very narrow (pressure rings 1.0 and 1.2 mm) and should give minimum friction with maximum sealing. Carrillo rod ready to accept a new piston. Here the right hand piston in place and ready to accept the cylinder. The squish band is now optimised to give 1 mm total height with the cylinder head gasket in place.

The valve guides were K-lined. I decided to go this route because it is much less intrusive than extracting and inserting completely new valve guides. Many Guzzis have been prepared with these valve guide linings with good results.

A wide-band lambda sensor is on its way from here.

Jan 2005, necessary stuff

Sport Corsa ain't the best bike for long journeys, but still it is good to have possibility to carry at least stuff with you. Therefore, here is a custom made rack and a modified top case. That top case is a very old Kappa propably from the eighties or something. The rack can be removed in minutes and the glassfiber cover changed back to the original rear seat for cleaner original look.

Winter season 2004/2005, hi-Comp pistons, some head and valve work to be done
In order to get some more punch from the engine I ordered hi-comp pistons from Mike Rich Motorsports. When opening up the engine for piston swap, I noticed to my rather big surprise that the valve guides and valve stems were badly worn even if the bike has only 33 000 kms on the clock. Well, this gave a good excuse to get also new valves from Mike Rich. When the heads are now under consideration I will also give some attention to the ports.

The new pistons look like this. New inlet and exhaust valves from the same place. Some channel pics before my Dremel tool got loose in there :  exhaust channel, inlet channel and inlet valve seat.