Large block – Monza 200/225

LARGE BLOCK MONZA 200/225 CYLINDERS

The Monza cylinder is a Tino Sacchi copy version of the TS1 Alloy Nicasil cylinder, but to be honest it’s not really in the same league, as port shapes and sizes were not as good without lots of work which becomes expensive. There really isn’t that many of these around so there isn’t a lot of feedback available on how people got on with them. They were launched into a market that was already full of barrel kits with long histories. There are hundreds of TS1 cylinders in use which have been well proven as standard or modified by someone to improve them. TS1 cylinders have become thin on the ground a few times so it’s possible the Monza may fill in a gap at times and there is the new Charlie Edmunds Super Monza which is nothing like the original Monza or TS1 cylinders. Also Harry Barlow is introducing his version of the TS1.

It seemed when they were first produced that the Monza kit was aimed at the middle of the road touring type engine, but it’s price was comparable with the TS1 kit so pound for pound it doesn’t seem like such a good idea.

Having said that, at the time it opened up options to use smaller carbs with a new inlet manifold comparing to a TS1 thereby helping with fuel economy – at the expense of a little top end power.

CYLINDER DESCRIPTION

On examination of the kit it appears to be a direct copy of the TS1 200cc barrel, but with the different, slightly smaller reed block. The manifold supplied is either an alloy or rubber Imola type manifold, which we looked at on the Imola page. The piston is a 66mm version of the later type Imola piston. Later cylinders used a different 70mm piston. As with the Imola the Monza cylinder was beef up on a second version, there was more area on gasket face for big transfers and crankcase inlet feed and there was more meat around the transfers for doing big race style transfers.

When these beefier versions became available there was a strong chance that we would choose them over the TS1 barrel for making the BIG cylinders we do without lots of welding and they made for some very fast high 36-37bhp engines with no welding and still using the original NSR125 Reed Block.

These later cylinders, especially using a blank machined cylinder made life so much easier to do the BIG tuning! We offered 70 or 71mm pistons with either Japanese or MB pistons and long stroked 60, 61, 62 or 64mm cranks. These later cylinders have all the improvements to make tuner life’s easier with increased transfer feeds, extra meat on the inlet gasket face for a inlet to casing port, thickened up exhaust area and extended cylinder height.

We have come across three versions of the Monza kit.

• 200cc, 66mm using a standard style 58mm crank
• 210cc, 66mm using a long stroke style 60mm crank
• 230cc. 70mm using a long stroke 60mm crank

But as with all Tino Sacchi products

• Imola
• Monza
• Super Monza
• Mugello
• Pistons
• Cranks
• Heads

Considering the Monza is a copy of the TS1 we offer these tuning services

• Open the inlet port to suit the better Yamaha reed block
• Full Race-Tour tune to blank Monza cylinder
• Reading the TS1 section will highlight other mods for the Monza cylinder

You really don’t know what you have, each small batch gets tweaked and altered and sometimes not for the better! It’s nearly impossible over the phone to supply spare parts without seeing what you have.

Left a new blank Monza on the right one with transfer feeds opened out, shaped and flowed

A Standard inlet port and boost port

 

A Monza inlet port opened with reed boost port re tuned from original

 

Left is a standard blank Monza cylinder with a tuned version on the right, note the boost ports in both

Standard unfinished boost port

And with a real boost port shape

Some blank cylinders came with the top extended allowing for longer stroked engines

This is a version machined with a spigot to locate and centralise the head. Note the little pin prick holes in the machined area, this is because of poor casting practices

Standard exhaust port

Tuned exhaust port

The Monza very ugly poorly cast inlet port, theres is no flow or shaping of the port where the reeds sit

Some are machined so bad from the suppliers they even send them out with the inlet port exposed to the stud hole, this one needed plugging up

MB do this conversion a lot, we cut the spigot that fits into the casing, it helps with cylinders bored out to 71mm and helps distortion when ceramic plating

Increased transfer feeds on a MB special tune, with shortened spigot

Fully tuned Monza 36bhp MB cylinder

If you have a question please email Mark mark@scooters.co.uk