imo no.....tolerances are one thing but 15% up over rovers quoted figures is obviously a little bit optomistic.
If that were a zs 180 running 15% high it would have been a zs 200 out of the factory...sorry it would be great but it just doesnt happen.
When a manufacturer dyno's theyre engine to publish a figure they wont just pick one willy nilly, they will dyno several and release figures from the best one already, hence why most cars make either spot on the book figures or a little under.
Ive been to several rolling roads and they all claim theirs is accurate because of so and so, but try 5 different rollers and you will get 5 different results so someones wrong...or all of them are, lol.

Just be happy as its obviously a nice healthy engine.

Sure is a high figure for the 110 if indeed stock. I would say there is something in there to add that much more over stock figures. Make sure you don't have an add-on that has caused this as it may invalid your insurance.

Update!

I've had a crazy nite to say the least lol. I got in contact with some lads over on mg-rover.org and we came to the same decision as we have on here, its a very high figure for a so called 1.6 110. Me and a friend over there started going through the stages with help from other members.

First of all I got my cars VIN number and using the MG-Rover VIN meanings chart started to match it all up to make sure everything is correct. 2 letters did'nt match on the chart....engine and body type. According to my VIN number and that chart my car should have had a 1.8 160 vvc engine in!!!

Obviously thats not true as it looks nothing like a VVC engine does. After a while we found the VIN was correct using some old MG/Rover software so there is nothing to worry about on that front.

The second thing I found out is this particular MG ZS was made in 2005! but registered on a 54 plate. I have been told by an ex- mg/rover employee that it would have been made to order car produced very close to the collapse of the company. Its been said at that time when they were running the final cars off MG/Rover would use any parts they could get there hands on to complete the cars. E.g. This could be using a 1.8 engine and trying there best to down tune it to a 1.6 or using different engine variation internal parts in a 1.6. Very unusal... I can almost certainly say myne is a 1.6 engine (??) but who knows it may have some 1.8 parts in it.

Finally a lad came along and said my figures match very closly to his car which is a Rover 25 1.8 (ZR 120 engine) with TF 135 cams. After looking at his power graph we were both in the 122/125 BHP area but he had over 115 ft lb of torque were I only have 108.2 lb ft (maybe). So maybe there is already TF 135 cams in the car, I looked and there is no Veniers but tomorrow may take the cam cover off and look for the codes on them to check.

Soooo to sum up. Its a 1.6 engine (VIN matches), it may/could have some other engine parts in the head that could affect the BHP (we will never really know) or it may be a stock 1.6 with 135 or Piper cams already installed.

Sorry for the massive post hahaha

the head on 1.6 and 1.8 is the same its the stroked length of the pistons that is different

Sorry meant to say the same internal parts not heads.

Edited.

Well sounds like its running well whatever you have hidden away, Theres no need for verniers with the 135 cams, so you could have some fitted. Its still a very good result for a 120, My 120 had 52mm tb, VVC inlet mani, VVC exhaust mani, Decat, Janspeed cat back, open cone and that made around 125-127! So sounds like youve found a nice motor :)

Very doubt that you have a missmash of an engine using various parts, the engines that got supplied to MGR were complete units from Powertrain, they weren't built on the production lines.
It has been known that a few engines from various manufacturers in the past have been slightly over quoted power outputs, a friend had a stock Ford Focus 1.8 Zetec, and that produced 121bhp, instead of the Ford quoted output of 115bhp, and it isn't the first time these things happen, just put it this way you have a very healthy engine to start from, work on the the premise that you have a stock output figure and take it from there, that way you will not be too disappointed when a mod that you have done doesn't live up to what is claimed on the box.
As for your car being built 2005, and having a 54 reg, means that it was probably built between 1st January 2005 and 28th February 2005 (54 reg starts 1st Sept 2004 and ends 28th February 2005)

My derv is a 2005/54 plate and was registered 19th Feb 2005.. What you need to remember is that manufacturers build on bulk, and leave them sitting in a field somewhere to gather dust and bird pooh before they're actually sold.. I would be surprised if mine was actually built in 2005, but could be wrong!

Best way to be sure is to get it to another RR day and see what it does on a different road..

From what I can gather MG-R were very slap-happy with their approach to building cars near the end, and a large number of vehicles turned up at the dealers with 180 kits when they hadn't bee spec'd, so I wouldn't be surprised if yours does have a few bits extra.. I would be surprised if the engine was any different as KevG said, they came complete ready to bolt in!

The only different bits would probably be interior/exterior fit and finish, as the powertrain side of this ie engine/gearbox etc will be complete units.

Rite-o cheers lads. Think i'm going to have to stop trying to figure it out as i'm either going to drive myself crazy or end up messing the engine up lol. I'll just use it as said above that the engine is healthy and ready for modding. :)

Only thing i'm going to look at is what Cams are already in the car, but that won't be until I go about fitting my new 135's.


Tom