Introduction
2015 saw two of the Kart Review drivers move to the KZ class. We attended a few meetings to gauge which engine was the one to have. Possibly the most expensive item you will buy in karting, we did not want to rush into buying something that was going to cause issues further down the line.
There are many engines available including options from Vortex, Parilla, Modena and Maxter to name a few. The one that stood out at meetings in the UK was the TM offering, the KZ10B. This engine is dominating grids and usually makes up 65% + of UK grids.That's not to say it's ultimately the "Fastest" but it enjoys excellent track side support, particularly from Andy Fairless Racing (AFR).
With this in mind, we decided to buy two brand new engines from AFR. These engines are not the standard KZ10B and are tuned by AFR. It has got all of the options fitted apart from the 22mm crank option. According to Andy at AFR, the 22mm crank does not offer any particular performance gains. We will take his word for it!
If you browse the web looking to buy this engine you will find a host of different "specs" and option packages. It does get a little confusing when you are not quite sure what you are after. The benefit of going through AFR is that he will not sell a standard engine, unless you specifically ask for one. He orders in the engine spec which sees maximum on track performance at the best price. Some of the options available online come with carbon exhaust silencers etc which don't really offer any performance gains, they just increase the price.
As we are limited to what we can review on engines due to our limited testing capabilities (Dyno etc), this review will focus on the day to day running of the engine and less on the performance.
That said, this engine is by no means slow, it's right at the front of Super 1 this year and Super 4 alike.
First Impressions
We received the first engine at Shennington KC for an MSA club meeting. Unfortunately this coincided with preparing a new kart so time was of the essence so we struggled to get many good images of the engine.
Engine comes complete with mount, carb, pump, sprocket, expansion chamber & silencer. Everything you need essentially.
The engine also comes complete with the fuel lines configured correctly.
The exhaust looks stunning when it's new. It's TIG welded by hand out of mild steel and looks the nuts!
This won't last long though as once it has had a few heat cycles and has been ran in the wet, it soon bronzes up.
The engine fitted to a Tonykart 401 with no real issues. The gear linkage bar was not required to be bent using an OTK size 2 seat. We did have to kink it slightly to fit a size 3 OTK seat though.
The engines comes with a clamp which is designed for 32mm diameter chassis rails so we found that the clamps dug in to the powder coating. It would be worth running a clamp designed for a 30mm chassis but we have not had any issues with the engine positioning so far.
You will also need to run an OTK rear clamp if you are fitting to an OTK chassis. We did find the engine could not be slid as far back as we would have liked as the engine clamp hit the weld were the sidepod bar is attached. This appears to be more of a fault with the chassis though as the second engine fitted fine to another new OTK chassis.
You will have to modify your right hand seat stay to avoid contact with the exhaust silencer, we did this by using a ball pein hammer and a tow bar!
We used the OTK adjustable seat stay on the second chassis which worked really well without any modification.
Possibly the only time I will ever have a brand new chassis complete with brand new engine!
General Use / Observations
I have used the engine for around 8 hours now and had a new piston at 4 hours. This cost £80 including fitting at AFR. I have also had two new clutch plates at £6 each. I change the gearbox oil after each meeting which works out at about £7 per meeting.
The engine will get a bottom end re-build after 10 hours which costs around £310. At this point you may as well put in a new piston too, so you are looking at around £380-£390.
KZ Re-build costs AFR:
4 Hours: Piston £80
8 Hours: Piston £80
10 Hours: Bottom end re-build + Piston £380
Total: £540
Total after 15 hours: £810
This is without a con rod or crank so obviously if the engine requires these the price will increase. Around £150 for a connecting rod.
Rotax Max Re-build cost OGDEN Motorsport:
15 Hours: Full Re-build £800
This is obviously not a comprehensive re-build schedule but it goes some way to comparing the costs of KZ to more popular classes in the UK.
When you fit the exhaust silencer, make sure it is secure and cannot rotate easily. Keep your eye on this after each session as if the silencer spout faces backwards onto your rear bumper, it will blow a hole right through it.
Generally, apart from the things mentioned, I have had no issues. I was expecting the engine to be a bit of a pain to have running correctly all of the time. I was wrong, the engine starts first time every time as long as you remember to blow your fuel through! On track I have not experienced any problems. The gear change is very positive on the up change, and as long as you keep your foot off the throttle the down changes are equally as positive.
One huge thing that has helped both drivers get the most out of the KZ10B is the excellent trackside assistance from Andy and Sue Fairless. If you ever have an issue or a query relating to the engine, you can bet your bottom dollar that they will be able to sort you out. This for us was a major factor in choosing the TM over the Vortex engine. They attend all Super 1 & Super 4 meetings as well as lots of club rounds in the UK.
This is not to say that other engine manufacturers do not have good track support, but for us the TM just made sense.
Engine in action...
Summary
Having two drivers with limited knowledge of the KZ class, it was important that we were on track as much as possible. The TM engine has the best turnout in UK grids and therefore excellent spares availability and support.
The engine is proven in Super 1, as well as at European and World championship level.
I would advise that anyone looking to purchase this engine gives Andy at AFR a call. They are very busy so they may need you to call them back. They really know what they are on about so don't be afraid of asking questions if you are unsure about anything.
AF Racing: 01539 562256
Pros
- Excellent performance
- Excellent trackside support
- Good reliability
Cons
- 32mm Engine clamp (not really a con, but we can't think of any others!)
