450cc Upgrade FAQ

We are happy that quite a few people took an interest in our 450cc project.
This FAQ last updated: 12.07.2020

We won’t offer the 450 upgrade any more, wait for the 477 to hit the road!

Q: What total cost must I expect for a 450cc conversion?
A: That depends on a lot of factors. An average expenses list based on prices I googled and based on you doing the work of changing cylinder and piston would look something like this (if you outsource the work add 3 hours worth of money):

Piston ------------------------------198.- EU
Postage ------------------------------25.- EU
Customs duty -------------------------40.- EU
Boring/honing ------------------------60.- EU
Gaskets that are not included: -------20.- EU
Special tool for valve adjustment ----40.- EU
Total ------------------------------ 383.- EU

You may not have to pay duty, may already have a valve tool and I have seen offers for single cylinder boring as low as 35 € (in the USA) – in which case it would only come to 280.- € total.

Q: What is the difference between your piston and that from Hitchcock?
A: The main difference is that while the H. piston basically requires a new sleeve ours can be fitted into the OEM cylinder by boring/honig it to size, thereby saving about 70% when compared. We have tried both and found no significant difference in torque gain between the two.

Q: How is the torque/power difference when compared to the
A: That is something we have been asked often, and are reluctant to answer as a scientifically precise answer is not possible at the moment and any subjective opinions by us can easily be dismissed as propaganda. However, we will do our best and because the answer is a little more involved we have put it on its own page: [click here].

Q: Is this a home made piston or from some other vehicle adapted to the Himalayan?
A: No, this piston was designed by a Brasilian/Italian engineer and is made by a specialised department working for Ducati in Italy. It is a professionally calibrated piece of engineering, not some home made contraption.

Q: If I purchase your 450cc piston what exactly do I need to do to get it on my bike?
A: That depends. If you can change a cylinder/piston yourself all you need to do is get your cylinder to a boring/honing company which will adapt your cylinder to the size of the piston. Mention to them that this is a forged piston for some extra breathing room (0.085mm). This procedure is usually quite cheap, somewhere in the ballpark of 50 US$. If you do not want do the changing yourself you should look for a reasonably priced bike mechanic as the work will take up to 3 hours (we needed 2.5h) and this could potentially be expensive. It does however not require any special skills or tools. Any bike guy should be easily able to do it. There is a video made by us showing the entire setup and workflow, you find it on the project page.

Q: Will the 450 big bore kit work with BS4? Since it is fuel injected, would I need to buy a Powertronic as well?
A: We have used it without any changes to the mapping on one EFI bike and it ran fine. The Italians have used this kit exclusively on EFI versions with their own fuel flow controller. However since the Powertronic enhances the output even without the added displacement I guess it won’t be a bad idea to get one. But there are other (cheaper) devices out there that allow fuel flow adjustments for EFI.

Q: The Italian guy who is developing with you, is he the same who traveled from Spain to Italy testing it?
A: Yes.

Q: I have a BS3, do I need to change the carburetor configuration or the carb itself?
A: The standard issue carb of the Himalayan is identical to the one on the 500cc Bullet. So the upgrading to 450cc is no issue as such. We have not re-jetted and the 450cc engine runs fine. After 2000km the spark plug look perfectly light brown as it should – not too rich, not too lean:

Q: Will the 450cc bike use more fuel than the 410cc?
A: No, it will use less, given comparable driving conditions.

Q: Will you publish measurements, charts etc. on your setup?
A: We are currently searching for a Dyno facility near us that would allow us such measurements at reasonable costs. When and if we find one we will certainly make the results public. If we receive data from Italy and permission is given we will also make that public.

Q: So the Italian piston is the expensive part. Why not manufacture one in India?
A: We have considered it. But making them one-by-one is almost as expensive in India as it is in Italy. Additionally there would be considerable development costs too and finally Italian quality in the motorsport sector has a well deserved reputation, India not so much.

Q: Are you using the factory liner bored to 450cc or are you providing the cylinder with a new liner when upgrading to 450cc?
A: We do not sell the cylinder for this piston but for our own bikes we only bore (and hone) the OEM cylinder to 450cc specs. The cylinder wall is still double the size of some older 3rd replacement piston/cylinder combinations used in older British bikes. It is very unlikely that the thickness of the cylinder wall should ever become a problem. In this context also see the next question please.

Q: Is this a cast or a forged piston?
A: It is a forged piston – It is important to inform the company that does the boring and honing about this fact as forged pistons need a bit more “breathing room” because they can expand under thermal load more than cast pistons. As a rule forged pistons are more sturdy and take abuse like overheating better than their cast siblings. A good explanation can be found here.
And a video explantion here:

Q: In your upgrade set do you provide everything I need for the upgrade or do I need special tools/other stuff to do it?
A: We now only provide the piston and the head gasket. But the tools you need are very common and are all listed in the “How To” Upgrade” video. We did it without even a torque wrench (if this is your first engine upgrade it may be a good idea to use one). There is one special tool for valve adjustment, you can order it from Hitchcocks.

Q: Will this piston give me a greater top speed?
A: Yes and no. If you are heavier than most or ride with pillion and luggage it will because you likely never red-lined the engine in such a configuration. However, if you are a small lone driver – then no. The red-line RPM is the same. To change that you would have to change the number of teeth on the sprocket to a lesser number (one less should do fine) – make sure the chain fits after that change. E.g. Hitchcocks offers such sprockets.

Q: Are there specific break-in rules I must follow?
A: Yes, there are. This piston should not be moved beyond 3000rpm for the first 500km. Then an oil change is needed and for the next 1500km 4000rpm should only be surpassed for short moments, few seconds. Due to the material the piston is made from it can take up to 4000km to reach full free running, up to this point top speed can be used for short moments but not sustained.

Q: My engine has run for over 20.000km, is there anything I should exchange/renew with the upgrade?
A: It is advisable to change the timing chain unless that was already done recently.

Q: Does your piston come with any kind of warranty?
A: The warranty is limited to delivery failures or damaged delivery goods see here. We have no influence on the boring/honing and on how the break-in is done. For that reason we do not warranty the piston as such. As unlikely as they are, failures could have any number of reasons outside our responsibility. BUT we do offer to sell anyone who bought a piston from us and experiences a problem at any time a factory new 410cc cylinder+piston set for 100.- € plus shipping.

With further questions, ideas, or any kind of input please contact us.

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