Here is a list of all the postings Glenn Royds has made in our forums. Click on a thread name to jump to the thread.
|Thread: Firefly Conrod issue 4435|
Sorry Jason just noticed your post 9 days late after your motor is running! but you are correct I've just checked the 3D model and its a 5mm dia (2.5mm rad). Its not crucial dimension and would just add a bit of meat to the conrod.
Well spotted ! I've uploaded an amended drawing for future ref.
|Thread: Jason's Firefly .46 Build|
Well Done Jason a top job, Alex will be over the moon with another baby.
Many thanks for taking the time to post the excellent photographs and informative build.
The finish of you engine is very impressive it just looks like it dropped off the production line.
I think all the Firefly's made take a bit of running in as its a plain bearing engine so they run a bit tight (hot) at first, also Alex also swears by quite high percentage of nitro in his to get the performance.
I know Alex has other engines in the pipeline very soon.
Wow excellent work Jason you are a glutten for punishment.
For everybody's info there is a lot of meat in the liner this was deliberate move to avoid distorsion when milling the ports.
If you compare this with mass produced japanese engines the liner thickness on the Firefly is way over the top, commercial liners are wafer thin in comparison and appear to be pressed then honed to size unfortunately we don't have this luxury.
Maybe we could have gone bigger in the bore get more capacity but at the risk of some folk scrapping their liners depending upon the quality of their machinery and tooling.
Keep up the good work.
I was just surfing on Google and spotted your build photographs so had to join the forum, I would like to thank for your excellent conrtibution to the Firefly 46 build.
To introduce myself I'm Glenn Royds the CAD monkey who produced the 3D Firefly drawings for Alex Whittaker. We have had several engines created from the drawing set so hopefully you should have little difficulty creating a working engine.
If you are unsure about any dimensions please shout out however the 3D PDF is to scale and can be relied upon to verify a dimension although my intention in created it was to make it easy to visualise the component parts.
I have not created the engine myself I basically reverse engineered as a virtual 3D model from Alex's prototype and added a few tweaks to loose some lard and make it look pretty
Please Note I cannot help out with engineering method/problems this is the proving groups domain.
I do like the addition fin work/cylinder head mod.
Keep up the good work
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.