S-25 Modified

[Luca610]

Hi guys,

In the video section I've seen a video about the difference between the s-25 standard and the modified... Which are modifications?

Thank you and I'm sorry if I make grammatical errors, I'm italian!

 

[savage25rocks]

removing shims from the engine or there is a guy on here who ports them

 

[Luca610]

thank you, but I don't find the meaning of "shims" :shrug:

What is a shim?

 

[Luca610]

Ok! I understood... But from where Can I remove shims? Under the head to increase the compression?

 

[savage25rocks]

from under the head it will raise compression I have not done this I'm pretty sure that there was a website on this but can't find at this moment

 

[Candyman]

The mods that were done were twofold from what I understand. First off, I believe he removed one shim from under the head. That ups compression a bit. The second "batch" of mods were to the sleeve. He ground specific parts of the sleeve to increase the efficient transfer of the fuel mix into the chamber. It is also possible to grind the transfer port in the crank to improve timing, but I'm not sure if he did that or not. These modifications were outlined in the January issue of RC Car Action. The article can be found here:

http://www.rccaraction.com/articles/htpporting_1.asp

 

[boilermaker13]

Who is guy here who ports the S-25 engine?

 

[Candyman]

I believe markallen has had a lot of success with his mods. He has a video in the vid section showing what his sleeve mods are capable of.

 

[tannera]

i just took a shim out of my .25 engine going to be runing it at the weekend and if there isn't to much compression i will take 1 more out. are let you now how it runs with them out.
now i have to jst go and put it together.

 

[jon2]

I will be doing a review on his engine mod pretty soon here and will have pics of it as well. Keep your eyes peeled!!!

 

[Luca610]

Thank you guys... I will change the engine, It's more easy!

 

[tannera]

i just run mine and you do see a big change in performance.