well i did modified that novarossi 3sct, i changed the timing on the crack to 65° ATDC and made those "fancy fangs" on the sleeve, and also poslish the fang on the cranck. this engine on track was a bullet, smooth, tons of low end, great middle and also impresive high, very consistent, great power, literally was a bullet. and the best things of all, great millage. 6 min no problem.

i'm pretty greatful with this tread with the help of Stefan and Roelof, both were great help. thanks

care to post us some pics of ur engine (crank, sleeve, etc) before n after mod??? thanks...

Awesome thread! Thanks for all the info and pics.

I am starting another mod job and would like to get the real numbers of it.

I have the degree wheel, how do I use it to measure the nitro engine?

That is disaster!!!
DO NOT TOUCH IT!!!!!! Then everything will be really good

I found a detailed article on how to read the timing numbers with the degree
wheel.

here they are inlet opens at 140 btdc
inlet closes at 63 atdc
exhaust opens at 84 atdc
transfer open at 110 atdc

any suggestions would be aprreciated

What motor is it?

Could you post a pic of your degree wheel? I made one once from a 360 degree protractor and an old serpent flywheel but didn't like it so I need to make another.

this is a HPI F 4.6 I am working on

Can you post the article you found on how to time please?

sorry, I miss spoke

the article is how to read the degree wheel. as far a adjusting time of the engine, it seems that is a gaurded secret in the modding comunity.

the little info I got is now sworn to keep secret

I did figuire it out with some help from some guys here and four other forums in pm's

thanks guys

use mini diamond jewelers files to alter timing, its not rocket science by any means....

For grinding the actual port in the sleeve you can use a Dremel and small diameter carbide bits to rough it out and finish it with a diamond bit. Make sure you chamfer the port slightly to get rid of any burrs with the diamond bit. For the crankshaft you can use the same method and then polish it up with Cratex

When you use a degree wheel make absolutely sure you have an accurate TDC. You can't just push the piston to the top and say that's TDC. You need to bolt something to the top of the engine that will hold the sleeve in place and stop the piston approximately 20 degrees before TDC. You need to get the same degree reading when turning the crank in both direction to the stop. Then 0 degrees will truely be TDC.

IDK carbide does not cut chrome plating overly well.....most timing changes require not much more then just removing the chrome plating, IMO using a carbide would be next to impossible to get a clean cut when removing as little material as needs to be removed.........A fine diamond bit works well but I Most definitely would never ever recommend using a Dremel for cutting ports..........Dremels are also not a very good choice for cutting ports. because their motors are so amll Dremels need to use excessive RPM to make any power. too much RPM causes vibration and bit runout which makes cutting cleanly very tricky......... I use a Jewelers grade flexible shaft tool which works extremely well....however I still dont think using a carbide works well at all, even in a flexible shaft...

Can you show us a picture of what you use to modify engines???