40mph speed secrets revealed

[Rockenstein]

The smoother the chamber is the less heat soak it is subjected to, so the less heat it absorbs. (and there is no offense inteded by this...) And really your chamber is far from smooth. Really you should get in there with a fine grit ball stone or perhaps even a sanding barrel. Also make a decent chamfer radius on the transfer from the chamber to the squish. Doing both these will make your engine more efficient by turning more energy into kinetic energy as opposed to heat energy.

I concur on a nicely finished combustion chamber...all sorts of weird things can happen if they are left rough, have sharp edges and so on. I made a comment at the start of this thread on a poor mans way of finishing a roughed out combustion chamber. I've used that method as I have no radius turning setup for either of my old manual lathes and with the 3 or 4 head buttons I've made for smaller engines I had to step cut them. It took some time and patience of course but the end result was near perfect. If you look at the pictures of the slant head I posted above you may notice lots of sharp edges and other design oddities, yea it obviously works and engines are running with them but I'll bet if you were to get the squish gap set proper you'd hear some pinging at some point in time. The engine this head came off of has 2mm or more worth of squish gap! Do I care? Do I want 1000 dollar BiZeta performance out of a 150 dollar Chinese motor? Nahhh....if it's pulls me along at 35 km/h for a summer and lives to tell about it life is good

 

[Creative Engineering]

As always...Good post Rock!

I've been reading along also...

Foximus...Not trying to give you a hard time, but please don't recommend that a stone be used on Aluminum. If you are experienced, you know that a stone will glaze almost immediately when used on Aluminum. Sanding scrolls work well as long as the RPM is kept low. Coarse burrs, and steady hand control, are best for removing material...and even then I use WD-40 to prevent chip welding. I have made a few parts here at the shop that required hand porting, I made these heads and valve covers from solid blocks of Aluminum...pics below.

Once you have had the opportunity to disassemble one of these engines, you are going to realize that there is very little to work with...believe me, I've had many of them apart!

Jim

 

[foureasy]

i used a carbide burr with the wd, i do have a lathe but no 4 jaw. stupid me spent the money on a tig

 

[Creative Engineering]

i used a carbide burr with the wd, i do have a lathe but no 4 jaw. stupid me spent the money on a tig

Ah yes foureasy...it is the dilemma...a man can never have too many tools!

What spindle nose do you have on your lathe? Is it Cam-lock, or threaded? I have quite a collection of stuff here that I couldn't bear to throw away. If I have one that will fit your lathe...shipping will be your only cost.

Jim

 

[foureasy]

i would say yes if i sent you a pipe too. i think it is a c-3. i wanna say its an 8x32, but i'm not sure. ill try and check tomorrow

 

[Foximus]

Yes, i know stones fill up quickly on aluminum, but its a cheap and quick way, as sanding barrels are cylindrical and nobody has spherical carbide bits usually.

 

[xlite]

Note that a few minutes in sodium hydroxide (lye/draino) quickly cleans aluminum clogged grinding stones.

 

[markeatmark]

i noticed if you keep your work wet < wd40, penetrating fluid> and work slow it wont clog the stone .

 

[Venice Motor Bikes]

Those are nice looking heads Jim!!! Vee Dub??

 

[Creative Engineering]

Those are nice looking heads Jim!!! Vee Dub??

Thanks Venice!

They won't fit a VW engine, but the engine they were made for was loosely based on a VW.

Roger, the owner of the race team had his own casting patterns made for the block and heads so he could build a heavy duty horizontally opposed 4 that would run on 90% Nitomethane.

He kept knocking the cast heads off the fuel engine that's in his rail. I made the billet heads shown above to solve the problem...it worked!

I'm helping him build another engine...We plan on getting to the track next month.

Rogers' website has not been updated in years, but there's a lot of cool stuff to look at. If you click the three photos at the top they will enlarge. In those photos the car was running the billet heads.

Billet Racing Engines

Jim

 

[foureasy]

jim,
i believe this is a 3c but i have included some measurements as well.

 

[Creative Engineering]

Foureasy,

I've got an 8" 4-jaw that is in good shape. The backing plate is 2"-8 threaded. You would need a camlock backing plate. I saw some new ones on ebay for a reasonable price, but I'm not sure if they are the right size.

Here's a link to the dimensional info you'll need to determine which one you have.

Specifications for lathe spindle noses

Jim

 

[foureasy]

spy pic of my top secret death race motor. i spent the afternoon doing the modifications necessary to physically bolt the components together. i'm waiting on some big and small rod bearings, maybe early next week. in the meantime i will be adding up to a centimeter to the stroke. i know i said bad things about it before, but i still like E85!

 

[Foximus]

Whered you get that cylinder?

 

[BarelyAWake]

... Cross between a HT and a moped?

if so - nice

 

[foureasy]

Whered you get that cylinder?

the question is, which cylinder is it?

 

[Foximus]

yes that as well...

 

[foureasy]

 

[Technocyclist]

i sure would love to hear what noise these engines are going to make... videos, audio files, anyone? please...

 

[foureasy]

YouTube - M2U00063


YouTube - M2U00062


YouTube - M2U00061