Tecomec pistons (PORTING HELP)

[Mkinslow]

Well at least it helped some

 

[huskihl]

Did you port that one bud

Yes.

 

[MustangMike]

HF just had their grinding tool on sale for $6.99, but if you missed it, it is regularly $8.99! I printed my degree wheel off the net. The folks on this site have already done all the heavy lifting and will give you advice. It is now just a matter of wanting your saw to run better!

That said, my best running saws have been sent out, but I have improved performance quite a bit, right here, by myself (with advice from others). It is work, but the rocket science part has already been done.

A great running saw just puts a smile on your face!

 

[Mkinslow]

HF just had their grinding tool on sale for $6.99, but if you missed it, it is regularly $8.99! I printed my degree wheel off the net. The folks on this site have already done all the heavy lifting and will give you advice. It is now just a matter of wanting your saw to run better!

That said, my best running saws have been sent out, but I have improved performance quite a bit, right here, by myself (with advice from others). It is work, but the rocket science part has already been done.

A great running saw just puts a smile on your face!

You are correct sir. They have done all the experiments and are very willing to help,I just need to get motivated , start finding the tools and get to figuring out how to do it.

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[Mkinslow]

HF just had their grinding tool on sale for $6.99, but if you missed it, it is regularly $8.99! I printed my degree wheel off the net. The folks on this site have already done all the heavy lifting and will give you advice. It is now just a matter of wanting your saw to run better!

That said, my best running saws have been sent out, but I have improved performance quite a bit, right here, by myself (with advice from others). It is work, but the rocket science part has already been done.

A great running saw just puts a smile on your face!

I've got a dremel hand piece that I do a lot with, but I can't see how I'd get in and around the exhaust/intake ports unless I just do it with a ball type. I'd imagine some can be done from outside in.

 

[XP_Slinger]

I've got a dremel hand piece that I do a lot with, but I can't see how I'd get in and around the exhaust/intake ports unless I just do it with a ball type. I'd imagine some can be done from outside in.

I’m a Dremel warrior too and outside/in is exactly how you get it done. 3” shank burrs are mandatory. Chamfer with a tapered stone bit. Transfers can be tricky if you don’t have removable covers. And the smaller the bore the more screwed you are with transfers and a dremel. I managed to work my 357XP “good enough” but any smaller bore than that and it really doesn’t work.

 

[Mkinslow]

I’m a Dremel warrior too and outside/in is exactly how you get it done. 3” shank burrs are mandatory. Chamfer with a tapered stone bit. Transfers can be tricky if you don’t have removable covers. And the smaller the bore the more screwed you are with transfers and a dremel. I managed to work my 357XP “good enough” but any smaller bore than that and it really doesn’t work.

Where did you get you 3" bits

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[XP_Slinger]

Where did you get you 3" bits

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This is the best source I’ve found for long shank bits of various cutter design and shape.

https://www.mcmaster.com/

 

[Mkinslow]

This is the best source I’ve found for long shank bits of various cutter design and shape.

https://www.mcmaster.com/

Good deal thanks

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[MustangMike]

I like to use the diamond balls for the chamfers, ebay has lots of low cost 1/8" shank stuff. If I need to lower the intake I will often do it with a half round file. Exhaust ports I do from the outside in, watching from the inside.

Transfers can be tough, but if you remove the plating with a diamond burr you can use a stone to remove aluminum, giving you a 90* angle.

If you think it through, it can be done.

But even before porting, a muff mod, timing advance +/or base gasket delete can really wake up a lot of saws. Some of them will run like they are ported.

If your transfers look good, leave them alone, you can mess things up. Get a good set of timing #s from someone who has experience with your model saw, check where your #s are, and come up with a plan.

I just checked a 066 jug with a Meteor piston on a Asian 660, w/o base gasket. Sq is only .010, Ex 98, Tr 122 and In 80.5. I think the #s are good, so I am going to sand .010 from the squish and widen the top of the exhaust and leave the rest of it like it is. I also filed .020 off the key to advance the timing a bit.

Once you start, and see the gains, it is addictive! I did several of the 440 BB kits, each time adding a few addl mods, and as the performance increased it encouraged me.

Good Luck with it.

 

[MustangMike]

066 with timing wheel I printed from the net, backed with carboard and some closed cell foam to grip the axle (also taped).

 

[Mkinslow]

I like to use the diamond balls for the chamfers, ebay has lots of low cost 1/8" shank stuff. If I need to lower the intake I will often do it with a half round file. Exhaust ports I do from the outside in, watching from the inside.

Transfers can be tough, but if you remove the plating with a diamond burr you can use a stone to remove aluminum, giving you a 90* angle.

If you think it through, it can be done.

But even before porting, a muff mod, timing advance +/or base gasket delete can really wake up a lot of saws. Some of them will run like they are ported.

If your transfers look good, leave them alone, you can mess things up. Get a good set of timing #s from someone who has experience with your model saw, check where your #s are, and come up with a plan.

I just checked a 066 jug with a Meteor piston on a Asian 660, w/o base gasket. Sq is only .010, Ex 98, Tr 122 and In 80.5. I think the #s are good, so I am going to sand .010 from the squish and widen the top of the exhaust and leave the rest of it like it is. I also filed .020 off the key to advance the timing a bit.

Once you start, and see the gains, it is addictive! I did several of the 440 BB kits, each time adding a few addl mods, and as the performance increased it encouraged me.

Good Luck with it.

Thanks for the encouragement bud. I'm gonna start looking and see what I can find. Once I get some stuff I may try it on my 2159 since I have an extra used cylinder for it. Then progress to another one.

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[Mkinslow]

What shapes of burs do yall normally use. I'm seeing quite a few options

 

[MustangMike]

I find the one that looks like a cut off ice cream cone to be the most useful. I think I recently found a package of 10 different ones for $12 on ebay. Have not used them yet.

Like this, all kinds of shapes:

https://www.ebay.com/itm/10-pcs-Tun...rentrq:c2dd19211670ab6b9b053cc0fffc921d|iid:1

 

[Mkinslow]

Got something done with this project today. Got my degree wheel made up

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[MustangMike]

Now just make a wire pointer that bolts to the case that you can adjust. Then use a piston stop and rotate both ways, adjust TDC to the middle.

Intake opens from the bottom, exhaust and upper transfer from the top. I use my bright bicycle light to see the upper transfer through the exhaust.

 

[Mkinslow]

Doesn't matter where on the case as long as it can be zeroed, right. I still gotta stop at hardware store tomorrow and pick up some stuff to finish with. Ordered a ball burr and egg shaped burr 1/8" shank by 3"long today. Those on Ebay look like 1/4 shank. I've got die grinders but I'd rather use my dremel. Wonder if they come in 1/8.

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[MustangMike]

The ones I posted are 1/8.

 

[Mkinslow]

The ones I posted are 1/8.

Oh ok. Sorry I really haven't got to look at them too much yet. Dang kids school programs and all that crap lol.

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[MustangMike]

Doesn't matter where on the case as long as it can be zeroed, right

Right.