Recommendations, boring, ballancing

[ArttuH]

For example here are a couple of photos what I did for my 1150 engine to drop compression:



Just food for thought.

I guess that you can't gain much volume by opening the combustion chambers without re-shaping them completely. Though you have quite much material to remove on the sides due to increased bore size. So you may get few cc's from there. I wouldn't remove the ridges between the valves, they are there for a reason.

[Mekanix]

Just food for thought.

I guess that you can't gain much volume by opening the combustion chambers without re-shaping them completely. Though you have quite much material to remove on the sides due to increased bore size. So you may get few cc's from there. I wouldn't remove the ridges between the valves, they are there for a reason.

Thanks, Pictures really help

I just spent the last hour doing something like that on a spare head with a dremel .

Just doing the sides I managed to get 3 cc's

I agree with you about leaving the ridges in the center. this is one of the areas they crack.



Should I keep going and make the angle's sharper like the original design or keep it slightly tapered.

[Mekanix]

lol

[7981GS]

8.00 or a little under in the 1/4 mile (7.92 best).

Eric

[Mekanix]

Very nice

[7981GS]

I lied.
This is the car that the engine came out of running...

http://www.youtube.com/watch?v=c49Wz4MWxM4

Eric

[Mekanix]

looks like its working good Eric


I was messing with the dremel and then I realized that there are more bits than I know what to use.


So what are all the bits designed for ?

Which ones would allow me to cut and shape aluminum the best ?

I've been using the small sanding tubes and small carbide tip for fine detail. Then I finish sanding by hand. ( all learned by trial and error on spare head)


What about polishing the combustion chamber when I'm done ?
(I started messing with the steel brushes bit)


How could I make both chambers the same instead of just by eye?



On the sides the transition is a sharp angle. Should I go for the same or just smooth it out so that its a gradual angle. In other words, should I make a bathtub shape or dome?

[pete]

looks like its working good.


I was messing with the dremel and then I realized that there are more bits than I know what to use.


So what are all the bits designed for ?

Which ones would allow me to cut and shape aluminum the best ?

I've been using the small sanding tubes and small carbide tip for fine detail. Then I finish sanding by hand. ( all learned by trial and error on spare head)


What about polishing the combustion chamber when I'm done ?
(I started messing with the steel brushes bit)


How could I make both chambers the same instead of just by eye?



On the sides the transition is a sharp angle. Should I go for the same or just smooth it out so that its a gradual angle. In other words, should I make a bathtub shape or dome?

If it was me I'd employ the power of cardboard.

Make a template of the shape and use that to verify uniformity between the two cylinders. You can then measure depth at pre-defined points on both sides evenly as well to ensure the depth is the same.

Just my 2 cents anyway coz most of this stuff is going way over my head...

[gearhead13]

I find the carbide cutters the best for removing material. The pinecone shape is my favorite. The stone type wheels are kind of useless for alu because they load up. Sanding drums work good in different sizes and grits.

[mawg]

I've been looking into building a stroker motor for my car and have found some interesting things about quench and compression ratio and preignition. Quench is the distance between the flat part of the piston,excluding the dome or dish and the flat park of the heads combustion chamber.(the squish aeras) Apperently if the quench distance is about 1.1-1.2mm the engine can have a higher static compression ratio without detonation.So, here's my two cents worth.First, find a piston with enough thickness to be milled.Maybe you can use the JE's,how thick are they? You might have to go custon, witch are more expensive,but not that bad, maybe twice as much? .Adjust bottom base gasket for zero deck hight, use a 1.1-1.2 mm thick head gasket for the desired quench, and calculate the piston dish for the desired compression ratio,witch I'd keep to <11.0:1. the dish should not be round but shaped like an Altoids box, a rectangke with it's long side at the front and back of the piston where the squish aeras in the head are. Don't know what the dimensions should be but but the idea is to try to keep as much of the factory squish areas as possible. This keeps the TSCC design, witch I think works good,and avoids messing with the combustion chambers,witch I'd just polish and bowl port. Love this thread,can't wait to hear it run!

[7981GS]

How could I make both chambers the same instead of just by eye?

To give you an idea of some kits available...

http://www.summitracing.com/search/?keyword=combustion%20chamber%20cc%20kit&dds=1

Perhaps some "experts" that don't even own these bikes or only run them stock,
will be chiming in to tell you how little that I know about engine building.
Choose wisely grasshopper.


Eric

[Mekanix]

To give you an idea of some kits available...

http://www.summitracing.com/search/?keyword=combustion%20chamber%20cc%20kit&dds=1

Eric

I made a plexiglass cover and I'm using a 5cc syringe. Same idea as that kit.

I know the volume, but while I'm reshaping the head I need something like a plaster mold to show me what is different.

What I wouldn't give for a cNc mill :P

[7981GS]

Trace the first finished chamber with a piece of paper and copy it to the other one?

Eric

[Mekanix]

I've been looking into building a stroker motor for my car and have found some interesting things about quench and compression ratio and preignition. Quench is the distance between the flat part of the piston,excluding the dome or dish and the flat part of the heads combustion chamber.(the squish areas) Apparently if the quench distance is about 1.1-1.2mm the engine can have a higher static compression ratio without detonation.So, here's my two cents worth.First, find a piston with enough thickness to be milled.Maybe you can use the JE's,how thick are they? You might have to go custom, witch are more expensive,but not that bad, maybe twice as much? .Adjust bottom base gasket for zero deck height, use a 1.1-1.2 mm thick head gasket for the desired quench, and calculate the piston dish for the desired compression ratio,witch I'd keep to <11.0:1. the dish should not be round but shaped like an Altoids box, a rectangle with it's long side at the front and back of the piston where the squish area's in the head are. Don't know what the dimensions should be but but the idea is to try to keep as much of the factory squish areas as possible. This keeps the TSCC design, witch I think works good,and avoids messing with the combustion chambers,witch I'd just polish and bowl port. Love this thread,can't wait to hear it run!

The pistons are 4.32mm (0.170) thick in the center and get thicker as it spreads out. I'm shooting for 1mm max depth.

Deck height is 0.25mm(0.010) out of the hole.

The head has 15cc's I need at least 21cc to get 11:1 and 23cc to be at 10.5:1

What do you think about this design?

That's +4cc's

[mawg]

See Arttu H's post, 152 first pic. Notice where he removed material, allabove the deck by making the cuts or grinds "steeper" not wider like you did?This gains volume,unshrouds the valves and dosen't affect the side quench areas,increasing volume and flow at the same time.Great job and excellent info-that picture and the next one of the piston dish design are worth studing carefully.I'm really liking the way that's done. Sorry, I have no idea how much or exactly where to remove material in the chamber,I'd be scared to go too deep and ruin the head.I wonder how many cc's he gained .