Piston holder for cutting valve reliefs...

[Admiral Akbar]

Good ol' Don showed me a piston holder some years ago that KB used to sell for modifying pistons..

I duplicated it..



Not much more than a fork, a yoke for the pin and an allen bolt to hold everything together.



Slide it into the piston.

Drop the pin in and tighten the allen.. Nice thing about the most pistons are the tapered inside of the piston which causes the  fork to close on the yoke and holds the piston tight..2 solid flats with tension to hold the piston straight..
Clamp in a "squared" vice.

Use a digital protractor to get what you want.. I wanted 25 deg..



and with the use of a fly cutter you can cut your valve pockets..



Nice thing about fly cutters is that you can grind a nice radius on the tool for the valve pocket..

Max

[mayor]

very nice!   

[Hillside Motorcycle]

Looks like a handy tool indeed.
Scott

[choseneasy]

Good pics, thanks!

[BVHOG]

Nothing that simple ever seems to work that well, good job!

[TXChop]

Nice work!

Just curious as to why that drastic of a cut was needed?

[Admiral Akbar]

For the same reason the SE cast pistons are cut, just on a mondo scale.. Max

[ejk_dyna]

<<For the same reason the SE cast pistons are cut, just on a mondo scale.. Max>>

yes but RP is supposed to know better...

[Admiral Akbar]

The pistons they have come from Wiseco with the valve reliefs already cut for stock heads with 2 in. (possibly only 1.94) valves..  Angle is different for the RP (ultima) heads..   Max

[Don D]

Nice work, good tool
Incidentally you can use the drawbar concept on a lathe too making other machine ops easy.

[Admiral Akbar]

Good idea...

Quick turn a spud with 3/8 hole to drop in the counter bore into, piece of thread all. maybe a bushing on the far end of the spindle... and you could dish a piston real easy..

Max

[Don D]

 

[TXChop]

Did you have to cut the heads to get the compression back to the same? Would the double eybrow cause any hot spots or flow changes?

Ultima sells cast heads for tc's?

[Admiral Akbar]

Did you have to cut the heads to get the compression back to the same?

Could have but didn't, Let the CR drop from about 11.5 to 11.. 

Would the double eybrow cause any hot spots or flow changes?

Possibly., The hard part is getting on it enough without killing yourself to keep the carbon from building up..    When I first put the motor together, I flowed  the heads.. Exhaust flow sucked.. This last build I got the flow up with AVnV valves.. 3000 to 5000.. This sucker is a monster..

Ultima sells cast heads for tc's?

Ultima made the head's for RP...

2.1 intakes.... 1.7 exhausts.. Parts are available right out of the Jireh catalog ( the the AVnV valves are better then the Ferreas.) 

Max

[REED]

Same heads I have on my 131 as well as pistons, rings + their nikasil cyls and like yours mine is also a monster.  The heads would be a deal even if priced considerably higher nicely cnc ported big valves and raised ports. REED

[wfolarry]

2.1 intakes.... 1.7 exhausts.. Parts are available right out of the Jireh catalog ( the the AVnV valves are better then the Ferreas.) 

Max
[/quote]

Why?

[Admiral Akbar]

2.1 intakes.... 1.7 exhausts.. Parts are available right out of the Jireh catalog ( the the AVnV valves are better then the Ferreas.) 
Max

Why?
[/quote]

Well the Exhausts picked up about 7-8% flow with and exhaust valve swap only.. The all Ferrea valve stems were worn about 0.001 after only 7000 miles..   Guides were still good though about 1/2 thou bigger.. AVnV stems are about 0.001 larger than the ferrea.. Got the guide clearance back to new specs.. 

Conversely a set of heads with all AVnV parts and 10K showed very little wear.. I'll see how the AVnV last in the Ultima heads but suspect they will do better..
Max

[Don D]

The chrome wears real well but there is this other snafu, they gall. The new 110 exhaust valves (ferrea) are troughing the stem tops very quickly too. These are HDs fixed "program" heads.

[Admiral Akbar]

The chrome wears real well but there is this other snafu, they gall.

While I've seen this with chrome stems and cast iron guides,, These stems with bronze guides were worn at the port end of the valve.. No gauling.. middle of stem was 0.001 bigger than the ends.. Might have been from the valve seal sealing too well?

Max

[wfolarry]

2.1 intakes.... 1.7 exhausts.. Parts are available right out of the Jireh catalog ( the the AVnV valves are better then the Ferreas.) 
Max

Why?

Well the Exhausts picked up about 7-8% flow with and exhaust valve swap only.. The all Ferrea valve stems were worn about 0.001 after only 7000 miles..   Guides were still good though about 1/2 thou bigger.. AVnV stems are about 0.001 larger than the ferrea.. Got the guide clearance back to new specs.. 

Conversely a set of heads with all AVnV parts and 10K showed very little wear.. I'll see how the AVnV last in the Ultima heads but suspect they will do better..
Max
[/quote]

I've had good luck with the Ferrea valves. Haven't seen the stem wear. If the tops are wearing it's usually caused by something else.
If that exhaust picked up 8% does that mean you need a smaller cam now that you're overexhausting?

[Admiral Akbar]

If that exhaust picked up 8% does that mean you need a smaller cam now that you're overexhausting?

Not if exhaust to intake flow was 65-70% before?  Max

[wfolarry]

So now you're around 75% which is supposed to be ideal? Was the flow improved through the whole range or just at max lift?  Just wonderin'.

[wfolarry]

Nice piston holder Max. Always like to see guys make their own tools.

[Admiral Akbar]

While the legend sucks.. The better of the lines pairs is where I ended up..



On the exhaust, most was from the valve change.. IIRC about 3% of the highest lift was from modifying the combustion chamber.   

Flow is at 10 inches..

Max

[wfolarry]

Those flow #'s look good. Changing valves & seeing a large improvement means the valve is controlling the flow not the port. Get those same #'s with a different valve & you become a head porter.