Mastermind Meets The MS660

[Mastermind]

To find TDC I use a homemade piston stop. Just an old spark plug tapped for a 3/8 bolt.

 

[Mastermind]

Now.......for the machine work.

I use these aluminum 4" X 4" X 3/8" plates. I've got a bunch of different ones for different base bolt patterns. Just 5mm all thread rod, washers and nuts. Simple stuff.

 

[Mastermind]

Here's something that makes my life simpler........a long reach dial indicator.



With it, I can indicate the upper end of the bore.....

 

[Mastermind]

Once I get zero runout at the top and the bottom of the jug, I'm ready to cut the squish band. You can't just check the top.....then check the bottom though. You have to go back and forth several times. If you move one the other moves.....but you keep getting closer with each movement, finally.......you get both good.

I use a Kennemetal 3/4 80* boring bar with carbide. It's a pretty sturdy piece.

 

[Mastermind]

Working up in a blind hole is a little scary. It takes some practice to find the starting point on the plating, and on the squish band. I'd recommend playing with some scrap jugs first. lol

Here's a little something I made that I'm right proud of........carriage indicator.

 

[Mastermind]

Now.......to keep from chipping the plating when I'm cutting the base, I cut a groove here at the bottom from the inside.

Touching off of the base.



And cutting.....



And done. Now when I cut the base, the plating is already out of the way.

 

[Mastermind]

And a shot of the cut squish band. I took .060" out.

 

[Mastermind]

I debur with this diamond burr. I bet I've done 300 saw with this one burr.

 

[Deets066]

Chitty stock numbers! Hope you can drop it far enough to get em where you want em

 

[Mastermind]

Now to see how much squish clearance we have since I cut the band.

This is .024" soft electronic solder. I've got about ten strands twisted together here. If I use the bigger solder, it's just too rigid, and it throws off me measurements.



Smashed.....but hard to see.



So......we have about .074"......

 

[Mastermind]

Chitty stock numbers! Hope you can drop it far enough to get em where you want em

Like I said Deets.......this model ends up pretty sporty, but a 28" bar is about all it wants.

 

[Mastermind]

Here's what I use for mandrels. It's some sort of PVC plastic stuff........works good though.

This one is the wrong one.........at this time I still though I was dealing with a 54mm bore. lol

 

[Deets066]

Like I said Deets.......this model ends up pretty sporty, but a 28" bar is about all it wants.

I bet if you dropped it as far as the piston would allow and epoxied the intake it might handle a longer bar? Possibly?

 

[Mastermind]

Here's another little trick I've picked up.

I flattened the end of one of my live centers. It sure helps when getting rid of the runout......







And we're spinning.

 

[Mastermind]

I bet if you dropped it as far as the piston would allow and epoxied the intake it might handle a longer bar? Possibly?

It ends up pretty good......

 

[Mastermind]

In this shot, you can see my first cut in the plating.......no chipping.



Checking final squish clearance.

 

[Deets066]

It ends up pretty good......

 

[Redfin]

All set up for timing measurements.




The port timing on this jug stock.....

Ex: 94*
Tr: 124*
In: 81*

 

[Mastermind]

If this was a 54mm jug......I'd be doing some clearance work on the case.

The black spots are where I grind on the 660......

 

[Red97]

Thank you.