Super Jet Squish opinion wanted.

Harbor

Harbor

Location
Stockton
Ya all the pieces on top the piston will be more accurate. My guess is the difference will be split squish @.0345
Strange the other guy got .007 too, good find
Wonder what that's about though and why I don't get that variance
Be interned to hear what you find

Edit: going to take my solder pieces to work and remeasure them with a digital caliper and see if I can pick up a different measurements on mine. Might re-do it again Monday night then re-measure with the digital and see what I get
 
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Harbor

Harbor

Location
Stockton
Amitchell, ok remeasured the solders from the two piece test with a dial caliper and got .048 instead of .055 on a single solder
Will redo the singles as well tonight and remeasure with this dial caliper, the only one I had at home last night was a vernier
 
amitchell

amitchell

Location
Victoria BC
Harbor said:
Amitchell, ok remeasured the solders from the two piece test with a dial caliper and got .048 instead of .055 on a single solder
Will redo the singles as well tonight and remeasure with this dial caliper, the only one I had at home last night was a vernier
Click to expand...

Ok sounds good, will be interested to see if you get the same difference.
 
amitchell

amitchell

Location
Victoria BC
Quinc said:
This thread has me confused and worried to check mine now...

What size solder do you use when you check?

Do you push it all the way up against the cylinder wall?

Do you have to have the head torqued down when you check?

How can a lame with no machinery change it if it is not correct?
Click to expand...


I used 0.062" rosin core solder. http://www.homedepot.ca/product/src300-3oz-rosin-core-solder/968182

Do not use Acid Core solder.

Yes it goes right up to the cylinder wall, then rotate coupler smoothly and without stopping over until solder is squished.

Yes head torqued.

I asked ADA and they don't recut, but can cut custom domes for a reasonable custom programming fee that is additional to dome cost. I assume an engine builder can cut existing domes for you.
 
Harbor

Harbor

Location
Stockton
Alright re-did the measurements, using Brown & Sharp dial caliper, 0-1 inch micrometer & vernier caliper. The vernier is to hard for me to see the hash marks so for accuracy that tools out. The dial caliper and 0-1 mic agree....
1 solder squish measurement method = .054
2 solder squish measurement method = .047

So the .007 variance is normal

Putting solder pieces directly on the piston while the head is off, held in place with grease then reassembled and the squish measurement taken would be more accurate when initially setting up squish.

I believe this method may deliver another number, even smaller than double solder method. If you try it let us know how much more than the .007 variance you get

For squish comparisons between different skis engines it would be best to use the same measurement method to avoid the variance we are getting between methods

You used the 2 solder method and got .031
I used the 2 solder method and got .047

As a Comparison of squish I'd say these are accurate

Edit: I like your double solder method I think is more near the real squish
 
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amitchell

amitchell

Location
Victoria BC
Harbor said:
Alright re-did the measurements, using Brown & Sharp dial caliper, 0-1 inch micrometer & vernier caliper. The vernier is to hard for me to see the hash marks so for accuracy that tools out. The dial caliper and 0-1 mic agree....
1 solder squish measurement method = .054
2 solder squish measurement method = .047

So the .007 variance is normal

Putting solder pieces directly on the piston while the head is off, held in place with grease then reassembled and the squish measurement taken would be more accurate when initially setting up squish.

I believe this method may deliver another number, even smaller than double solder method. If you try it let us know how much more than the .007 variance you get

For squish comparisons between different skis engines it would be best to use the same measurement method to avoid the variance we are getting between methods

You used the 2 solder method and got .031
I used the 2 solder method and got .047

As a Comparison of squish I'd say these are accurate

Edit: I like your double solder method I think is more near the real squish
Click to expand...

Thanks for doing that.

Good to know that 0.007in variance is normal. I don't think I will bother with doing the solder/grease method.

Now I just need to get my domes sorted out.
 
Harbor

Harbor

Location
Stockton
Your welcome :)

You gonna look for someone near your area?

Thrust innovation supplied my custom cut domes on my 865 but I don't know who did the actual cutting or who they ordered from
 
amitchell

amitchell

Location
Victoria BC
Well I got my Jetmanaic custom 35cc domes and custom base gasket in today. The domes have 0.010" extra squish clearance, and the base gasket is 0.010" thicker than stock.

My new squish measurements are:

0.046" using two pieces of solder, and 0.052" using one piece of solder.

So I am happy with what I have for squish now.
 
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