Squish standards

[stian]

Just wondering, since ive got a problem finding 2,5mm solder/tin wire, im looking at decent numbers for squish and what gaskets are used.

Ive got :
0,15mm - squish? = under 1mm
0,30mm - squish? = 1,2mm
0,50mm - squish? = over 1.6mm

I just put in a new piston, and running a single 0,30 with the head untouched.
Seems to me that the squish is over 1mm, due to not touching the 1mm diameter solder ive got.

Anyone knows what squish you have with one 0,15? or one 0,50?

[(F5)]

Originally Posted by stian

Just wondering, since ive got a problem finding 2,5mm solder/tin wire, im looking at decent numbers for squish and what gaskets are used.

Ive got :
0,15mm - squish?
0,30mm - squish?
0,50mm - squish?

I just put in a new piston, and running a single 0,30 with the head untouched.
Seems to me that the squish is over 1mm, due to not touching the 1mm diameter solder ive got.

Anyone knows what squish you have with one 0,15? or one 0,50?

It could be variable depending on your engine but 1mm would be pretty ideal as a final number. the problem is that if you shave the head & I think I had to do mine 1.3mm to get a 1mm squish you will end up with a compression ratio way too high.

You have to commit to doing the head mod properly or not at all really. Try a plumbing shop or area of your hardware to get some fat resin cored solder rather than electronic solder. Do a search on my thread about head mods for more reading, but it seems RB is the easy way to get the job done for not much money, but you do need a measurement.

[stian]

Originally Posted by (F5)

It could be variable depending on your engine but 1mm would be pretty ideal as a final number. the problem is that if you shave the head & I think I had to do mine 1.3mm to get a 1mm squish you will end up with a compression ratio way too high.

You have to commit to doing the head mod properly or not at all really. Try a plumbing shop or area of your hardware to get some fat resin cored solder rather than electronic solder. Do a search on my thread about head mods for more reading, but it seems RB is the easy way to get the job done for not much money, but you do need a measurement.

Yeah, ive done the squish a 10-15 times on other engines, but squish has been under 1mm. Squish at 1,5-3mm is enormous.

Re-did the gasket job yesterday, took me a solid hour. Changed 0,3mm gasket against 0,5+0,15, giving a total gasket value at 0,65mm. Now the engine wont even start.

Going to put on a 0,3 again, and use a 180 mainjet, 42pilot. Want the engine to go rich, but tried with a 188, and the thing wont get on the pipe.

Note: with 0,65 and un-touched head, my squish seemed pretty well over 1.6mm. Tried with a rosin cored solder 1.6 thick. Did not touch it.
Edit Note: With a single 0,3mm bottom gasket, still not under 1.5mm squish.

[(F5)]

Engine won't start? unrelated but interesting.

Yeah crazy squish clearances are common. They run nicer when closed up & a better chamber shape/squish angle. Worth the effort or money.

[jimjim]

You can find the solder @ napa online.

[stian]

Originally Posted by (F5)

Engine won't start? unrelated but interesting.

Yeah crazy squish clearances are common. They run nicer when closed up & a better chamber shape/squish angle. Worth the effort or money.

Yeah. Checked everything (and I do really mean everything.) kicked it over a thousand times, starter-gas and did emty the crankcase in case 2 times. Also changed the gear oil. After 2 days of cranking, it did start. Did spit massive oil.

In the winter time im going over the engine, new bearings and seals, clutch and going to cut down the head and raise the cylinder more.

Thanks.

[2taddict]

http://youtu.be/AJMv2bxPwgA

May help

[lonetree]

i have two 09 engines here, both have 1.3mm of base gasket stack, this is to get the piston level with the exhaust port at BDC....(standard from factory)
both had squish readings around 2mm, as standard... one i have had machined to bring the squish down to 1.3mm the other is waiting for spair cash....
changing base gaskets changes the port timming as well as squish...
get the head machined...
as for the solder, twist 2 or more strands together to get a thicker "rope" of
solder...

[(F5)]

I don't know why everyone gets so worked up about the bottom of the port lining up with the piston at BDC. It is the very least important attribute.

[Jakobi]

Originally Posted by (F5)

I don't know why everyone gets so worked up about the bottom of the port lining up with the piston at BDC. It is the very least important attribute.

It was just an easy reference point for a lot of people. Saying this, for the minimal time the engine is actually at BDC its not the be all or end all, and quite often dropping the jug can result in a much broader or more enduro specific spread of power.

I know with the 2013 model that the relationship between the transfers, boost, and exhaust ports are all different to that on my 2010 model.

What we all agree on is that having less tolerance at the head generally results in a cleaner, more efficient running engine.