rovan 32cc squish meausuring

[MonsterAir]

Hello

Just a tip,, use some large tygon fuel line and slide over the spark plug cable,,to guard interference

That's not a terrible idea. I tried tape, RF collars and come to think of it I actually put tubing over the throttle and brake linkages all to no avail. My little guy moves just fine that I didn't need any extra spark. 71mph with a 27cc.

 

[Wholeshot]

That's not a terrible idea. I tried tape, RF collars and come to think of it I actually put tubing over the throttle and brake linkages all to no avail. My little guy moves just fine that I didn't need any extra spark. 71mph with a 27cc.

Nice

 

[davehour]

Hi,

Do Tygon shields against RF interference?

 

[Seandonato73]

Never seen a rubber or synthetic used purely as rf shielding. Normally it's a grounded foil type. In our vfd's at work they are super sensitive to rf interfearance and have a double shield built into power and signal wires. One foil and the other a stainless weave. They are tray rated cables and live out doors so have a very heavy synthetic rubber outter jacket. Jacket doesn't really do much.

 

[szaki75]

More then on one occasion I've seen people get greedy with squish clearances and have a head banger. In reality there's no reason to go under .020".

Variable compression rods are a thing. Increases compression as you accelerate and prevents damage caused from detonation.

 

[Wholeshot]

View attachment 82368
Variable compression rods are a thing. Increases compression as you accelerate and prevents damage caused from detonation.

Nice example haha ....but wont happen in our toy car engines

 

[szaki75]

i actually checked without the gasget and still 1.3 mm so waist of time .zenoah will fix it.

if you have access to a lathe, you can cut the cylinder base to come to a squish of 0,02", like i did on my rovan.

my initial squish was 1,4mm.
as someone correctly pointed out, you need to restore the port timing after lowering the head.

alternatively, you can consider to change the crank to the rovan stroker, but then you might have issues with some free-porting at exhaust side (@tdc) and on the intake side too (@ bdc). the later can be easily corrected with some JB Weld work.

this case you do not need to cut the base and can still use the base gasket (you actually have to, to ensure the minimum squish clearance)