Anyone Do Their Own Porting?

[buzzkill]

you guys should try hydraulically locking a motor !! We used to do this once in a while in Jetskis ! man it would KILL things blocks cranks etc. rods trash

 

[Seandonato73]

We 4 wheeled for years, hydro lock kinda happened every now and then. Worst was my brothers comanche, 2 bent rods and a section of the head gasket was literally pushed out between the head and block. That was a long day.....

 

[buzzkill]

We 4 wheeled for years, hydro lock kinda happened every now and then. Worst was my brothers comanche, 2 bent rods and a section of the head gasket was literally pushed out between the head and block. That was a long day.....

ya hydro is the WORST for sue !

 

[evssv]

ya hydro is the WORST for sue !

yeah sue hates it ? mary don't like it either

 

[MonsterAir]

 

[Seandonato73]

Skipped around on it abit, but yeah very tidy way to show what your looking for.

 

[Rep732]

I also remember that stroker engines weren't known for high revs but more torque and im not 100% sure about bending rods on strokers but I think you'll see valve float before a bent rod

 

[Seandonato73]

I also remember that stroker engines weren't known for high revs but more torque and im not 100% sure about bending rods on strokers but I think you'll see valve float before a bent rod

That depends on your spring set up, fortunately we don't have that issue with 2 strokes.

 

[john addinall]

did a 28.5cc for a friend today. no over the top port work. just added some timings on exh and inlet.

 

[szaki75]

did you lower the squish?
if you do that with thinner base gasket, you actually increase the inlet duration w/o touching the port

 

[john addinall]

did you lower the squish?
if you do that with thinner base gasket, you actually increase the inlet duration w/o touching the port

yes i did remove base gasket but was still far away from where i wanted to be with the inlet timing.

 

[szaki75]

i've cut my CY26 (25,4cc) to 173deg on exh and 155deg on inlet. but did not try it yet. TP's were just cut to flow... similarly to yours
how is your port durations that you wanna try? ... if i may ask

 

[john addinall]

squish 0,350
inlet 157 and exh 188

 

[Seandonato73]

If your squish is in inches that's really high, should shoot for 0.015 to 0.020"

 

[szaki75]

i’m sure it’s meant in mm.
0,35” would be 8,89mm.
0,35mm (0,014”) is on the low side, but OK’ish ?

 

[Seandonato73]

Hard to know when it's not stated, I've seen heads with 0.035" squish.

 

[john addinall]

jip that is in mm.
this is not a race motor, so i kept it moderate

 

[szaki75]

i do not want to open a new thread for this:
i'm about to port one more rovan g320rc for the +2mm stroker crank (for a non-reed case). when i calculate the blow down, i have 2 transfer ports. the one next to the exhaust port supposedly the main transfer, the other is the auxiliary. on a downstroke, the main opens about 3 deg LATER than the auxiliary (closer to the intake port).
which transfer port i should use to define the blowdown?

thanks in advance!

 

[Seandonato73]

Whichever opens first. But it's used to get the old charge moving out of the cylinder faster. The main transfer event is both of them open.

 

[Jshaff16]

Whichever opens first. But it's used to get the old charge moving out of the cylinder faster. The main transfer event is both of them open.

You gained a bunch more respect for that. So far over my head. Keep doing what you do Mr. Donato!!