stroker ?s

[trx750gsxr]

Any buddy know the diration needed as well as the spacer plate and dome size for a prodesign cool head on a 86 +4 stroker???

[Langbolt]

Duration is for the type of motor you want to build.

Low for woods - Med for MX - High for TT or Drag Racing

What I recommend is getting yourself a good vernier caliper.

Do you have a Spacer plate already ? (0.090" ?)

Install the cylinder on the motor and put the piston to TOP DEAD CENTER.

Measure how far the Piston comes OUT of the cylinder. This is the deck height value (negative if piston is above cylinder top)

Then Measure the distance from the Deck (top of cylinder) to the Top of the Exhaust port. This is the Exhaust port value

Stock bore - 66mm (Or is it bigger ?....port timing isn't affected by bore so I'll assume STOCK)

Stroke = +4 so 72+4 = 76mm

Rod Length = 125.5....for '86....but the piston skirt would hit the crank....I think you have a '87-89 style rod (Does it have HA 2 stamped on the beam ?)....if so it's a 130.5mm rod length

We're gonna want 30 degrees for blow down so I calculated your Transfer height as 57.0mm If your MORE than this....time to PORT your cylinder.

Are running a head gasket ? or O-Rings ??

I'll assume O-rings...hence the 0.0mm headgasket

Are you planning on running RACE fuel or PUMP gas ??

I'll assume Pump gas....

Here ya go!

[trx750gsxr]

wow thats pretty sweet. Yes i do need an 87/88 crank. Called hotrods today and waiting to here back from them. Said there might be something different on the mag side.....any input?

[Langbolt]

I thought you wanted to use the +4 stroker Crank ? So why would you need a 87/88 crank ? Or do you mean CONNECTING ROD ?

It'll take some time and machining to get it done.....but if you want a high torque motor it's well worth the effort.

My 275 is a +3 stroker and it runs awesome!



:devil: