What does this porting job look like

[michaelbrenner]

I think this isn't much more than what people generally do to 'clean up' the sleeve/cylinder mismatch but it's hard to tell. Could you guys give me some opinions. It's a 61x cylinder of course with a 62t case that has been epoxied and mildly blended in not really 'notched' just smoothed and blended in on the case work.

My question is, how do you think this engine will respond to a factory pipe? Should I run a limited chamber or would this cylinder benefit dramatically from a mod chamber? I think the head has been milled to run around 170-180psi but haven't done a compression reading yet. What do you guys think? The exhaust port looks pretty good to me! All the blending is really smooth and appears to have been done nicely.

 

[eel]

It's not bad, the ex. port roofs are a bit different in shape. One of the transfers next to the boost is a bit wonky. It lacks a bit of attention to detail but if the port timing suits what you want to do, it will make good power. Without knowing the durations it's hard to give pipe advice. I would be tempted to run the ltd chamber.

 

[Matt_E]

Transfer duration and exhaust duration is raised.

Not the best for bottom end. But give it a try. Good compression, pipe and ignition should make it go.

 

[RideItLikeYouStoleIt]

Exhaust definitely looks alil high for bottom end.

 

[michaelbrenner]

So to take advantage of what kind of powerband it already has I might want to stay really shallow on the impeller and get a swirl 12/17 cutback right. To get it up in the rpm quicker.

Should I go with a mod chamber? One person says limited. Even if it's not THE best for bottom end, having a limited chamber should help out and the porting isn't extreme I don't think from what I've seen. I guess it'll have some good midrange pull.

I've filled the crossover on the intake and will run stock 38's with an MSD and lightened 6m6 flywheel. That should help too right?

My goal is to have a reliable and realitively economical (on fuel) surf/bay ski. Top speed is very secondary.

 

[Matt_E]

Limited is the best for bottom end, with that cyl.

 

[jetskiier]

Your piston is #$%@ed!

 

[eel]

'[]=-----------------------------------------------------------------------------.

That was the cat's opinion.

Go the ltd pipe.

 

[John_Ciocca]

Greg Beaver from Circuit Jet Sports in Huntington Beach, CA ported the cylinder and cases. This engine came straight out of his "rec" ski that he owned for many years.
Greg makes engines more for racing than freestyle, which explains the raised ports. Either way the price was good....This engine should make good power.....

JC

 

[michaelbrenner]

John C actually hooked me up on this motor. I just took it apart and cleaned it up since it had some sand on the crank from storage and that bothered me a bit. I think the motor will make great power. It's currently at 82.5mm and the bore looks ok. Might have to go to 83mm to clean it up. 84mm might, even be in the future. We'll see. Just need a B pipe and ponying up $750 seems like highway robbery.