Looper exhaust porting

[Merc 2.5]

I'm curious as to why not go vertex or similar? They can sure take a beating also without the siezeco problems. Just curious

[FMP]

Are those stock OMC piston not forged, it was posted they are? Wisecos aren't the issue.

[Merc 2.5]

Are those stock OMC piston not forged, it was posted they are? Wisecos aren't the issue.

Gotcha. Thanks. For sum reason I was thinkin forged, to lazy to read back thru whole thread

[FMP]

It least I think it was mentioned?

[powerabout]

Gotcha. Thanks. For sum reason I was thinkin forged, to lazy to read back thru whole thread

there are 2 engines in this thread, 2.7 with stock and now the 3.0 with wiseco

[Captain75]

how much bigger are you bores than 3.685"?
dont forget they are forged so expand more then permamold/hypereutectic stock pistons, hence seem loose when cold.
Personally wouldnt use them unless running well over 7k all day

3.685” = 93,599mm

#1: 93,609mm
#2: 93,579mm
#3: 93,619mm
#4: 93,579mm
#5: 93,599mm (spot on)
#6: 93,619

The figures might seem big, but for exemple #6 is +0,02mm which equals 0.00078”...

[Captain75]

I'm curious as to why not go vertex or similar? They can sure take a beating also without the siezeco problems. Just curious

Because the only +.010” I’ve found so far is WSM...

[Merc 2.5]

That's what I'm runnin in modded 2.5 200. So far so good. Just looked at bores with few hrs on it. Seems be doin fine, theres few other guys using em with good reports, but prob not reving 7k or much more

[mrichartz]

You already have the wiseco so just need to figure it out and get it back together
But Vertex is the way to go..what I have in my new power heads
I had wisecos in my other motors for 15+ years but never ran them above 7200 and still running good when I took them off except the one that ate a Reed stop but that doesn't count

[racer]

IMO pistons measured 90 degrees from pin, 1/2 inch from bottom. Looks to me maybe not clean enough prior to assembly, ring tip clearance too tight or a cooling issue. IMO when running 2.7 heads on a closed deck engine the gap between the chambers on the heads needs to be filled in like the standard closed deck heads, I also see you have very early style thermostats which may have not been controlling temp correctly, I would get new style with 70HP covers and springs

[mrichartz]

IMO pistons measured 90 degrees from pin, 1/2 inch from bottom. Looks to me maybe not clean enough prior to assembly, ring tip clearance too tight or a cooling issue. IMO when running 2.7 heads on a closed deck engine the gap between the chambers on the heads needs to be filled in like the standard closed deck heads, I also see you have very early style thermostats which may have not been controlling temp correctly, I would get new style with 70HP covers and springs

[powerabout]

3.685” = 93,599mm

#1: 93,609mm
#2: 93,579mm
#3: 93,619mm
#4: 93,579mm
#5: 93,599mm (spot on)
#6: 93,619

The figures might seem big, but for exemple #6 is +0,02mm which equals 0.00078”...

looks good then

[FMP]

If they're round, clean up hone, new rings, check cooling?

[Will hedrick]

I just stick my stuff in the dishwasher when the old lady is at work. It comes out clean.

That is one of the cleanest boats I've seen, hats off

[Merc 2.5]

That is one of the cleanest boats I've seen, hats off

Hey will. See your from tn. Where bouts?