Looper exhaust porting

[Captain75]

[QUOTE=Captain75;2983533]Just put this block out for sale here in Sweden...
Attachment 385199

This baby was sold a couple of weeks ago to norwegian guy and his father, with the intention to power a custom made boat just exiting the mold.
They came all the way by car, and were really nice people! Hope the block and all the porting hours will make them happy

[Captain75]

Still waiting for my pistons to arrive from the U.S. In the mean time I am working with the cooling system. Since this closed deck will use an open deck thermo and control valve arrangement, I need to adjust at least to things:
1. Remove the poppit valve next to cyl no 2 and replace this one with an alu cover and a fitting. The coverplate has been made, but my question is how big should the outlet be?
2. The block needs to be tapped in order to fit the open deck control valve.

plate and possible fittings.

brw; can anyone give me the inside dia of the stock cooling hoses used on the open deck? I am not at home so I can’t take a measurement.

//Anders

[Captain75]

Finally, my pistons and bearings arrived from the U.S.!!



Beautiful stuff!
Right now trying to decide wheather I should enlarge the f/p holes to match the sleeves!?
The small paper sheet in front of the piston is a rub-off copy of the lower part of the sleeve, where the mixture will enter on its way to the ports.
There is definately a difference in size, I just feel an aversion towards the idea of grinding these beautiful parts. But if it will provide more power then I will do it

[Captain75]

Project moving forward, slowly... A bit too much at work and two of three sons having hockegames every weekend.

modifying the new pistons:


Difference between stock and modified f/p windows.

[NosBoss]

Looks good! I did the same to mine. Are you going to weigh the pistons and try to match them?

[Captain75]

Looks good! I did the same to mine. Are you going to weigh the pistons and try to match them?

I will try in the same way I did during the 2.7 build earlier in this thread.
Those were stock, hope these forged ones are closer from the beginning...
Within 6-8grams

[NosBoss]

I have one at 470 grams, 4 around 477 and one that is .010 bigger at 480. Not sure if I can get ten grams off that one.

[Captain75]

I have one at 470 grams, 4 around 477 and one that is .010 bigger at 480. Not sure if I can get ten grams off that one.

If you look on the inside you can see the pistonwall being thicker around the f/p windows, perhaps you could find 10g there?

[NosBoss]

What about the two protruding pieces sticking down from the top? They're small. I'm unsure why they are even there. I figured I would start by grinding them off.

[Captain75]

What about the two protruding pieces sticking down from the top? They're small. I'm unsure why they are even there. I figured I would start by grinding them off.

I think one of them covers one of the piston ring stoppers.
I think the other one use to do the same when the other pin used the stock location - in the fingerport area. Compare to a stock piston and you will see what I mean.

[NosBoss]

I just got home and took a look. You're right. The ring pins are in those spots.

[Captain75]

All f/p windows done. Once a have an evening available, I will make the final weight adjustments before starting reassebly.

[olboatman]

Good lookin work there Capt.!!!!!
Gary

[NosBoss]

Yup, looks good! What did you use to enlarge the holes? I used a reamer and cleaned it up with a dremel. Mine turned out nice.

[FMP]

If you look on the inside you can see the pistonwall being thicker around the f/p windows, perhaps you could find 10g there?

Drill it out off the pin?