Looper exhaust porting

[racer]

H2O is saying any edge on the liner needs to have the edge cleaned and have a small radius. Also looks like the cross hatch is too flat.

[Captain75]

H2O is saying any edge on the liner needs to have the edge cleaned and have a small radius. Also looks like the cross hatch is too flat.

These kind of inputs are the best! Helps me to put a critical perspective on things before reassembly!
Better pic of cross hatch:
Ok or too flat?

If I were to add more chamfer/radius to any of the edges, do I need to end up with a couple of passes with the honing device or leave it as it is?
What are your opinions?

I am thinking that edge-grinding creates sharp edges aswell (and so does rigid honing...)

[powerabout]

I think they meant the ports below the piston, where the air is going in not out, hence rounded edges?


Do you use a profile brush after honing?

[Captain75]

I think they meant the ports below the piston, where the air is going in not out, hence rounded edges?


Do you use a profile brush after honing?

That was my understanding aswell, but since I’m not native in english, sometimes I don’t see the actual meaning. And no, no profile brush. I have a ballhone, but its sized to fit the smallbore.

[H2OPERF]

Yes.. Not really below the piston but below the rings. The lower round finger openings and port runner feeder openings look sharp no chamfer radius.. it doesnt need to be as aggressieve as the upper port windows that the rings cross but the piston skirt rides in that area... also the skirt crosses the bottom edge of the sleeve.. I chamfer everything bottom and top... wipe the cylinder with a cloth and see what grabs fibers.

[Captain75]

Yes.. Not really below the piston but below the rings. The lower round finger openings and port runner feeder openings look sharp no chamfer radius.. it doesnt need to be as aggressieve as the upper port windows that the rings cross but the piston skirt rides in that area... also the skirt crosses the bottom edge of the sleeve.. I chamfer everything bottom and top... wipe the cylinder with a cloth and see what grabs fibers.

Tnx H2!
I will check again and adjust the sharper ones, guess I will do that w/o honing afterwards. If I just go over the grinded areas gentle with some 400grit emery w/o messing up the cross hatch. Ok!?

Did some head mods while waiting for you guys to wake up and give me some food for thought:

A couple of short pieces of hose

And some JB high heat putty

[racer]

Cross hatch looks ok from the side. Make sure even the vertical edges are not sharp. A cylinder brush is a good idea but not a ball hone once it has been rigid honed. What clearances do you have and with what pistons?

[Captain75]

Cross hatch looks ok from the side. Make sure even the vertical edges are not sharp. A cylinder brush is a good idea but not a ball hone once it has been rigid honed. What clearances do you have and with what pistons?

I am going over all the edges again to be sure.
Wiseco pistons, bores are 3.687-3.689.

[racer]

3.689 is getting loose

[Captain75]

3.689 is getting loose

I know. It was the price for straight and round...
I had the possibility to use an industrial 3-point gauge with far higher precision than my ordinary bore gauge. Compared, it seems my gauge reads a couple of 1/100mm too little.

The price for continous learning...

[Captain75]

Back again after an intense period at work.
Some more small mods were made before final reassembly.
Didn’t take more than appx two revs before it fired right up to a smooth but slightly high idle (on hose)

For that crackling sound...



If I want more noise...

[SS Minnow]

Tnx H2!
I will check again and adjust the sharper ones, guess I will do that w/o honing afterwards. If I just go over the grinded areas gentle with some 400grit emery w/o messing up the cross hatch. Ok!?

Did some head mods while waiting for you guys to wake up and give me some food for thought:

A couple of short pieces of hose

And some JB high heat putty

Have to ask, why would you do that to the heads? I get it, more power, but how does that help?

Also, thanks for posting all this stuff. I read all this type of stuff and just wish I had more time for this. One day.....

[Captain75]

[QUOTE=SS Minnow;3138189]Have to ask, why would you do that to the heads? I get it, more power, but how does that help?

It is a mod to make the cooling more effective when you use heads designed for open deck blocks on closed deck motors.
The hoses are used to create a mold until the epoxy has cured.
This is just a small part of a more extensive series of mods intended to level the temp btw higher and lower cyls.
Some of the OMC gurus can probably till you more if you are interested!

//Anders

[SS Minnow]

I ran a search on closed and open deck blocks and read a bit, looked at some pictures for reference, and yes, it makes sense now.

Open deck just kind of washes through where a closed deck guides the cooling water through. When you swap heads, you lose the controlled flow unless you do what you did. Am I close?

Thank you.

[Captain75]

I ran a search on closed and open deck blocks and read a bit, looked at some pictures for reference, and yes, it makes sense now.

Open deck just kind of washes through where a closed deck guides the cooling water through. When you swap heads, you lose the controlled flow unless you do what you did. Am I close?

Thank you.

In one of the last pages of Instigators thread ”Looper tech tips”, you can view a series of pictures showing the majority of the other mods included when modding closed deck cooling.
However some parts are missing, for example plugging water entrances next to the bottom cyls. This part is hard to show in a pic, you need to flip your P/H uppside down an access via the big cooling entrance that leads to the headers and rectifier etc.
I will see if I have a pic.

Ready for water an further break-in.
Once again, a big thanks to CCMS who provided me my c/c stuffers. The motor is extremely easy to fire up, probably the result of higher c/c pressure and thereby a strong and immediate signal to the carbs.