288 Piston in a 660

[Vintage Engine Repairs]

Thanks for bringing us along Al, I can’t wait to catch the first start!

 

[Brewz]

Thanks for the reply. Wanted to try one for myself.

I’ve heard it’s a lot of work for not much more gain. I’m only at 65% bore width on the exhaust, which is where many take their builds without a lot of short circuiting. In addition, I’m right on the edge of the stock piston‘s skirt, I probably coulda gotten away with it, especially with a the winged skirt type slug.

I didnt do fingers, hard to make them not just push the flow circuit back towards the exhaust. I am making sure to have at least 40-45* of case compression and to keep the transfers as tight as possible to prevent short circuiting. In addition, opening the transfers at the ex side first gives them a better chance to push charge away from the exhaust.

The piston is already lighter than an 066 one. And it’s gonna lose even more weight when I clean up the casting flash and add a 395 pin.

As for the exhaust, I always do rearward placed side exhausts. Front openings don’t allow the sounds waves to collide and cancel each other out. It’s just loud without a lot of gain.

Guess I’ll see if the lemon was worth the squeeze.

use a tapered 880 pin and grind it to length.
The husky pins are thicker and heavier

 

[drf256]

use a tapered 880 pin and grind it to length.
The husky pins are thicker and heavier

Ain’t got one. Piston and pin are currently lighter than the stock OEM 660 piston and pin. I may bore out the meteor pin. It’s super thick.

I’ll post pics when I get there.

 

[Brewz]

Don't have one...... Stihl shops sell them haha
Only gets you a couple grams.
Not really important unless you are chasing every last bit.

 

[drf256]

Buttoned up the long block last night after work.

 

[drf256]

Wound up using the Duke piston and pin, and the meteor circlips and Caber ring.

 

[drf256]

 

[Glock37]

Great work Al
cases look great should be awesome when done

 

[drf256]

Great work Al
cases look great should be awesome when done

You did the powder. Excellent work, as always.

 

[drf256]

Gathered up some parts. Going all NOS OEM on this one wherever I can.

Weekend supposed to be a rainout. Will give me some saw time.

 

[drf256]

Had the stuck oil pump syndrome. It had to come apart.

 

[drf256]

Got a few hours in on the saw. Rough time of the year.

This saw, which was supposed to be all OEM came to me with a load of AM parts. They make the work 6 times as hard to do. I have to search my parts bins for brake parts and redo most of what I did yesterday at this point. Plastic covers I generally use, but usually nothing else. The brake assembly cover is warped, or is cast wrong and hits the spring.

 

[drf256]

 

[drf256]

Done. Run next week. Needs some fine tuning still. The carb box plate, unbeknownst to me, is am and not fitting correctly. Also need to find an oem oil cap.

 

[drf256]

Here’s an annoyingly long test and tune video. Seems to have lived. Tuned around 13500 in the video.

Didnt have any really big wood to test it in.

 

[drf256]

Best oil cap I could find. Upon first fueling, I remembered that new oem tanks don’t include fuel filters, luckily had one.

Gonna run a few tanks through her, then she’s heading to the new owner after a detour to Red97.

 

[Powerstroke Cowboy]

Very nice build! If you don't mind. What color and type of paint did you use for the crankcase?

 

[Johnmn]

Very nice build! If you don't mind. What color and type of paint did you use for the crankcase?

I'm sure it powder coated by @Glock37

 

[NateSaw]

Being dyno'd?

 

[NateSaw]

Immaculate work doc
Things gonna be IGNORANT when the rings seat.