Poulan 3400,3700,3800, 4000 stroked crankshaft project. Part 1

Mycamaro_68 said:

Also, how does adding stroke affect the port timing? All of this is very interesting and I try to learn anything I can.

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I bought a 2800 and was thinking of putting a bigger P & C on it. Aaron/Eccentric pointed out Ed/Arrowhead's thread and I have been studying the thread. I had planned on using the 2800 until recently. The 3450 has a wider case and more room in the carb/air filter area. I'll be better prepare to decide between the 2800 and the 3450 once I have the 3450 apart.
I like Ed's idea of using the MS380 magnum cylinder because it is such a large bore for a short stroke, the bolt pattern is small in relation to the bore and the transfers are closed at the bottom.
Port timing doesn't seem to change much. On the saw in this thread, the piston goes up .047" further and .047" further down. Between cutting squish and base, it can be moved where desired.
On the next project with 41.1 stroke, I'm using a piston and cylinder from a saw with 40mm stroke. That comes out to piston movement .021" further at each end(up and down).

After all this work how will it compare to a 5200?

I posted a video link earlier in the thread. I don't expect it will ever be anywhere near a 5200 in performance. When I get a 4000 piston and cylinder on it and port work done, I will post another video. I'm hoping for a noticeable gain.

If you need any bottom end parts i have a pile. Yours for shipping.

jeepsnchainsaws said:

After all this work how will it compare to a 5200?

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It will definitely be a hell of a lot lighter

@dieselfitter is what cc is your 3450? I think I read somewhere they made them in both 60cc and 54cc.

Mycamaro_68 said:

It will definitely be a hell of a lot lighter

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I don't think my 5200 is to heavy, but I have never ran a 3400 either. This build is very interesting... Can't wait to see it rip!

For what they are, I don't think the 5200 series of saws is too heavy either but I am pretty sure the 3450 and similar saws are around 12 lbs or so.

Wagnerwerks said:

If you need any bottom end parts i have a pile. Yours for shipping.

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Thanks for the offer. I'm sitting pretty good. That's the thing about these saws, they are cheap and easy to come by. When I'm finished with these projects, I'm cleaning house on all the extra parts.

Mycamaro_68 said:

@dieselfitter is what cc is your 3450? I think I read somewhere they made them in both 60cc and 54cc.

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Mine is 54cc. I wish it were a 3450 type 3, 60cc. I would like to try one of the 60cc cylinders on a 3400, 3700... family saw. I suspect it would mount easily and have a better intake port/carb mount.
In fact, the 54cc 3450 uses the same piston as the Poulan Pro 335. The Poulan Pro 335 is a 54cc version of the 2800.

Just swapped a 335. It was a great saw. I kinda miss it. Lol.

My PP335 has a scored piston. I'm going to put the 3450 piston in it and get it running. I need to chase down an air filter and air filter cover for it.

Great stuff Tim. Looking forward to part 2

dieselfitter said:

My PP335 has a scored piston. I'm going to put the 3450 piston in it and get it running. I need to chase down an air filter and air filter cover for it.

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I may have the cover... Ill have to check.

Wagnerwerks said:

I may have the cover... Ill have to check.

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Thanks Kris. I just got a part saw with a cover on Friday. Now just needing an air filter. If you are needing anything, let me know. I have some extra 2800 parts.