Poulan 3400,3700,3800, 4000 stroked crankshaft project. Part 2

[Nitehawk55]

If it were me I would keep the compression to 180-ish just so it's not too hard on the bottom end as well as the recoil .

And I should add it may delete the need for a decomp .

 

[Jonsered_raket]

Looking good Tim! We have to see what kind of compression it's making, we got to be nice to those needle bearings. Hopefully the ported saw polishers don't knock my work too much, These ports are not done yet! Glad to be able to help on this project, it's been a great learning experience.

 

[Red97]

Looking good Tim! We have to see what kind of compression it's making, we got to be nice to those needle bearings. Hopefully the ported saw polishers don't knock my work too much, These ports are not done yet! Glad to be able to help on this project, it's been a great learning experience.

You happen to remember the port numbers? Curious to see where they ended up before/after.

Tim, you plan on adding a decomp in the head?

I really like where this is going.

 

[dieselfitter]

Gentlemen, the brains behind this project has arrived.
The new cylinder head is about 3/8" shorter than the original. The plastic covers can be lowered a bit.

 

[dieselfitter]

You happen to remember the port numbers? Curious to see where they ended up before/after.

Tim, you plan on adding a decomp in the head?

I really like where this is going.

I'm thinking of putting a decomp on the left side. It's looking like it may be a challenge.

 

[Jonsered_raket]

I remember exh was 105, trans was 121 and intake had around 156 duration. That's all I can remember. Once we get head on we can nail down numbers. I didn't have exact tdc on wheel. I was just checking to see where the heck it was at, it's pretty damn close for being such a frankensaw I thought.

 

[Jonsered_raket]

If we keep comp at 170-180 you won't need a decomp, itd be nice for a guy with a bad shoulder but not necessary. I'm guessing it was making more than that in first trial video.

 

[Jonsered_raket]

And Tim you have ecodrain spelled wrong on your sig.

 

[Jonsered_raket]

Gentlemen, the brains behind this project has arrived.
The new cylinder head is about 3/8" shorter than the original. The plastic covers can be lowered a bit.

Haha Tim is giving me way to much credit, I'm just the guy with piles of parts. He's the one doing the work, don't let him fool you.

 

[Red97]

I remember exh was 105, trans was 121 and intake had around 156 duration. That's all I can remember. Once we get head on we can nail down numbers. I didn't have exact tdc on wheel. I was just checking to see where the heck it was at, it's pretty damn close for being such a frankensaw I thought.

Yeh that don't seem too bad for a shake down/baseline run.

 

[dieselfitter]

UPS has come and gone. No head bolts today. I re-routed the kill wire through the case and along side the cylinder spacer block. I used liquid electrical tape to seal around the wire where it goes through the case. I milled a groove into the block and used silicone to hold it in place.

I relocated a wire hold down tab.
I made some block off plates for the carb and exhaust. Adam is bringing a hand vacuum/pressure pump to check the crankcase for leaks. I have 2 of them, they don't hold pressure/vacuum. The degree wheel is set up for Adam to do his thing.

 

[Wagnerwerks]

UPS has come and gone. No head bolts today. I re-routed the kill wire through the case and along side the cylinder spacer block. I used liquid electrical tape to seal around the wire where it goes through the case. I milled a groove into the block and used silicone to hold it in place.

View attachment 49135 I relocated a wire hold down tab. View attachment 49136
I made some block off plates for the carb and exhaust. Adam is bringing a hand vacuum/pressure pump to check the crankcase for leaks. I have 2 of them, they don't hold pressure/vacuum. The degree wheel is set up for Adam to do his thing.
View attachment 49137

I love this build...

For the vac testers, find a little check valve for a car an run it in line to get them to hold. Ive done this to my own for work and my old mityvac when they started to leak down. Super cheap and effective.

http://www.siliconeintakes.com/liqu...m-one-way-check-valve-8mm-barbed--p-9581.html

 

[dieselfitter]

It pressure tested good. Adam did his porting thing. It is ready to put together, just waiting on head bolts. The plan is to put it in wood tomorrow night when Adam gets off work.

 

[Rob Stafari]

It pressure tested good. Adam did his porting thing. It is ready to put together, just waiting on head bolts. The plan is to put it in wood tomorrow night when Adam gets off work.

Excellent! Been looking forwards to this. Well done sir.

 

[old guy]

Dang Tim, if it wern't so cold I'd come over & watch.

 

[czar800]

It pressure tested good. Adam did his porting thing. It is ready to put together, just waiting on head bolts. The plan is to put it in wood tomorrow night when Adam gets off work.

Can't wait for the show to start!

 

[dieselfitter]

The head bolts arrived. I fired it up in the fixture. I had put new rope in the recoil. The knot pulled through last time we started it. Today it pulled through or broke twice. I put another new, longer rope in it today. It sounds good. I'll get in wood later. I have other commitments to attend to.

 

[awol]

That is very nice! Sounds like a really warm 288 at idle!

 

[dieselfitter]

It exceeded my expectations of a first cut. There is more to get out of it with tuning.

 

[dieselfitter]

The chain is fresh off the roll Oregon. The wood is dried Boxelder. Boxelder is a soft wood. When dry, it cuts like Oak.
Adam and I think the timing could be advanced.