Stroker Kit

[MichBC3]

In all of the stroker discussions that I've read so far, nobody seems concerned about the additional cylinder side wall thrust force that would be generated. I've had two different blocks checked for cylinder wall thickness and they generally measure not much more than 0.100". That's not very much - especially if a block has to be bored. In that respect, a standard stroke combo would be better for reliability.

Some have also mentioned camshaft to connecting rod interference issues which require machining the connecting rod or rod bolt a bit. Not desireable - could compromise strength.

Has anyone experienced oil pan rail and internal block clearance problems that require some grinding? Has anyone ground through into the block's water jacket to gain adequate clearance? Haven't heard that reported yet. Perhaps that's not a problem with a 109?

 

[dank GN]

What kinda heads are you planning on running? You definitely need a free flowing set as the stock heads are pretty crappy in the flow department. You need to think about your entire combo . Here is a picture of the stock intake ports to a felpro 1200 gasket just to give u a idea of there restrictions.

 

[MichBC3]

Hi dankGN - Not sure if you are addressing me, but I appreciate all input. Like many others, after experiencing some engine trouble that now requires a teardown, I am going to purchase an all forged bottom end and go to internal balancing to upgrade things while I'm in there.

I am considering changing to a stroker combo, so am doing some research before purchasing parts. From previous experience with small block Chevys, I know that increasing stroke by 0.250" makes a huge difference when it comes to torque. And that increased torque comes at practically no difference in cost for my conceptualized re-build/forged turboBuick combo.

But anyway, I have been using heads ported by Champion since 2010. No worries about intake gasket match. Power/flow was plenty good enough for street driving before the rings got pounded out from a weak fuel pump that I didn't know about. FP gauge in passenger compartment now installed...

 

[dank GN]

If you have the cash to go stroker go for it . You will feel more power down low. The thing with these motors u have to have a competent machinist do the block work . As long as you do that it sounds like you will have a decent street/strip car. I was referring to you believe it or not there is guys out there that would cheap out like that . Go with a nice stroker setup then slap some bone stock poor flowing heads on it . Anyway keep us updated on your build . Okay

 

[Mr.Spool]

In all of the stroker discussions that I've read so far, nobody seems concerned about the additional cylinder side wall thrust force that would be generated. I've had two different blocks checked for cylinder wall thickness and they generally measure not much more than 0.100". That's not very much - especially if a block has to be bored. In that respect, a standard stroke combo would be better for reliability.

well i have posted several times about the limitations of the 109,with a killer tune and builder.the limitation is in the block itself specifically in the cylinder walls

 

[MichBC3]

well i have posted several times about the limitations of the 109,with a killer tune and builder.the limitation is in the block itself specifically in the cylinder walls

Sounds right to me. So that would be a good reason not to stroke the 109. However, as we know there are a lot of folks running stroked 109s that rave about them. If they DO ever develop a problem, it might be hard in failure analysis to determine for certain that it was due to extra stroke and thin block walls.

So I'm still 50/50 on making a decision. I appreciate the discussion and opinions though.

My preference is not to use a 6.350 connecting rod as some kits offer. The piston pin gets moved up into the scraper ring. The ring package gets bunched up and the top ring gets very close to the top of the piston. To my way of thinking, that's not good for reliability. In a street engine, not necessary. I've basically decided to stick with a 5.960 rod no matter what stroke I ultimately choose.

 

[dank GN]

Sounds right to me. So that would be a good reason not to stroke the 109. However, as we know there are a lot of folks running stroked 109s that rave about them. If they DO ever develop a problem, it might be hard in failure analysis to determine for certain that it was due to extra stroke and thin block walls.

So I'm still 50/50 on making a decision. I appreciate the discussion and opinions though.

My preference is not to use a 6.350 connecting rod as some kits offer. The piston pin gets moved up into the scraper ring. The ring package gets bunched up and the top ring gets very close to the top of the piston. To my way of thinking, that's not good for reliability. In a street engine, not necessary. I've basically decided to stick with a 5.960 rod no matter what stroke I ultimately choose.

If you stroke it you need to run a longer rod to get the proper stroke to rod ratio. 6.350 is perfect for a 3.625 stroke . I’m running a 3.625 stroke with 6.5 rods now that is alil on the long side . You should read up on rod to stroke ratios and there benefits. With a short rod your pistons will be rocking like crazy in the bore amongs
Other things . Anyway would love to know how it turns out for you

 

[Mr.Spool]

However, as we know there are a lot of folks running stroked 109s that rave about them

Sure,but you need to understand compression plays a huge role in how the motor will feel and the response the turbo will have.a stock stroke 109 with compression and the right cam and heads even with a stock crankshaft will support more than the block will tolerate.

 

[captndave737]

I stayed with stock stroke when I rebuilt mine. I did go to 9.47:1 compression and it pulls like a beast. Forged bottom end, ported heads and intake and roller cam and rockers may come into the equation as well.

 

[Clark6]

I went with 5.960 rods as well,,, I think my compression is 8.645 mine wasn't coming from stock though more like lo 12s with items in my sig 10s was easy. at 24 psi boost.

 

[jasjamz]

I stayed with stock stroke when I rebuilt mine. I did go to 9.47:1 compression and it pulls like a beast. Forged bottom end, ported heads and intake and roller cam and rockers may come into the equation as well.

"Pulls like a beast"... dont all turbo buicks give that feeling. I get what you're saying but others may need a bit more of a comparison.

Sent from my SM-G955U using Tapatalk

 

[captndave737]

"Pulls like a beast"... dont all turbo buicks give that feeling. I get what you're saying but others may need a bit more of a comparison.

Sent from my SM-G955U using Tapatalk

Before and after the rebuild is night and day. 659 hp onthe dyno.