JP magazine's Stroker "Insane Inline" is DEAD

[jsawduste]

Flash,
reread tirods and my post(s). What we are trying to say is that the engines are designed within a set of defined parameters. When something upsets that defined parameter a stock part will likely be a compromise or a failure.

Take your example of rocker arms.
First off a used arm should never be reused if the cam lift is changed for the very reasons you state.

The stock rocker arms are not designed to run .480 lift cams. Thus a set of rollers would be a better choice.

However if the block or head is milled. A shorter pushrod will bring the valvetrain back into the original design parameter.

Look at the big picture then break things down into smaller ones. Read the fine print and go from there.

I know my answer jumps around a bit and does not take all the nuances that could happen. The engineers who designed this engine did a pretty fair job. Try and look at what you are doing through there eyes.

[Flash]

Yeah, I agree with every thing.

the rocker arm example, was just somthing for those thing about a stroker or 4.0L with a bigger cam and can't justify the extra price for a roller rocker that is intended to handle more life and spring pressure.
(acutualy, it was somthing, that just clicked in my head when i read the previous post and deside to share )


Flash

[John]

Flash,
reread tirods and my post(s). What we are trying to say is that the engines are designed within a set of defined parameters. When something upsets that defined parameter a stock part will likely be a compromise or a failure.

Take your example of rocker arms.
First off a used arm should never be reused if the cam lift is changed for the very reasons you state.

The stock rocker arms are not designed to run .480 lift cams. Thus a set of rollers would be a better choice.

However if the block or head is milled. A shorter pushrod will bring the valvetrain back into the original design parameter.

Look at the big picture then break things down into smaller ones. Read the fine print and go from there.

I know my answer jumps around a bit and does not take all the nuances that could happen. The engineers who designed this engine did a pretty fair job. Try and look at what you are doing through there eyes.

Well said. There's a lot more to building engines than assembling parts from a recipe found somewhere. When we modify a component, without considering what else will be affected is foolish. Every time I change something I find a couple of things that must be addressed because of the first modification. Sometimes that ripple effect goes a long way. That is above the proper selection of components that should be changed during a major rebuild anyway. The stroker community has barely defined a reliable baseline stroker build. We all knew that guy who built motors that blew up. Ran like hell for a while...
John

[jsawduste]

John and Tirod,
Thanks much for putting into words, the thoughts I have been trying to convey to the stroker community but have failed miserably.

[John]

Why do you think you failed, I have listened and nodded yes.
John

[jsawduste]

John,
Your comments are held in the highest regard.

Perhaps my thoughts are jaded. It just seems that an awful lot of effort is placed on trying to band aid an approach that deviates from the original (proven) design parameter. A stroker is really a simple beast.

A contradiction of sorts.
All we are really doing is adding to the overall displacement of the engine. Along the way it is possible to improve on some factors such as bore to stroke ratio and potentially rod length to bore/stroke ratio. In addition increasing the intake and exhaust charge/discharge event(s). Thus increasing the potential efficiency of the engine. Some factors, such as quench have
proven to optimized at what was a close match to factory design.

An example I have struggled with is the use of aftermarket pistons. Without the proper piston pin height (location) there is the risk of pulling the piston to far out of the bore at BDC for it to be properly supported. The catastrophic stroker failures that I have seen have followed this pattern. Folks have concentrated on the compression, quench and deck height without addressing the opposite end of the BDC spectrum. A factor the requires as much thought as the event at TDC.

Another is the use of a cam to "bleed" off compression as a means to control detonation and/or pre ignition. Two separate things. A cam should be used as a tool to match what you are looking for the engine to do. Granted there are proven events that a cam can do to (an)engine event(s). For the most part those advantages are lost in a (this) engine design(ed)/used as most strokers will typically see.

Again John, thanks for the kind words. I may not have the ability to express myself in the best way but I have tried to think the stroker engine as the sum of the individual parts and how they work together.