Stroker???

[matt texass]

here are some questions, concerns and things ive just had on my mind about a stroker motor....... a lil late i guess since i already sent off for it but owell. What is piston slap and what causes it (ive heard of some strokers having problems with this), with the stepped up displacement how will the computer react... even though it will have a custom tune im just curious. And does anybody have any other usefull knowledge or things to watch out for?

the stroker will be using stock top end for now. JBA longtubes with catted mid pipe. Hooked up to a tci 3000 stall speed converter. I will also be lookin to up my giggle gas shot from 100 to 175 or 200. (this info is just incase you need more)

Thanks

 

[ChevyKiller]

To put it simply and easily, some have said you can get 0 slap, but there is some degree of slap on any stroker. The degree IMO is purely based on piston clearance, i.e. a motor with a .004 clearance is going to have more slap than a motor with a .003 clearance.

The tighter the piston clearance, the less slap and noise you will here IMO.

I should point out though that it doesn't necesarily mean that tighter is 'better' - just the clearance effects how much slap and noise you will get especially when cold.

Talk to your builder about what you want and what you're looking for and he should be able to recommend a clearance that works for you and what you want to accomplish.

 

[94tbird]

+1 mark is dead on with his assesment above!

 

[cekim]

+1 mark is dead on with his assesment above!

I would add to that:

Geometry of the longer stroke means more extreme angles of the rod relative to the piston at various points in the cycle (i.e. the rod going out sideways relative to the piston/bore). That movement puts side-load on the piston/pin/bore that gets larger as the stroke gets longer relative to the bore...

As for the tune - some quantity of the tune adjustment is accomplished with a "displacement" coeficient that fixes a number of calculations, but any time you make significant changes to the engine, the amount of timing/cam it will want changes as well...

When you start moving things around, you are likely to change the effective compression ratio (if you dont change the mechanical out-right). This also will influence the timing parameters...

 

[Larry_H]

Whether or not you will have noticable piston slap is determined by the factors mentioned above and how your motor is built. Forged pistons vs. Hypereutectic pistons, applied secondary coatings, and piston to cylinder wall clearance, etc. Some builders will tell you that piston slap is a "cost" of having a stroker. Some know the tricks of how to negate the effects of the stronger sideloading that can cause piston slap. Find a builder that knows the tricks.

 

[ZmanM3]

Hmm some good information being put out here.

 

[94tbird]

i went the route of non stroker. from everything i have read, they tend to be not as reliable as the stock displacement. i dont know how true that is but reliability is key for me

 

[MrClean]

i went the route of non stroker. from everything i have read, they tend to be not as reliable as the stock displacement. i dont know how true that is but reliability is key for me

+1 on the reliability, although the added displacement is nice in terms of low end torque.

Granted, I only have 2800 miles on my car (I will have had it for 8 weeks on April 18th), and I've only had the C&L+Doug's tunes for about 2 weeks, but I'm still amazed how this car hauls in the almost stock condition. I especially love the switch to the secondary cam at 4500....

 

[thump_rrr]

+1 on the reliability, although the added displacement is nice in terms of low end torque.

Granted, I only have 2800 miles on my car (I will have had it for 8 weeks on April 18th), and I've only had the C&L+Doug's tunes for about 2 weeks, but I'm still amazed how this car hauls in the almost stock condition. I especially love the switch to the secondary cam at 4500....

BTW there is no secondary cam.
It's a SOHC.
What you are feeling is the CMRC opening the butterflies in the intake which comes on at around 3500rpm.

 

[94tbird]

BTW there is no secondary cam.
It's a SOHC.
What you are feeling is the CMRC opening the butterflies in the intake which comes on at around 3500rpm.

+1 no second cam. peters dead on

 

[MrClean]

BTW there is no secondary cam.
It's a SOHC.
What you are feeling is the CMRC opening the butterflies in the intake which comes on at around 3500rpm.

Oops! I coulda sworn it was a DOHC unit...my bad ...and I rag on people that don't the tech about their car!

Whatever it is...I feel it at 4500....what a rush.

OFF TOPIC: BTW, I guess the switchover to Sr Member comes at 100 posts, 'cause I am one now! (I'm probably one of the "senior" members in another context ...looking at 94tbird's profile he's only 24...but thump is in my neighborhood!)

 

[ZmanM3]

Oops! I coulda sworn it was a DOHC unit...my bad ...and I rag on people that don't the tech about their car!

Whatever it is...I feel it at 4500....what a rush.

OFF TOPIC: BTW, I guess the switchover to Sr Member comes at 100 posts, 'cause I am one now! (I'm probably one of the "senior" members in another context ...looking at 94tbird's profile he's only 24...but thump is in my neighborhood!)

Geezer!

 

[MrClean]

Geezer!

Getting old beats the alternative !

 

[ZmanM3]

Getting old beats the alternative !

You have a point!

 

[travelers]

It's not time to push up daisies.

 

[MrClean]

It's all good...just making a point...