Poor man’s (kid’s) stroker

[89 MJ]

I want to build a stroker for my MJ as it needs a new crank anyway. I was just going to buy a new crank, but I wanted to know what all it takes (parts and money wise) to put a 4.2 crank in a 4.0 and how much HP it gives. Thanks. 

[JustEmptyEveryPocket]

site:comancheclub.com poor man's stroker

 

Plug that into Google and read threads to your heart's content.

[Eagle]

The stroker guru is Dina Savva.

 

https://duckduckgo.com/?q=dino+savva+stroker&ia=web

 

The biggest issue is compression. The deck height of the 4.0L engine is slightly different from the deck height of the 258/4.2L engine. If you just use the 4.2L rods along with the 4.2L crank and stock 4.0L pistons, the compression is too high. There are ways to deal with that. Too much to get into here -- follow the links in that search page I posted, and happy reading.

[89 MJ]

10 hours ago, JustEmptyEveryPocket said:

site:comancheclub.com poor man's stroker

Thanks I’ll do this. 

[89 MJ]

5 hours ago, Eagle said:

The stroker guru is Dina Savva.

 

https://duckduckgo.com/?q=dino+savva+stroker&ia=web

 

The biggest issue is compression. The deck height of the 4.0L engine is slightly different from the deck height of the 258/4.2L engine. If you just use the 4.2L rods along with the 4.2L crank and stock 4.0L pistons, the compression is too high. There are ways to deal with that. Too much to get into here -- follow the links in that search page I posted, and happy reading.

This site has been very helpful. 

[Limeyjeeper]

The biggest issue is the no 6 lifter which has a habit of collapsing on a stroker. Normally caused by going with too heavy a spring rate. If you stay stock springs and cam and use oil with zddp such as Amsoil Z rod you will be ok. As Eagle said getting the quench and compression right are key. However it is extremely hard to build a stroker that will run fine on 87. All mine have needed at least 91 to perform. Expect to pay at least $2k for a stroker with all the machine work and parts. A poor mans stroker with new crankshaft, bored +060 block, 4.0 rods, new pistons will probably give you 220-230hp in the real world. I have a Mopar stroker in mine right now which is advertised at 215hp but is really more like 230hp. The highest HP stroker I ever did had a ported head, headers, intake, performance cam and I got about 265hp out of it. Expect your fuel consumption to increase significantly.

As a minimum you will need, crankshaft, bearing set, new pistons +030 or +.060 bore, the block will need decking to get the right quench and CR. timing chain, cam bearings, gasket set. Good to get the rods balanced and cleaned up. New pins etc. I am sure there is more. Dino's page is by far the best. Strokers forum is ok but there can be a lot of confusing info on there. Dino's site is http://www.angelfire.com/my/fan/stroker.html

 

[89 MJ]

Thank you!

[fiatslug87]

7 hours ago, Eagle said:

...Dina Savva.

 

WOW! Now that's a blast from the past!

[ghetdjc320]

On 9/15/2019 at 1:44 AM, fiatslug87 said:

 

WOW! Now that's a blast from the past!
 

LOL, no kidding. I built my first stroker with his "recipes". http://www.jeep4.0performance.4mg.com/photo3.html