Stroker Rods Decision

[Billman]

@Caterpillar

You said on a previous post that: the longer rod/stroke ratio,more rpm,less stress on the pistonsQuirt and sylinderwalls.

Onlsonjus said also that the most stress is with the 155 and not with the 158 rods!

[Audi_CQ]

Is there enough space to fit the 158mm rods (i mean on the block downside walls)!

So most of you think i should go for the 158mm 23mm pin, dont you???

I'm using ~155mm rods with Verdi rods and had to grind a bit to make clearance at the bottom of the block. No problem at all with a dremel or similar

[AnLe]

this maybe stupid question, but why dont you just buy the pistons and then you see what rods you need? it much easyer to order custom rods than pistons.

[Billman]

I prefer to have the right rods and then to look for pistons!

[Billman]

So, after this i can see th efollowing aspects:
As always for the SPM rods:

1. 158mm 23mm: Good Rod/stroke ratio (less cylinderwall loading), good piston Pin

-Will there be sure enough space for the Piston Rings and compression height?? Also will they fit on the block? Is there enough material to Grind?

2. 155mm 20mm: Nice Rod/Stroke Ratio (more cylinderwall loading), enough space for OEM compression height

-Can this Piston Pin handle much Power?

I personally be happy if i can do it with the 158mm 23 Pin!

Thanks For your help till now!

[caterpillar]

you may get in org form 159(!!!!) mm in 4syl application(2,0liter)....20mm xpin you may use if you dont exide over 700hp..... i will go for a bulletproof bottom end,and go for a safe engine,because i have a really BAD car to change the engine,if it broke.have not a s2,but a 32b vw(quantum)

[olsonjus]

The amount you have to grind at the very base of the cylinder is very small. There is plenutm of material there, so you dont have to worry about grinding too thin.

Like Caterpillar said, the vw 2.0 8v comes stock with 159mm rods with 21mm pins. You could use the factory rods from this motor and you wouldn't have any issues with clearance. The problem you get into is the aftermarket rods are physically larger, and require small amounts of grinding at the base of the cylinder walls.

The ABA rods are what I'm using in my motor buildup and am confident that the wrist pin is large enough to take the 800hp I'm looking to make. I'm using off the shelf pauter rods made for the ABA 2.0 8v.

[Billman]

I want that the engine will be very strong! Not going for 800 HP but i want it strong!

since you say there is no problem with the long rods and pistons (compression height) and the cylinderwalls then I go for the Sten Parner 158mm 23mm pin!

@Olsonjus
The piston with the 158mm 23mm pin must be almost the same as with the 159mm 21mm pin dont they (in a AEL diesel block and 95,5 crank)?

[Audi_CQ]

The piston with the 158mm 23mm pin must be almost the same as with the 159mm 21mm pin dont they (in a AEL diesel block and 95,5 crank)?

They have to be 1mm higher since rod is 1mm shorter.

[olsonjus]

The compression height will be 30.25mm, but the actual space for the ring package will be 18.75mm. What bore diameter are you going to run? Is your cylinder chambers stock, or have they been enlarged? what headgasket will you be running? Specifically what thickness is it when compressed and what is its bore diameter?

Regards,
Justin