Stroker Rods Decision

[Billman]

Hallo everyone, after talking with some members and looking in the forum i got many different opinions about witch conrods to take! Because this group buy is going on i must have some clear answers.

Block and Crank come from the Audi Diesel AEL-AAT engines.

The Rods are from Sten Parner so we have these 2 Rod options:

1. 158 mm length, 23mm Pin Diameter (opinions on this: good Rod to stroke ratio. High friction on the lower cylinderwalls there will be much pressure from the pistons, would they work good on this Block-crank setup?)

2. 155 mm Length and 20mm Pin diameter (Opinions on this: nice Rod to stroke ratio, but will the 20mm Piston pin hold the Power?)

Sten Parner suggests 155mm 20 pin but i need some more opinions! How should i choose the pistons after that? He said i should use the Audi 5 cyl gas pistons but i dont get it!(Piston spec i would like: 8,5:1 CR and non-interfearance)!

Thanks for your help

[Billman]

Nobody??

[olsonjus]

Quality 20mm pins will hold the power. I've personally seen vw 1.8t owners pushing 800hp(760whp) on 20mm pins with 144mm rods. This is on a 4 cylinder, so logically 20mm pins can do 1000hp in a 5 cylinder application.

Myself am going with 159mm pauters with 21mm pins. ($900 USD shipped is my cost on a set). I can get you some if your interested. They are ready to ship with no lead time right now.

Regards,
Justin

[Billman]

I will go for the Sten Parner ones! Are the 158mm 23mmpin good with the Diesel block and 95,5 mm crank ?? Caterpillar told me that on the lower cylinderwalls the longer rods will ask more pressure and i think he has a good point on this!

What do you think about it? What about the piston thing?

[olsonjus]

You could probably have them made with a wrist pin bore of 23mm. The only problem you get into is space for your ring package. The larger wrist pin takes up more space, so less room for your rings.

Cylinder loading should be less with longer rods as there is less of a angle formed between the rod and crank when the crank throw is parellel with the ground. Draw a right angled triangle: The bottom side of the triangle is half your stroke. The hypotenius is your rod length. The angle between the two sides becomes larger as the rod length increase. This applies rotational motion in a more up and down motion with less cylinder loading. Sorry for the long explenation, but I'm rather tired.

Regards,
Justin

[Billman]

OK now! I am more confused! With the 158 mm 23mm rods will there be enough space for the rings??

or should i go for the 155mm 20mm pin so that i have more room for rings but worster cylinder loading?

Can someone give some infos on the piston specs for such applications?

[Albert]

I have 22mm pin and piston(CP Pistons) / rod (Pauter) combo is ok

[Billman]

@Albert
how long are your rods?? Do you have diesel block and crank?

I want the combo that holds power better and are the best for the engine longlivity!

Thanks for your help

[caterpillar]

in volvos redblock(b19-230) you may get 158mm conrods too,and the 3rd ringset hold together the wristpin !!! with a alupart from the piston inside...no prob. the longer rod/stroke ratio,more rpm,less stress on the pistonsQuirt and sylinderwalls. look at the motorbikes.....long conrod as h*** and short stroke... the best stroke ratio are to reatch the 2,0 faktor

[Billman]

@Caterpillar

sorry, i dont know if it is for me! I have an Audi AEL-AAT block - crank! 95,5 stroke! The question is how long must the piston be in order to work properly ?

[caterpillar]

i am sorry,cant tell you how high/long the piston have to be. have you sutch this forum "my stroker projekt" ?? i have to make an CUSTOM order pga the 94,5(!!!!!) crank and the 158 conrods,and the 23 wristpin.......

[olsonjus]

Well, the combo I'm going with (AAT block, 159mm rods, 21mm pins) gives me a 29.25mm compression height( the distance from the centerline of the wrist pin to the top of the piston). Compression height = (Deck Height)-(Rod Length)-(stroke/2)

The actual ring package has (compression height)-((wrist pin diameter)/2)=18.75mm of space.

Your combo with 158mm rods and 23mm pins gives you the same ring spacing as my combo (18.75mm). You shouldn't have trouble with those rods.

Regards,
Justin

[Billman]

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???

[Billman]

??

[caterpillar]

the 158 con rods may have som little file and struggle in the lower syl walls,spec if you use the 95,5cranc.....i havent done the test myselves,have the block(s) and cranck,and conrods. the easy way are to use the 155mm.....