Stroking an s50

[Uber E30]

Ok so i have been reading a bit and i decided i want to stroke my s50. I have an s52 crank and 135mm rods. I have read that i need s52 pistons as well because of the wrist pin placement. Any advice?


Specs:

S50
Bore: 86mm
Stroke: 85.8mm
Rod Length: 135mm

S52
Bore: 86.4mm
Stroke: 89.6mm
Rod Length: 135mm

[2002maniac]

my advice:

get forged pistons with 11:1 CR and 87mm bore.

[Uber E30]

thats some pretty big money, would like to keep it on a budget

[416stroker]

It wond be that bad if you have a machine shop order your pistions and skip out on the companys that already have it all figuerd out. you probably could get a set of pistons for about 600-700 tops

[sharksforthecup]

my advice:

get forged pistons with 11:1 CR and 87mm bore.

Thats what I'm putting in!

[MIKe30]

Thats what I'm putting in!

Mine's already in :D

but the motor's not in the car yet :(


edit: For a budget build I also have low mileage s52 pistons with brand new rings on them for sale. The small bump in compression and bore is arguably not worth the extra money unless you have to do it anyway like I did. (my block didnt clean up with a hone, needed a bore). Considering the price of brand new rings alone, it's a good deal. Feel free to shoot me a pm.


annnd I'm a dork and didnt realize you were the one they're pending sale to!! Just returned your pm.

[Pudmunkie]

Depending how my touch hone goes this week I may have S52 pistons up for sale while I + size my S52.

[Uber E30]

yeah im buying mikes, he is just a tard =P

[jrdeamicis]

Alex, with the S52 pistons and crank you should be set to do an OBD1 S52.

Since you got a brand new crank you can just order BRAND NEW main bearing shells. We will pull the rod bearings and see how they are doing.

[Uber E30]

I already ordered this:

11241278209 Rod Bushings x6
07119934460 Piston Snap ring x12
11211706847 Main Bearing set
11241284849 Rod Bearing set
11241739728 Rod Bolts x12
11112244286 Main Cap Bolt x14

We should be good to go once everything gets here =] Plus no cleaning since the bottom end now has to go to the shop too, i will just have them do it.

[zav3n]

the wrist pin on the s52 piston is ~ 2.5mm higher than the s50 pistons, which will result in a very low compression.. nuttin a used and abused head + a MLS cant make up for tho..

[rneedham1979]

I would not put a smaller rod in. Using a 135mm will lower the rod ratio which will hinder performance gains to include torque. If you want to stroke the S50, run the crank, 140mm rods and have custom pistons made. This will allow you to run the longer stroke, rod and the pistons will not hit the head.

[Uber E30]

The rods from the s50 and s52 are the same. The wrist pin location is slightly different though. Im basically just making an s52 bottom end though with an s50 block bored for s52 pistons and throwing the 3.2 crank in there.

Wonder if that means im running a stroked s50 or just an s52 =P

[erik325i]

Why didn't you just buy an s52 shortblock instead of trying to build an s52 in an s50 block? How much is all the machine work going to cost you?

Erik

[Uber E30]

Well i got the s50 STUPID cheap and found out it had some bent valves. The crank isnt a big deal because i sold my s50 one for a little less then the s52 one. Got a good deal on the pistons and rings too. So even if the machine work cost me a pretty penny it would all come out to be the price of a normal s52... only everything is nice and fresh this way and i dont have to bother with obdI conversion.