3.8 .030 Piston options?

[Sleeper]

Hi need some help.

I have a 3.8 block that is .020 that was having blow by issues. Long story short...Measured bores and it need to go .030 now.

This is a very light hybrid street car, so decided to go with hyper pistons instead of forged. Having a hard time finding 0.30 Speed-Pro hyper pistons Summit lists a Speed-Pro Hypereutectic Pistons H521ACP30 for $339 but after ordering them they later notified me that they are not available.

Can’t seem to be able to find any suppliers who have them in stock. What are my other options here without breaking the bank?

I’ve also read that I can use a Forged piston and run a tighter clearance (.003 vs .005 especially if I’m running a 160 deg thermostat ) to eliminate the start up noise and potential blowby

Thoughts? Thanks

 

[william B.]

I had a 3.8 turbo eng with hypers in it,every piston skirt was broken,wouldnt use that type,do it once and put forged pistons in, good luck

 

[WarWagon]

Silvolite from Keith Black.
UEM-1735HC-030

 

[Sleeper]

Thanks for the replies. Still searching.

 

[Mr.Spool]

Do yourself a favor and get a nice forged piston for the car with a good set of rings

 

[Reggie West]

Check out DSS Racing pistons.

You can get a .030 over forged piston set with pins and rings for $900 shipped.

Good stuff.

 

[Craig Gill]

I have a set of new Speed Pro Forged pistons 0.030" over that I'll sell.

 

[Sleeper]

Thanks I appreciate all the replies.
I have been pouring over old Buick info and there seems to be an agreement on Forged vs Hypers

Also that this was a decent explanation about Cast, Forged and Hypers.

Forged are no doubt stronger but require larger piston to wall clearances for thermal expansion. (.003-.005)
So, for a street driven car with realistic boost levels on pump gas, kinda overkill plus will have issues of startup piston rock and slap noise until proper operating temps are reached, that will lead to premature ring wear and greater chance of blowby.

Hypers are weaker and wont tolerate detonation very well, but require less piston to wall clearances (.0010-.0015) for thermal expansion so better suited to a street driven car with lower boost levels etc., and will have no piston rocking/slap/premature ring wear/blowby issues etc.

This brings up having also read that if forged are used in a street car application clearances can be run slightly tighter to avoid above mentioned issues Like closer to .003.
Any first hand feedback here?
Thanks for your patience here.

 

[Turbo Archie]

You are over thinking this. If you run pump gas you will denotate and need to run forged.
I have bought several second hand NEW sets or slightly used for around $400-600