4.1 4" bore forged piston options

[MNcarbturbo]

I've got a stock bore 4.1 block id like to drop a set of forged pistons into.

Full Throttle had a set posted for stock stroke 4" bore but I reached out to check stock status and they are discontinued.

Any other suppliers or anyone have a batch # for a 4" bore stock stroke forged piston?

I'm open to go 3.975-3.995 but I know ring packages get poor in this range.

Thanks!

 

[liquidh8]

2nd this, I am mostly in the same boat except I want to go stroker, have a block @ 3.995, same story with them being discontinued.

 

[THensley]

custom pistons from CP was not a big problem I did not order the it was Dan at DLS 15 years ago

 

[1KWIKSIX]

I thought Earl Brown was able to do some custom sized pistons. Why not reach out to him

 

[BEATAV8]

DSS Racing or Diamond will make whatever you need, custom order. If you need tech help with the ordering, order through Full Throttle Speed.

 

[Reggie West]

Call DSS Racing pistons. Very good to deal with

 

[mikemcvaney]

I've got a stock bore 4.1 block id like to drop a set of forged pistons into.

Full Throttle had a set posted for stock stroke 4" bore but I reached out to check stock status and they are discontinued.

Any other suppliers or anyone have a batch # for a 4" bore stock stroke forged piston?

I'm open to go 3.975-3.995 but I know ring packages get poor in this range.

Thanks!

I had a set made for my car. By the way the downpipe I got from you works great .

 

[Undercover87T]

I've got a stock bore 4.1 block id like to drop a set of forged pistons into.

Full Throttle had a set posted for stock stroke 4" bore but I reached out to check stock status and they are discontinued.

Any other suppliers or anyone have a batch # for a 4" bore stock stroke forged piston?

I'm open to go 3.975-3.995 but I know ring packages get poor in this range.

Thanks!

Diamond was the supplier for Full Throttle. Have you reached out to them directly? I have a set of those pistons, 6.350 rods and a stroker crank in my 4.1.

 

[liquidh8]

I have not, though I suppose that's a good plan.

 

[MNcarbturbo]

I reached out to Full Throttle and they are no longer offering custom pistons and the 4.1 set that was posted is intended for their build with an aftermarket crank and rods.

Full Throttle recommended reaching out to DSS for my goals.

JE and Diamond both quoted $1600 which is more than I was hoping for as this is a stock rod/crank street build.

I'm still waiting for DSS to provide a quote. My machinist recommended race tech and I have an RFQ out there.

I might have unrealistic expectations but I was hoping to have a more 'drop in' on a stock rod and crank piston under $1000. Full Throttle mentioned DSS is likely the place for what I want. My understanding is a JE or a Diamond is going to be a higher quality part but at my power level I don't need that extra strength.

At under $1000 it's worth building the 4.1 but at $1600 I'll just grab a 3.8 block and drop in a set of $400 speed pros.

 

[liquidh8]

Thank you for that update, I am planning on the stroker crank and rods. but alas, it it is that much money, I don't know.

 

[dynoman]

Have you tried RaceTec pistons ? Thats what I have in my motor. The last pic is after SwainTec coating the top with TBC and the skirt with Poly Moly .

 

[Chuck Leeper]

Ask Earl Brown. He makes pistons......

 

[MNcarbturbo]

I sent Earl a message a few weeks ago and no response. Unsure if he's active here or has a business page elsewhere?

I also called Husek as he put together my trans a couple years ago. Seeing the turbo Buick performance logo above jogged my memory on a conversation I had with him a few years ago. He's got some options that I'm going to look into.

From what I gathered the autotec (racetec) 4032 alloy on a .927 pin with a molnar rod is potentially the most cost effective combo for my goals. The .940 pin adds complexity sourcing piston blanks. I'd like to keep a stock rod for balance and cost reasons for my modest power level but I'm likely trading cost in pistons for stock rods that could be spent on a better rod.

I chased down the forged 283 SBC piston on a 6.3" rod that was posted on some 25yr old thread and the piston is discontinued.

Even speed pro hypers for a 4.1 are getting scarce. Silvo-lite has some on backorder but I'm not holding my breath.

 

[Chuck Leeper]

or has a business page elsewhere?

E Bay

 

[liquidh8]

Great information. My 4.1 build is mostly street driven, and don't plan on full tilt output. I hope you can source a piston. I am looking myself, I though of Earl first, then I guess follow some leads here unless I stumble upon something different which I'll post.

 

[MNcarbturbo]

Well final final update, decided to pivot a bit on this.

Both Earl Brown (got ahold of FB) and Husek can do a custom set. They highly recommend .927 pins that causes the need for molnar or eagle rods with .927 ends. Rods are $800 ish and pistons ended up in the $1000ish range. Putting forged pistons on stock rods is dumb anyway with the additional bushing requirements with floating pins or custom pins in Buick diameter. Then if it's got forged rods why am I running a cast crank..

I took a step back and reevaluated my goals and shelved the forged piston idea for the time being. My goals are a 11.50 max build mostly street use with maybe a drag and drive thrown in and a cast piston will accomplish that. Without a cage or plan to cage the car and a faster car in the fleet no need to turn this into a high dollar build.

I thought I could get a drop in forged replacement with minimal adjacent part impacts which isn't the case.

Found a set of .020 silvo-lite cast pistons in stock and I'm just going to build around that. This block is a backup to my existing 4.1 in the car that's .030 over with a rust stain on one cylinder wall.

4.1 stuff is attainable just not at a cost similar to 3.8 stuff. If I blow up a cast piston on e85 running mid-high 11's I'm doing something wrong tune wise and If my 4.1 block stock runs out I'll just build a 3.8 with off the shelf parts.

Good learning exercise but I'm limiting the bleeding and scope creep on this one. Keep it simple.

 

[liquidh8]

Nice to hear you got some pricing, I need to get back of FB I suppose to get ahold of Earl, I already need custom oversized pistons myself.

I think your right, keep the tune conservative and your not beating it repeatedly and mainly street use, you won't be trying to ring ever ounce of power out of it (maybe), lol.

 

[Turbo Archie]

I think have a few new sets of the old budget 4.1 cast std pistons if anyone is still looking and willing to run those.

 

[liquidh8]

Personally my blocks is already @ 3.995, grr. Thank you for the offer!