Piston recomendations for a 4.1 "291" block

[RATROASTER]

I scored a complete 4.1 291 block.

I'm not going to go to crazy with this build. I'm going to use what stock 3.8 parts I can find, port the heads & intake and bore it 60 over for a big cube 6-banger. What pistons do you guys recomend. I want to stay under $500 for the set.

Also do the 4.1's use a different water pump from a 3.8?

Thanks,

Dave

 

[49-blues]

You can get sealed power .030" over for a 3.995" bore and leave enough for a 4.00" build next time-i believe the water pumps are the same some covers have bolt holes for a 14 bolt oil pan,some for 20 bolt oil pans and some aftermarket ones have for both bolt provisions.

 

[charlief1]

From what I've read you don't want to go over 4" bore due to cylinder wall distortion.

 

[rw87tt]

pistons

The machinist that checked my block said the max is 60 over. He likes to stay below that or 40 as max. He also recomends Silvolite which are made by kieth black and are used in differant race classes or the speed pro. Both are hypers. I'm going to use which ever is cheaper.

 

[RATROASTER]

I checked out Summit and I saw I can get Federal Mogul Speed-Pro Hypers for $43 a piece. I'm not a track star and I usually only look to make moderate power increases, but never the less I salivate over the opportunity to drop a punched out 4.1 in my last NA Regal. See if this link works for the Summit pistons:

REGAL, 4.1L/252, BUICK, 1983 - summitracing.com

 

[usetaboost]

better tag along for this. thinking about doing a 4.1 or maybe even a stroker if I ever get the car back together

 

[RATROASTER]

After talking to my machine shop. I'm going to check out the Keith Black forged pistons.

 

[usetaboost]

pm me when you start your build thread

 

[whitehot1]

I checked out Summit and I saw I can get Federal Mogul Speed-Pro Hypers for $43 a piece. I'm not a track star and I usually only look to make moderate power increases, but never the less I salivate over the opportunity to drop a punched out 4.1 in my last NA Regal. See if this link works for the Summit pistons:

REGAL, 4.1L/252, BUICK, 1983 - summitracing.com

i believe the pistons you want to use are the STL-H471P part numbers and those are $32.00 each.

 

[getchasum]

After talking to my machine shop. I'm going to check out the Keith Black forged pistons.

Forged? Didn't know they offered a 4.1 forged. Share the details once you get them.

 

[Ken Adams]

KB Forged 4.1 Pistons

X2

 

[getchasum]

X2

Ken, do you have info or are you requesting it a well?

 

[charlief1]

I've done an extreemly thorugh search for pistons for my 4.1 project and currently no manufacture makes a forged piston except by paid request. only custom work and it's around $1200 to $3000 to get what I'm looking for. I looked for about 6 months so if you find some TELL ME PLEASE!!!!

 

[V6gofast]

I've done an extreemly thorugh search for pistons for my 4.1 project and currently no manufacture makes a forged piston except by paid request. only custom work and it's around $1200 to $3000 to get what I'm looking for. I looked for about 6 months so if you find some TELL ME PLEASE!!!!

We can supply you with pistons custom built for your application for much
less than that giive me a call if you are interested .

 

[Ken Adams]

KB Forged Pistons

After researching Keith Black website, all I find available for the 4.1 is the hyper pistons. RATROASTER, maybe your machine shop can shed some light on these KB forged pistons for the 4.1 they say are available.

 

[ek02]

I had JE make me a set of forged pistons for my 4.1 with a stroker crank. I filled out the custom piston form, and 2 months and
$900.00 later, my pistons were finally done and delivered with pins, spirol locks, friction coating, and file fit Moly rings. A long wait and a lot of money, but worth it.

 

[RATROASTER]

After talking to my machine shop. I'm going to check out the Keith Black forged pistons.

Sorry guys didn't mean to get you hopes up, but it would be a custom piston.

 

[getchasum]

Weber's at one time offered a forged Wiseco 4.1 drop in for a production stroke at a great price. Think it may have been a chevy 4" pistion that would take the bore to .035. At one time there was a post about them in the vendors section. It's been several years back, but you may could give them a call.

Edit....
Here it is http://www.turbobuick.com/forums/advertiser-specials/170787-weber-forged-pistons.html

 

[TexasT]

Flatlander Racing - High Performance Racing & Engine Parts: TRW Forged Buick Pistons

Might try these guys.

 

[getchasum]

Flatlander Racing - High Performance Racing & Engine Parts: TRW Forged Buick Pistons

Might try these guys.

Budget build Hypers......

Part #'s starting with "H" = Hypereutectic
252 Engine (3.965 Bore x 3.400 Stroke)
Part # Notes CID Comp. Ratio
48cc Comp.
Dist. Piston
Dome Shape Price
H471P
H471P-30
H471P-40
H471P-60
H471CP
H471CP-30
H471CP-40
H471CP-60 Turbo