Blower pistons::whats the differance?

[dirty dan]

Other then the need for very low compresstion.
What is the differance between a standerd piston(cast or forged)
and a blower piston?

[1972roadrunner]

the price?

that is a good question though.

besides basically being bowled on the top (from what i've seen in pictures), what IS the difference?

[gotcha]

Dan.....while certainly no expert on blower motors, you will see a dished design on the gasoline or nitro blower pistons (7.5-8.0 to 1 C/R.....with slightly different ring spacing and ring thickness. Also the use of the Dykes type ring (matter of engine builder opinion). On stroker motors you will have buttons instead of keepers.

The alcohol motors use a different piston design (flat or domed) to achieve about 11.0 to 1 CR., with the appropriate ring spacing and design. Stroker motors again will most likely use buttons.

[dynorad]

The crown is thicker on a blower piston. The ring pack may be lower as well.

[sanborn]

I'm not an expert on this-my blower experience is 30 years old.
The blower piston has a thicker deck, to help absorb the combustion heat better, to maintain better dimensional stability(stays round better) and is generally a full skirt piston to stay square in the bore. The ring stack is generally down the piston further to help protect the rings from heat as well. And yes, they are significantly heavier.

Don't have any experience but I would guess that good nitrous pistons would be have some of the same characteristics.

[Maxwedge]

The pistons are also almost always Forged pieces. If something goes wrong(and the forced induction unit always makes that more probable) the forged piston will dimple instead of crack and explode like a cast piece will.
Forged piston GUUUUD, Cast piston Bhhhaaddd.

[dirty dan]

thanks for the info.
All that was mentioned sounds like good piston characteristics for such an application.
Except for the added weight.
I was considering the possibilities of a blown RB.
But it seems the piston weight would be a real draw back.
I don`t recall for certain ,but isn`t the stock cast piston between 800 and 1150 grams in a 440?
As I said I don`t recall .
The 1150 may be what my trw`s weighed before ballanceing.
I aready know what 1100 gram pistons do to bearings.
So Iam wondering what a blower piston might weigh.
Anyone have any Idea?
Thanks again
Dirty Dan

[Sam Davis]

If you are going with a blower I have a set of pistons out of 440 motor that had a 671 DBS blower on it. motor was taken out of six pack bee to put org. motor back in, Good pistons for sale if you want them. Sam D.

[dirty dan]

Originally posted by Sam Davis
If you are going with a blower I have a set of pistons out of 440 motor that had a 671 DBS blower on it. motor was taken out of six pack bee to put org. motor back in, Good pistons for sale if you want them. Sam D.

Sam D
thanks for the offer.
But Iam still trying to decide wich way to go.
RB or B block stroker.
Do you know who made your pistons and or how much they weigh?
Inquireing minds want to know.
Thanks
Dirty Dan

[Sam Davis]

the pistons were in a show car and did not have many miles on them I do not know what brand they are, I only heard it run on T.V. and i bought the car to restore, the pistons where in a 68 440 block, owner had sold the blower. The motor was set up for NOS but never had it hooked up, but looked good for show. Sam D.