pics and details for 409 stroker pistons

[indyjps]

I am looking into some variations of the stroker W engine. can anyone post detailed pics of the pistons used for these and also measurements of the top of piston to top ring land on high and low side. If the stroker pistons are not available a stock hi comp piston info would also be useful. I need to better understand how these engines work regarding stroke with the 74 degree or is it 76 degree angle. I am accustomed to 90 degree engines. thanks

[CDNpontiac409guy]

Indy, I have a number of pictures of pistons, but these are my own design.

Left to right:
Two pictures of my 10:1 compression 409 piston, using 454 crank and 6.385" rods.
This is a rather conservative example, which I plan to use in the new engine for my tow rig. You can see the very small dome required for the comp ratio. Also, the wrist pin location across the oil ring land. These require a oil ring support in that area. Looks crazy, but it's actually quite common in long rod / stroker applications.

Two pictures of my 10.5:1 compression 348 piston, using stock 409 crank and 6.135" rods.
You can note pin location and dome volume relative to compression ratio.

[models916]

Ross forged blank. Machined by C&A.

[dq409]

Hummmm, I posted a responce with a link to Aubreys site and where is it??:dunno

O,, Well,,, you got your answer AND you can see the difference between Aubreys design and the stock Ross pistons.

I know which ones are in my engine, can you guess ?:brow

[CDNpontiac409guy]

It may have been removed, JIMMM!...
protocol, ya' know:nono1: :coffee:
This isn't a sponsored site, so directly using it to promote a one's business, is not appropriate. Yes, it would have been much easier for me to simply post a link to my page with the pictures of pistons, but I knew that would be out of line.

Models posted the pic of the C&A piston for comparison. We should probably see a Ross and Venolia as well. Maybe even an old cast Jahns power slot:dunno

I tried to choose a few shots of my pistons ( these are the only pistons I have pictures of:p ), which show the areas that Indy asked about:dunno .

Indy ?
Does this makes sense ?

[models916]

Is your piston top similar to the Johns power slot? Never seen one, but have been told it worked well. i think TRW had a unique top also.

[CDNpontiac409guy]

Models... the Jahns piston was 12-13:1... cast aluminum, VERY heavy.
The entire top was finished to the same angle as th edeack, and at TDC, was flush with the deck. The only combusion chamber, was a roughly 1/4" deep trough cut in the top, at an angle corresponding with the intake and exhaust valves.
Yeah, I suppose the breathing was a little better. But that was COMPLETELY nulified and countered by the side loading of the piston under pressure:doh .

TRW was the factory 11:1 piston. With a little weight removed from the inside of the big side of the dome... it's the second best piston that was made;)

[indyjps]

that helps out quite a bit. thanks guys.

[indyjps]

Im used to my stroker pistons looking like these in the pic.
CDNPontiac, are those pistons available off the shelf?, whats the compression ht and the measurement from piston top to top ring land, for the 348 and 409.
Im assuming the angled area is closest to the oil valley and set sthe quench area depending on the cut??

I love building storker motors and have a couple of 348 blocks available for mock up but the cracked piston wall in each means I proably wont invest the $ in them. So Im looking for a block. the BBC stuff I have piled up so thats not an issue.

[CDNpontiac409guy]

Off the shelf, Indy ?
Not really. "Shelf" pistons are a compromise. Too many variables.
My "common" stroker pistons, which I DO stock all the time now.... are the 348 w/ 409 crank, 6.135" rod, .060" over... and 409 w/ 427 crank, 6.385" rod, .038" over, lightened.
Both in 10.5:1.

That picture you just posted is the same idea as that 454 cranked piston that I posted... just add the dome:deal

Yes, the angled/belvelled side form the "squish" area against the cyl head.


BTW... those 348 blocks... you can sleeve 'em:deal ... no problem

[indyjps]

ive considered sleeving them, and will pass them onto someone else if I dont go that route. I know of a few old school busses sitting at the back of a yard that I have to check out first!!!!
the build will be a slow one as I have another project that comes first and will receive the pistons that are in the pic, a 434 small block for a 69 camaro.