16v head comparo

[n xntrx volvo]

i the middle of decided which head gets cut up for a porting guide and which one gets ported.
below are the reference pics.
the penta unit has a larger chamber, better for high boost apps. but its all along the side. imho this would cause a "pocket" of unspent gas to sit there, also not allowing as smooth a flow of air.
thoughts?
-Aaron


100262 stock (auto, b234f)

100532 stock (penta aq171)

100262 modified (auto, b234f)

 

[MikeHardy]

considering the larger section on the penta chamber is furthest away from the plug i don't like it that much

the car head the chamber (even those sides) look like there push the mixture towards the plug on the compression stroke ready for ignition.

 

[n xntrx volvo]

the rounded sides (#3) are better since it is within the flame ring area. the stocker at top creates a "shelf" that partially blocks flow along with being an edge withing the cc area (heat riser).

 

[John V outside agitator]

Chamber volume kiddies?
What's the cylinder volume of each?
The car thing sits atop a 2300 yes?
That's what per cylinder?
Look at the chambers and which has greater volume?
What's the Penta?
CCs please, then maybe this difference makes more sense.

And no it's not a "heat riser." Try reading a bit on "quench".

 

[n xntrx volvo]

48 vs 57cc's
cc/ cyl (yes, not a misprint or error)
but even with the smaller one it'll be 9.07 with the dished pistons.
jv, couldnt search for the prop term, (board issues) so listed as how i think of it.

 

[John V outside agitator]

48 vs 57cc's
742cc/ cyl (yes, not a misprint or error)

Huh?
I thought B234 were 2300cc
and most of the Penta stuff were 2500cc?

What's this 2968cc you speak of.

To make comparisons, start by looking at what original useage was, and that'll help understand the why.

but even with the smaller one it'll be 9.07 with the dished pistons.
jv, couldnt search for the prop term, (board issues) so listed as how i think of it.

What dished pistons, with a 16V and a turbo you ought top be thinking of forged, and with forged you can specify the dish diameter and depth and even the radiius at the top and bottom of the dish. At least I do whan I order.

And you can google the terms we use here. all knowledege is not found here on T-bricks
And really the concepts are the same motor to motor.

You doing some beautification of the short side rdius in the ports??

 

[n xntrx volvo]

yes, forged. approx 99.5mm (exact specs are at home)
billet crank, much longer stroke then the current penta
the ports are being matched to the turbo header/ gaskets

along with mild bowl, guide and divider shaping

*note this head was scrapped, starting over
also was able to increase the cc 6cc's with the mods pictured.