robertbartsch

I'm now running 60CC chambered ported ls6 heads on a stock bottom end.

..will likely go with a bigger cubed project this winter...

What is my best option with these heads - a 395CI stroker or a all bore set up?

I heard that an all bore unit would need to reshape enlarge the combustion chambers; is this right?


Also, I assume I will need to run dished pistons; are these an impediment to a full burn chamber?

Phil99vette

iTrader: (11)

With an all bore your going to need to enlarge the combustion chamber to unshroud the valves. This will drastically help how the head flows at low and mid lift. I would try and mill the heads as little as possible and use a thinner head gasket if your trying to pick up compression. The pistons are another story.
Phillip

robertbartsch

I'm not sure I can open the chambers too much now since the heads have already been milled .055

...so I guess I'm asking, given this, I'm I locked into the stroker? I like low end torque so bagging an all bore project is no big deal...

...thinking about a 4.125 crank in a new stock alumium block...

Nasty N8

iTrader: (33)

There is no problem opening the chamber with the heads you have. You just want to make them a little bigger to match the larger bore. 4.125 stroke is WAY too big for a stock bore block. You would have zero rev, I don`t recommend a stroke over 4.00 to anyone. Much better off going with an all bore. I have seen much more power and almost as much TQ as the stroker motors. And as far as pistons you would run what will give you the desired compression you are looking for.

Nate

99 Black Bird T/A

iTrader: (4)

A Big Bore has less stress on the rods, pistons, and cylinder walls with the stock stroke crank than with a stroker with a stroker crank does. With current intakes the Big Bore seems to have the edge in power output. Big Bore make almost as much torque. Big Bores rev quicker.

Just make sure the person doing the machine work on your Big Bore really knows what they are doing. Very few folks out there I'd want a sleeved block from.

Ragtop 99

iTrader: (7)

big bore has traditionally made better power, but strokers were king when a H&C car breaking over 400 RWHP was big news. Getting 440 RWHP was a decent result given what H&C cars were doing.

It would be interesting to see how a 4.00" stroker does with a current set of JPR AS, or TEA heads. In an A4, you could probably make a damn fast car by producing 400 RWTQ at 3500 rpm & 450 RWTQ by 4500 even if peak HP at 6000 was 460 RWHP. Given the improvement in heads and the use of bigger cams today, a stroker might be more competitive then assumed and you don't have to worry about resleeving.

robertbartsch

Why is a 4.125 stroke crank "way too big" for a stock block LS1?

...I really don't mind if the engine can't rev past 5500....for me, low end torque is king for street engines...