Ordering Pistons - cam or no cam

[bluthndr]

Posted here because I figure this crowd has the most experience with the topic. I'm Building a 12v for street/Dyno/sand toy in a Dodge. 362/475 (may go bigger but that's what I have) compounds, maxed 913 pump, 5x.018 dual feeds, fire rings, 14mm studs, stockish head. The truck will be street driven up to a couple thousand miles a year. Hoping 700-800 rwhp on a Dyno on fuel only, and run on the dunes at silver lake. Never driven in the winter, never tows.

I'm ordering Pistons and my question is this: when I order Pistons (286110 design Mahles) do I get them with reliefs and run a bigger cam with lower (15:1ish) compression, or do I leave them flat and run a smaller cam (or stock even) with more compression (16.x:1) and put the $1000 (fly cuts + springs + cam) somewhere else (480 or bigger primary maybe)? For what it's worth my (stock) piston protrusion measured .028-.030, and the head has been surfaced twice, so a decent "drop in cam" is likely a no go without reliefs.

Thanks in advance.

 

[bluthndr]

A better title would have been:

"Ordering pistons: compression vs camshaft"

but for whatever reason I can't edit or delete the post.

 

[56cummins]

286210 if your going to cut it. I would try to keep it in the 16.5 +-.5 range.

 

[zfaylor]

For those goals I would up the turbo size a hair and run a mild cam with no reliefs.

There are a pile of opinions on how to make 700 hp with a 12 valve, though. $.02

 

[EricStaab]

Here is the deal. You should be able to get the pistons cut and keep your compression up. The max cam I would do would be our 208/221, and that requires at most a .150 deep valve relief. The reality is, you could get away with what most call a drop in our 187/220 cam and still make that power no problem. But I would still consider a .050 valve relief just in case you need it. Some times, when the block has been decked, and where you set your valves, can make the larger drop in cams not fit with out a valve relief. If you cut the pistons now you could always get the cam later with out pulling down the engine. Also I would put my money on having the block bored for cam bushings, and getting a good set of turbos, then consider the camshaft after that.

 

[bluthndr]

286210 if your going to cut it. I would try to keep it in the 16.5 +-.5 range.

I don't really "want" to cut it at all, but through my WD I can get the Mahle Performance Cast with the valve reliefs .150 in them for about $100 extra for the set, so there's a decent cost savings there compared to having them cut after the fact. However, those pistons put the CR down around 15 - which I gather makes for less responsive street engine. Appreciate the advice.

For those goals I would up the turbo size a hair and run a mild cam with no reliefs.

There are a pile of opinions on how to make 700 hp with a 12 valve, though. $.02

Any recommendations on a cam profile/manufacturer that actually WILL drop in if I'm not retarded when setting the valves? I originally was thinking Hamilton, but after reading their min specs for "drop-in", I know my numbers are way beyond what their minimums are. I measured 3 different 12 valves I have apart and every one of them had more than their "maximum .018 piston protrusion".

Incidentally, I'm not opposed to making more than 700hp, but I used reasonable numbers to prevent this from turning into a turbo/fuel discussion, and keep on track about compression vs cam for a "drive to the event" type truck.

Here is the deal. You should be able to get the pistons cut and keep your compression up. The max cam I would do would be our 208/221, and that requires at most a .150 deep valve relief. The reality is, you could get away with what most call a drop in our 187/220 cam and still make that power no problem. But I would still consider a .050 valve relief just in case you need it. Some times, when the block has been decked, and where you set your valves, can make the larger drop in cams not fit with out a valve relief. If you cut the pistons now you could always get the cam later with out pulling down the engine. Also I would put my money on having the block bored for cam bushings, and getting a good set of turbos, then consider the camshaft after that.

I'll check out your website Eric thanks! I kind of want to stay away from bushed cam and custom valvetrain stuff this go around, but there's always next year or the year after...