Time to clean up my mess

[TireSmoke420]

Ok so i dont know if any of you guys remember but a couple monthes ago i freaked out and did a buncha stupid stuff to my truck without throughly checking it all out. First i took it to one guy that said the number 7 cylendar had no compression. so i jumped to the conclusion that there was a hole burnt in the piston so i took it to my buddies house and ripped it all apart. i didnt compress air in the cylendars to see where it was not compressing from, i figured id pull the heads off and there it would be right there in front of my face. so now i actully have the mony to fix it. so now i got the truck back in my own garage i bought a stand and now i have the motor all torn down to bare bones. now i dont see anything in the pistons or any thing bottom end that wouldnt make it run bad.now heads confuse me so i dont really kinow what to look for there they look alright valves not obviously burn they are covered in soot though. so yea anyways guys help me build my motor. what cam should i upgrade to. i wanna upgradew the ignition system too what should i do there

[TireSmoke420]

also whats the difference between dished and flat and hyperetectic pistons

[shadetree]

Things that may have caused low/no compression: leaking head gasket (leaks should be visible on old gasket), bad rings (scored cyl walls a sign), busted piston (that is "in your face" obvious), dropped valve (again, obvious), cracked head/block (hard to see, magnafluxing is really needed), leaking/warped/bent/burned valve(s) (not so abvious, a machine shop should be able to help).
To build this engine, my opinion is: establish a good base. Rebore the cyl, get new oversize pistons & rings. Do a full valve job (grind valves & seats, redo valve guides, new seals, new valve springs, ect) or buy new heads.
Cam? My favorite for the street is the old 268-H, but you really need good advice here. Jegs or Summit can help, and so can most cam companys.
An HEI distributor (either a new one, or a re-habbed junkyard one do), is my favorite for the street.
I want to stress, have a good machine shop help you with the bottom end, then don't scrimp on the heads.

[xtreme80]

Before you start "building" your motor, you need to figure out where the problem lies. If #7 has no compression, it's probably rings. It's either bad rings or burned valves. You might wanna take your heads to a machine shop to have them checked out first, or just buy a new set. I strongly believe that a good set of heads are the key to building a good motor.

If they are stock heads, I would suggest upgrading to a set of 1.94 heads. A cam isn't gonna do too much to an engine that can't breathe right.

If you're set on using your current heads, at least have a machine shop clean em up and check to make sure they are still in good shape. You wouldn't wanna put your motor together to find that your valves need to be replaced.

Next up before the performance would be a good set of rings / pistons. I'm not sure what exactly hypereutectic pistons are composed of, but if you plan on building big power or going with boost, go with them. For a mild engine, it's just a waste of money. I've got a 300hp crate motor and it uses aluminum pistons, and I could suck quite a bit more power out of that engine before I would have to worry about upgrading the internals.

As far as a cam, I don't know what the emissions laws are where you live, but in AZ, a big lopey cam wouldn't be a good idea, because there's a good chance you won't pass emissions with it. I have a cam with a 222 degree duration, and it provides plenty of mid to high range power for me. I don't have the lopey sound from this cam, but it works great with my setup (1.94 heads, etc.)

Start with the basics though. I mean if you have it apart anyways, you might as well cam it. But make sure you get a decent set of heads, and a good intake manifold. Fuel is important too. There's no point in making big power when you are just starving the engine for gas.

Good luck.

[TireSmoke420]

k as for boreing engine out more don think i need it engine only has about 15000 miles on it, and its at .40 already. there is no ridge at all no scratches on wall no nothing. a butt load of carbon on everything inside.

[xtreme80]

It's still a good idea to have the cylinder walls resurfaced... If not you'll deal with burning oil like crazy

[TireSmoke420]

i planned on running a hone through them