basic DD 350 build

[othtim]

Heres the build I'm working on right now. Looking for some advice as to power levels, parts choice, etc.

So I just picked up a rebuilt 350 bottom end, 90k km's on the rebuild. Just the short block. stock cast crank, PM rods, forged pistons.

I'm going to be re-ringing and re-bearing this block. This will be the first time I've done this. Up till now, only ever done head work, never reassembled a rotating assembly. Suggestions?

I'm looking at getting a set of vortec heads that have been rebuilt. How will I know if they are warped or not? I was asuuming I could re-install them with plastigauge and check. Also, if they are slightly warped (very slightly) is there a way I can deal with that without getting them decked? I am trying to keep this low-budget.

Also, if the block is slightly (Very slightly) warped (which I think it may be) is there a way I can deal with that via head gaskets or studs or some such? Would using a thicker head gasket and head studs help sealing?

Also, I was considering running a roller cam/roller rocker setup. Comments?

It's going in an 83 monte w/ a th350 and a 2000 rpm stall. Will be running a quadrajet and a dual-plane manifold.

Anyone have any cam suggestions for this combo?

This is my DD. Can be slightly lopey, very very slight. Too much lope will be annoying, must have good low-speed torque.

Thanks! I'm considering starting a build thread somewhere, where would that go on the forums? :S

 

[megaladon6]

first off good luck!
building an engine is pretty simple, just make sure you go step by step and torque everything correctly--by torque level and order. this is especially important on the bearings and the intake. (vortec intakes are very prone to leakage if not torqued correctly.)
what forged pistons do you have? stock/factory or aftermarket? are they iron, aluminum, d-dished, flat top, dished, valve reliefs, etc. what compression? (assume 64cc on the heads)
the heads and block tend to be slightly forgiving on warpage. you can put a straightedge on them to check. they don't have to be perfect, but if you can see a gap between the edge and the block/head you should get them machined.
unfortunately i don't think there's any other way but a machine shop.
also, measure the depth of the piston in the cylinder. you want a total of about .035-.045 between the piston and head (counting the head gasket). if you have almost no clearance this is actually good. it allows you to use a set of MLS gaskets. they are very tough and the multiple layers are more likely to seal on a warped surface. however i seem to recall that they need a very smooth surface.
as for a cam, first make sure that the block is or is not an original roller block. if it is, buy a set of stock lifters and the retainer from GM. they're cheap but very good. if it's not a roller block the cam/lifter kit will be expensive--but worth it.
i'd probably go with a comp cams 268 or a step smaller.--best advice, go to compcams website and download camquest 6. it allows you to put in your engine data and it will recommend a cam. it also gives you approximate power.
with the vortec heads you need to have the valve guides cut down to take lift over .500, some say .475 but many people have run .480-.490 with no problems.
for a build thread, i'd say in the engine/swap or the monte forums.

 

[othtim]

What I was planning on doing for measuring my piston-valve clearance was to measure without the head gasket - that way I can know how thick of a head gasket crush I can use. Would this be safe? I don't want to waste a head gasket - would I be able to re-use it if I put it on, torqued the heads down, then removed the heads to check clearance, then replaced them with the already torqued gasket?

 

[megaladon6]

well quench and clearance are 2 different things. if you have tight quench ( the space between the head and the piston at TDC) you can run lower octane, higher compression, more advance and it will be more efficient and cooler. piston to valve clearance is more about valve lift and timing.
unfortunately most head gaskets are NOT reusable at all. once they're compressed that's it.
but if you have good clearance w/out the head gasket you're obviously good with it.