Aftermarket Springs and Retainers with aftermarket cams?

[airman86]

Hey all, i'm starting to do a little bit of research on what i'm going to need when building my future 240sx. I want a '91-'94 S13, but I plan on fully rebuilding it. Because i'm going to be building it anyways, I'm looking for one that needs help (like a blown head gasket, or something along the lines that can be found for cheap). However, that's against the point.

So, block will be bored 20 or 30 over, new rods, pistons, crank turned/resurfaced, yada yada. As far as head work though, I plan on going with a more agressive set of 264 or 272 cams. I will be turboing this setup eventually, but i plan on doing things one step at a time, as i'm not going to rush the project. More questions on that later.

ANYWAYS, my question is this. I will be having the head machined/cleaned up/etc, but since I'm throwing some nice big cams in the car, is it necessary to spend $300-$400 on a set of BC springs and retainers, or some other name-brand? It will, of course, be getting new seals and have the valves cleaned up, unless I am recommended to spend the money on a set of aftermarket valves as well, or if they need replacing anyways. If they just need replacing, would an OEM set of valves for less than a third of the cost of BCs be okay?

For example, I had my head from an old eclipse of mine machined and fixed up and it went from this:



to this:



Those are the original, stock valves, all cleaned up. The machine shop I deal with does VERY good work.

With a built bottom end, like I am planning on, I am looking for ~400hp which I think that is reasonable if I take my time and do it right. With horsepower levels that high, as far as head work goes, i know i will at LEAST be doing cams/new seals/cleaning valves/resurfacing the head. What do you guys think about spending over $600 for a set of valves (assuming the ones in it aren't worn or need replacing), springs, and retainers? Necessary?

I have set my goal for 400whp, which i'm pretty sure is reasonable. But with a built bottom end, forged pistons, built (although not sure how "much") head, and something like a GT30R, and i'm pretty sure the gt30r can do ~25psi, assuming correct fuel delivery, suspension, all electronics goodies, etc, would this setup hold that and not fall apart?

Also on a side note, besides the necessity of a new clutch that can hold this amount of power, will the transmission need to be beefed up? Most of the projects i have dealt with are no more than 300hp, and I didn't have to modify the transmission at all.
Modified by airman86 at 5:58 AM 3/13/2009

[airman86]

bumpage?

[airman86]

srsly no one?

[mexicanracer03]

I run Brian Crower Springs, Titanium Retainers, and No problem.

I do have supertech valves. GL

[airman86]

I run Brian Crower Springs, Titanium Retainers, and No problem.

I do have supertech valves. GL

but are they 100% necessary? that's a lot of money to shell out for a few hunks of metal. i realize that with the extra lift/etc from the cams that they may take more wear and tear, but honestly how much?

also i am not naive about cars. i'm a mechanical engineer so it's my nature to FULLY understand something before i throw money into it but, i do realize there are plenty of small things that can be underestimated in building an engine.
Modified by airman86 at 6:29 PM 3/13/2009

[liquid_cool]

but are they 100% necessary? that's a lot of money to shell out for a few hunks of metal. i realize that with the extra lift/etc from the cams that they may take more wear and tear, but honestly how much?

also i am not naive about cars. i'm a mechanical engineer so it's my nature to FULLY understand something before i throw money into it but, i do realize there are plenty of small things that can be underestimated in building an engine.

Modified by airman86 at 6:29 PM 3/13/2009

if your running a larger lobe duration cam..ya there nessisary to keep your valves closed..what happens under high rpm's is the cam is spinning so fast that it actually does not give the valves time to opertate "close and open" with a standard spring rate..with the added spring pressures you can get them to close under high rpm's with the larger cams.....if your planning on a turbo aplication.......may i sugest..to use a solid copper head gasket..and have your shop..do a meatal oring around your cylinders and a reciever groove on the head..this will allow you to run higher boost preshures with out having to worry about blowing the head gasket..you will need rod , main, head studs allso.

[airman86]

...if your planning on a turbo aplication.......may i sugest..to use a solid copper head gasket..and have your shop..do a meatal oring around your cylinders and a reciever groove on the head..this will allow you to run higher boost preshures with out having to worry about blowing the head gasket..you will need rod , main, head studs allso.

hmm i like the idea about the groove - would i need a special gasket for that? how is that "ring" attached to the block? is it machined out? (that would raise compression...) or attached somehow? that's new to me, tell me more. any pictures of this being done? i'd like to see it.

as far as a copper head gasket - why copper? i was planning on going with a cometic head gasket, which doesn't look copper to me.

arp studs and bolts are a gimme, for sure.