Aftermarket Springs and Retainers with aftermarket cams necessary?

[airman86]

I tried posting this in the technical forum but after 36 hours I only had one reply. 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.

[PapaSmurf2k3]

Lots of questions you have there...Anyway, you shouldn't need aftermarket springs and retainers, but you should definitely ask the manufacturer. Usually, if they do require that stuff, it says it very explicitly. Your machinist will be able to tell you if you need to replace them or not. I can say that most cams are designed to work with factory everything.

The transmission should be fine, but definitely upgrade your clutch and resurface your flywheel, or buy a new one. For 400 horsepower, the $600 spent on springs and valves for the head would be better spent on forged rods and methanol injection.Visit the KA-T section for some damn good info.

[airman86]

Lots of questions you have there...Anyway, you shouldn't need aftermarket springs and retainers, but you should definitely ask the manufacturer. Usually, if they do require that stuff, it says it very explicitly. Your machinist will be able to tell you if you need to replace them or not. I can say that most cams are designed to work with factory everything.

The transmission should be fine, but definitely upgrade your clutch and resurface your flywheel, or buy a new one. For 400 horsepower, the $600 spent on springs and valves for the head would be better spent on forged rods and methanol injection.Visit the KA-T section for some damn good info.

great info there. yeah, lots of questions and more to come :P

i'm already getting forged rods and pistons for sure. if i'm boring .020 or .030 over, i know i'll need new pistons to fill that gap, but is it worth nearly $500 for a set of racing pistons? i know rods for sure, as they are what transfer the energy to the crank. i found a combo deal online for eagle rods and weisco pistons for ~$725 when bought together.

so, would aftermarket pistons be NECESSARY or could i find some near-OEM ones that are oversized to fit my bore?

as far as the transmission goes, i'd probably replace the pilot and throwout bearing. i know a new clutch is necessary and definitely no point in not having the flywheel resurfaced while that's being done.

i know i want a big set for sure, 264 or 272. on the brian crower website, the 264/264 doesn't have any extra requirements. the 272/272 set does say it requires the BC0210 spring kit which is about $360, found here: http://www.maperformance.com/b....html

on a ~400hp application, is it worth the extra $360 (for spring kit) for the extra tiny bit of 0.026" extra lift and duration?
Modified by airman86 at 6:13 AM 3/15/2009

[PapaSmurf2k3]

Pistons are DEFINITELY worth it. The KA24DE needs pistons more than it needs rods. Pistons are the weak link in a forced induction application. The ring lands are weak and tend to blow if there is any detonation. I recommend getting pistons if you push any more than 250 rwhp, and rods if you push any more than 350rwhp. Is it possible to run with stock pistons and rods? Yes, but there have been lots of cases on here where people blow rods as low as 350 whp.

Again, your money would probably be better spent on methanol injection as opposed to cams/valves/springs. If anything, just get a set of cams that doesn't require you to upgrade valves and retainers.

zeroforum/170

[24j0hn]

wow... u r brave my friend... i was planning on doing the same thing but even if you get a good deals on everything youll be spending up to $2500

so im just going sr... good luck tho looks good so far... im fixing my blown head gasket right now

[airman86]

wow... u r brave my friend... i was planning on doing the same thing but even if you get a good deals on everything youll be spending up to $2500

so im just going sr... good luck tho looks good so far... im fixing my blown head gasket right now

yeah, $2500 sounds about right for what i'm planning. however i'll have a fully built machine ready for drag.

[PapaSmurf2k3]

to be honest, I don't see how you are going to accomplish this for $2500. Lets break it down:Engine work at the machine shop (boring, decking, hot tanking, plastigaging, headwork)- $700-$1800Turbo: $600Pistons and Rods- $700-$1000IC & Piping- $400Z32 MAF- $100Walbro 255 lph fuel pump- $90exhaust- $400 mincouplers and fittings (IC and oil lines, etc)- $200Wastegate- $180Fuel management/tune- $400injectors- $300Blow off Valve- $120Clutch/flywheel- $350

So right there I'm up to $4540 on the low side of things. Don't kid yourself, it takes a lot of money to put 400hp to the wheels. And that doesn't even include the cam stuff you are talking about, or methanol injection.

[airman86]

I'm up to $4540 on the low side of things. Don't kid yourself, it takes a lot of money to put 400hp to the wheels. And that doesn't even include the cam stuff you are talking about, or methanol injection.

the machine shop is boring for .020 over, hot tanking, resurfacing, pressure testing, headwork/reassembly with new valve seals and polishing the crank (if needed) for $350. i will be assembling the components myself.

the car already has a full catback exhaust. i get parts for wholesale due to my connection to a performance car shop. plus, i have a few freebies (ic/wally 255/maf). i probably have a few people who have some 550cc or so injectors laying around i could get for cheap.

trust me, i'm not cheaping out anywhere. that's the last thing i'm going to do.