hydraulic vs solid lifters?

redlinedeath · #1 08-10-2010, 08:51 PM

So im not very familiar with top end workings, and have a very base knowledge on cams and cam profiles. so my question is this one: our cars come with hydroulic (sp?) lifters, but everyone seems to convert to solid lifters, or suggest the conversions. on an na build, why is this recommended? Running 10-40 oil, and possibly different(if availiable) valve springs wouldnt be as reliable?

any info (in depth even, i catch on quickly, and if im stuck the internet is a good place to have) would be appreciated. my car died again, this time with massive over heating (melted my ign. coils!) and found fresh coolant in my fresh oil after i replaced my radiator. likely warped heads. so this time, im doing a full rebuild, but trying not to break the bank, parts stores dont exactly pay well...

redlinedeath · #2 08-10-2010, 10:03 PM

wait, any weight of oil resists compression just the same, right?

svxfiles · #3 08-10-2010, 10:19 PM

There have only a few people to convert to solid lifters.
It is a very expensive upgrade.
Unless you are running a much higher redline that 7200.

redlinedeath · #4 08-10-2010, 10:22 PM

whats much higher? ive seen it would be quite the expensive upgrade sadly.

svxfiles · #5 08-10-2010, 10:25 PM

What transmission do you have in your SVX?

redlinedeath · #6 08-10-2010, 10:59 PM

right now, the stock one. when that motor gets done, itll be a jdm ra trans. i need to replace 2nd gear though.

redlinedeath · #7 08-10-2010, 11:00 PM

i have trans, rear diff guts, pedal assy, clutch slave and master, and hopefully a driveshaft if its the correct one, and shifter assy. not everything, but almost there.

dynomatt · #8 08-10-2010, 11:21 PM

Not that expensive. Mine cost me a $200 for 4 WRX heads and about the same for custom shims.

The reason people chase solid lifters (or buckets) is because the stock springs and valve lengths limit available lift to something like 8mm. People who are doing NA builds (myself included) are chasing lift close to 11mm and therefore change gear.

Subaru WRX (EJ20T) valve train drops straight in. With some gutted stock lifters (or even any other 33mm solid bucket) you get a very flexible top end that enables a wide selection of cams.

M

redlinedeath · #9 08-10-2010, 11:26 PM

hmm, really? thanks matt. i hate to be a pain, but could you describe what all would get changed? and how difficult the process is? if i can use ej20t parts, id be a bit more willing to consider it.

dynomatt · #10 08-10-2010, 11:29 PM

It's been a while and there's posts somewhere here about what I (and subsequently others I believe) have done.

Get WRX heads. Strip valves, springs, retainers and collets. Throw away buckets.

Get SVX heads. Strip valves, springs, retainers and collets and throw them all away. Keep buckets.

Install WRX parts. Cutting new valve seats, may as well install new stem seals while they're all out.

Gut buckets. I used a lathe with a cutting tip and ran it around the edge of the hydraulic base. Time will tell whether this is a suitable option, but so far, none have failed. (when you do this you will realise that the shim sits on the bucket in a less than perfect way...it works, but less than perfect). I've since found that some shim over bucket options at 33mm exist, just remember that for large lift, the shim will be too small.

Measure clearances, and order shims that sit on valve stems to obtain correct clearance.

This is all pointless if you haven't got new cams that have more than 8mm lift BTW.

M

redlinedeath · #11 08-10-2010, 11:36 PM

thank you! im planning on new cams, but havnt decided on a profile just yet, still looking into cam info. ive developed quite a few brain overloads researching... lol.

the guy i got my trans from blew his motor early last season, i wonder if hed let me look at his heads and buy the parts if its good, then id need two more cyls worth of parts, he built a whole new motor for his rally car. i think his is a 2003 wrx. that would work right?

dynomatt · #12 08-10-2010, 11:37 PM

Can't remember the specifics, just need to match valve diameter (unless you go for bigger valves, which would need new seats etc) and valve stem diameter.

Length is all the same.

M

redlinedeath · #13 08-10-2010, 11:46 PM

hmmm, thanks for all the info! i think i am going to lean torwards this mod. either way, my car will be down for a loooong while. so if i were to go for aftermarket valves, would that come with needed hardware you think?

dynomatt · #14 08-10-2010, 11:51 PM

I doubt it...unless it's ap ackage of some sort.

redlinedeath · #15 08-10-2010, 11:56 PM

yeah, i looked around, no luck. thanks for all the info though!