93M6Formula

Hey guys, so my uncle has a brand new set of LT4 springs that he got with his Hotcam kit a few years ago and he's trying to pawn them off on me. I've been thinking about it for awhile and thought maybe it wouldn't hurt to throw them in with some 1.6 RRs for now until I can afford my heads and cam. I assume my springs could possibly use replacing after 19 years and 111K of who knows what on top of me racing at the track and the street for over 4 years now. And this is about the last bolt-on I have left and i'm still trying for my goal of a 12.99 with bolt-ons and this should do it I think.

So my question is, how hard is it to replace the springs with the heads on and motor in? I've heard you can rotate each cylinder to TDC and do both springs then do the same all the way around. Mostly what's keeping from doing this is that it just looks like a PITA to do but i'm willing to try it I guess. Also, will I have to get new pushrods if I change to 1.6s?

Thanks for any input!

defaultexistence

iTrader: (11)

Your 93 has hardened push rods , so your good there.. Search "tims tool" here or go to eBay and buy one .. It makes the spring swap so much more doable.. New springs such as those or some from alexsparts.com will be better than the wore out ones under some 1.6 rr's

93M6Formula

Are those pushrods a '93 thing only? I notice a new difference on '93s every day I swear! lol

Anyway, I'll have to check that out. I've seen a lot of posts about those alex springs, might do that too but my uncle is selling the LT4s cheap.

guppymech

iTrader: (7)

I swapped in some LT4 springs last fall and used the KD Tools valve spring compressor with the **** on top, it worked good. My old springs had 117k on them and I noticed a difference when running up to redline with my 1.5 ratio stock rockers. btw this was before I installed the hotcam itself.
If you're going to 1.6 rockers you should check to make sure the stock PR are the correct length also.
Shoebox has a good 'how to' on in car valve springs swap.

93M6Formula

Thanks that's good info!

96capricemgr

iTrader: (1)

The hardened pushrods was up through I believe 95.

LT4 springs are a good match to a stock cam and 1.6 rockers.

I am going to muddy the waters for you a little though.

Since it sounds like you want a more serious setup later IMO you should consider ARP 7/16" studs, guideplates and 7/16" rockers right now so that stuff is all ready to reuse with your later heads/cam setup. Cost a little more now but many of us have learned the lesson that a little overkill now is cheaper in the long run.

I bought some 1.5 ProForm rockers to use with a ZZ4 cam because the iron Caprice heads couldn't handle 1.6s on the exhaust, then I bought some CAT 1.65s to try on the intake side, then I did the AI heads/cam and bought the 7/16" ProMagnums, I first had a set of Comp guideplates that didn't fit right, then tried GMPP plates that fit better but badly wore in one year's time before going with Isky adjustable guideplates.

Hundreds of dollars wasted there.

93M6Formula

Good to hear! And way ahead of ya, I'm just now getting serious about the spring swap and already decided i'm gonna get my valvetrain setup for when I do the cam and heads probably next year or after. So far I decided on ARP 7/16 studs, GMPP guideplates, Comp Pro Mag 1.6s, and then the LT4 springs. I'll of course upgrade (most likely using LE or AIs kits) when I get the heads done.

Do you suppose i'll gain around 20 HP or so after this? Also, will I need pushrods for sure or is stock length okay for 1.6s??

WS Sick

Stock length will be fine.

93M6Formula

Okay good. Valvetrain has always scared me for some reason and I don't want to screw it up.

Another question, when I install the springs, will it just be a swap and go or will I need shims or any other stuff like that? This is about the only thing i've never messed with on a car because i'm not 100% sure how to figure all that spring height, coil bind and whatever else is involved.

guppymech

iTrader: (7)

^^^ That's the beauty of the LT4 springs for this kind of upgrade, they work with stock spring seats and retainers/locks. They also have enough travel for the stock cam with 1.6 rr. They are drop in and go, you don't need to measure spring height and seat pressure unless you want to. IIRC the LT4 springs are now the GM service replacements for the LT1 springs.
Don't forget to change the valve guide seals while you're at it. I used Felpro SS72861 seals and they looked identical to the OEM ones that came off.

93M6Formula

Sweet! Thanks, that makes me happy now and more excited to do this haha.

Badazz 97 TA

iTrader: (18)

The "Tims valve spring tool" makes it easier. For the most part a spring swap is easy. The job is kind of a pain to do and takes a little time to do, but for the most part somewhat easy.

joelster

The last cylinder on each side can be a little rough. When you get the valve covers off stuff a lint-free rag into the oil drainback holes so you don't accidentally drop anything down there. You will find that you may not even have to rotate the engine over at all to do this. The TDC method works, but sometimes there is enough tension from the valve seals to hold the valve up by themselves. The stock stroke is 3.48" and the valves are roguhly 5" long, so don't worry about a valve falling into the cylinder, it simply cannot happen. If one of them drops down, simply rotate the motor over by hand and the piston will slowly push the valve up. I can swap a set of springs up top in under an hour. You may tear your hands up a bit if you have one of those spring compressors with star shaped handle that you twist.

Adam1203

iTrader: (5)

I just pulled apart a 1994 lt1 and it didn't have hardened pushrods, however my 95 did. I was under the impression that it was something they did in 95 and only 95 but i could be wrong.

You can tell a hardened one from one that isn't because the hardened on have a dimple on the side of the push rod where they tested it.