Valve spring question... Buying the BC kit...

[mhubble91]

I'm getting the BC Cam, Spring and Valve kit and I have a question...

I've only installed valve springs once on a Chev. 350, and I'm wondering how I find out what spacers, if needed, go under the valve springs so they're all equal in force? This is for my S13 Blacktop.

Anyone who has done valve springs knows what i'm talking about...

Thanks!

[Mikester]

This doesn't directly address your question, but it helped me immensely when I did my BC springs. I also have the tool he used brand new still in the plastic if you need it. How to Build a 9000-rpm Head for your SR20DET (http://www.nicoclub.com/archives/how-to-build-a-9000-rpm-sr20det-head.html)

--Mike

[mhubble91]

This doesn't directly address your question, but it helped me immensely when I did my BC springs. I also have the tool he used brand new still in the plastic if you need it. How to Build a 9000-rpm Head for your SR20DET (http://www.nicoclub.com/archives/how-to-build-a-9000-rpm-sr20det-head.html)

--Mike

Thanks for the reply... I've seen that post a million times! lol....

Maybe to be more specific so someone else can maybe answer...

I'm wondering where I find the correct specification of the valve spring force?

[codyace]

Thanks for the reply... I've seen that post a million times! lol....

Maybe to be more specific so someone else can maybe answer...

I'm wondering where I find the correct specification of the valve spring force?

It's not like a SBC at all, you install them as is.

With that said the BC seat pressures are super huge too.

[rcdad123]

you should be able to find the answer you`re looking for in their web site. if not, you can contact them. not a lot of people actually blue print their engines when it comes time to assemble them, so they are designed to be installed just like how the factory springs are. but what you want to do can only make it better.

[mhubble91]

you should be able to find the answer you`re looking for in their web site. if not, you can contact them. not a lot of people actually blue print their engines when it comes time to assemble them, so they are designed to be installed just like how the factory springs are. but what you want to do can only make it better.

Hm, I had never actually thought to contact them, thanks for the tip! And yeah, I'm starting to realize a lot of people don't really take the time for all the small details. I guess I'm just that kind of person :D

[mhubble91]

It's not like a SBC at all, you install them as is.

With that said the BC seat pressures are super huge too.

Sorry, what do you mean by 'SBC' ? Just unfamiliar with that term.

So what you're saying, though, is that I DO NOT put the small, washer-looking spacers under the spring to compensate for variances in spring pressure?

[rcdad123]

SBC=small block Chevy

[mhubble91]

SBC=small block Chevy

:picardfp:


And I'm sure of what he means... by "you install as is"....

No you don't? Not a small block.... lol?

[Kingtal0n]

It's not like a SBC at all, you install them as is.

With that said the BC seat pressures are super huge too.

There is a hidden message here. bigger seat pressure means... what? I know we all look at upgrade valve springs and... automatically assume that the largest force holding the valve closed is the best thing for an engine.

Well, its generally true that large seat pressures are nice for holding valves shut. There is, however, one other detail everybody overlooks: a large force holding a valve shut, means that a similarly large force needs to be applied in order to open that valve.

In the SR20DET, the cam lobes do this job. They are made of metal. They establish a wear pattern. They experience wear and tear.

Therefore, the stronger the spring, the more camshaft wear and tear we might expect. It would then make the most sense for us to install the weakest spring, that will still give acceptable high performance for application.

[jr_ss]

Kingalton, I understand what you are saying, but man I swear you are high or fucked up on something at times when you post shit...

DO NOT install the weakest spring you can find. Cam lobe wear takes thousands of miles to occur unless you run into oil starvation issues, then you have bigger problems than cam wear.

What Cody meant, is there is not a special procedure to install the springs. You simply remove the old one and install the new one. As long as you keep all your valve stem shims inorder, you don't have to adjust anything hence " Install as is".

[rcdad123]

Sorry, what do you mean by 'SBC' ? Just unfamiliar with that term.

So what you're saying, though, is that I DO NOT put the small, washer-looking spacers under the spring to compensate for variances in spring pressure?

you still need to install the spring seat shims. those are there to prevent the valve springs from gouging the aluminum surface of the head.

[Kingtal0n]

Kingalton, I understand what you are saying, but man I swear you are high or fucked up on something at times when you post shit...

DO NOT install the weakest spring you can find. Cam lobe wear takes thousands of miles to occur unless you run into oil starvation issues, then you have bigger problems than cam wear.

What Cody meant, is there is not a special procedure to install the springs. You simply remove the old one and install the new one. As long as you keep all your valve stem shims inorder, you don't have to adjust anything hence " Install as is".


I never said install the weakest spring you can find. I said, and I quote, "It would then make the most sense for us to install the weakest spring, that will still give acceptable high performance for application"

Riddle me this, you want 400 horsepower, MAXIMUM. Will I install a GT42 or a T04E ? both will support 400 horsepower, but one will do it "better". And by "better" I simply mean the the benefits of both, while being equal, are not equal, because one will give a more acceptable high performance for application.

Wear and Tear is part of the equation. minimize it.

[jr_ss]

Riddle me this, you want 400 horsepower, MAXIMUM. Will I install a GT42 or a T04E ? both will support 400 horsepower, but one will do it "better". And by "better" I simply mean the the benefits of both, while being equal, are not equal, because one will give a more acceptable high performance for application.

What does that have to do with the mans question on valve springs?

[Juantwo3]

does that spring compresser they use in the post the snap on one work on KA motors aswell??? cuz i have the keeper remover ordered and if that thing makes it easy er then fuck ima send it back. anyone else have any exeriance using the snap on valve spring compresser???

[rcdad123]

from my experience, i only use the keeper remover to remove the valves, i use the Snap On tool to install springs back on because i am not strong enough to press the valve springs with that little tool to install the springs. i also found that bolting the head to a bench makes it easier to install the springs. just make sure you slip all of the valves in the guides before you bolt the head to a bench.

[codyace]

Sorry, what do you mean by 'SBC' ? Just unfamiliar with that term.

So what you're saying, though, is that I DO NOT put the small, washer-looking spacers under the spring to compensate for variances in spring pressure?

SBC = Small Block Chevy, my fault there

The little washer looking deals are the new lower spring seats, not spacers. Unless BC has changed their packaging to include spring seat spacers..which I doubt as the BC spring already come with a titanic sized amount of spring presssure.

you still need to install the spring seat shims. those are there to prevent the valve springs from gouging the aluminum surface of the head.

You do realize there are factory spring seats right?

When I made the comment, it may have been generic..so I'll restate 'you install them just like you took it apart'.

does that spring compresser they use in the post the snap on one work on KA motors aswell??? cuz i have the keeper remover ordered and if that thing makes it easy er then fuck ima send it back. anyone else have any exeriance using the snap on valve spring compresser???

JWT makes a slick tool you can use for the KA
http://www.jimwolftechnology.com/wolfpdf/VQ_SPRING_REMOVER_INST.pdf

I've never used it, but have used similar. They work great

[codyace]

There is a hidden message here. bigger seat pressure means... what? I know we all look at upgrade valve springs and... automatically assume that the largest force holding the valve closed is the best thing for an engine.

....
Therefore, the stronger the spring, the more camshaft wear and tear we might expect. It would then make the most sense for us to install the weakest spring, that will still give acceptable high performance for application.


I'd exchange the word 'weakest' with 'better designed' truthfully, but your point remains the same across any usage of parts (and I think most don't realize that). Why put 800 lb springs on your car when 600 are ok, why run 1000cc injectors when 555 are more than ok, etc etc etc.

Anywho (not directed at you, just in general to the O/P and others)

Bigger spring pressures can induce all sorts of wacky valvetrain issues (this obviously goes beyond and way before BC) and there are tons of youtube videos showing the ill effects. Atop of that, cam profiles also play a big role in how it all works. Huge seat pressure <> bad (obviously) if the cam is designed around it...the issue is most people on this forum throw the cheapest spring they can find at the cheapest cam they can buy, and consider it "good 'nuff"...and then wonder why cams break, or the motor doesn't make the power it should, or compression is odd, etc etc etc.



Anywho, for those curious some simple google searching can help you learn more about the theory behind cam design. Granted some of it is even above my head, it's still worthwhile stuff to read and begin to understand. For now i'm off to the AutoX haha.

[Kingtal0n]

I'd exchange the word 'weakest' with 'better designed' truthfully, but your point remains the same across any usage of parts (and I think most don't realize that). Why put 800 lb springs on your car when 600 are ok, why run 1000cc injectors when 555 are more than ok, etc etc etc.

very good, the whole point of any parts replacement, on any vehicle, comes back to this right here, that is all I meant to address.

Problem is, when you say "better designed" in reference to valve springs, many people automatically assume you mean strongest spring. That was the reason for my post, ["better designed" <> spring pressure], as we clearly demonstrated. Cody these things are clear to us, but not the vast majority. Nobody is making posts on forums about how stronger springs do not make for better designed springs.

It's our job to point this out, because we know better. If I hadn't posted, you would never have posted: "Bigger spring pressures can induce all sorts of wacky valvetrain issues " And yet this could have been on your list of issues to address. Should have been.

[mhubble91]

Hm, Well I didn't keep the shims in order, because I thought it wasn't necessary because I was replacing valves, springs, and cams, and rockers. Obviously replacing all of these would require to re-shim.

[UNITEDMASTER]

Tomie make different spring seat shims.Here is how I go about equalizing seat presures. First take all the neww springs and test them in the spring pressure tester ,i do it at 1" and at 1/2", this is to get an idea how consistant the springs are,taking note of the heavy ones,mark them & keep track of their placement .

Now it is highly important that whoever did the valve job was not a screw ball. Because if the cut the hell out of the the actual valve seat this may affect installed spring height.Also if they did a shit jod grinding the valve tips this will affect max lift values accross the head also. Quality vale job is highly critical if your gonna go this far with a cylinder head.

Now put the head together(keep track of the heavy springs location) .Check what all the installed spring heights are.Take notes of all . On some engines you can use different thickness spring seats &/or shims some heads you can actually machine the head where the spring sits.


Do the math & adj/shim accordingly. Once you have the heights all equal now you need to make a rig of some sort with a dial indicator on it & a helper is good. It REALLY helps if you have a rig to bolt/clamp head to with the chambers open on bottom

Look at your cam card find what your max lift is, have your helper using the rig with dial indicator or turn the cam to compress the spring to the max lift value,then with your machinist rule & flash light measure the compressed height. NOW if you did all the other stuff correct then the all should be verry close

The installed height plays a big part in actual seat pres. closed & coil bind .open.

Now to equalize seat pressure closed,then you will need to shim the actual spring.Now you gotta measure their pres. at the correct installed height,then shim sprigs up(more coil tension) This process is kinda a trial & error hit or miss deal, and take time. Thats why it important to start with a good set of" MATCHED" springs that are all very close to each other from the begining at the 1" & .500 test.

Hope this makes sence, this is just a vauge idea of whats involved in blueprinting a head