Valve springs, to dual or not to dual

[ProjectSQ]

Ok everyone I'm getting a little annoyed messaging shop after shop for advise and basically getting vague oh that's good or go with these answers and then no answers to follow up questions.. So my question is.

272 duration 11.5 lift cams. Can I go with a good name brand of single springs like GSC beehive or super tech or will I need dual springs? If I get dual springs won't the seats need to be changed or modified??

I will be running solid lifters and dual slotted shims. Stock size valves...idk what else if you have questions let me know

[XMcEvilson]

what engine?

[ProjectSQ]

SR20DET


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[ProjectSQ]

??


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[ixfxi]

SR20DET


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??


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The SR20DET is part of the SR family of engines from Nissan.

It is a popular inline four cylinder engine fitted into a variety of cars, generally the Nissan Silvia and 180SX. It also came in the Pulsar GTI-R and the Nissan Bluebird. This engine replaced the CA18DE and CA18DET that originally powered the Silvia and 180SX

[brndck]

Ok everyone I'm getting a little annoyed messaging shop after shop for advise and basically getting vague oh that's good or go with these answers and then no answers to follow up questions.. So my question is.

272 duration 11.5 lift cams. Can I go with a good name brand of single springs like GSC beehive or super tech or will I need dual springs? If I get dual springs won't the seats need to be changed or modified??

I will be running solid lifters and dual slotted shims. Stock size valves...idk what else if you have questions let me know

may i ask why you're choosing such an aggressive set of cams?

[ProjectSQ]

Lol I know what an sr20 is. As for the cams I got them cheap and they are going towards my engine build. I have the M7960 for right now but in time I'm going to upgrade to top mount t3/t4. So right now I'm building the block and internals so I can have piece of mind and because I can lol


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[ixfxi]

Lol I know what an sr20 is.

It also came in the Pulsar GTI-R and the Nissan Bluebird. This engine replaced the CA18DE and CA18DET that originally powered the Silvia and 180SX. The CA18 was deemed too expensive to produce and no longer met Japanese emission standards, so it was replaced by the SR20. The SR, just like the out-going CA, was a turbocharged intercooled engine in top form. Nissan also produced a cheaper naturally aspirated version called the SR20DE.

[ProjectSQ]

You're very helpful and knowledgable ixfxi thanks again for your insight..so does anyone have suggestions on quality springs?


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[OBEEWON]

You didn't ask this but don't put those cams in or you will have a bad time. Get some HKS or Tomei 264's and some BC springs/retainers. Your midrange will thank you.

[ixfxi]

You didn't ask this but don't put those cams in or you will have a bad time. Get some HKS or Tomei 264's and some BC springs/retainers. Your midrange will thank you.

why are you spreading misinformation, obeewon?

Dino Dale Carbonfibre already posted a lengthy article that specified what type of cam/spring setup to run. the only reason you dont want to say is because you want Your Skyline™ to be the best Skyline™

[OBEEWON]

And I would have gotten away with it if it wasn't for those meddling kids.

[slow40sx]

I would run Eibach Sportline springs with Koni adjustables, that way you'll have better traction for the hole shot

[ProjectSQ]

You didn't ask this but don't put those cams in or you will have a bad time. Get some HKS or Tomei 264's and some BC springs/retainers. Your midrange will thank you.


I've considered it at this point. Why is it so hard to get information? Thank you for the info


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[ProjectSQ]

I know I'm noob to the engine I didn't think the cams would be that big of a pain in the ass on these.


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[brndck]

As for the cams I got them cheap and they are going towards my engine build.
terrible reason to select a part.
You didn't ask this but don't put those cams in or you will have a bad time. Get some HKS or Tomei 264's and some BC springs/retainers. Your midrange will thank you.
TROOF.
I would run Eibach Sportline springs with Koni adjustables, that way you'll have better traction for the hole shot
holeshot is lyfe.
I've considered it at this point. Why is it so hard to get information? Thank you for the info


because you ask uninformed questions instead of doing research.

[ProjectSQ]

Thanks brndck I realize it was a pretty uninformed question I guess really what I was wondering is if there's a required seat pressure and lift pressure when going for larger cams.


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[PoorMans180SX]

Ok everyone I'm getting a little annoyed messaging shop after shop for advise and basically getting vague oh that's good or go with these answers and then no answers to follow up questions.. So my question is.

272 duration 11.5 lift cams. Can I go with a good name brand of single springs like GSC beehive or super tech or will I need dual springs? If I get dual springs won't the seats need to be changed or modified??

I will be running solid lifters and dual slotted shims. Stock size valves...idk what else if you have questions let me know

Those cams are fine. Most of these guys just followed the typical Nissan-owner build path of downpipe, FMIC, boost controller, 2871r, 264 cams, etc.

What most fail to realize is that with the right turbo, big cams can be awesome, really waking up the midrange powerband. Those aren't even "that big" if we're comparing to what most of the four-cylinder world runs.

I would get beehives like GSC or Kelford, we use beehives in nearly all of our engine builds. Kelford gives you max lift and duration with each of their two valve springs types.

[ProjectSQ]

Bam! An answer thank you very much PoorMans180SX


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[OBEEWON]

Those cams are fine. Most of these guys just followed the typical Nissan-owner build path of downpipe, FMIC, boost controller, 2871r, 264 cams, etc.

What most fail to realize is that with the right turbo, big cams can be awesome, really waking up the midrange powerband. Those aren't even "that big" if we're comparing to what most of the four-cylinder world runs.

I would get beehives like GSC or Kelford, we use beehives in nearly all of our engine builds. Kelford gives you max lift and duration with each of their two valve springs types.


I mean I actually tried two sets of 272's and wanted to punch my former self for being stubborn and not listening to people. Dropped in 264's and was hype beast #1. Most of the 4 cylinder world isn't SR20. 272's on a 4G is WAY different than 272's on a SR.

[ProjectSQ]

But what was the issue if you don't mind me asking?


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[OBEEWON]

I had to wait til tomorrow to get full boost. The car was only fun in 4th gear.

There's a reason each motor has a marque build.

[ProjectSQ]

With what turbo? I could see that being the issue with a large top mount but a TD06 has a pretty awesome response


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[OBEEWON]

2871R. But don't take my word for it. Look at dyno sheets or just try it.

[PoorMans180SX]

I mean I actually tried two sets of 272's and wanted to punch my former self for being stubborn and not listening to people. Dropped in 264's and was hype beast #1. Most of the 4 cylinder world isn't SR20. 272's on a 4G is WAY different than 272's on a SR.

I have experience with both engines. If you bought BC cams, there was your mistake. The tune becomes much different from a mild cam to a large cam, the same enthalpy tune simply will not do.

Also, a big cam is the wrong cam for a little T25-flanged turbo, they won't like each other.

There are LOTS of factors that go into cam selection, but simply stating that a cam is too big is not going about it the right way.

[Kingtal0n]

I always use the minimum spring for the application. For example, if I had just rebuilt an sr20det to OEM specification, I would use the OEM spring, with an OEM compatible camshaft like the S3 or S4. By keeping the OEM spring and redline, I enhance the durability of the engine by minimizing those forces that would seek to destroy it.

[PoorMans180SX]

There's a reason each motor has a marque build.

Yes that's true, there are two reasons:

1. It's easy and/or cheap
2. Someone has already done it, so it "works".

Sadly there are usually and most often better combos to be had.

The issue you had with boost coming on late had less to do with the cams than it had to do with the 2871R.

With what turbo? I could see that being the issue with a large top mount but a TD06 has a pretty awesome response



Hmmm, maybe not the greatest choice for a TD06 unless you're trying to rev it out or it has a smallish compressor wheel.

What a lot of people don't understand is that a bigger turbine wheel can benefit from larger cams. This increases the overall VE of the engine, and if you get a proper divided housing setup, you don't miss the little low-end you lost when the massive mid and top end comes in.

[brndck]

I have experience with both engines. If you bought BC cams, there was your mistake. The tune becomes much different from a mild cam to a large cam, the same enthalpy tune simply will not do.

Also, a big cam is the wrong cam for a little T25-flanged turbo, they won't like each other.

There are LOTS of factors that go into cam selection, but simply stating that a cam is too big is not going about it the right way.

this basically reinforces my point. if he is building the engine to work with those cams, and has a properly sized turbo, and an actual plan, then great.

the OP stated that he selected those cams cuz he found them for a cheap deal. not because he's building an engine that will work with them, and not a wise choice IMO. :picardfp:

[ProjectSQ]

^^this is true they are Greddy/trust cams I got for less than $350. However the TD06Sl2 is by no means small and in long term (I mean like another year or so) I'd like to go top mount t3/t4 I. Which case the cams will be more fully utilized. I'm looking for springs that will be able to hold up against the aggressive lift and that will help the higher rev limit with the larger turbo. With the TD06 it might not be worth higher rpm and that shouldn't be the topic of conversation...I know. What I want to know is if dual springs vs beehive. What seat pressure and lift pressure should I look for to live with these cams...


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[OBEEWON]

I have experience with both engines. If you bought BC cams, there was your mistake. The tune becomes much different from a mild cam to a large cam, the same enthalpy tune simply will not do.

Also, a big cam is the wrong cam for a little T25-flanged turbo, they won't like each other.

There are LOTS of factors that go into cam selection, but simply stating that a cam is too big is not going about it the right way.

I do as well. Not that it makes me an expert. I had BC first then HKS. They both made me sleepy.

Yes that's true, there are two reasons:

1. It's easy and/or cheap
2. Someone has already done it, so it "works".

Sadly there are usually and most often better combos to be had.

The issue you had with boost coming on late had less to do with the cams than it had to do with the 2871R.


Right...so why make it hard or expensive??

Yeah, the 2871 was not the greatest turbo. But with 264's it was pretty much what I wanted. This chap doesn't look like he is going for anything bigger than a T2 flanged turbo right away, 272 is not even the greatest with a T3 flanged turbo for response unless he is going to be running anti-lag, twin scroll and all the trickery to get a SR to pretend to make TQ.

But if you have ground breaking stuff no one has tried...cool?

[OBEEWON]

Yes that's true, there are two reasons:

2. Someone has already done it, so it "works".


http://cdn.makeagif.com/save/rPgksC

[TheRealSy90]

Anybody had success running stock springs with bc retainers? I've got a built head with BC springs and retainers, but I'm thinking about changing the springs out for stock ones that aren't so stiff. Planning on revving to at least 8k.

[ProjectSQ]

I would stick to the bc's..why would you want softer? If you're concerned about your HLA's then go solid...but then again I made this thread because I don't have much experience with head mods on the sr so hopefully someone else can chime in


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[TheRealSy90]

Just because of the added stress on the valvetrain components with the stiffer springs, as Kingtal0n was talking about:

I always use the minimum spring for the application. For example, if I had just rebuilt an sr20det to OEM specification, I would use the OEM spring, with an OEM compatible camshaft like the S3 or S4. By keeping the OEM spring and redline, I enhance the durability of the engine by minimizing those forces that would seek to destroy it.

But I think for what my rpm goals are, the stock retainers aren't the problem, and the springs are. So I guess I'm staying with all the BC stuff, except the BC cams, sold those for JWT's of course. Although I have heard of people doing 8k on stock springs with no issues?

[ProjectSQ]

I've also heard a lot of things, most of which I wouldn't put my faith in. It might not exactly be "cutting corners" but still


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