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Valve Springs For Rb25det?

muaythailuke
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muaythailuke Rising Star

muaythailuke

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G'day Fella's.

I’m installing some new HKS cams and want to replace the valve springs, so I was wondering if anyone could tell me what the installed height of the valve spring (in&ex) on an RB25 is? I can only find the specs for the RB26 in my R33 service manual and I thought that they'd be different seeing they are solid lifters and all.

Does anyone have any recommendations on what springs to use and where to get em from?

Also I don’t want to pull the head off to do this job, has anyone bought or made a good tool for this job before? as the only tools I have to do it won’t fit or need the head off to do it.

Any thoughts would be appreciated.

:(

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danielson Proficient

danielson

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G'day Fella's.

I’m installing some new HKS cams and want to replace the valve springs, so I was wondering if anyone could tell me what the installed height of the valve spring (in&ex) on an RB25 is? I can only find the specs for the RB26 in my R33 service manual and I thought that they'd be different seeing they are solid lifters and all.

Does anyone have any recommendations on what springs to use and where to get em from?

Also I don’t want to pull the head off to do this job, has anyone bought or made a good tool for this job before? as the only tools I have to do it won’t fit or need the head off to do it.

Any thoughts would be appreciated.

:(

stock lift is 8.5mm, and if you wana do a changeover without taking off the head, get a hose fitting the same thread as your spark plug, use your compressor and compress the cylinder.( watch fingers, engine will turn over) and then remove springs... the compressed air stops the valves falling into the bore.

Edited by danielson
muaythailuke Rising Star

muaythailuke

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stock lift is 8.5mm, and if you wana do a changeover without taking off the head, get a hose fitting the same thread as your spark plug, use your compressor and compress the cylinder.( watch fingers, engine will turn over) and then remove springs... the compressed air stops the valves falling into the bore.

Cheers man, the problem im having though is compressing the spring so im able to crack the collets off. As the spring compressor I have needs to go down the side of the spring which there is no possible way with the RB heads, I need some sort of tool to press the spring down I may have to make or modify a different tool to do it, so I just thought someone else may have done the same thing and be able to point me in the right direction of the easiest way to do it :D

:laugh:

I'm pretty sure that they would still be fine, I'm using them on 8.9mm of lift :D

Hmm maybe but it would always worry me, so im gonna look about a bit more before I go back to them

:(

Edited by muaythailuke
  • 2 weeks later...
muaythailuke Rising Star

muaythailuke

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Performance Springs do them and for the NEO as well now.

Hmm yeah well, they are the springs I have in the car atm and they are shit sorry to say, I dont mean to bag this company out but I pulled an in & ex spring out and both only just had 50psi seat pressure and neither got anywhere near 200psi even at full compression :P and id bet if we had heated em up it would have dropped even further so they are just way too soft so... i think i will steer clear of them thanks.

:)

muaythailuke Rising Star

muaythailuke

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dumb question but will the tomei 8.8mm valve springs be ok with 8.5mm stock lift with my tomei step 1 cams??

Yeah they'll shit it in, they are recommended for anything up the 8.8mm lift so 8.5mm will be fine :(

Im thinking of getting myself a set now as I cant find anything else, my intake cam has 8.8mm lift so it will be fine but my exhuast has 9.0mm but I cant see that 0.2mm will make that much difference but im trying to get some spec's on them to find max coil bind hieghts and seat pressures etc.

muaythailuke Rising Star

muaythailuke

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muaythailuke, would the queensland performance spring be better in my application where im only using 8.5mm lift? what seat pressure would stock valve springs use? what were you reving your motor too with those springs? did they cause the valves to float? at what psi ? rpm?

Ive spoken to a few people that have used the qland performance springs and had no worries but other have ive spoken to wouldnt use em in a fit, I may have just got a bad batch I dont know but.... :

The problem I was having started about 4000rpm and just got worse, even at low boost (8-9psi)I had problems and just got worse with more boost (up to only 15psi).

Even when I chaged back to my standard cams the problem was still there.

My rev limiter is set at 7700rpm and I couldnt rev it anywhere near that with these springs.

The seat pressure of the standard spring I dont know but I going to test them once I find my old ones but the description that my tuner gave me after he had tested the performance springs I pulled out was, "just a couple of wound up paper clips"

Hope that helps

:P

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