RB25DET head rebuild?

[RBnMY240]

hi im looking to rebuild my head and was thinking of going with the TOMEI 256/256 Camshaft and the TOMEI RB25DET Valve Springs.i was wondering if anyone has used this setup and if it was any good?or does anyone have any other suggestions that i should go with?^_^

[ItzGenX]

What kind of driveability and power are you looking for? Usually the Tomei head equipment is awesome. What you've selected is for a mild street/track setup for the mid-mid/high rpm range.

[RBnMY240]

i appreciate your feedback thanks ^_^ MmMm maybe some where between.. 450-500hp? im going with Cp forged pistons and Eagle rods also getting the head port and polishso..maybe ill be close to that rang, driving street and a lil track.

[otightitzjim]

im runnin that set up. love it. the mid range is beautiful. the head is pretty mildly ported, tomei poncams 256 in/ex, tomei springs, supertech valves, valve guides. cant go wrong. the whole block is built except the crank. im currently makin 506whp at 18psi. a little high for a gt3040 but was done on a dynojet.

[RBnMY240]

sweet thanks ^_^i cant wait to get these parts i was searching around and i found your posted saying you had the tomei 256 cams with a bunch of other stuff lol on the build.what valve guides did you go with?do i need to get the TOMEI Solid Lifters?im not sure on wut all to get, kinda new to this rebuild

[boosted98gst]

sweet thanks ^_^i cant wait to get these parts i was searching around and i found your posted saying you had the tomei 256 cams with a bunch of other stuff lol on the build.what valve guides did you go with?do i need to get the TOMEI Solid Lifters?im not sure on wut all to get, kinda new to this rebuild

You should be be fine with the hydrolic lifter unless you plan on running over a 9.5 lift cam. The valve springs and cams pon cams should be good with the oem lifters

[RBnMY240]

yeah i did some search too and i guess ill be keeping the hydraulic lifters but thanks for everyone's feedback ^_^

[otightitzjim]

yeah keep the hydros unlesss lik stated above. youll want to get the solids if you wan to rev past 8.5k along with the tomei procams.

[Chaos the Xile]

yeah i am running the (well not running yet) tomei procam 270/10.25mm lift and the solid lifters are a must when running a lift that high, plus you need to purchase a shim kit to get the lifters installed properly and it takes up and crap ton of time doing that, but your setup should be fine for the hp numbers you seek! good luck!

[jlaudio_21]

You dont necessarily need to replace the valve springs even do you>? Never bad too! The TOMEI PONCAM 256/256 only have lifts up to 8.5mm.... Opposed to the stock configurations are as follows: In/Ex 240/240 and 7.8mm In /7.8mm Ex. Choices for me right now are between the Tomei Poncams 256/256- 8.5/8.5 (as you are talking about) or also heard some great reviews on the HKS camshafts as well? More of a choice when it comes to the HKS ones though. They offer a choice of two Ex Cams, offering a longer duration as well as a bigger lift? HKS has for stage 1 (compaired to the Poncam 256/256) In/Ex 256/256 with 8.8mm of lift and an Ex with 264 and 9.0mm of lift... Any help here discovering why this is so and or benefits/losses??? Just want to help you out with decision as well as if it helps me too! Thanks for the common interest!!

[nyc240sx]

nice info

[Darius]

You can get 450-500 hp through the stock valve train. No need to upgrade really.

[jlaudio_21]

Thank you

[jlaudio_21]

Opening the valves and having a longer duration does make it allowable to have a higher boost though right? Do to the compression of the RB25DET (9-1) being high isnt as safe to boost high as opposed to a lower compression? Thus creating a more constant "flow" opening the valves more would make sense for safety of the motor and being able to have more power of coarse! Correct me if Im wrong please ! This is how I understand the replacement of cams. Thanks again to everyone interested in this. -Brian C.

[mott6904]

Yes because bigger cams will actually bleed off some of the compression.

[RustspecS13]

9:1 is not high compresson.

Maxima guys and 350z/g35 guys boost the crap out of the stock engines. They have cast pistons that have 10 to 10.6:1 compresson. The 95-01 maxima has the VQ30DE and the 02+ maximas and of course 350z/g35's have the vq35.

There's plenty of people in the 300-450whp range with stock high comp nissan motors.

As far as the rb25 goes, there's a guy on the hybridz forums that runs 9's in a 240z and his rb25 dynos at around 550whp and then he also has 125 shot of nitrous he uses too. Completely stock block.

~Alex

[jlaudio_21]

RB25DET 'CAN' and 'WILL' handle HIGH HP built stock but for how long?My purpose of doing cams is lets say "security" for my engine components to last day after day after day and so on..... I want to have a high number without having concern of blowing the motor or stressing it too much. Please understand this is not going to be a RACE car as to going to the track every weekend to try for that low number 1/4 mile, but for strictly street use and driving it constantly and when the power is needed .... it will be there... as my favorite slogan... RUN YOUR CAR NOT YOUR MOUTH! hahaAnyways back to my original plot of this I think I have decided to go with the TOMEI PONCAMS 256/256 8.5/8.5 TOMEI has been the leader for cams on the RB's as opposed to there is nothing wrong with HKS at all! but Tomei is known more when it comes to dealing with the cams for the RB's. I dont think I would gain that much opposed not sacrificing idle issues with the extra .3mm lift that the HKS has.... help me out please..Thanks again everyone!-Brian C.

[boosted98gst]

Yeah but did you read what he posted about how the motor is taking it? He even stated he knows the motor is not going to last long, its more put together for a glory pass then anything. Im sure he wants to set goals as the first rb "long block" this and that.

[boosted98gst]

RB25DET 'CAN' and 'WILL' handle HIGH HP built stock but for how long?My purpose of doing cams is lets say "security" for my engine components to last day after day after day and so on..... I want to have a high number without having concern of blowing the motor or stressing it too much. Please understand this is not going to be a RACE car as to going to the track every weekend to try for that low number 1/4 mile, but for strictly street use and driving it constantly and when the power is needed .... it will be there... as my favorite slogan... RUN YOUR CAR NOT YOUR MOUTH! hahaAnyways back to my original plot of this I think I have decided to go with the TOMEI PONCAMS 256/256 8.5/8.5 TOMEI has been the leader for cams on the RB's as opposed to there is nothing wrong with HKS at all! but Tomei is known more when it comes to dealing with the cams for the RB's. I dont think I would gain that much opposed not sacrificing idle issues with the extra .3mm lift that the HKS has.... help me out please..Thanks again everyone!-Brian C.

The funny thing about 240 owners is they always seem to think they know whats best for this and that, yet they never seem to prove themself through their work. Its always easy to claims things and tell people about other peoples cars, and what parts are the best when 85% of the people have never even done it themself. your best bet is going to be calling and talking to people that have time tuning and running both cam's that would be the only only person Id even listen too. If you never have buillt a 500-600hp dont act like you have, let the people with hands on knowledge speak. I am in no way saying I know everything, because I am here to learn more then run my mouth unless ive had first hand experense.

[Darius]

Cams and valve train upgrades will not decrease the wear and tear on any other engine components. They simply allow more air to flow through the engine by opening wider and having less loss through the head.

Like I said, for 450-500hp save the $1000 and put it towards turbo, fueling, and tuning. You do not need cams for that power level nor will they make your engine last longer at higher boost levels. That is all in the tuning and the strength of the internal components themselves. OEM internals will do 500 hp too as long as you have a good tune.

[eh?]

Cams and valve train upgrades will not decrease the wear and tear on any other engine components. They simply allow more air to flow through the engine by opening wider and having less loss through the head.

Like I said, for 450-500hp save the $1000 and put it towards turbo, fueling, and tuning. You do not need cams for that power level nor will they make your engine last longer at higher boost levels. That is all in the tuning and the strength of the internal components themselves. OEM internals will do 500 hp too as long as you have a good tune.

Upgrading your cams can affect dynamic CR. But otherwise +1.Who buys cams for "Security" at only 500hp?

[jlaudio_21]

Boosted...Please dont be to quick to judge. I have done almost EVERYTHING myself on my s13 rb25det swap. Most of this has been done with compliments to people who CAN be trusted. (perfect time to shout out at ( http://store.driftingshop.com/d1grandprix.html ) The people here are strictly into HELPING those who are searching for the that piece of info. There dvds do show alot of detail, rather boring at times to watch but show almost EVERYTHING there is to the swaps. Anyways .....240 owners "NEVER" being able to prove themselves through their work!?!? Come on mane please dont flame. That is rather harsh Some have proved their work very nicely as well! Please dont turn this thing upside down now. Im not flamin you either just take my 10 year "child" aka 240 in a different way others might take their cars lol. As for callin around... well that is a very good idea. Will try that any help is better than no help. As for the "RUN YOUR CAR NOT YOUR MOUTH" its strictly a saying dont get it confused with its intentions towards anyone here please. Sorry for the possible confusion we all cool thou.. I will post pics of my ongoing s13 rb25det swap as soon as i get enough time to do so.Thanks everyone, meens alot to those out there willing to help.-Brian C.

[jlaudio_21]

Upgrading your cams can affect dynamic CR. But otherwise +1.Who buys cams for "Security" at only 500hp?

http://www.empirenet.com/pkelley2/DynamicCR.html

Does understand to me now about how the way work in sense

I would want to buy cams for security of being able to further on the limits and always keep moving on.... dont really know where its gunna go from here. Everyone has plans but how many peoples plans change To everyone this is my first rb and have learned alot so far with doing many things to it but still by bar a rookie. Everything is stock internally except CX RAD, KU IM, Vibrant FMI, 90mm TB, header, Complete 3" exhaust, and Apexi SAFCII to control it. Customed alot of things including all the coolant lines and IAC valve plumbing. but most of all completly wire tucked Again Thanks,-Brian C.

[Chaos the Xile]

Cams and valve train upgrades will not decrease the wear and tear on any other engine components. They simply allow more air to flow through the engine by opening wider and having less loss through the head.

Like I said, for 450-500hp save the $1000 and put it towards turbo, fueling, and tuning. You do not need cams for that power level nor will they make your engine last longer at higher boost levels. That is all in the tuning and the strength of the internal components themselves. OEM internals will do 500 hp too as long as you have a good tune.

PREACH BROTHA DARIUS!!!

+1 I totally agree, there are a slew of other things that can be done that can get you close to your desired power levels while retaining the stock valvetrain!

[boosted98gst]

Boosted...Please dont be to quick to judge. I have done almost EVERYTHING myself on my s13 rb25det swap. Most of this has been done with compliments to people who CAN be trusted. (perfect time to shout out at ( http://store.driftingshop.com/d1grandprix.html ) The people here are strictly into HELPING those who are searching for the that piece of info. There dvds do show alot of detail, rather boring at times to watch but show almost EVERYTHING there is to the swaps. Anyways .....240 owners "NEVER" being able to prove themselves through their work!?!? Come on mane please dont flame. That is rather harsh Some have proved their work very nicely as well! Please dont turn this thing upside down now. Im not flamin you either just take my 10 year "child" aka 240 in a different way others might take their cars lol. As for callin around... well that is a very good idea. Will try that any help is better than no help. As for the "RUN YOUR CAR NOT YOUR MOUTH" its strictly a saying dont get it confused with its intentions towards anyone here please. Sorry for the possible confusion we all cool thou.. I will post pics of my ongoing s13 rb25det swap as soon as i get enough time to do so.Thanks everyone, meens alot to those out there willing to help.-Brian C.

Geeeez you're making this harder then it really is , but how are you helping someone to decide a cam or spring or lifter when you personally have never ran that product in a RB??? If you dont have first hand experence with the cam and sping he is asking about how is that helping? I am here to learn just like everyone else But just because I do not post much ,does not mean that I do not give back to the RB community! My lift , heated garage and air tool's have been used to put in prolly over 20 motors from member's on from nico, zilvia,240sxforums, Cr,Cdsm,zeroyon free of charge, mostly to younger 240 kids that do not that the money to pay a shop to do it or have the tools or gargage. I will stop rambling on but I just do not see how helping someone is giving advice that you yourself do not know its true.

[Darius]

This thread is getting a bit off topic. Skip the valve train mods until your research leads you to believe that the head is restricting the engine's potential. Guys are quick to spend money on head mods that aren't needed quite yet.