MJTru

Well mate im running a 6 boost top mount manifold. Not a stock unit. So what im wondering is will it really help in power gains. At the moment the bowls are clean and have a way better transition. But now im looking at those big bumps. Please keep in mind that thw hp goal is 600hp .

Thanks piggaz. For the photos. I didnt mean that it cant work I just wanted to say that it would be closer to the water galleries. But I have heard that if people are running after market manifold that these humps need to go. Some even say its a must. But I like to look at the benefits of having it out. Exhaust flow is critical in making power. Can you say from experience that it made a difference in power. Or did you do it for a peace of mind. What led you up to the point where you choosed to take them out. Thanks mate. I value your insight.

Can you expand a bit on this subject. Cross sectional area of the poet is what im meaning. Thanks in advance mate. I ask because im still confused. I have just finished cleaning uo the bowls, but now im looking at the bumps in the exhaust and I can contest in saying that this hump does not seem to be there because of the exhaust studs. There is plenty of room or material for the stud. I do agree that the walls might be thin or close to the water ports.

I would say not much. Lol. Why dual spring. If a single can do the job. From what I would imagine is the only reason for 2 spring is more seat or operating pressure. But to much isnt good. You should first need to know what it is you want, and then build around that. Just using the maximum seat preasure just simply overwhelming the valve train. As a guess would kill longevity.

In my most humblest opion which is based on not have proven to myselft through real live data. First I would think that 9.15 lift is to much for a stock spring to handle. Im basing this on the fact that a 2jz motor can only run 8.5mm the very most on stock springs. So I really cant say for sure on the stock springs, but I always side on being cautious. From what I know the stock spring can olny be crushed so much which works hand in hand with lift. So in short you can be able to google the maximum lift on the oem springs and then give yourself a margin of error for me its always 90%. So if max you can run is lets say 8.5mm lift on oem spring ill look at it at max being 8mm. Thats just off the top of my head. As for the duration I would ask what you max rpm you are planning on running. Cause that will then affect the pressure of the spring. Or opting for lighter valves. Like titanium and so on. Its complicated stuff. But no one knows it all. So its always good to ask. This is why I use this site. When I first joined this site people looked at me as a stranger and didnt help me at all. But tried to steer me a stray. But cause of my mechanic and technical background all I need is a few words and I can filter out who are just trolls and who knows what they are talking about. I just wish that I can contest to have moded rb heads but I just smilpy have not. I have always recon heads and run them stock and made really good power. But now im forced to do so. So I turn to this same site for all my insight. Cause I would be an ignorant prick to think this site hasn't done nothing for me. Its so easy now more than ever that I know the mates on here by name. As to the ones that knows shit. At least to the point of a particular subject. I even notice that by using kwy words and the way I make my questions they then would answer. Lol. But they are always reading evwn though they are way past the subject at hand. Sorry to get off topic here but I just needed to getwthis out. Wow. Thanks mates.

Well I would recommend getting new springs cause those set you got right now are straight up old and can be compromise a little. A fresh set would be good. Spring that is. I got new spring but im just like you. Im thinking of going with new valves.

As we speak im cleaning up the bowls in the new head. After im done I will try and up load some photos. Its not that hard. Im making sure that I dont remove material that not needed to be removed. As I do it, I'm think of the air coming in and just work on the transion that machines left behind. Im an advocate of velocity. Lol The very most I would like to spin the motor is 9000 rpms. With these new springs. [email protected] total net lift is 16mm. Now for valves im a little confused. Because my head shop over here cant even do a angle job. This is in the bahamas a place close to florida. If I get the valves I would need to send it all to miami florida to have it all installed. As for what whats to use I was wondering is supertech ss valve would do tye trick. Please keep in mind the car is only for drag. If it was a old recon head then I would most likely go that way. I just want to know if these parts will work for my goal of 600hp. Max rpm 9000. GTS Boy are you in florida???? Hope you are having a good time.

Lol. I remember seeing that old station wagon in your photo around in some good topics. Your a smart guy. I agree with you 100%. I really can put that 1k into somthing way better than 1mm oversize valves and having the job done right. Iv see a friend close to me with a v8 motor cut the seats, not replace them. Then he went with bigger vavles. Sad to say one of the seats came loose and fell off. For a 600hp goal would you recommend the stock valves or do you think after market standard size would do the trick. Any insight would be helpful. Additionally thanks to everyone on this forum for such insight. To date I have all my rb success do to this site. Thanks to all.

But ive seen so much photos with people taking them off. Now all thats needed is somone to blow it wide open and post some dyno results with it in and the other with it removed from the head. But I guess it wouldnt be a well worth while venture. Or even flow chart showing the difference with it in and having it out. (The difference in the way the head flows air)

I see your point now. I want to resuse my valves but dont know how to check to see if they are worn. The stem area that is. I have an idea though. The head is new with new seats and guides. But if I was to get new ones then it would makes sense to go bigger ones, and not oem valves. One quick questions titanium valves. Whats the hype all about. ???

I guess the question should be asked. What limits are the stock valves good for??. Ive seen a 1300hp gtr my RH9 and after his motor failed. It was because the only stock part the guy mentioned thats in his motor was stock exhaust valves, and sad to say he dropped an exhaust vlave. So these valves are good for some high hp levels. I plan on only 600hp. So im thinking that they should be able to do those levels of hp on oem valves.

Ok. This is way better. So ill leave the bump in the exhaust ports. As we speak I have already clean up those areas. I was just wondering about those bumps in the exhaust ports. I came across an artical that mentions removing them if you are going to run aftermarket exhaust manifolds. Can anyone tell why these bumps are there in the fist place.????

Im going through the same thing right now. I have some 272 hks cams and im thinking of getting some vavles now to. From your list of mod tje only thing I ant got is that enlarged oil pan. I got the new head from nissan as well. Im interested to hear what people will say about this topic because im sorry to say that I never moded a nissan head before and this will be my first time doing it. interneting.

Mate buy a power fc and save yourself some time and lastly money. As I value time over money. A power fc did wounders on my gtt r34.

I have people questioning my abilities to assemble a rod to a piston. But I am not percect. So I ask knowing I might be wrong. So in saying that I can either assemble a connecting rod 2 ways. Having the bearing locks facing the oil filter side or the exhaust side. So if I got a con rod that has manley brand name facing one side of the h beam. I can have some facing backwards to the flywheel side and some facing the crank pulley side. I like to keep things all the same as removed. So as simple as this question may be I challange anyone to bring the solution to this simple issue to light. Thanks

Ok I looked at a video of an rb build in japan. The bearing locks need to be on the oil filter side period. It is good practice to put things back the way they came out I would guess. Because parts are build which that in mind. To make sure im right ill look at an rb20 I have with the oil pan off and confirm. Bearing locks on the oil filter side.

Is that looking at it from the from right side up. Cause its on the engine stand right now, but I can spin the motor so im assuming front right side up. Please can anyone conform this.

Hi when assembling the connecting rods which way would the bearing locks be placed to the exhaust side or the intake side.??? I cant remember as its the only thing I forgot to mark on the rip down of the motor.

So off topic I didnt learn nothing about the damn hump in the exhaust ports.

Piggaz is right those are the stock cam specs. But can anyone answer my question as to the supertch sping specs will work or not. Eather hks steps in sure of the duration, but ill mesure the lift today and tell you.

Are these the right springs hks step 2.

Supertech SPRK-M1007S/RB Specs: Outer Spring O.D.: 28.10mm Outer Spring I.D.: 20.00mm Seat: 70 @ 40.7 (lbs@mm) Open (lift): 188 @ 11 (lbs@mm) Max net lift: 16.00mm Coil bind: 24.70mm Rate: 10.50 lbs/mm

I have done a lot of reading in those threads but thats about a year ago. I decided to go with the head drain as insurance. I understand by putting the restictor in the head will reduce the amount of oil in the head and really make the head drain redundant. I was looking over the oil pumps manual and it does say that I need a enlarged oil pan. Does anyone know of another option thats cheaper that 1100 usd offered by raw brokerage. It looks to be a very clean unit with extended oil pick up and oil pan baffles. As for the cam. Yes sir. Its intended for drag racing. I will attach the supertech part number for the valve springs. With such duration I will need stiffer springs to avoid floating valve effect right. This is the reason I want to post the part number I got. I have heard that this duration will kill low end power but make up for it on the top end. Can you please explain just a little about the subject. Like pros and cons.

I didnt choose these cams they came with the motor from japan. Valve float did cross my mind. The turbo is a PT 6262. I personally was planning on selling them and going for stock ones, cams that is. I got the set of valve springs for stock lift. I was told that I can increase the lift a little. But will be fine use the hks cams. Yes I was told by the old owner of the car that the cams are stock lift and 272 duration. These numbers didnt come from me but the person who got them. In my head thats risky. Im already turned off. So I guess ill just get a set of stock cams. I can remember reading an old thread where people made better power using there oem cams over several brands out there. It had mentioned that if the whole valve train wasnt looked at it may be better to go back to the stock cams. Any ideas on the oil pan.

Ok I have been asking for advice on my build and as we speak. I have got the following parts. 1. Set of rods and pistons. Manley rods with 625 bolts, cp pistons with 9310 pins. 2. Tomie over size oil pump 3. ACL race bearings. 4. ARP head studs and main studs. 5. Cometic 1.3mm thick head gasket 6. 1.1 head oil restrictor 7. Supertech intake and exhaust valve seals. 8. Head oil drain kit. 9. New OEM cam and rear oil seals. Im waiting on a new oem crank with the long oil pump drive and a new cylinder head. With some valve and spring. Then I can start the build. I have a few queation regarding a set of new hks cams and for my goal of 600 hp should I use them. I plan on drag racing the car more than driving ir on the streets. I have a stock r33 gtr for street use. The cams specs are stock lift but 272 duration. I dont have much experience with cames as I always go stock cams on my builds. The biggest difference going from a gtst to a gtr is that I just launch the hell out the gtr rpms are in the 8000 area all the time. Will these cams help me or slow me down for my 600hp goal. My next problem is. I know of the rb oil issues and have never had real big oil pump failures in the past. Thats on rb25 builds. Now with this new oil pump. (Tomie) should I go with the ovwrsize oil pan or is it a waist of money?? I see that Raw Brakerage has a service to inlarge my pan for 1100 usd. They also put the head return on the pan but on the intake side. Is this a good idea.