Fix Thread turned into Re-build thread! (built rb25 neo)

[Darius]

Agreed. You can't put that head back on your brand new bottom end. The squish pad will just become a source of knock at the very least. And it will piss you off to no end when you're trying to tune on pump fuel and are getting knock prematurely (i.e. normal boost levels). From the looks of the head surface, it doesn't look like they milled it very well either. Or didn't you ask them to?

This build has been great up to this point and I don't want to see it go south because of a busted up head. It looks repairable, but it will take some effort (read money) to get it back into stock shape.

[sickness14]

Forgive me for sounding dumb but what are these squush pads you speak of? I'm not too happy with the results of the head either but I don't know what to do guys.

I don't want to do anything half assed. My shop said it would be fine but it looks rough

[Darius]

If you look down at the head, the combustion chamber is round except for the two sides which are straight. If you flip it over, it becomes a flat portion of the top of the combustion chamber. These flat areas of the head coincide with the flats on the pistons. When the piston rises to the top of the compression stroke, the flats meet up and "squish" or "quench" the air/fuel misture away from the edges of the combustion chamber and towards the center. The pads are still in tact so that is good.

The main issue I see is the jagged edges created by the motor chewing on valve pieces. Any jagged edge in the combustion chamber is going to superheat. As it heats up under high load, it gives the air/fuel mixture the ability to ignite before the spark plug fires, which causes knock.

[Coolwhip]

great explanation!

[sickness14]

Thanks guys. I'm going to take the head to rlz engineering out of concord nc and have them rebuild the head properly making it the way its supposed to be.

[Darius]

Glad to hear it! You won't be disappointed in making the extra effort here because it would haunt you later on down the line.

[noodl35]

great choice. I DO NOT want to see another rebuild thread again lol.

[sickness14]

haha. Thanks guys. I want this motor to be perfect after all of this trouble.

I want to see at least 500whp. Is that reasonable with one walbro, stock lines, stock rail, nismo fpr, and 800cc injectors?What's needed to make more than that? And would you recommend it based on my setup?

I want to take advantage of what I've done to it so far but at the same time I don't want to max out any components.

Darius, cjmartz2k , and s14neo what do you guys think

[Darius]

You'll be able to get 500whp out of the components you have listed. No worries there.

[Cjmartz2k]

That one walbro is going to be pushing it for 500rwhp, maybe not enough. Either another walbro to add to it, or get a bigger pump.

[noodl35]

while you have your engine out, i'd also replace the tension stud (some reason been seeing some of those fail) also replace the clutch pivot with a strengthened version b/c i see alot of those fail too!

[sickness14]

while you have your engine out, i'd also replace the tension stud (some reason been seeing some of those fail) also replace the clutch pivot with a strengthened version b/c i see alot of those fail too!

Where is the tension stud located? I don't believe pull type clutch uses a pivot does it?

That one walbro is going to be pushing it for 500rwhp, maybe not enough. Either another walbro to add to it, or get a bigger pump.

I may have to get a second walbro then and run dual -6an feeds to a greddy rail. Can I use the two pumps in the tank and have two pickups attached in there? And then have two new lines brought up through the pump cover or something. I guess I need to look at some pics first. If I get an s14 in tank walbro kit it should come with the pump pickup attached already right? Would you run a seperate 10ga wire to the second pump or run both pumps off one wire.

[Coolwhip]

i believe the tensioner pulley for the timing belt stud he's referring to. Old ones snap flush in wosrt cases and render your engine a paper weight.

[Darius]

I have a hard time believing that the tensioner studs just shear off because they are old. I'm betting the tensioner bearings failed causing torque to be transferred to the stud and fatigued it to failure. Does anybody know of someone with a new tensioner where the stud snapped? The shear strength on any bolt is massive, so I can't believe that they just fail because they are old.

I agree that the walbro will probably be near its operating limit, but previous conversations have led me to believe that it is theoretically possible based on the pump curve and assumption of 14V at the pump. Either way, I wouldn't put twin walbros in. I'd go with a single Bosch 044. My advice initially is to put the walbro in for now and upgrade all that stuff in the future as needed. Don't bother with the braided lines or fuel rail yet. Wait until you tune it up to max out your current setup, then upgrade everything at once.

[sickness14]

I have a hard time believing that the tensioner studs just shear off because they are old. I'm betting the tensioner bearings failed causing torque to be transferred to the stud and fatigued it to failure. Does anybody know of someone with a new tensioner where the stud snapped? The shear strength on any bolt is massive, so I can't believe that they just fail because they are old.

I agree that the walbro will probably be near its operating limit, bkut previous conversations have led me to believe that it is theoretically possible based on the pump curve and assumption of 14V at the pump. Either way, I wouldn't put twin walbros in. I'd go with a single Bosch 044. My advice initially is to put the walbro in for now and upgrade all that stuff in the future as needed. Don't bother with the braided lines or fuel rail yet. Wait until you tune it up to max out your current setup, then upgrade everything at once.

Good call. Sounds like the bosch intank is the way to go.

I still need to get -harmonic balancer-injectors-clutch- possibly cam gears...

Waiting for shortblock to be assembled and I'm trying to contact rlz about fixing the head but they aren't picking up the phone.

[Coolwhip]

for lack of better words, lol. sry

[sickness14]

for lack of better words, lol. sry

Its all good.

[mott6904]

That head is still fixable. I have seen numerous turbo bike heads get messed up like that and all we do is grind out some of the trashed materail weld it back up and have it milled again. Sometimes you will need a valve job afterwards depending on how hot the head gets after the welding process.

I say the main reason why the tensioner stud breaks is becuase people are over-torqueing the stud when installing the belt. Just my opinion.

Like i said before keep up the good work because you will be happy you took the extra steps in making this build right.

[sickness14]

Thanks!

Also considering selling the power fc to get an aem ems. Do they make one for the neo? I've got one potential buyer for the apexi at $800. I posted a fs thread on here and zilvia. Its actually listed as a wtt power fc for aem ems.

Any opinions should I keep the pfc or get the aem??

[eh?]

nope no aem for Neo's.

[sickness14]

Thanks. Ill stick with the pfc then lol. I just need a data logit.

[l0nestar]

Thanks!

Also considering selling the power fc to get an aem ems. Do they make one for the neo? I've got one potential buyer for the apexi at $800. I posted a fs thread on here and zilvia. Its actually listed as a wtt power fc for aem ems.

Any opinions should I keep the pfc or get the aem??

What about NisTune or Haltech? (I really don't know, just throwing out options)I was checking out the Haltech at SEMA at the begining of the month, their Platinum EMS is pretty nice, got to play with one for an R33 RB25 that they actually had there !

[l0nestar]

Good call. Sounds like the bosch intank is the way to go.

I still need to get -harmonic balancer-injectors-clutch- possibly cam gears...

Waiting for shortblock to be assembled and I'm trying to contact rlz about fixing the head but they aren't picking up the phone.

As far as the clutch & cam gears, O.S. Giken is now selling cam gears for the RB's for ~$125 ea. as well as their dual-disc clutch kits for ~$1400. I spent a fair amount of time talking to them. I got to use one of the dual-disc clutches, they are smooth and their 'base' model holds up to around 800 HP if I remember correctly. SPEC has improved drastically and has their dual-discs for $800, and it's fully rebuild-able.. and they are only a few hours from you..

I'm debating heavily between the two.

As far as balancer, Ricky carries the Ross units that are supposed to be :tits:.

Injectors.. that's a good question. need moar info. Are you running gasoline or E85?

Is Kognition making pieces again? I need to find out if he is making the inserts for S13's.

[sickness14]

As far as the clutch & cam gears, O.S. Giken is now selling cam gears for the RB's for ~$125 ea. as well as their dual-disc clutch kits for ~$1400. I spent a fair amount of time talking to them. I got to use one of the dual-disc clutches, they are smooth and their 'base' model holds up to around 800 HP if I remember correctly. SPEC has improved drastically and has their dual-discs for $800, and it's fully rebuild-able.. and they are only a few hours from you..

I'm debating heavily between the two.

As far as balancer, Ricky carries the Ross units that are supposed to be :tits:.

Injectors.. that's a good question. need moar info. Are you running gasoline or E85?

Is Kognition making pieces again? I need to find out if he is making the inserts for S13's.

Lonestar, you're always quiet during all the chit chat back and fourth but i must say, you always pull through with some of the best information! haha.

I'll honestly leave the cam gears alone, dont want to mess with the VTC.

I want a streetable clutch, so from what i've heard the twin disc's have a pretty harsh engagement. Im interested in finding out more about this SPEC company close to me.

The balancer would definitely be from ricky. he's the man.

Injectors... ill be running gasoline, and the ones im looking at are the following in the 800cc option.

http://www.deatschwerks.com/ca...d=208

Kognition is in fact making pieces for the S13 and S14, but it seems like they do it occasionaly now, through group buys. I just bought their S14 sunroof delete! cant wait to get it.

[Cjmartz2k]

Hey John, I'm doing a little write up on Stec mani's--think I can swipe some of your pictures to put in the thread? They are about the best most detailed pictures out there of them believe it or not.

[l0nestar]

Thanks man!

I am not sure about the engagement. Personally I was concerned with pedal feel / weight, not engagement. Currently I have an RPS Max (single disc with HD pressure plate) and received a larger left calf as proof.

10-4 on the balancer and gears.

I'm not a fan of Deatschwerks injectors because they are heavily re-flowed, but thats my personal opinion.

I need to get a hold of Kognition when they do another buy on the inserts. (Mine leaks)

Lonestar, you're always quiet during all the chit chat back and fourth but i must say, you always pull through with some of the best information! haha.

I'll honestly leave the cam gears alone, dont want to mess with the VTC.

I want a streetable clutch, so from what i've heard the twin disc's have a pretty harsh engagement. Im interested in finding out more about this SPEC company close to me.

The balancer would definitely be from ricky. he's the man.

Injectors... ill be running gasoline, and the ones im looking at are the following in the 800cc option.

http://www.deatschwerks.com/ca...d=208

Kognition is in fact making pieces for the S13 and S14, but it seems like they do it occasionaly now, through group buys. I just bought their S14 sunroof delete! cant wait to get it.

[sickness14]

Hey John, I'm doing a little write up on Stec mani's--think I can swipe some of your pictures to put in the thread? They are about the best most detailed pictures out there of them believe it or not.

Chris, no problem at all.

They're on my photobucket here:

http://s269.photobucket.com/al...t=all

good luck!

Thanks man!

I am not sure about the engagement. Personally I was concerned with pedal feel / weight, not engagement. Currently I have an RPS Max (single disc with HD pressure plate) and received a larger left calf as proof.

10-4 on the balancer and gears.

I'm not a fan of Deatschwerks injectors because they are heavily re-flowed, but thats my personal opinion.

I need to get a hold of Kognition when they do another buy on the inserts. (Mine leaks)

What do you mean by re-flowed. do they basically drill out the smaller injectors!? wtf. thats ghey. ugh.

[Cjmartz2k]

Thanks John! Stec has been using RC injectors lately. I'm not sure their manufacture technique, but he's used like 3 or 4 different sets all the way up to 1000cc ones, and he said they were really easy to tune, and idled really nice. Take that for what it's worth. I think Nismo/Tomei are abotu the best out there, but you'll sure as hell pay for them. I'm of the opinion you can never have big enough injectors as long as they idle well. The 1000's do. Ignore what the douches on skylinesaustralia.com say. 1000cc injectors idle the same on a 900hp car as they do on a 250hp car with a stock turbo. Don't aim for your hp level. Just go big from the beggining. That way you'll never need to upgrade, and you can give yourself the option of ethanol.

[meet07]

1000cc injectors in a rb25 sounds good. Let say you plan on making around 500-600 hp from the crank and want a meth or nitrous kit for upgrades. How much bigger do you need to go as far as injectors. Ive alway heard that with a meth/water injection you have to add like double the fuel...

I know about running 2 walbros around that power level....

thanks

sorry for thread jacking john...figured it would be useful info for the both of us.

[meet07]

Thanks guys. I'm going to take the head to rlz engineering out of concord nc and have them rebuild the head properly making it the way its supposed to be.

that is the best idea yet....When it time to do head work on my Rb im taking it there also. The guy I went to the rock with has a fully built h22 stocked to a 2.4 and his head was done at RLZ. We had to replace the head gasket when he 1st bought it and man that head was absolutly PERFECT!!! and I mean perfect...foreall

let me know when you drop it off we can all take a trip down there. I would probably let them tune it also..