Forged Rb20

[R31Nismoid]

Ok guys think about what everyone is saying. i know that the rb25/26/30 is better, but here in the states its a $2500 swap.

I was reading a few threads on here last night and saw roy himself say that he thinks the turbo he was using was holding him back not the cams or head.....

A better flowing head will increase both bottom end and high end(granted more highend then lowend). Now because your moving more air in and out you get a faster spool and there is more midrange. Then you ad cams because once the head flows a bit better the cams will start to show gains. Yes cams are known for moving the powerband higher, but that is what cam gears are made for. Cam gears arent made to make more power, they are made to adjust the LSA (lobe seperation angle). When you adjust the lsa it moves the powerband around. Thats why when you buy a cam for older v8s they ask what lsa you want.

http://www.team-integra.net/forum/14-performance/15390-cam-gear-tuning-basics.html

^ that is an Integra site, but its the same with every engine as alll engines make power the same way.

If this sounds like I am just arguing with everyone, I am sorry. I just come from a world where in order to make power you work with the head cause thats where all the work is done and the bottom end just needs to be able to hold the power.

Just to throw a bit of a spanner at you…

By porting/enlarging, more area to fill. How can you fill something that is larger, faster?

When you pre-load a car then most certainly, you can.

However on/off throttle filling larger spaces takes more time.

Also remember you are dealing with forced induction, not N/A.

[eightsixboy]

Just to throw a bit of a spanner at you…

By porting/enlarging, more area to fill. How can you fill something that is larger, faster?

When you pre-load a car then most certainly, you can.

However on/off throttle filling larger spaces takes more time.

Also remember you are dealing with forced induction, not N/A.

Plus the fact that a 2l six has really small combustion chambers compared to a 2l 4 banger, thats why cams work so good on most 1.6-2l 4 cylinders, they have a bigger area per cylinder and by adding cams you can maximisse the air intake and flow, where as on a 2l six the stock cams are actually pretty big for the area, so yea only a 240 degree cam but compared to a 2l 4 banger its like 260-270 degree cams.

The bigger you go with cams your only going to move the rev range up even higher then what a 20 is already good for, thats why cam gears are good, you can bring on boost earlier and gain a little power while still have a broad power band of 4-8k while keeping stock cams.

And cams arnt cheap, atleast the brand name ones anyways, so why waste money on a mod that most people will tell you is a waste of time.

As far as head work goes, sure while the head is of clean it up but just dont go to nuts with it. Once again the gains will be very small from head work on a 20.

I think you'll find the casting isnt that bad and it prob flows pretty good for the design of the head

Edited July 1, 2011 by eightsixboy

[Driftnuttz]

Just to throw a bit of a spanner at you…

By porting/enlarging, more area to fill. How can you fill something that is larger, faster?

When you pre-load a car then most certainly, you can.

However on/off throttle filling larger spaces takes more time.

Also remember you are dealing with forced induction, not N/A.

Yeah I know this, but the point of porting is to make the head flow better NOT to make the ports as bigg as you can. A lot of times you can get more flow from a reshape or just a little bit of grinding here and there. Making the ports as bigg as you can is stupid, plain and simple. I have seen many honda guys do this and end up with a big hunk of junk called a head. My buddy made more power by making his ports narrower and taking a grinder to the port floor on his b20 integra.... Maybe this is what the rb20 needs. Object is to get the air to flow as sraight as possible cause thats what it wants to do. If there is a bend your better off taking some out of the inside of said bend to soften the bend a bit. Now you cant take too much out cause your adding volume to the port and too much volume will slow the air and lose power. If you can get the port to flow 5% more cfm (cubic feet per minute), then you will gain power and your cams will love the added flow........

[Roy]

The point is for bugger all money you can drop a stock rb25 in which will do what you want for ~$1500.

If thats all it costs you then you are right...but nobody does an engine conversion for $1500. You need to change the wiring, hell yo uneed to drop the A/C gas and re-charge, Oils and coolant. Mad to put a used engine n your car without changing at least the timing belt and idler/tensioner bearings. To that you shoudl really look at the water pump as well.

Then there are the things that I am not sure of, as I have never done an RB25 transplant. But belts for PS etc? I am not sayings its hard or a big job, its pretty simple in the world of things. But all of the above is likely to throw at least another $100 to what you are quoting and that is doing it all yourself. And then you are stuck with an untunable ecu and crappy 200rwkws turbo...

[Driftnuttz]

If thats all it costs you then you are right...but nobody does an engine conversion for $1500. You need to change the wiring, hell yo uneed to drop the A/C gas and re-charge, Oils and coolant. Mad to put a used engine n your car without changing at least the timing belt and idler/tensioner bearings. To that you shoudl really look at the water pump as well.

Then there are the things that I am not sure of, as I have never done an RB25 transplant. But belts for PS etc? I am not sayings its hard or a big job, its pretty simple in the world of things. But all of the above is likely to throw at least another $100 to what you are quoting and that is doing it all yourself. And then you are stuck with an untunable ecu and crappy 200rwkws turbo...

Yeah and here is the USA the swap alone will cost 2500 or so. then to put it is a s13-14 you will need mounts, driveshaft, and intercooler........ The rb20det is a 1500 swap that will need mounts, and intercooler stuff. Thats not including paying someone to do the swap. I had 3k(us) in my last s13 coupe that had a rb20det swap and I did everything myself. I even found a swap for 1000(us).

[R31Nismoid]

Why don't you put an injected V8, surely that would be 10x cheaper?

A RB20 here costs $500 AUD from a wrecker lol... $1500 on an 25yo 2ltr motor is madness

[Driftnuttz]

Why don't you put an injected V8, surely that would be 10x cheaper?

A RB20 here costs $500 AUD from a wrecker lol... $1500 on an 25yo 2ltr motor is madness

1500 usd is 1398 aud just to give you a good idea of how much it is. Also for that 1500 you get motor, trans, wiring harness, computer, turbo, and all the sensors and intake stuff. We can get just the complete motor for around 700 usd

lol here for a good v8 its like buying a car.....lol ls1 is 3-4k us just for the motor. sr20's are like 2k. We get raped in the us.....

I like the rb20det, and if I had the money to do a rb25 with a better turbo I would. I am doing a rb20 swap now and will be going through the motor checking everything out. I will be cleaning up the ports and seeing if I can improve them any. I am also going to port match the intake manifold and head, along with the exit side. I have a full redtop eccs now, but will be putting on the silvertop head and all the silvertop electronics and computer. I will be using the redtops intake cam as its a 248 dur, thinking about trying to find a nother one for the exhaust. I will be using the neo turbo for now till I can save up some money to buy a better. I also have a 10lb (4.5kg) flywheel. I thought about getting the head shaved a bit to up the compression a point or two, but am still looking into that and am not sure if thats the best route to take. LOL maybe I should start a build thread instead of putting it in here........

Edited July 1, 2011 by Driftnuttz

[Bl4cK32]

US...the home of small block v8s...I know what I would be slapping in.

[Rolls]

Ok guys think about what everyone is saying. i know that the rb25/26/30 is better, but here in the states its a $2500 swap.

I was reading a few threads on here last night and saw roy himself say that he thinks the turbo he was using was holding him back not the cams or head.....

A better flowing head will increase both bottom end and high end(granted more highend then lowend). Now because your moving more air in and out you get a faster spool and there is more midrange. Then you ad cams because once the head flows a bit better the cams will start to show gains. Yes cams are known for moving the powerband higher, but that is what cam gears are made for. Cam gears arent made to make more power, they are made to adjust the LSA (lobe seperation angle). When you adjust the lsa it moves the powerband around. Thats why when you buy a cam for older v8s they ask what lsa you want.

http://www.team-inte...ing-basics.html

^ that is an Integra site, but its the same with every engine as alll engines make power the same way.

If this sounds like I am just arguing with everyone, I am sorry. I just come from a world where in order to make power you work with the head cause thats where all the work is done and the bottom end just needs to be able to hold the power.

$2500 for the swap is cheaper than building a motor and doing experimental head work that won't give guaranteed results.

it is still a no brainer

[Driftnuttz]

$2500 for the swap is cheaper than building a motor and doing experimental head work that won't give guaranteed results.

it is still a no brainer

That may be the case most of the time, but in my case I will all readdy have the head off and am not "building" the engine. So 2500 is not cheaper then what I am going to do. That and I do all my own work.

Its not really "experimental" head work, as air wants to flow straight. The straighter the air flows the less the air has to slow down and the more power that the head can make. It really doesnt matter what head its trying to flow through, it wants the same thing. Just because not many people port the rb20 head really is invalid. If you can straighten or even soften the bend in the port it will flow better and more cfm, you dont need more volume to flow more air, if you can get the air moving faster then your going to make more power.

Forgot about smoothing the ports over what they are from the factory. That aloan can gain power and flow. Not too smooth.

Edited July 1, 2011 by Driftnuttz

[Rolls]

If all you are doing is head work and nothing else and can get it done for bugger all, then it is worth a shot.

[Driftnuttz]

If all you are doing is head work and nothing else and can get it done for bugger all, then it is worth a shot.

I am sorry, but please explain what your saying here. No clue what you mean by "bugger all"...... Again sorry, I am in the USA and not used to some of the words you guys down under use....

[Rolls]

I am sorry, but please explain what your saying here. No clue what you mean by "bugger all"...... Again sorry, I am in the USA and not used to some of the words you guys down under use....

If you can get it done for cheap, eg it doesn't cost much.

[Driftnuttz]

Oh ok I got you thanks. Thats what I was thinking just wanted to make sure. lol

Edited July 1, 2011 by Driftnuttz

[Kris..]

having gone down the path of doing a forged rb20 in my current car i can say its not worth it, just go 25 man

[Driftnuttz]

having gone down the path of doing a forged rb20 in my current car i can say its not worth it, just go 25 man

I cant speek for the OP, but if I was going to go into the block I would do a 2.4 build using the rb26 crank and rods. Considering I have the rb20. Here in the USA it would cost about the same as a forged rb20.

[Roy]

I get what Team USA is saying about head work, I think what is being lost in translation between convicts and pilgrims is that R31_Nismoid is sayign dont do things to mess with velocity, ie big porting or the inlet and outlet, etc etc. You are right in saying that anything you can do to lessen the resistance of air without dropping velocity is going to be a good thing. Match porting etc etc.

But the key is not just flow, flow is great, more the better, but its the velocity that gives you good culinder filling and torque/response which in a turbo car works well. Get the turbo on speed and the engien delivering torque and then jsut squeeze as much as you can in there with psi!

[Driftnuttz]

I get what Team USA is saying about head work, I think what is being lost in translation between convicts and pilgrims is that R31_Nismoid is sayign dont do things to mess with velocity, ie big porting or the inlet and outlet, etc etc. You are right in saying that anything you can do to lessen the resistance of air without dropping velocity is going to be a good thing. Match porting etc etc.

But the key is flow is great, more the better, but its the velocity that gives you good culinder filling and torque/response which in a turbo car works well. Get the turbo on speed and the engien delivering torque and then jsut squeeze as much as you can in there with psi!

"team usa"

Edited July 1, 2011 by Driftnuttz

[BlueRB240]

Driftnuttz if you really want a pro to look at the head send it to PortFlow in Southern California. Most of the time the head just needs a good 5 angle valve job to get the CFM's up.

[N1 RB26]

Why don't you put an injected V8, surely that would be 10x cheaper?

A RB20 here costs $500 AUD from a wrecker lol... $1500 on an 25yo 2ltr motor is madness

i'm in SA and if i could find a 20 for 500 bucks i'll take 6 the cheapest i've ever seen is 1100 and it didn't include turbo or the intake manifold and a few other bits