L28ET vs RB20DET - which engine to use?

[240Zed]

OK, I have 2 engine choices for my 240z.

 

In my shed I have an L28 and a bunch of L20ET parts to build an L28ET.

 

I also have an RB20DET.

 

I like the idea of either engine in a 240z.

 

What do you guys recon? Which engine should I put in?

 

I guess i'm trying to get a pros and cons list for each engine to help me decide.

[cybermecium]

Depends on how much work you want to do. The L28ET will drop right into your 240, same size and mount location as the stock engine. Also, if you use a NA ZX 5 speed (rather than the Borg Warner T5 that goes with the L28ET), the tranny will bolt right in and work with your stock driveshaft with no mods. The NA 5 speed is a direct fit to the L28ET and a direct fit to the 240 driveshaft and tranny mount location. Also, with the NA 5 speed you don't have the shifter location issues that you would with the T5. I don't know anything about the RB or the tranny that goes with it, but I know it isn't as much of a bolt in swap as the L series motor would be.

 

Jake

[badjuju]

I just fired up my l28et in my 73 for the first time about an hour ago and it's a fuc kin rush. I'd go with that personally, unless you want a total project car, then go rb all the way. I like the idea of a 240 with an l28, not sure why.

[cpt jack]

I just fired up my l28et in my 73 for the first time about an hour ago and it's a fuc kin rush. I'd go with that personally, unless you want a total project car, then go rb all the way. I like the idea of a 240 with an l28, not sure why.

 

 

itz cuz of that tq my friend i helped my buddy with his 70 i believe z and we plopled that bitch in and took it for a spin wow!

[Matadem]

a few friends of mine have rb20 in 280zx and 300zx, rb25 in a 280zx also a 280zx rb26tt in the making

 

as for the rb20 vs l28et go with the l28et

the l28et pulls allot stronger than the rb20det (rb20 at 13psi stock ecu,turbo and bigger intercooler vs l28et stock at 10psi with crappy ic and haltech not fined tuned )

 

a rb25det would be another story

for the rb to fit driveshaft mods has to be made as for the oil pan they cut it and flip it the lower part of the oil pan goes in front not to hit the crossmember

[z_cars_rule]

being in Oz, i would say RB20DET.

 

I have one in my 280ZX, that was a bolt in swap, all i needed was the 200ZR sump and oil pick up and it all bolted right in.

 

The engine mounts have the same distance from the bolt centers. engine mount - gearbox mount distance is the same. Same bolt size for gearbox mount. shifter location was about 1 inch forward.

 

cant see any major probs in a S30.

 

lighter weight in the 240Z will be better than my car. And there is just something about spinning to 8-9k rpm in a Z.

 

I am still using stock turbo + injectors etc etc, and made 221rwhp on stock boost.

 

where in Oz are you?

[240Zed]

I'm over in WA. Yeah I was thinking that I'd put the RB in the 240Z and build the L28ET for another project - a heavier Datsun around the same vintage.

[240Z_Master]

I would say.... don't waste the time for the RB20DET. For bolt on fun and low budget... do the L28ET.

 

I mean... do what you must, but just consider the extra .8 liters of displacement.

[mannyvig]

I would lean toward the rb20det. I have a 240sx with one relatively stock and it pulls hard- really hard. Looking at numbers you wouldnt think so but from experience it does. many people here in town are in awe by what the 2.0 will do. I took some measurements and it looks like it might drop right in to an s30.

a good 28et will go a long way but this is a little more rare, not much but enough. If you don't want to, you dont even have to take the 20 apart they are stout right away.

Ob viously you can tell my opinion.

Good luck

[ZDrifter]

Sell the RB20 and build the l28et, You can make good power cheap with these motors. Hook up megasquirt and tune it and you will have a sick lil 240z. Use some money from the RB20 and get some suspension mods if you havent already. Good luck!!

[Cal Poly Zmanaustin]

Trade both motors for an RB25 then it will really get exciting. Anyboby else want to second my idea?

[Canadianz]

Hmmm, Ive found the Rb25 to be a little on the expensive side, my brother and I got into the "while were at it" mode and the bills do add up N1 oil and water pumps etc . . . I would personaly go maby for the L28 and do the mega squirt and some injectors, that should satisfy. I think it would be really cool to see a Rb20 in a 240z, as said above a 8-9k redline is pretty cool. I guess go with whichever one you feel more comfortable with, as the Rb swap is fairly involved and will be more expensive for a straight drop in, mounts + new driveshafta at the least. Both awsome choices so good luck !

[Pete84]

I guess go with whichever one you feel more comfortable with, as the Rb swap is fairly involved and will be more expensive for a straight drop in, mounts + new driveshafta at the least. Both awsome choices so good luck !

The RB20DET and 25DE both bolt in.

http://forums.hybridz.org/showthread.php?t=106436

[Thanh]

Depends on how much work you want to do. The L28ET will drop right into your 240, same size and mount location as the stock engine. Also, if you use a NA ZX 5 speed (rather than the Borg Warner T5 that goes with the L28ET), the tranny will bolt right in and work with your stock driveshaft with no mods. The NA 5 speed is a direct fit to the L28ET and a direct fit to the 240 driveshaft and tranny mount location. Also, with the NA 5 speed you don't have the shifter location issues that you would with the T5. I don't know anything about the RB or the tranny that goes with it, but I know it isn't as much of a bolt in swap as the L series motor would be.

 

Jake

 

Rb20det with the transmission with bolt up to the stock driveshaft no problem. I think you do need to cut the shifter location 2 inches up though. Its fun to be in an Rb20det, a guy in pasedena took me for a ride six months ago. Definitely fun the boost gets you hanging on to your seats and everything. Its fun and cheap, but theres little ways to upgrading affordably on a rb20. L28ET everything about the swap is beneficial. No fitting issues and bolts in like a charm. On top of that if your L28 does break down you can "find" parts for it. If your RB20 breaks down, its going to be hard to search for those little parts. My friend probabaly spent 3000 dollars on the whole l28et swap so far and hes making well over 320 WHP. Thats with a bigger turbo, injectors, exhaust and bov and few other small things. Its really up to you what you prefer though. You want to hit 8-9K Rpms get an RB20. You want something fun and to save you from blood rushing to your brain get L28ET.

[z_cars_rule]

I think what alot of you need to realise is that we are both in Australia.

 

We never had the L28et over here, NO ONE makes turbo parts for them.

 

where as we have an abundant supply of skylines and cefieros and laurels which all have the RB20DET.

 

it would be atleast 10 times easier to find RB20 parts here than it would L28et parts. so the argument about finding parts is invalid.

[Thanh]

I think what alot of you need to realise is that we are both in Australia.

 

We never had the L28et over here, NO ONE makes turbo parts for them.

 

where as we have an abundant supply of skylines and cefieros and laurels which all have the RB20DET.

 

it would be atleast 10 times easier to find RB20 parts here than it would L28et parts. so the argument about finding parts is invalid.

 

My bads . So its the other way around for us then . I thought he was from the US of A

[george.bryant]

I would personally go with the RB as there is a larger market for parts in Australia and from here (New Zealand). If I was you I'd sell all those parts and build a RB30DET:icon10:

 

Oh and do you have any spare L20et parts

[Pete84]

I'm over in WA. Yeah I was thinking that I'd put the RB in the 240Z and build the L28ET for another project - a heavier Datsun around the same vintage.

OP, I kinda like that idea of yours.

[chrism]

I am currently putting an RB20DET in my 75 280Z. This may not help you but I will let you know what issues I had to overcome.

The driveshaft is splined and will fit into the transmission that comes with the RB20DET swap and the RB20DET mounts will line up with the existing mounts on the frame. What I noticed with my 280Z and maybe you won't have this problem with the 240z but ,if you use the RB20DET motor mounts, the RB20 will go in 2 inches forward and sit a little bit high. This will leave the drive shaft about half way out of the transmission and that isn’t good.

Also, your shifter will be forward about 1 to 1.5 inches. You might be able to shift the car but if you have a center dash, you can kiss that good by. The L28 stick shift is bent in a way that will allow for the transmission to sit forward but that is not what is going back in. You will have to us the shifter from the RB20 and that one is not bent.

Also, the engine sitting forward by a couple of inches leaves less room for piping the radiator and an intercooler along with making the MAF unit very tight. If you don't want AC in your car, you might be ok with fitting the MAF and filter. The stock radiator has the upper hose on the opposite side of where the RB20 hose connects. This means that you will have to run that hose across to the other side to connect it. Also, The z has one access hole on each side of the radiator support that you can run Intercooler piping to. Because the intake routs across the top of RB20 to the driver side, you will have to route yet another pipe back across the front of the engine to take advantage of the access hole on the passenger side.

For a small amount of money compared to the headaches, get some motor mounts made and do not listen to anyone who says that it will just drop in.

I also had a double pass radiator made with both hose outlets on the passenger side along with an electric fan and harness . This cleans up the piping a bit and gives you room to run piping for a FMI. Also this leave room for the MAF and filter without taking out the AC compressor.

Another thing that I did was use the Throttle cable from an RB20DET and connect it to the old solid linkage on the firewall so that I would not have to screw around with the gas peddle inside.

Depending on what your budget is, you can get an RB20DET in cheap but it will be clunky. Or you can spend around 1k and get some custom parts to make the headaches go away.

All of my ideas came from this forum. There is a lot of great advice if you dig a little bit.

[Pete84]

With the custom motor mounts, did you move the motor & transmission back so that the driveshaft fit in proper? How was the clearance with the firewall?

 

PICS?!?!?