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R31 engine swap, SR20 or RB20?

Dori
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Dori Rookie

Dori

Posted
Posted

Hi guys im new on these forums (upto 2 posts i think) and im a bit of a newbie.

Anyway right now my '86 r31 has a big crack in the exhaust manifold and possibly needs a new head gasket so i was thinking about just doing an engine swap and i've narrowed it down to either an SR20DET or RB20DET.

Can anyone please tell me the ease of droping one of these into the r31, pro's and con's of both engines and some information on the two.

Dori

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Bluprint Veteran

Bluprint

Posted
Posted
Hi guys im new on these forums (upto 2 posts i think) and im a bit of a newbie.

Anyway right now my '86 r31 has a big crack in the exhaust manifold and possibly needs a new head gasket so i was thinking about just doing an engine swap and i've narrowed it down to either an SR20DET or RB20DET.

Can anyone please tell me the ease of droping one of these into the r31, pro's and con's of both engines and some information on the two.

Dori

RB20 would be easier to put in, mounting points are all the same, except for the gearbox

Both are about as capable as each other, maybe the RB20 could be taken a little further

R31 POWER Mentor

R31 POWER

Posted
Posted

As Bluprint said it all bolts in easy,R32 motor and 5speed went straight into my Oz R31 with no welding grinding,it was just like putting a Rb30e in but the RB20det looks more sexy :headspin:

Dori I gather your R31 is oz and if it is the R32 gearbox will bolt up,I'm not sure about imports thou

Plus the Rb20det sounds so much better than the SR20 :aroused:

NismoR31Jet Community Regular

NismoR31Jet

Posted
Posted

What R31 is it? Is it a pinny or a skyline?

Pinny's have different gearbox mount locations to skylines. If it is a skyline any rb engine will physically bolt straight in. The wiring is a different story.

I am not sure on the mods needed to make an rb engine fit into a pinny shell, or dropping a sr20 into an R31.

If you have a manual R31 skyline for example and you stick an sr into it, they have a 3.7 diff, and I would assume the sr has less torque then an rb? that would make it a bit of a slug down low.

Also, what do you want the car for? Daily driver? drags? or just to be different? Different would be going sr, a nice daily would have to be an rb30 turbo.

fatz Grand Master

fatz

Posted
Posted

r31 skyline

the sr20 will bolt in you just have to use the cross member from a silvia and extand the bolt holes at the front 1 inch (cost about 20 bux to do) seeing as you have used the sr20 crossmember you usethe sr20 struts and you have a far better choice of coil overs for cheap thus your car will handel better especially with the light weight

now wack in a skyline auto diff (higher ratio so lower top speed but will still get to 200 very quickly)

if your insydey come around and check mine out when its running and make the decision because it will be worrth the compare

and you wont look back from the sr20

pete

rrrr Enthusiast

rrrr

Posted
Posted

what sort of budget are u looking at?

What computer will u run the motor with? (stock ?)

will u do the conversion your self, or will u be paying a workshop to complete it?

Have u also considered selling your car and buying some thing that is already turbo? ( e.g: R31 GTX coupe, GT passage etc?) Doing a conversion may prove more time consuming, exspensive and heart breaking than u may have ever thought?

My 2 cents.......

Dori Rookie

Dori

Posted
  • Author
Posted

hey guys thanks for all the replies

sorry its taken me so long to reply but i crashed my car and have been busy tryin to get it back on the road.

just a couple things about the car for those that asked

its an Oz R31 skyline

it will be used for daily driver, drags and maybe a bit of drift further down the track

and lately i've also looked at doing a rb30de conversion

anyway any conversion done i'll be doin myself and maybe a coulpe of friends

i'll be using stock ecu's unless doing the twin cam head swap

any conversion i do i'll be using the r31 5 speed but will replace it later on ( i've just rebuilt it so will try to make the most of it)

not to sure about the budget probably 3-4 grand

umm think i've answered them all

one more thing the only problem i have with doing the rb20 swap is the lack of torque down low. are there any mods i can use to increase power in the low rev range? if i do go the rb20 that is.

anyway thanks for all the help

Cheers

NismoR31Jet Community Regular

NismoR31Jet

Posted
Posted

I would sujjest for that sort of budget just turbo the rb30, using VL turbo injectors, ecu, exhaust manifold and turbo. stick a cooler on it and about 10-12 psi and you will have a torquey and powerful R31. Talk to the boys in the R31 skyline club....A lot of them have done it with great results.

Browny_r31 Newbie

Browny_r31

Posted
Posted
that a killer conversion, nismor31jet! rb26 in a r31.....never thought itld happen

i think a few people have them now. I know three coupes do but i think thats the only 4 door (that i know of anyway)

the rb engine is soo cheap now. U can pick up a rb20det with gearbox (out of a r32) for 1650 ready to drop in

fatz Grand Master

fatz

Posted
Posted

yea i already have a rb26dett hr31 skyline

goes quite nice i must say... however just blew the turbos

budget for the sr20 conversion

4door r31 registered to august (very rough car... very rough) 1k

i already had the sr20det so for me free butyou will need a front cut so 3k

do it all yourself

there you go 4k on the road

engineer it 600 bux

4.5 k

im hoping to do it for about 2k on the road but like i said above i already had the engine

should be gravy!

putting the engine in tommorow

pete

if your in padstow come around and help out

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