Thread 28494247 - /o/ [Archived: 503 hours ago]

Anonymous
7/3/2025, 3:11:50 PM No.28494247
rb20det
rb20det
md5: 04f94ce050e3abd9e19d7a8d3f5cd1e0🔍
I'm building an RB20DET for street use. I'm planning to reuse the stock internals and cams to keep costs down. Goal is around 400 bhp.
I've figured that I should do at least these
>new rings
>ACL bearings
>ARP head bolts
>Cometic head gasket
>adjustable cam gears
>valve springs
>valve stem seals
>oil sump enlargement
>add oil drain at the back of the head
Am I missing something?
Also, do I need a better oil pump or is OEM good enough?
Replies: >>28494290 >>28494562 >>28494705 >>28494907
Anonymous
7/3/2025, 3:16:12 PM No.28494257
I forgot to add that I'm also going to install RB26 throttle bodies and intake manifold (probably won't make any more power but I have a set laying around).

I was even looking into installing a used set of RB26 cams but then I'd need to find solid lifters somewhere and I'm not sure the Tomei ones would work with the original Nissan cams.
Replies: >>28494726
Anonymous
7/3/2025, 3:30:08 PM No.28494290
1719978065590954
1719978065590954
md5: 752b791e241f34a5add07bb9ec66ba1a🔍
>>28494247 (OP)
>stock cams
>adjustable cam gears
Replies: >>28494430
Anonymous
7/3/2025, 4:42:13 PM No.28494430
>>28494290
I read that adjustable cam gears can help gain some power even with stock cams but I might drop them off the list.
Replies: >>28494452
Anonymous
7/3/2025, 4:54:58 PM No.28494442
brainlet limit
brainlet limit
md5: 090a12a2cffa96e408523f1b99a50e4e🔍
Anonymous
7/3/2025, 4:59:25 PM No.28494452
>>28494430
they can move your torque curve, effectively gaining or losing you power up top or down bottom depending on whether you advance or retard the cam. cam size has nothing to do with the effects of this, ignore that guy posting self portraits.
Replies: >>28494646
Anonymous
7/3/2025, 5:51:44 PM No.28494562
>>28494247 (OP)
>rb20det
>400bhp
That's pretty close to the safe limits of stock internals.
>Am I missing something?
arp rod bolts, you don't want them stretching.
Replies: >>28494629
Anonymous
7/3/2025, 6:16:08 PM No.28494629
>>28494562
ARP doesn't seem to have a rod bolt kit for the RB20. However, it seems that SR20 or L28/VG30E bolts might fit?
Anonymous
7/3/2025, 6:20:49 PM No.28494646
>>28494452
>just adjust your cams bro! you can gain +5hp at 3000rpm at the cost of -10hp at 6000rpm it'll be great bro!
Adjustable cam gears are for dialing in aftermarket camshafts and accounting for deck height timing offset, that's literally their only purpose.
Replies: >>28494656
Anonymous
7/3/2025, 6:25:00 PM No.28494656
>>28494646
I'm going to have the block and head surfaces machined, and use a MLS gasket instead of the OEM type. Would that warrant using adjustable cam gears?
Replies: >>28494661
Anonymous
7/3/2025, 6:26:24 PM No.28494661
>>28494656
No.
Anonymous
7/3/2025, 6:35:23 PM No.28494688
https://www.youtube.com/watch?v=bnIsNwdKnCw&ab_channel=Garage4age
Anonymous
7/3/2025, 6:43:44 PM No.28494705
>>28494247 (OP)
Read this thread
https://driftworks.com/forum/threads/my-r32-gts-t-daily-driver-rb20-big-turbo-big-power-but-small-budget.187808/
Anonymous
7/3/2025, 6:51:08 PM No.28494726
>>28494257
I don't think the RB26 ITBs fit an RB20. IIRC the 26 had a unique port design or some shit. As an aside, you should use VR38 injectors (Subaru STI are the same) and VR38 ignition coils.
Replies: >>28494798 >>28494844
Anonymous
7/3/2025, 7:28:20 PM No.28494798
>>28494726
You can buy weld on adapters.
https://speedtekautoracing.com/products/nissan-skyline-diy-itb-rb26-to-rb20-rb25-weld-on-plate-kit#
Replies: >>28494844
Anonymous
7/3/2025, 7:50:52 PM No.28494844
>>28494798
I didn't even know those were available. I just designed my own weld-on adapter with AutoCAD and will have it laser cut at a local shop.

>>28494726
How many ccs are the VR38 injectors?
Replies: >>28494945
Anonymous
7/3/2025, 8:14:51 PM No.28494907
>>28494247 (OP)
>add oil drain at the back of the head
I am guessing this is to do with the RB's tendency to throw all the oil up top and cause trouble in the bottom end? Another thing I've heard of is adding a restrictor in the gallery where the oil enters the head to help with this. Obviously you should look into this yourself and ask for advice from someone that isn't a Subaru stoner on an anonymous West African mud hut construction forum, but I figured I would throw it in since you are asking for suggestions. Good on you for giving the 20 another chance at life on the road by the way. Best of luck in your endeavour, OP.
Replies: >>28494911 >>28494937
Anonymous
7/3/2025, 8:18:14 PM No.28494911
>>28494907
That's for crazy high HP builds with upgraded oil pumps running custom oil pressures and volume.
A proper head drain is sufficient for a stock 20.
Replies: >>28494937 >>28495239
Anonymous
7/3/2025, 8:27:06 PM No.28494937
>>28494911
>>28494907
If I'm gonna upgrade the oil pump I'll put in a restrictor. I'm not sure yet if I want to go that route as the aftermarket oil pumps are quite expensive.
Anonymous
7/3/2025, 8:29:03 PM No.28494945
>>28494844
>How many ccs are the VR38 injectors?
VR38 and late STI use the same injectors with different part numbers, both are 565cc, made by Denso. Good for 500hp+ on a 6 cylinder.
Anonymous
7/3/2025, 10:46:56 PM No.28495239
>>28494911
Ah yeah that does sound familiar noiw you mention it