Engine fully forged,springs and valves,ca18det

[Pignoises13]

Hello guys!! 😊 I am a new member, I am Italian, I know that you are competent people, good people, prepared, I need help, as you may have read from the title, I am modifying the engine of my Nissan s13 (engine code ca18det) performed compression test, immediately after purchasing it, I decided to rebuild the engine,..I took a lot of things .. pistons 84 RDC 9.0.1, connecting rods, connecting rod bearings and crankshaft, reinforced nuts and bolts , reinforced seals, water-oil pump, 4-stage clutch, injectors, turbo still to be chosen etc. etc., now from the rectification they tell me that the valves can be fine and that they will be correct, sanded as usual, but listening to different people I don't know what to do..they said that rectifying the valve would be "rough" or that it could wear out soon or weaken, so there are those who tell me to change the valves with something new and perhaps more reinforced and who instead of leaving the valves and changing the springs, with stronger springs .. engine 135.000 km the car has the target 350 HP that will surely reach easily, so it will have to hold twice the CV ... what do you think?!?

[s13 @ fullboost]

Greeting & welcome to Zilvia. I am not sure I totally understand what you are asking. Are you asking if you need a upgraded valvtrain or are you asking if you should just do a valve job on your factory head ?

[Pignoises13]

be patient, I apologize for my English, let me explain, the engine will have 350hp (twice the original) I don't know what to do with my head the options are 3 1 grinding, original valves? 1 put new valves? 1 leave the original valves, change the springs?

[jedi03]

I would suggest at minimum do the springs/retainers...if you want everything refreshed then doing stronger or even bigger valves would help flow but add time/labor costs to the project...

[s13 @ fullboost]

I would suggest at minimum do the springs/retainers...if you want everything refreshed then doing stronger or even bigger valves would help flow but add time/labor costs to the project...

Well if you are not using factory camshafts then I highly recommend having the valvetrain completely gone through & upgraded.

[Pignoises13]

Camshafts stock, I explained myself wrong

[gaz_moose]

if the valve seats are not worn then I would just regrind them, and put a set of new springs in.

[Pignoises13]

I gave orders to rectify everything, updates soon!

[Izento]

I would personally get different cams. Tomei Poncams are a perfect upgrade. 256/256 in/exh has great improvements in the top end and doesn't sacrifice the low end torque that much. In your other post you specified that you wanted 350 hp and good spool times for the turbo. This will help your torque curve all around.

As for the valvetrain, you don't need to upgrade the valves/springs to hit your target hp number. Those are for the big boys.

Also, if you haven't already ordered those pistons, I highly recommend going 83.5mm instead of 84mm. The CA18 doesn't have a lot of metal in between cylinder walls to allow for generous boring. Only bore enough to refresh the walls. If you can get away with it, a simple polish would be good so that you can stick with 83mm. But most likely you'll need to grab a 83.5mm.