DIY Engine Rebuild?

[No Crust Racing]

Picked this up on the weekend for the track car, apparently approx 150ks and removed as a "runner", toying with the idea of attempting the rebuild myself - which I've never done but always really wanted to try. 

I've got a basic workshop, most tools, have done turbo/head/manfiold swaps and have over a decade experience with Nissan platforms etc etc so I have half an idea. 

Standard rods don't like going past 220 or so rwkw apparently and as my current motor is an original bottom end with some basic bolt ons I wanted something fresh anyway. 

Parts list will look something like this. 

• Spool forged kit which has rods, bearings, pistons, rings, pins, metal head gasket etc. 
• Headstuds
• New gaskets and hoses throughout.
• New oil and water pumps, timing belt, idler tensioner.
• Some tomei 256 cams I have sitting in a box brand new. 
• Either new OEM or basic upgrade valve springs and some new lifters (lifters needed?)
• New balancer. 
• Mild porting/port matching, nothing crazy, remove butterflies and possibly relocate injector ports. 
• A GTX2860R I have sitting here which is new, could swap for 63 or 67? 
• A little Tiual 38mm external gate.
• E85
• Use my existing Nistune. 
• Re-use existing oil cooler/intercooler/radiator fuel setup etc. 

I would want the basic bottom end balancing done, but once the initial weigh/measure/balance is done and you install the rotating assembly can you/should you then have it balanced as a short block? I've seen people do this with clutch attached also which seems odd, given the clutch could die tomorrow and be different. 

Same for the head, the guy I would have do some porting could likely do the valves/springs and clearances while he's there. leaving me cams/fit head to block which I'm OK with. 

With the 2860, I can't see it making more than 230-240rwkw, which is fine given I have no big plans for new gearsets or box swaps. 63 and 67 would go a little further but run the risk of hurting the box sooner - Box which is just a stocker with a nice clutch and fluid and no present issues. 

The alternative is I break the motor down, get all the parts, then deliver it all ready for assembly to my mechanic and collect assembled short block, an assembly head from the head guy, and do the final assembly and swap myself. 

I know it's not a "simple" task, but for those who have DIY'd a rebuild, would you do it again? What caught you out, anything else to throw in? 

 

 

 

 

[NEO25T]

Im about to get my engine back from machine shop and will be my first time putting one together.

From what ive read cleaning is super critical, i got a moroso brush kit to clean out all the passages which will be done a number of times, drying between each time.

I asked the machine shop to check all bearing clearences for me.

Another thing i got is a tapered ring compressor as i heard they work better.

Dont forget to prime oil pump ?

[No Crust Racing]

I would have thought you'd have the block cleaned after machining? 

[NEO25T]

Yeah i wish it would come back like brand new but apparently they dont from what i read.

A guy i use to work with many years ago built engines at home, he told me saturday is for cleaning and sunday is for assembly.

I never heard about one of his engines letting go so even if you spend a whole day cleaning and dont find a spec of crap or a shaving at least you can be 100% sure its clean, cheap insurance for the money spent me thinks

[No Crust Racing]

Good to know. 

[WantGTR]

would hit up youtube to get an idea on anything you might be unsure of, eg timing

[No Crust Racing]

Timing is fine, as i did a full strip down and replacement of all the timing gear on the other motor when it was due for a belt. 

It's the bottom end stuff I'm not sure of, installing bearings, checking clearances etc. 

[KiwiRS4T]

There is a whole thread on engines that have made over 300kw unopened i.e. on stock rods - so unless you are hell bent on spending money you could pull your engine apart and measure up to see if you could just do rings and bearings.

If you do want to do a full rebuild then you may as well read up as much as you can, watch a few videos and see what you need to do. It is not rocket science but you do need to pay attention to precise measurement, absolute cleanliness and doing things in the right order. If you take your time I am sure you can do a good job!

[No Crust Racing]

Unopened 300kw RB25 thread yes. I'm missing 2 cylinders and rings and bearings wouldn't do much for the leaking seals and 28yr old hoses my current original motor has. 

The goal was a freshen up + more power, both of which are easier to do with the engine out, if it's out, might as well put something nicer back in. 

 

[Navara96]

It's not super difficult, if you are mechanically minded and are familiar with the engines it shouldn't be a problem ( it's not like there is anything super advanced about our 90's Nissan engines). A factory manual is a huge help, goes through everything step by step and what and when tolerances need to be checked etc. get the machine shop to measure up your crank and journals if you don't have at least a micrometer, places that specialise in this work tend to be more accurate/ have more accurate means to check. Order the right stuff to suit and clean it, measure it again.... clean it again and torque it down! We have built 10-15 engines ( including a silly rb27 Neo and rb26 with 500+) without a failure/issue yet... give it a go! Always rewarding to hear something start for the first time you built yourself

[33GTRV]

Zero balance as much shit as you can, wieght match the rods, dont worry about pistons, cp are f**kin good at what they do, arp flywheel bolts, hack out the oil returns in the block and drill to 12mm, its about 60 bucks for a 12mm hss drill thats 450 long, rocol is your friend, if studding the bottom end get it tunneled, spool oil pump gears and restrictors, basic head service and clean up the short turn, make sure the clearances are good then work out squish and run the thinnest gasket you can to achieve 9.5 to 1 and enjoy a f**king weapon off boost and on

 

[Dobz]

My 2c

Make it rev hard with heavier valve springs, porting and bigger cams. The ca will feel more usable when you have a higher rpm ceiling, they’re basically a 4cyl version of an rb20.

[No Crust Racing]

20 hours ago, Navara96 said:

It's not super difficult, if you are mechanically minded and are familiar with the engines it shouldn't be a problem ( it's not like there is anything super advanced about our 90's Nissan engines). A factory manual is a huge help, goes through everything step by step and what and when tolerances need to be checked etc. get the machine shop to measure up your crank and journals if you don't have at least a micrometer, places that specialise in this work tend to be more accurate/ have more accurate means to check. Order the right stuff to suit and clean it, measure it again.... clean it again and torque it down! We have built 10-15 engines ( including a silly rb27 Neo and rb26 with 500+) without a failure/issue yet... give it a go! Always rewarding to hear something start for the first time you built yourself

Who's we? Are you a workshop or doing this at home? 

Why are you building so many engines 0_0

[Navara96]

Doing it from home, potentially looking to start up a business with it in the future. Building them for our own cars ( there's 10 cars between the 3 of us) along with other friends cars and the odd cash job that's over the last 5 years or so

[No Crust Racing]

Was talking to a mate of mine who's a diesel mechanic, built 1000s of motors and he's confident I can do it so I might give it a go 0_0

 

 

[NEO25T]

On 27/02/2018 at 1:56 PM, ActionDan said:

Good to know. 

Here is the brush kit that arrived today