Oem VS Forged SR

[jared420sx]

i'm at a fork in the road regrding my motor build.
I know there are sides and opinions for each route to go.
Which do you prefer? Forged or oem bottom end?
Some reasons why, how long have you had which ever setup you chose.
And if you say forged include what you did to make your engine not explode.
Ive heard some bad stories about people going forged and would not like to replicate that if i do go that route.

[KAT-PWR]

With the question you ask, you're bound to blow either so just build a stock one.

[jared420sx]

Not at all. Nice try though.

[JM216S14]

You really just need to know what your doing... along with a machinist who also knows what he's doing..

[bardabe]

Originally Posted by JM216S14

You really just need to know what your doing... along with a machinist who also knows what he's doing..

This about sums it up.

[jared420sx]

I know about clearances and all that crap and mic everything its not the most complicated thing i just wanted to hear peoples opinions and expierences more than anything. The more you know. But you guys think i could push 27psi on my oem block with a safc 370s and a t28??

[jared420sx]

Jk jk lmfao^

[ixfxi]

Originally Posted by jared420sx

i'm at a fork in the road regrding my motor build.
I know there are sides and opinions for each route to go.

you are not at a fork with your build, you are at a fork with your wallet. If you have an infinite amount of money, then forged internals make sense.

any time you service something, you need to pick your priorities and budget accordingly

stock engines are capable of X power levels.
build engines are capable of more, until you break the next weakest link.

As a side note, I picked up an S14 SR20DET a long while ago that I've been rebuilding. I needed slightly over-bore pistons and so I chose Mahle 86.5 (forged) but stuck with stock rods. Since its being built as a street car setup, I did not see the need to get all crazy with the internals since it will be running an S15 turbo. I'm sure rods break at some power level, but I'm pretty confident I wont be seeing those levels.

So, research your configuration and budget accordingly.

[Busta]

Prepare to pay to play if you want things to last. Pushing on stock block pistons id say 300whp max is reliable/safe long term if engine is healthy to start with; past that you better rebuild the block and throw in forged pistons,metal headgasket,bearings

Il have an s13 sr20det redtop engine i built in 2009 thats been through 70000km tuned at a very modest 350whp at 17 psi and is as healthy today as when it got built 8 years ago. It gets daily driven, some circuit and beaten regularly compression and leak downs are perfect. Mahle 86.5 pistons,eagle rods, all arp studs,apex headgasket and royal purple oil

Good maintenance,lubes and products make a huge difference in the equation

[ixfxi]

anyone have an estimate on how much beating the rods can take before bending?

[TheRealSy90]

300whp is definitely not the max of stock internals, that's hardly pushing them hard at all.
I've personally seen 500whp on stock rods, not sure how long that engine lasted though.
Honestly a stock bottom sr20 can and do hold up 400whp all day long, it's ALL in the proper tuning and reliable setup of the engine and supporting parts.
You aren't going to have a healthy 400hp stock bottom sr with an safc "tune". However throw in a good standalone, a proper tune, and e56-e85 for example and that thing will take all you can give it.
In my own opinion, I'd trust a healthy, unopened oem sr20 that's properly tuned at 400hp than I would some random built engine at the same power level.
However, if the engine already needs a rebuild and you insist on building it and not just throwing another good sr20 in then go for it.


I personnaly just sold my spare built engine that I've had sitting for a year because I don't want more than 400whp and my current stock sr has been in my car for over 8 years with no issues. If it goes by this point I'd feel it fulfilled it's purpose. My goal at this point is having the engine tuned with the AEM Infinity and failsafes to where I shouldn't be able to blow a stock engine up if I tried, aside from a catastrophic failure.

[jared420sx]

Originally Posted by Busta

Pushing on stock block pistons id say 300whp max is reliable/safe long term

*inserts sileighty_85 roasting you for saying oem sr interals can only take 300whp*

[jr_ss]

Originally Posted by ixfxi

anyone have an estimate on how much beating the rods can take before bending?

I would imagine reliably, it's in the 400-500 range. This is assuming your tune it spot on and no detonation occurs. A completely stock motor less cams made 600+ yrs ago. Who knows how long it actually lived for though.

The motor I acquired my VE parts from was run at 491whp for a time. Add 18% to that for motor figures and I think it's safe to say they can handle quite a bit of power.

I'd recommend upgrading hardware if you're shooting for those goals though.

Waiting on Kingtalon to give me a full essay on what motor you should swap in instead of aiming for large power goals on a small motor. I bet he recommends an LS swap or a 2JZ.

[RalliartRsX]

Originally Posted by jr_ss

Waiting on Kingtalon to give me a full essay on what motor you should swap in instead of aiming for large power goals on a small motor. I bet he recommends an LS swap or a 2JZ.

OP, if you have to ask then.........well.

[ixfxi]

Originally Posted by jr_ss

I would imagine reliably, it's in the 400-500 range. This is assuming your tune it spot on and no detonation occurs.

Waiting on Kingtalon to give me a full essay on what motor you should swap in instead of aiming for large power goals on a small motor. I bet he recommends an LS swap or a 2JZ.

thats more that this engine will ever see. all i care about is a flat powerband.

kingtalons posts can be used as toilet paper

[jedi03]

I have seen personally a 500hp sr horsebeat for 3 years and daily driven before something gave up...but also seen stock unable to hold stock power due to mismeasured clearances... I am currently running fully forged Manley rods with. 5 over pistons using stock headgasket arp studs and toda 264 cams...daily driven for about 8 months now...so just like me turned above do your work right, measure correctly and spend money where it matters and it will last along time!

[jared420sx]

Thanks to all responses keep em coming. Would like to hear more people on oem bottoms and what refrshments they did.

[NiSilS14]

Originally Posted by jared420sx

Thanks to all responses keep em coming. Would like to hear more people on oem bottoms and what refrshments they did.

If the engine is still runs strong but just showing age, doing an oil pump and timing kit will bring back any old nissan engine back to life. Obviously along the way you will be replacing gaskets associated with replacing those parts, so that will also help with the longevity of the engine. I just did SR refresh with new bearings, main bolts, oil pump, timing kit, metal HG, head studs, and gaskets. Everything mic'd in spec, and runs great. As mentioned before, assess your goals, do your research, and budget accordingly.

[Pblesh85]

This thread is lame.

There is no point in discussing people's luck with a built sr or a stock one. There are too many variables in the equation(the car being tuned correctly, the parts that they used, their ability to assemble an engine correctly, how they drive the car, and list goes on).

For every success story you're hear, there are just as many horror stories. Personally I've blown up two. But on the other hand I have an SR that's built and tuned by a VERY reputable tuner. That sr craps on lsx's all day long and has 30k+ miles on it.

Do yourself a favor, build or buy whatever fits your budget. Spend some time to build it correctly AND tune it correctly. Take proper care of it and don't drive like a douche. Your engine will last as long as you Take care of it.

[RalliartRsX]

Originally Posted by Pblesh85

This thread is lame.

There is no point in discussing people's luck with a built sr or a stock one. There are too many variables in the equation(the car being tuned correctly, the parts that they used, their ability to assemble an engine correctly, how they drive the car, and list goes on).

For every success story you're hear, there are just as many horror stories. Personally I've blown up two. But on the other hand I have an SR that's built and tuned by a VERY reputable tuner. That sr craps on lsx's all day long and has 30k+ miles on it.

Do yourself a favor, build or buy whatever fits your budget. Spend some time to build it correctly AND tune it correctly. Take proper care of it and don't drive like a douche. Your engine will last as long as you Take care of it.

This right here.

[jared420sx]

Originally Posted by Pblesh85

don't drive like a douche.

What is your deffinition of

[Pblesh85]

Originally Posted by jared420sx

What is your deffinition of

If you have to ask...

We're all adults here, everyone should know the answer to that.

[jared420sx]

Originally Posted by Pblesh85

If you have to ask...

We're all adults here, everyone should know the answer to that.

I'm not even legal to drink yet.

I guess i'm fucked cus beating the piss out of it on a track might fall under the douche driving

[bataangpinoy]

Not exactly. These engines are old, and often need to be caught up on maintenance. Ran a whole season of track use AND a year of DD use on my S15 SR20 with a GT2650RS at 12PSI, motor was in good overall health to begin with. Did all the things I listed, never showed a sign of trouble even when hot lapping or at WOT for extended periods. Only once did my oil temp get to my alarm (215*F), which was in May 2015. Took it easy and let it cool down for the rest of the lap.

In either case, its always good to start with an untouched/near stock motor. If you're smart you'll have set up a bunch of reliability upgrades, done a good bit of preventative maintenance to reduce your chance of total engine failure.

There are a bunch of things you can do for little money.
1) A quality baffled oil pan,
2) S14 sr oil pick-up tube (better design than s13 SR)
3) Fresh oil pump
4) Fresh oil changes before each track day
5) Use the best oil filters you can afford

Next: a smart driver will also try to preserve the driveline. A few tricks:

Don't beat on it until the motor/trans are up to operating temp,
Don't clutch kick the piss out of it (your thrust bearings won't like it in the long-run)
Don't hang it on red-line too often. Change up a gear if you need the wheel speed.
Keep the temps down (take a cool down lap if it starts to get hot)
Set up warning lights on your gauges, and don't ignore them.
All these little things will do a lot for keeping your motor alive for longer.



If want to keep it simple and near stock then find a good engine builder, have them spec the tolerances in the bottom end. If they're at the upper end of the OE limit, toss in new OE rod and main bearings. Nissan offers them in all the sizes they'd need, and have decent longevity. While many get away with just STD sized bearings, one glance at the service manual would tell you that there are variances in tolerance throughout. Simple is better. It means less problems, more seat time and more money for other things.


If you decide to go forged internals, make sure you get the ENTIRE rotating assembly balanced after it gets put together (this includes the flywheel and harmonic balancer). and as you might have guessed, its not really that affordable.

But if you had to be told these things.. well. You get the idea.