Downsides to SR20DET

[1tsilviabad]

I was just curious if there were any downsides to having this wonderful engine? I haven't really heard of any.....just wondering about common installation problems...problems with stock driveshaft...things like that.....if anything else should be replaced or updated ahead of time?------------
Thanks in Advance-----------------------
BillC

[Jsquared]

the only downside i can think of is that some parts might take a while to get from Japan if you happen to break something. other than that, i can't really think of any, and the upsides compared to a KA are plentiful... better weight distribution, more power, easier to modify, etc...

[1tsilviabad]

Are maitenence parts hard to get?

[andrave]

I think that by now, most places stock things like headgaskets and stuff, so those aren't hard to get. some items, like oil filters and such, you can get for I guess the Sentra SE-R or something, from autozone.
I think the problem comes from parts like alternators and stuff... but most of those parts you can have rebuilt.
I don't have an sr20det... yet... but I've been trying to keep my ears open for about a year now on the swap.
hoping to get my clip this fall.

[1tsilviabad]

Good Luck with getting that clip!!!!!.............. I've been just waiting for a coupe in decent condition...once I get that I'll have the motor in ; in like a week and a half............I can't wait!!!!

[andrave]

friend of mine just bought his clip and is going to VA to pick up a dohc s13 hatch this weekend, so I'm hoping to do the swap with him in may.

[DoriftoSlut]

Originally posted by James
I have one- no big deal- only means I spent $1,800 to get one.
Check out SRSWAP.com and read their FAQ- that's the best advice to a newb.
Not alot of guys have this engine on Zilvia.
But as you can see everyone will speculate about things they don't know firsthand.

1tsilivabad - you don't have a 240, huh.
your nick = want a silvia bad, funny!
Yeah, the prices kind of eat donkey schlong b/c of the popularity, but I had NO problems getting parts (besides the blasted starter motor!)

Thats one thing: My starter motor solenoid stud was lobbed off to take off the ground wire when extracted from its clip. Luckily the SOLENOID is the same as the KA24E's, but the whole Motor is different, anmd runs about $250 USED! Grr. LOL. Anyway, it all works now.

Also, the engine is not and never will be legal, so you have to accept that risk and the consequences, no matter how slim or big the risks.:rolleyes: :)

[Jsquared]

where'd you get an engine for $1800? ECU, ignitor, harness, etc? mine's gonna cost like 2300...

[S13CRAVE]

downside to SR, let me count the ways... all aluminum, quad lobed cams rather than eight lobed units, once you get one you'll be the talk of all the rice boys "he's got an SR, just like in SCC!!!" and the fact that it is overly trendy.

~Ian

[Jsquared]

what's wrong with all-aluminum? have something against weight reduction?

quad lobed cams rather than eight lobed units
what the hell does this mean? use some normal terminology please

once you get one you'll be the talk of all the rice boys "he's got an SR, just like in SCC!!!" and the fact that it is overly trendy.
A) 75% of riceboys wouldn't know the difference
B) it isn't "trendy," it's "popular," and it's popular for a reason: the KA sucks and the car should have had the SR to begin with.

[Jsquared]

yes, any engine can be made to perform, but some are designed that way to begin with, and others, well, are designed to be fuel-efficient (the NA engine (5S-FE) in the MkII MR2s) or power trucks (the KA24DE) and aren't going to get the same returns as a properly/similarly prepared performance engine (e.g. the 3S-GTE in the MR2 example or the SR20DET in the 240SX example).

[andrave]

please don't turn this into a KA vs SR post, there have already been lots of those.

do a search if you think you need to talk about that. chances are, you don't.

I think that all around, the sr20 is a good motor, which is why it was in production for so long. correct me if I'm wrong, but it offers lightweight, stout torque, excellent HP, and decent gas mileage. On top of all of this it has proven to be a durable engine that can last a long time, even making more power than stock.

The downsides in the US are legality and obtaining parts. If you don't live in cali the first part may not be a big deal. It doesn't play in at all here in west virginia. However, the second you really can't get around, but it would HELP if you lived in cali.
Yes, this is ironic, but the most draconian state also offers the most importers of jdm clips and things.

I think there is a chart online somewhere that lists all the US applications that share parts with the sr20det, if someone has that link?

Anyway, I think that being "trendy" shouldn't play in...

[Jsquared]

someone please explain to me why an engine being all-aluminum is a bad thing?

-block and head expand and contract at same rate (since they are same material)
-much lighter overall weight
-better weight distribution
-SRs can hold 20psi on that block, so strength isn't a problem (Porsche 951 engines can hold even more on 85%-Al/15%-silicon blocks; strength is as much in the design as in the material)

[andrave]

my guess is that the person who posted it as a liability was thinking of the fact the ultimately, an iron block is stronger than an aluminum block.
in the case of the SR20 though, its one hell of an aluminum block, and its got **** loads of iron reinforcements throughout. Its a stout block by anyone's scale, especially for an aluminum one.

[AKADriver]

Originally posted by Jsquared
what the hell does this mean? use some normal terminology please

SR cams only have four lobes each... two cams makes eight lobes total to drive 16 valves.

The rocker arms are forked so that each cam lobe can drive a pair of valves.

It's a pretty efficient system, cheap to make, but it's weak... Can't hold up to very high revs without some modifications.

[S13CRAVE]

Originally posted by Jsquared
someone please explain to me why an engine being all-aluminum is a bad thing?

aluminum. think honda. think coca cola can.

SR cams only have four lobes each... two cams makes eight lobes total to drive 16 valves.
The rocker arms are forked so that each cam lobe can drive a pair of valves.

It's a pretty efficient system, cheap to make, but it's weak... Can't hold up to very high revs without some modifications.

thank you. my terminology was not wrong. keyword in the above statement is WEAK.

[DuffMan]

Downsides, well you are putting at least $2000 into the car with not much gaurantee that the motor is in good condition or will run.

I think you just need to look at the worst case scenario and be prepared to deal with it if it happens.

[AKADriver]

Originally posted by S13CRAVE
aluminum. think honda. think coca cola can.

That's a pretty weak statement in its own right.

As was already stated, Porsche, Ferrari, etc. use alloy engine blocks. Alloys are used all over in racing, in aviation, etc. The SR block is built just like those exotic and race engines; aluminum alloy with cast-iron cylinder liners. It's a proven setup.

[Jeff240sx]

Originally posted by Jsquared
someone please explain to me why an engine being all-aluminum is a bad thing?

-block and head expand and contract at same rate (since they are same material)
-much lighter overall weight
-better weight distribution
-SRs can hold 20psi on that block, so strength isn't a problem (Porsche 951 engines can hold even more on 85%-Al/15%-silicon blocks; strength is as much in the design as in the material)

Hold up. First, your entire post has 2 correct items, 2 incorrect items, and 2 useless items.
The head and block contracting won't make any difference, because if the engine was designed to use and iron block / Al head combo, that difference has already been factored in. Toss this in the useless column, yet sadly, you correct.
The sr can hold 20psi on the stock block. It all depends on the turbo. A KA or even a 3-cyl Geo Metro engine can hold 20psi off a t25. You know why? It's only about 12psi, and a bunch of hot air because you're out of the compressor efficiency. Also, the CFM of such a small turbo is inexistant. You ever wonder how people can get 350hp at 18psi on a KA when people with the s14 sr get 260rwhp at 15psi? Turbo sizing = more CFM = MORE IMPORTANT THAN PSI! Mark up 20psi into the correct column, but moreover, useless to know. Push the same 18psi through a SR that I pushed through my KA with a straight T4, and guess what? It'll go boom like my engine did.
Then we'll go into the "much lighter overall weight" and the "better weight distribution." Since you're wrong on both accounts, I'll just tackle these together. Weight distribution involves the location of the engine. Move the engine lower and towards the firewall, better distribution. Higher and towards the bumper is worse distribution. The SR motor sits on the same motor mounts that the KA does, and doesn't change the location nearly as far as this debate point would imply. And the "much lighter overall weight" point.. why haven't people read THAT article in SCC? It clearly states that the engine/tranny combo of the KA v. SR is 3 pounds, and Don at PDM Racing has confirmed that. Wrong and wrong.
Stick a fork in them. I'm done.
-Jeff

Edit: I really am not taking a stand in this debate, as my choice has already been made a year ago, and it is too late to change now. The merits of the SR and KA don't need to be further explained (so I didn't get into those), but the quoted post needed to be corrected so that people don't continue thinking incorrectly. After re-reading my post, I can see how it would come out pro-KA, when it wasn't my point at all. Simply clearing up misinformation.

[DuffMan]

Actually, jeff, that's not a very good explanation of turbo sizing and how it works.

A T25 at 20psi, is not actually 12psi, its 20psi. The power loss is from heat, exhaust restriction from the small compressor and from boost falling off as rpm increases because the turbo is maxxed out.

And a SR is lighter than KA + turbo by a more significant amount. That was a comparison of a stock KA to a stock SR with the turbo attached. Weight distribution is slightly better as well, since the engine is in roughly the same spot but the weight is less.

I dont think an SR would neccessarily blow from a 18psi spike, even on a big turbo. If it had fuel delivery that could support it, i seriously doubt it would blow.

[Jeff240sx]

Originally posted by DuffMan
Actually, jeff, that's not a very good explanation of turbo sizing and how it works.

A T25 at 20psi, is not actually 12psi, its 20psi. The power loss is from heat, exhaust restriction from the small compressor and from boost falling off as rpm increases because the turbo is maxxed out.

And a SR is lighter than KA + turbo by a more significant amount. That was a comparison of a stock KA to a stock SR with the turbo attached. Weight distribution is slightly better as well, since the engine is in roughly the same spot but the weight is less.

I dont think an SR would neccessarily blow from a 18psi spike, even on a big turbo. If it had fuel delivery that could support it, i seriously doubt it would blow.

Yea. I tried to dumb it down, seeing as this is a KA v. SR thread. 12psi = 20psi in terms of power on a over-boosting little turbo, but the 20psi is going through the engine, yadda yadda.
Also, you're right. That's about a 50 pound difference in my turbo and manifold, bringing everything up to a 53 pound difference. I'm sure that a welded mild steel manifold and t25 turbo would be a significant weight loss on the KA (compared to my cast iron RH mani and T4), or you could go the other way and add a really nice (and probably heavy) aftermarket manifold with a t3/4 or a T4. Then what would the weight difference be? 20 pounds? It's really not that much to complain about IMO. It's sprung weight, non-rotational, ect.
Also, my last paragraph (20psi on a T4) goes with your last paragraph. A KA motor (or 2, T.Y.'s and Dennis's) are running 15-18psi on their stock internals with the proper fuel on t3/4 turbos. I have yet to see a stock internals SR motor run similar boost levels with a similarly sized turbo. Also, just because a motor can doesn't mean it will. That ties into the fuel problems you brought up. I didn't have the fuel, blew motor at an "acceptable" ammount of boost for the KA. The same is true for the SR.
Anyway.. I'm sorry that I left so much to be desired from my post. I've driven for 6 hours today, and am really tired.
-Jeff

[bl200sx]

hummmmm........ Ok I got a good question, if the KA engine is such a great engine to boost, why didn't Nissan use this engine in the Silvia and 180SX.

[Jeff240sx]

Originally posted by bl200sx
hummmmm........ Ok I got a good question, if the KA engine is such a great engine to boost, why didn't Nissan use this engine in the Silvia and 180SX.

Saying that the KA is "a great engine to boost" is like saying that the B16a or B18b is a great engine to boost. Japanese automakers are notorious for overbuilding engines, and to extremely tight tolerances. For these reasons, Import engines in general can handle boost much better than domestic engines.
So, the SR motor is "older" than a ka24 motor, and was created in Japan, whereas the KA motor was created by Nissan of North America.
People make due with what they have here, and KA-Ts exist. Bringing over the sr20det was quite possibly a waste of money and could have overpowered the 240sx's target market. Nissan of Japan also knows the target market in Japan, and used the best engine available there.
This is pure speculation, but seems like something that international corporations do all the time. Like.. if McDonalds sells hamburgers, how can they possibly have a chain in India. Change products to suit demands and taste.
-Jeff

[AKADriver]

displacement taxes/classing
higher rev limit in stock tune

Both the SR and the KA were compromises for their particular markets.

[AKADriver]

Originally posted by Jeff240sx
For these reasons, Import engines in general can handle boost much better than domestic engines.

I'm just going to say I don't agree with this and leave it at that since it's waaaaay off topic for this thread.

So, the SR motor is "older" than a ka24 motor, and was created in Japan, whereas the KA motor was created by Nissan of North America.

Same engineers, and the KA exists in Japan in 2.0 and 2.4 form. It just wasn't used in the S-chassis. They did put them in various SUV type things, though, and some Bluebirds I believe. BTW... SR = 1990, KA = 1989. And actually, the KA series directly derives from the Z series which goes back to the '70s.

Bringing over the sr20det was quite possibly a waste of money and could have overpowered the 240sx's target market.

Could have if we were looking at this through the eyes of Nissan execs in '88, wouldn't have though. I don't think Nissan figured on the DSM happening. Of course a 240SX turbo would have been priced out of the market, just like the Celica All-Trac Turbo was. The DSM had that whole Chrysler partnership going for it in terms of the bottom line.

[DuffMan]

Well the KA and SR come from 2 different design schools.

The KA comes from a long line of SOHC engines, both performance and utility. There were turbocharged versions of L series and a Z series (i think) which were the predecesor to the KA.

The SR was all new, and had major some differences. The version used in the S13-15 had a cost saving valvetrain and actually wasn't that expensive.

I think Nissan could have sold the SR20DET version of the car here and made money off it. DSM's and celicas had awd which made it more expensive. Also they were using a completely different engine for NA and turbo, unlike with the SR.

The MR2 was low volume because of practicality concerns from only 2 seats and no room.

The SR20DET (at least in rwd) was a low cost performance engine compared to the 4G63 and 3SGTE which were in some ways superior engines.

The real problem is the Z32. The Z32 was somewhat of a failure in Japan. It was as expensive as a Skyline but performance wasn't even close. Even though they were low volume in Japan, it was the US market that kept the car alive. And still it died after a while. A turbo S13-15 would have costed sales of the high profit margin Z's.

The original concept Z33 was using a SR20DET correct? I also believe it was based on a modified S15 chassis. So basicly when the Z32 was gone, Nissan thought about bringing the SR20DET over here, but didnt give it a body that people liked, and tried to link it to the Z heritage which wasn't really appropriate.

[ca18guy]

Originally posted by Jsquared
someone please explain to me why an engine being all-aluminum is a bad thing?

-block and head expand and contract at same rate (since they are same material)
-much lighter overall weight
-better weight distribution
-SRs can hold 20psi on that block, so strength isn't a problem (Porsche 951 engines can hold even more on 85%-Al/15%-silicon blocks; strength is as much in the design as in the material)

To make up for the lose of strength over a iron block most alum. blocks have an extra thick block design which makes up for the lightness of aluminum. Thats why the sr isn't that much lighter then a ka-t (i'd guess it at 40lbs less wieght) and also ca18 which is iron.

[sykikchimp]

and any weight advantage you may have gained over the NA KA is somewhat negated by the turbo, add big front mount IC, and IC piping

[andrave]

the sr20, with turbo and manifold and tranny, weighs less than the KA-T.
its already been factored into that comparison.

ANYWAY, why don't you guys crunch some numbers and realize that 50lb weigh difference between engines is going to increase your front to rear weight distribution by what, half a point?
someone did the math in a previous post, talking about the rb26, and I think he found that for a 90 pound or 100 pound difference, it changed the balance by like 1 pt.

And if weight dist. is an issue, move the battery to the back. That would help a lot.

[Jim96SC2]

Depends on what your building.

Street cars won't really mind an extra 50-100lbs sitting around. You maybe do a few stoplight drags, hit a track once a year if that? You don't need a super tuned car to run the 1/4 on weekends for fun. The extra weight gives more power, which is nice for the weekend cruise or when you need to get out of trouble quick.

Race cars are a whole different ball game. The KA and the SR have about the same max power output + or - 20hp (if at all). Race cars (road course, not drag) see lots of brake usage which is helped by less weight (less weight, less inertia, less brakes, less heat, less fade). In racing every pound helps.

[Fireball240SX]

Originally posted by DuffMan
DSM's and celicas had awd which made it more expensive. Also they were using a completely different engine for NA and turbo, unlike with the SR.

DSM's had a 4G63 Turbo and N/A only difference was the head to make it turbo.:)

[Fastback180]

Originally posted by Jsquared
where'd you get an engine for $1800? ECU, ignitor, harness, etc? mine's gonna cost like 2300...

Hahahaha....You're a donkey. I can get you one in the same condition as the $2300 one for $950!!!
When I first got my 240 and was looking at SR's and they were all like $1300, now everyone and their mom is getting them and places have jacked the prices way up. I'm sayin, it's gone up over $1000 in the past year! They're still good, but people are getting fisted when they buy them. DO YOUR HOMEWORK AND LOOK AROUND YOUR AREA!

[Fastback180]

Originally posted by ca18guy
Thats why the sr isn't that much lighter then a ka-t (i'd guess it at 40lbs less wieght) and also ca18 which is iron.

Here's the facts...

SR20DET- 490lbs
KA24E- 493lbs

[timmybgood]

i'd really appreciate it if you can enlighten us to where you can get an SR for $950

[ca18guy]

Originally posted by Fastback180
Here's the facts...

SR20DET- 490lbs
KA24E- 493lbs

Add a T to the KA, thats why I estimated 40 lbs extra.

[Fastback180]

Originally posted by timmybgood
i'd really appreciate it if you can enlighten us to where you can get an SR for $950

NOYAN IMPORTED ENGINES
9136 EUCLID CT, MANASSAS, VA 20110
(703) 365-7590

[nrcooled]

Originally posted by Fastback180
NOYAN IMPORTED ENGINES
9136 EUCLID CT, MANASSAS, VA 20110
(703) 365-7590

I can verify that!

Back on topic. Sourcing parts has not been a issue for me so far. As far as reliability, the SR has put up with me being stupid on more than one occasion and hasn't missed a beat. I love it but it has gotten way too trendy. Everyone that sees my car goes "you should put a SR in there" I don'bother to tell them I have one:rolleyes:

edit: typing one handed and letting my daughter bang on the keyboard sucks:D

[1tsilviabad]

Good answers......I got the info I was looking for...(and alittle more)......as far as it being trendy....I think trendy is a strong word...... I DO think it's getting to popular for it's own good!!!!.... There are prob. gonna be alot of engines around with LOTS of miles cause they're just gonna keep getting recycled...and people'll keep BSing the mileage!!!....... That's why I might just get the engine before the car....I can't find a decent coupe anywhere!!!!:mad:
:D -----thanks for the great replies......
BillC

[DoriftoSlut]

Originally posted by Fastback180
Here's the facts...

SR20DET- 490lbs
KA24E- 493lbs
----Taken from the SCC article last year. But no one has verified (they did not write back to emails sent to them) whether that was with or without the KA tranny. The quote they have in theri mag says:
"With the transmission, turbo and alternator, the SR20DET weighs 490 lbs. The KA24E we removed weighed 293."

They did not verify that the KA had the tranny with it or what indeed was attached. Also, that was a KA-E. Add another camshaft, a different head, different manifolds, etc.. etc.. and you do not have the same weight for a KA-DE. Those are the facts.:rolleyes:

[andrave]

didn't respond to your emails?
I had jacquot and coleman email me back like 20 times with me pestering them with questions.
the weight for the engines was for both of them with the trannies on.

[DoriftoSlut]

Originally posted by andrave
didn't respond to your emails?
I had jacquot and coleman email me back like 20 times with me pestering them with questions.
the weight for the engines was for both of them with the trannies on.

Cool. Well he didn't reply to me or Asad, or a couple other FA folk.:rolleyes: Guess they like you more than us.

[Jsquared]

jsquared is all talk.
Been seeing you make alot of hardcore replies like you know what you're talking about.
But then you're also the guy asking us to explain every little thing to you.

put down the Import Tuner ----> www.google.com
A) import tuner sucks. as does super street, honda tuning, etc. pick an import magazine, if it isn't parts of SCC, it probably sucks. also, how does getting info from a magazine make my opinions any less valid? does the fact that i read about Saab's variable compression engine in Car and Driver mean that the stuff I now know about it is meaningless? and how is it any different than gaining information on a forum? people do stuff, then write about it. some of it is good, solid info and some is bunk. same deal.
B) all talk? want to stop by my house to see all the talk that is sitting in my driveway? how about the other talk i've helped my friends with? domestic carbed talk, German high-performance talk, or my little Japanese forced induction talk. how about some of my dad's pain-in-the-rear-to-work-on Italian talk?
C) you are a trolling little clown. all you do it seems is go into threads and insult people. i have not liked you from the moment i "met" you on this forum. ditch the snobby "i'm better than everyone because i'm older" attitude and maybe my opinion will change.

Hold up. First, your entire post has 2 correct items, 2 incorrect items, and 2 useless items.
The head and block contracting won't make any difference, because if the engine was designed to use and iron block / Al head combo, that difference has already been factored in. Toss this in the useless column, yet sadly, you correct.
The sr can hold 20psi on the stock block. It all depends on the turbo. A KA or even a 3-cyl Geo Metro engine can hold 20psi off a t25. You know why? It's only about 12psi, and a bunch of hot air because you're out of the compressor efficiency. Also, the CFM of such a small turbo is inexistant. You ever wonder how people can get 350hp at 18psi on a KA when people with the s14 sr get 260rwhp at 15psi? Turbo sizing = more CFM = MORE IMPORTANT THAN PSI! Mark up 20psi into the correct column, but moreover, useless to know. Push the same 18psi through a SR that I pushed through my KA with a straight T4, and guess what? It'll go boom like my engine did.
Then we'll go into the "much lighter overall weight" and the "better weight distribution." Since you're wrong on both accounts, I'll just tackle these together. Weight distribution involves the location of the engine. Move the engine lower and towards the firewall, better distribution. Higher and towards the bumper is worse distribution. The SR motor sits on the same motor mounts that the KA does, and doesn't change the location nearly as far as this debate point would imply. And the "much lighter overall weight" point.. why haven't people read THAT article in SCC? It clearly states that the engine/tranny combo of the KA v. SR is 3 pounds, and Don at PDM Racing has confirmed that. Wrong and wrong.
Stick a fork in them. I'm done.
-Jeff

thank you for adding things into my post that i did not say:

A) i did not say anything about 20psi on the T25. i know you are gonna blow stuff up much above 13-15 on that turbo. i do, however, know people running 20psi in SRs on T3s and hybrids, and the block is fine.

B) they use the same mounts, but the SR sits closer to the firewall than the KA, meaning better weight distribution. i will measure the difference in distance for you when the swap is done if you don't believe me.

C) a 493-lb SR includes the turbo and most of the other extra heavy metal bits, whereas the 490-lb KA24E is NA. make it a KA24DE, and the weight is even more for an NA engine. add to that the fact that the KA needs a turbo to make somewhat-biggish power, and you're adding even more heavy metal bits.

D) thanks for the correction on the different-metal thing, for some reason at night i don't think of the obvious sometimes...

ANYWAY, why don't you guys crunch some numbers and realize that 50lb weigh difference between engines is going to increase your front to rear weight distribution by what, half a point?
someone did the math in a previous post, talking about the rb26, and I think he found that for a 90 pound or 100 pound difference, it changed the balance by like 1 pt.

it doesn't just affect weight distribution, it also affects polar moment, but i don't feel like going to more calculations (voluntary extra homework? yeah, right) at the moment.

[andrave]

alright, well that homework assign was voluntary anyway.
but this one isn't:
CHILL OUT DUDE!

man you make me tired just reading your rants.

[turboex]

Ill post my .02cents. I have had my sr for about 4 months. I have had to do nothing at all to the motor, its runs perfect and comp test read all good no probs at all. Ok the down side, is prices on parts is kinda high compared to honda. But the pluss part is.... ok today i went out and raced my boys 97 acura integra, with intake, exhaust, ls/vtec, header, quaife LSD and a few other mods. My car has, stock everything, except sr20det at 6psi, s14LSD and greddy bov. we raced 3 times and he had no chance. The sr does not feel as fast as it is. When a honda is fast you can tell due to its lack of torque that it pulls you harder as the revs climb. But the sr just sets you in the seat hard and you stay there. Oh well a bit offtopic but i figured i would post that. Hey ill throw up some videos soon. My car goes in the shop for complete paint job, removal of dents and rust. and pull the crazy ass dents from my silvia conversion. Ill post before and after pics.