L20et - Building For 250kw+

[dwayne293]

Hey all,

Some may remember me from this section of the forum a couple of years ago. I own an MR30 hatch with an L20ET, did have a wolf 3d, supra front mount, R200 LSD and other goodies. Due to poor tuning, it detonated and cracked a compression ring in cylinder 5. I have decided to revive the long dead R30 and have big plans for the entire car but focusing on engine first.

Ghostrider, Stagefumer, looking to you guys for this one.

Do you think it is possible to pull around 250kw at the crank of a stock capacity L20ET while having any low down pull? I would rather stick with the L20 for easier rego and all that, but your answers will influence me either way.

Does anybody know of anywhere who does forged pistons and rods for the L20? What about L24E? Is the crank/block any weaker in the L24E as I could use that bottom end with the L20 head if it will stand up to the punishment.

I am considering using a metal head gasket to lower the already low CR of the L20 so it can handle high boost levels, but not too sure how this will affect off boost performance. Also hesitant on using an aggressive camshaft as that will take away even more bottom end.

Will an L24E, L28E(T) or L26 intake manifold have correct port sizing for the L20 head? I want to get a neater manifold without the spaghetti vacuum lines which all seem pretty useless, if not I might disconnect all but the neccessary lines and plug/ weld them up.

Injectors - what fits? I am going to be using a newer version of the wolf ecu so no worries on what the standard computer will run. Also trying to figure out what flow rate I will need for 250kw+, I'm guessing at least 800cc/min.

Also are there any aftermarket fuel pumps that will mount in the same area (under right rear door) that will support this power level?

Is it worth haveing the head ported, etc?

Anything else I should know please feel free to mention sorry for the massive post, there just isn't much info on the L20 on the net and I would love to stick with it instead of chucking an RB in (I already own a 32 GTS-t) as I would like the engine bay to be as bare as possible without all the newer crap in there.

Thanks guys,

POST AWAY!!!!!!

[the big JC]

I was looking at turboing my L24E motor using L20ET gear about a month ago but had to pull the plug because no one would insure me.

What i was told was that the L24E motor wouldn't handle any more than about 10psi of boost and would only produse about 160-170kw at the wheels. The L20E and L20ET intake manifolds fit the L24E so i would imagine the L24E ones would fit the L20ET i think. I was also told that the N47 head on my L24E had larger ports and larger combustion chambers so the N47 head might work good with the L20ET bottom end might lower the compression but i don't know enough about that sort of stuff.

Hope this is of some help to you

Cheers Josh

[blind_elk]

L20ET is already compressing at 7.5 - how much lower do you think it needs to go?

Couple of things I know about the engine:

a RB20 / RB25 turbo bolts straight on, so there is potential to get something extra out of the engine.

It will probably tolerate some extra C/R, so fitting flat-top pistons may be possible.

Std) L24E has tiny ports in the head. And a tiny combustion chamber. It might go better with a 240Z head (larger ports, larger chamber - is that the N47?), and 240Z flat-top pistons.

L28ET is probably the way to go.

If you want forgies for the L20 (or any other engine), talk to Bill at Australian Precision Engine Parts in Melbourne (03-98871299)

Hope that helps some.

[stagefumer11]

Its a big ask. but im sure it can be done. Sorry i missed you on msn. I was asleep.

To get the goals you want the WOlf3d ecu maybe enough, but it could not ggive enough tunning rebroad minded personions. (sp)? (i still want it tho )

l20et's are gutless down low. The only way your going to get the low down toruqe you require is to get some custom pistions and bring the compression ratio up to around 8.:1 or 8:5. You could possibly rase it with a l24 head, For the flow you require for that kind of power a l28 head will be your best bet. but you will need to jotch the Block BIG TIME!. for the vavles to clear.

Rpms will play a big role also. So get the crank and rods shot peend and polished. And ballance the crank ( check) The mojor hold back will be the head and cam setup. So a fully custom cam. And stronger vavle springs are required. Your looking at 7k max with this work. Dont forget a huge port and polish . Another thing that pop'd to my mind is, Make sure you get a floating connection pins for the piston. Dont go with anything else or oil starvation will kill it.

Turbo. something like a Hx35 holset or a custom t3/t4 / tb04 or td06. Will be plenty for what you need. Dont forget the fuel gtr injectors 444cc should be enough.

Ill post up more when i think about it in depth

[dwayne293]

Thanks heaps for the replies,

Stegefumer, the Wolf I was going to sell you is long dead but I will use the new version (much improved over V3).

I am going to try to stick with the same cylinder head and block, as with capacity. My budget isn't enormous, I just want a bit of boot so I guess 200rwkw would make me happy ;-)

I have read somewhere that VG30 injectors fit, is this the DET or DETT? Do GT-R injectors fit?

I think a mid size turbo (~450HP) would be enough, and I'm not too sure about the lag as I have heard the original turbo is laggy more due to design than physical size and output. I will get a custom manifold made up to minimize length and therefore cooling area of the exhaust gas, and heat wrap it. I am hoping to gain the desired power output at boost levels under 1.5 bar depending on turbo choice.

As I said before, I am a bit hesitant to use an aggressive cam as it will only decrease off boost response and I now doubt I will use a metal head gasket....

Just wanna get a good power figure out of the old girl and prove the L20 has potential.

Any more ideas no matter how crazy they sound please don't hesitate to post

Cheers

Dwayne

[stagefumer11]

Thanks heaps for the replies,

Stegefumer, the Wolf I was going to sell you is long dead but I will use the new version (much improved over V3).

I am going to try to stick with the same cylinder head and block, as with capacity. My budget isn't enormous, I just want a bit of boot so I guess 200rwkw would make me happy ;-)

I have read somewhere that VG30 injectors fit, is this the DET or DETT? Do GT-R injectors fit?

I think a mid size turbo (~450HP) would be enough, and I'm not too sure about the lag as I have heard the original turbo is laggy more due to design than physical size and output. I will get a custom manifold made up to minimize length and therefore cooling area of the exhaust gas, and heat wrap it. I am hoping to gain the desired power output at boost levels under 1.5 bar depending on turbo choice.

As I said before, I am a bit hesitant to use an aggressive cam as it will only decrease off boost response and I now doubt I will use a metal head gasket....

Just wanna get a good power figure out of the old girl and prove the L20 has potential.

Any more ideas no matter how crazy they sound please don't hesitate to post

Cheers

Dwayne

Correct vg30et injectors bolt right in. Only 270cc tho. Im using them myself

[stagefumer11]

Thanks heaps for the replies,

Stegefumer, the Wolf I was going to sell you is long dead but I will use the new version (much improved over V3).

I am going to try to stick with the same cylinder head and block, as with capacity. My budget isn't enormous, I just want a bit of boot so I guess 200rwkw would make me happy ;-)

I have read somewhere that VG30 injectors fit, is this the DET or DETT? Do GT-R injectors fit?

I think a mid size turbo (~450HP) would be enough, and I'm not too sure about the lag as I have heard the original turbo is laggy more due to design than physical size and output. I will get a custom manifold made up to minimize length and therefore cooling area of the exhaust gas, and heat wrap it. I am hoping to gain the desired power output at boost levels under 1.5 bar depending on turbo choice.

As I said before, I am a bit hesitant to use an aggressive cam as it will only decrease off boost response and I now doubt I will use a metal head gasket....

Just wanna get a good power figure out of the old girl and prove the L20 has potential.

Any more ideas no matter how crazy they sound please don't hesitate to post

Cheers

Dwayne

Correct vg30et injectors bolt right in. Only 270cc tho. Im using them myself

[paulmac]

Correct vg30et injectors bolt right in. Only 270cc tho. Im using them myself

do they fit all L series??? thanks paul.

[floody]

I know you want to keep the L20, but what about a basic low-blow setup on a L28? Surely almost 50% more cubes would be useful in achieving your goal?

[dwayne293]

I am just trying to avoid the L28 as I will need to get it inspected at transport SA if I do the change, and I don't think they will look too kindly on a big turbo hanging off the side along with aftermarket engine management, etc.

I was told today by a z car shop mechanic not to bother with forged pistons for only 250kw as the L20 internals are strong as f**k and I should use a garret GT3040 or similar just as long as I have the fuel system to back it up, intercooler and exhaust.

So now I'm confused as hell. Either way the engine is out so I'm cleaning it all up and searching for new big end and main bearings (what a mission, any ideas?) and replacing timing chain as well as the piston rings, but I have no clue whether to bother with forged pistons and I definitely won't if it is unnecessary.

Hmmmmmmmmmmmmm

[stagefumer11]

I am just trying to avoid the L28 as I will need to get it inspected at transport SA if I do the change, and I don't think they will look too kindly on a big turbo hanging off the side along with aftermarket engine management, etc.

I was told today by a z car shop mechanic not to bother with forged pistons for only 250kw as the L20 internals are strong as f**k and I should use a garret GT3040 or similar just as long as I have the fuel system to back it up, intercooler and exhaust.

So now I'm confused as hell. Either way the engine is out so I'm cleaning it all up and searching for new big end and main bearings (what a mission, any ideas?) and replacing timing chain as well as the piston rings, but I have no clue whether to bother with forged pistons and I definitely won't if it is unnecessary.

Hmmmmmmmmmmmmm

he's correct. You dont need to change the pistons, one mod you can do to them is. Shorten the lower skirts. This helps more oil get up around the rings and prevents them burning out at high rpms. Also converting the piston pin to a Floating system is easly done also. Dont forget some ARP rod bolts.

Talk to repco about the bearings. ACL currently still do them from what i remember, but they will be spec for a l20a out of a fairlady, Same diff anyway.

I can difinitly vouch for the strenth of any L serries 6's Froged crank's and 7 bearring bottom ends Really make them one tough cookie!

[stagefumer11]

Correct, same fittings and all. They look identical to l20et ones

[dwayne293]

Thanks for the help again.

Does anybody know if the timing chain for L20ET is the same as for L24E or does anybody have the correct part number?

I will try repco again for bearings, did not realise they were the same as L20E.

Don't know about injectors gonna go have a sus at what others will physically bolt in, hopefully GT-R ones fit.

I'm pretty confident now that the L20 could handle around 1.5 bar from a GT3040 without blowing apart since they are built to last and have such a low compression ratio, which should reel in a low 200rwkw figure...... hopefully.

Now I think the only major mods I will do are try and shorten the piston skirts, port the head, custom manifold to fit turbo, maybe a bigger cam, injectors, ECU, oil cooler, big front mount.

Now the search begins for rings and bearings

Anything at all related, you know where to post.

Cheers

Dwayne

[works 510]

Just talking to a guy called andrew (datsqik, dont know if hes on these forums). he says that the l20et rods are alot weaker than other L6's...

http://us.a2.yahoofs.com/users/43bbb011z59...h4K6qEBmhRhdaiY

Just something to have a thought about.

[dwayne293]

Hmmm... Getting way too many headf**ks trying to find rings for this thing. Seriously contemplating using the L24 and just bolting on the L20 turbo gear. As far as I can tell everything bar the bore and stroke are pretty much the same so all the external components should work... All vacuum lines go to the same place, all anti pollution shit is the same so I think it would just be a matter of bolting on the gear. Will have to get a metal head gasket or decomp spacer made up though otherwise it won't handle the boost I'm gonna throw at it.

In two minds about this shit I really want to stick with the L20

DOES ANYBODY KNOW THE PART NUMBERS OR A SUPPLIER OF L20(A)ET BEARINGS, GASKETS AND MOST IMPORTANTLY PISTON RINGS??????

I have tried everywhere but no luck so far.

Please help me this is bordering on insanity

[rsx84]

DOES ANYBODY KNOW THE PART NUMBERS OR A SUPPLIER OF L20(A)ET BEARINGS, GASKETS AND MOST IMPORTANTLY PISTON RINGS??????

I have tried everywhere but no luck so far.

Please help me this is bordering on insanity

i'd try Ghostrider for that kind of info, maybe even try an importer like www.slidewize.com they may be able to get what you want from japan???

[stagefumer11]

Actaully with that rod infromation, IT is partily true Early l20ets had lager big end bearings ect and slightly beafyer rods. LAter l20ets has large amounts of weight reduction weight removed off all parts. You will find the blocks are diffrent and the rods are a lot weaker.

I wish i could find this information again. It was off a jappa forum that i translated i had a great read alot of detailed information on the l20et. Still has a huge modding comunity behind it over there.

[stagefumer11]

Hmmm... Getting way too many headf**ks trying to find rings for this thing. Seriously contemplating using the L24 and just bolting on the L20 turbo gear. As far as I can tell everything bar the bore and stroke are pretty much the same so all the external components should work... All vacuum lines go to the same place, all anti pollution shit is the same so I think it would just be a matter of bolting on the gear. Will have to get a metal head gasket or decomp spacer made up though otherwise it won't handle the boost I'm gonna throw at it.

In two minds about this shit I really want to stick with the L20

DOES ANYBODY KNOW THE PART NUMBERS OR A SUPPLIER OF L20(A)ET BEARINGS, GASKETS AND MOST IMPORTANTLY PISTON RINGS??????

I have tried everywhere but no luck so far.

Please help me this is bordering on insanity

Its been coverd before. Repco Aus will be able to get ACL gaskets from here in NZ. Im using a L20/24/26/28 headset. bm380mt i think it is........Everything is the same. If someone in your local repco is being a dumb ass ask to talk to someone else.

Hey i know this i work there!!!

Id also try and check some l20a bearings and rings. I swear we have a listing on our database... Ill get back to your tomorrow with part numbers. If i remember

[works 510]

thats interesting stuff stagefumer.... What years was the earlier l20et's and would you know what engine numbers the early models would have?

[dwayne293]

Thanks heaps stagefumer if you could get me some part numbers for gasket kit/ head gasket, piston rings, main bearings and big end bearings that would be awesome!

I don't care if they have to come from NZ I just wish someone here would help me.

Hmmmm, hoping mine is an early L20 will check engine number may give me some clue.

Thanks again

Dwayne